Exhibit A - Addendum to FEIR — Menifee City Council, December 6, 2023 (part 10 of 14)

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Rainfall intensity = 1.329(In/Hr)
Program is now starting with Main Stream No. 2

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 121.000 to Point/Station 122.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 193.000(Ft.)
Top (of initial area) elevation = 1546.000(Ft.)
Bottom (of initial area) elevation = 1544.700(Ft.)
Difference in elevation = 1.300(Ft.)
Slope = 0.00674 s(percent)= 0.67
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 8.702 min.

Rainfall intensity = 1.530(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.722
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
RI index for soil(AMC 1) = 57.00
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 1.071(CFS)
Total initial stream area = 0.970(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 122.000 to Point/Station 123.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1537.700(Ft.)
Downstream point/station elevation = 1531.700(Ft.)
Pipe length = 496.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 1.071(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow = 1.071(CFS)
Normal flow depth in pipe = 4.96(In.)
Flow top width inside pipe = 8.95(In.)
Critical Depth = 5.70(In.)
Pipe flow velocity = 4.28(Ft/s)
Travel time through pipe = 1.93 min.

Time of concentration (TC) = 10.63 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 122.000 to Point/Station 123.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 2 in normal stream number 1
Stream flow area = 0.970(Ac.)
Runoff from this stream = 1.071(CFS)
Time of concentration = 10.63 min.

Rainfall intensity = 1.376(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 124.000 to Point/Station 125.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 960.000(Ft.)

Page 17 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Top (of initial area) elevation = 1549.500(Ft.)
Bottom (of initial area) elevation = 1539.000(Ft.)
Difference in elevation = 10.500(Ft.)
Slope = 0.01094 s(percent)= 1.09
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 15.003 min.

Rainfall intensity = 1.147(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.649
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.400
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.600
RI index for soil(AMC 1) = 47.88
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 3.413(CFS)
Total initial stream area = 4.590(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 125.000 to Point/Station 123.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1532.000(Ft.)
Downstream point/station elevation = 1531.700(Ft.)
Pipe length = 26.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 3.413(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 3.413(CFS)
Normal flow depth in pipe = 8.84(In.)
Flow top width inside pipe = 10.57(In.)
Critical Depth = 9.48(In.)
Pipe flow velocity = 5.51(Ft/s)
Travel time through pipe = 0.08 min.

Time of concentration (TC) = 15.08 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 125.000 to Point/Station 123.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 2 in normal stream number 2
Stream flow area = 4.590(Ac.)
Runoff from this stream = 3.413(CFS)
Time of concentration = 15.08 min.

Rainfall intensity = 1.143(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 124.000 to Point/Station 126.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 1000.000(Ft.)
Top (of initial area) elevation = 1549.500(Ft.)
Bottom (of initial area) elevation = 1539.000(Ft.)
Difference in elevation = 10.500(Ft.)
Slope = 0.01050 s(percent)= 1.05
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 15.375 min.

Rainfall intensity = 1.132(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.657

Page 18 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.300
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.700
RI index for soil(AMC 1) = 50.16
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 3.720(CFS)
Total initial stream area = 5.000(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 126.000 to Point/Station 123.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1532.000(Ft.)
Downstream point/station elevation = 1531.700(Ft.)
Pipe length = 20.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 3.720(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 3.720(CFS)
Normal flow depth in pipe = 8.52(In.)
Flow top width inside pipe = 10.89(In.)
Critical Depth = 9.85(In.)
Pipe flow velocity = 6.24(Ft/s)
Travel time through pipe = 0.05 min.

Time of concentration (TC) = 15.43 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 126.000 to Point/Station 123.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 2 in normal stream number 3
Stream flow area = 5.000(Ac.)
Runoff from this stream = 3.720(CFS)
Time of concentration = 15.43 min.

Rainfall intensity = 1.130(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 1.071 10.63 1.376
2 3.413 15.08 1.143
3 3.720 15.43 1.130
Largest stream flow has longer time of concentration
Qp = 3.720 + sum of
Qb Ia/Ib

1.071 * 0.821 = 0.879
Qb Ia/Ib

3.413 * 0.988 = 3.373
Qp = 7.971

Total of 3 streams to confluence:

Flow rates before confluence point:

1.071 3.413 3.720
Area of streams before confluence:

0.970 4.590 5.000
Results of confluence:

Total flow rate = 7.971(CFS)
Time of concentration = 15.429 min.

Page 19 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Effective stream area after confluence = 10.560(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 123.000 to Point/Station 120.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1531.700(Ft.)
Downstream point/station elevation = 1519.500(Ft.)
Pipe length = 800.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 7.971(CFS)
Nearest computed pipe diameter = 15.00(In.)
Calculated individual pipe flow = 7.971(CFS)
Normal flow depth in pipe = 15.00(In.)
Flow top width inside pipe = 0.00(In.)
Critical Depth = 13.37(In.)
Pipe flow velocity = 6.50(Ft/s)
Travel time through pipe = 2.05 min.

Time of concentration (TC) = 17.48 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 123.000 to Point/Station 120.000 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 2
Stream flow area = 10.560(Ac.)
Runoff from this stream = 7.971(CFS)
Time of concentration = 17.48 min.

Rainfall intensity = 1.057(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 21.267 11.36 1.329
2 7.971 17.48 1.057
Largest stream flow has longer or shorter time of concentration Qp = 21.267 + sum of
Qa Tb/Ta

7.971 * 0.650 = 5.178
Qp = 26.445

Total of 2 main streams to confluence:

Flow rates before confluence point:

21.267 7.971
Area of streams before confluence:

31.320 10.560

Results of confluence:

Total flow rate = 26.445(CFS)
Time of concentration = 11.355 min.

Effective stream area after confluence = 41.880(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 120.000 to Point/Station 128.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1519.500(Ft.)

Page 20 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Downstream point/station elevation = 1509.000(Ft.)
Pipe length = 1360.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 26.445(CFS)
Nearest computed pipe diameter = 27.00(In.)
Calculated individual pipe flow = 26.445(CFS)
Normal flow depth in pipe = 21.47(In.)
Flow top width inside pipe = 21.79(In.)
Critical Depth = 21.54(In.)
Pipe flow velocity = 7.80(Ft/s)
Travel time through pipe = 2.91 min.

Time of concentration (TC) = 14.26 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 120.000 to Point/Station 128.000 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 1
Stream flow area = 41.880(Ac.)
Runoff from this stream = 26.445(CFS)
Time of concentration = 14.26 min.

Rainfall intensity = 1.178(In/Hr)
Program is now starting with Main Stream No. 2

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 158.000 to Point/Station 159.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 245.000(Ft.)
Top (of initial area) elevation = 1720.000(Ft.)
Bottom (of initial area) elevation = 1659.000(Ft.)
Difference in elevation = 61.000(Ft.)
Slope = 0.24898 s(percent)= 24.90
TC = k(0.530)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 6.320 min.

Rainfall intensity = 1.813(In/Hr) for a 2.0 year storm UNDEVELOPED (poor cover) subarea
Runoff Coefficient = 0.609
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 60.60
Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 1.225(CFS)
Total initial stream area = 1.110(Ac.)
Pervious area fraction = 1.000

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 158.000 to Point/Station 159.000 **** SUBAREA FLOW ADDITION ****
______________________________________________________________________ COMMERCIAL subarea type
Runoff Coefficient = 0.849
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 36.00
Pervious area fraction = 0.100; Impervious fraction = 0.900

Page 21 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Time of concentration = 6.32 min.

Rainfall intensity = 1.813(In/Hr) for a 2.0 year storm Subarea runoff = 0.631(CFS) for 0.410(Ac.)
Total runoff = 1.856(CFS) Total area = 1.520(Ac.)

Rainfall intensity = 1.813(In/Hr) for a 2.0 year storm Subarea runoff = 1.093(CFS) for 0.710(Ac.)
Total runoff = 2.949(CFS) Total area = 2.230(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 160.000 to Point/Station 161.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1650.000(Ft.)
Downstream point/station elevation = 1512.000(Ft.)
Pipe length = 965.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 2.949(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow = 2.949(CFS)
Normal flow depth in pipe = 4.35(In.)
Flow top width inside pipe = 8.99(In.)
Critical depth could not be calculated.

Pipe flow velocity = 13.95(Ft/s)
Travel time through pipe = 1.15 min.

Time of concentration (TC) = 7.47 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 160.000 to Point/Station 161.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 2 in normal stream number 1
Stream flow area = 2.230(Ac.)
Runoff from this stream = 2.949(CFS)
Time of concentration = 7.47 min.

Rainfall intensity = 1.659(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 162.000 to Point/Station 163.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 945.000(Ft.)
Top (of initial area) elevation = 1717.700(Ft.)
Bottom (of initial area) elevation = 1520.000(Ft.)
Difference in elevation = 197.700(Ft.)
Slope = 0.20921 s(percent)= 20.92
TC = k(0.530)*[(length^3)/(elevation change)]^0.2

Page 22 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Initial area time of concentration = 11.229 min.

Rainfall intensity = 1.337(In/Hr) for a 2.0 year storm UNDEVELOPED (poor cover) subarea
Runoff Coefficient = 0.573
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.700
Decimal fraction soil group C = 0.300
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 63.56
Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 3.552(CFS)
Total initial stream area = 4.640(Ac.)
Pervious area fraction = 1.000

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 163.000 to Point/Station 161.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1513.000(Ft.)
Downstream point/station elevation = 1512.000(Ft.)
Pipe length = 23.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 3.552(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 3.552(CFS)
Normal flow depth in pipe = 5.85(In.)
Flow top width inside pipe = 12.00(In.)
Critical Depth = 9.66(In.)
Pipe flow velocity = 9.35(Ft/s)
Travel time through pipe = 0.04 min.

Time of concentration (TC) = 11.27 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 163.000 to Point/Station 161.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 2 in normal stream number 2
Stream flow area = 4.640(Ac.)
Runoff from this stream = 3.552(CFS)
Time of concentration = 11.27 min.

Rainfall intensity = 1.334(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 2.949 7.47 1.659
2 3.552 11.27 1.334
Largest stream flow has longer time of concentration
Qp = 3.552 + sum of
Qb Ia/Ib

2.949 * 0.804 = 2.372
Qp = 5.924

Total of 2 streams to confluence:

Flow rates before confluence point:

2.949 3.552
Area of streams before confluence:

2.230 4.640
Results of confluence:

Total flow rate = 5.924(CFS)

Page 23 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Time of concentration = 11.270 min.

Effective stream area after confluence = 6.870(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 163.000 to Point/Station 161.000 **** SUBAREA FLOW ADDITION ****
______________________________________________________________________ UNDEVELOPED (fair cover) subarea
Runoff Coefficient = 0.556
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 1.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 61.80
Pervious area fraction = 1.000; Impervious fraction = 0.000 Time of concentration = 11.27 min.

Rainfall intensity = 1.334(In/Hr) for a 2.0 year storm Subarea runoff = 0.445(CFS) for 0.600(Ac.)
Total runoff = 6.370(CFS) Total area = 7.470(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 161.000 to Point/Station 128.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1512.000(Ft.)
Downstream point/station elevation = 1509.000(Ft.)
Pipe length = 567.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 6.370(CFS)
Nearest computed pipe diameter = 18.00(In.)
Calculated individual pipe flow = 6.370(CFS)
Normal flow depth in pipe = 12.56(In.)
Flow top width inside pipe = 16.53(In.)
Critical Depth = 11.71(In.)
Pipe flow velocity = 4.84(Ft/s)
Travel time through pipe = 1.95 min.

Time of concentration (TC) = 13.22 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 161.000 to Point/Station 128.000 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 2
Stream flow area = 7.470(Ac.)
Runoff from this stream = 6.370(CFS)
Time of concentration = 13.22 min.

Rainfall intensity = 1.226(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 26.445 14.26 1.178
2 6.370 13.22 1.226
Largest stream flow has longer time of concentration
Qp = 26.445 + sum of
Qb Ia/Ib

6.370 * 0.961 = 6.119
Qp = 32.565

Page 24 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx

Total of 2 main streams to confluence:

Flow rates before confluence point:

26.445 6.370
Area of streams before confluence:

41.880 7.470

Results of confluence:

Total flow rate = 32.565(CFS)
Time of concentration = 14.262 min.

Effective stream area after confluence = 49.350(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 128.000 to Point/Station 129.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1509.000(Ft.)
Downstream point/station elevation = 1499.100(Ft.)
Pipe length = 333.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 32.565(CFS)
Nearest computed pipe diameter = 24.00(In.)
Calculated individual pipe flow = 32.565(CFS)
Normal flow depth in pipe = 16.76(In.)
Flow top width inside pipe = 22.03(In.)
Critical Depth = 22.74(In.)
Pipe flow velocity = 13.90(Ft/s)
Travel time through pipe = 0.40 min.

Time of concentration (TC) = 14.66 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 128.000 to Point/Station 129.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 1
Stream flow area = 49.350(Ac.)
Runoff from this stream = 32.565(CFS)
Time of concentration = 14.66 min.

Rainfall intensity = 1.161(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 130.000 to Point/Station 131.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 994.000(Ft.)
Top (of initial area) elevation = 1521.000(Ft.)
Bottom (of initial area) elevation = 1508.600(Ft.)
Difference in elevation = 12.400(Ft.)
Slope = 0.01247 s(percent)= 1.25
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 14.819 min.

Rainfall intensity = 1.154(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.622
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.700
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.300
RI index for soil(AMC 1) = 41.70
Pervious area fraction = 0.500; Impervious fraction = 0.500

Page 25 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Initial subarea runoff = 1.680(CFS)
Total initial stream area = 2.340(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 131.000 to Point/Station 129.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1499.400(Ft.)
Downstream point/station elevation = 1499.100(Ft.)
Pipe length = 22.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 1.680(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow = 1.680(CFS)
Normal flow depth in pipe = 6.49(In.)
Flow top width inside pipe = 8.07(In.)
Critical Depth = 7.14(In.)
Pipe flow velocity = 4.93(Ft/s)
Travel time through pipe = 0.07 min.

Time of concentration (TC) = 14.89 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 131.000 to Point/Station 129.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 2
Stream flow area = 2.340(Ac.)
Runoff from this stream = 1.680(CFS)
Time of concentration = 14.89 min.

Rainfall intensity = 1.151(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 132.000 to Point/Station 133.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 636.000(Ft.)
Top (of initial area) elevation = 1526.500(Ft.)
Bottom (of initial area) elevation = 1519.100(Ft.)
Difference in elevation = 7.400(Ft.)
Slope = 0.01164 s(percent)= 1.16
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 12.569 min.

Rainfall intensity = 1.259(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.700
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
RI index for soil(AMC 1) = 57.00
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 1.199(CFS)
Total initial stream area = 1.360(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 133.000 to Point/Station 134.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** ______________________________________________________________________

Page 26 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Top of street segment elevation = 1519.100(Ft.)
End of street segment elevation = 1510.100(Ft.)
Length of street segment = 806.000(Ft.)
Height of curb above gutter flowline = 6.0(In.)
Width of half street (curb to crown) = 18.000(Ft.)
Distance from crown to crossfall grade break = 16.000(Ft.) Slope from gutter to grade break (v/hz) = 0.020
Slope from grade break to crown (v/hz) = 0.020
Street flow is on [1] side(s) of the street
Distance from curb to property line = 10.000(Ft.)
Slope from curb to property line (v/hz) = 0.020
Gutter width = 2.000(Ft.)
Gutter hike from flowline = 2.000(In.)
Manning's N in gutter = 0.0130
Manning's N from gutter to grade break = 0.0130
Manning's N from grade break to crown = 0.0130
Estimated mean flow rate at midpoint of street = 3.498(CFS) Depth of flow = 0.337(Ft.), Average velocity = 2.833(Ft/s) Streetflow hydraulics at midpoint of street travel:

Halfstreet flow width = 10.527(Ft.)
Flow velocity = 2.83(Ft/s)
Travel time = 4.74 min. TC = 17.31 min.

Adding area flow to street
SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.630
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.500
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.500
RI index for soil(AMC 1) = 45.60
Pervious area fraction = 0.500; Impervious fraction = 0.500 Rainfall intensity = 1.063(In/Hr) for a 2.0 year storm Subarea runoff = 4.501(CFS) for 6.720(Ac.)
Total runoff = 5.701(CFS) Total area = 8.080(Ac.) Street flow at end of street = 5.701(CFS)
Half street flow at end of street = 5.701(CFS)
Depth of flow = 0.385(Ft.), Average velocity = 3.176(Ft/s) Flow width (from curb towards crown)= 12.915(Ft.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 134.000 to Point/Station 129.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1499.400(Ft.)
Downstream point/station elevation = 1499.100(Ft.)
Pipe length = 25.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 5.701(CFS)
Nearest computed pipe diameter = 15.00(In.)
Calculated individual pipe flow = 5.701(CFS)
Normal flow depth in pipe = 10.20(In.)
Flow top width inside pipe = 14.00(In.)
Critical Depth = 11.60(In.)
Pipe flow velocity = 6.41(Ft/s)
Travel time through pipe = 0.06 min.

Time of concentration (TC) = 17.38 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 134.000 to Point/Station 129.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 3

Page 27 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Stream flow area = 8.080(Ac.)
Runoff from this stream = 5.701(CFS)
Time of concentration = 17.38 min.

Rainfall intensity = 1.061(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 32.565 14.66 1.161
2 1.680 14.89 1.151
3 5.701 17.38 1.061
Largest stream flow has longer or shorter time of concentration Qp = 32.565 + sum of
Qa Tb/Ta

1.680 * 0.984 = 1.654
Qa Tb/Ta

5.701 * 0.844 = 4.810
Qp = 39.029

Total of 3 streams to confluence:

Flow rates before confluence point:

32.565 1.680 5.701
Area of streams before confluence:

49.350 2.340 8.080
Results of confluence:

Total flow rate = 39.029(CFS)
Time of concentration = 14.661 min.

Effective stream area after confluence = 59.770(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 129.000 to Point/Station 135.100 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1499.100(Ft.)
Downstream point/station elevation = 1498.000(Ft.)
Pipe length = 107.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 39.029(CFS)
Nearest computed pipe diameter = 30.00(In.)
Calculated individual pipe flow = 39.029(CFS)
Normal flow depth in pipe = 23.06(In.)
Flow top width inside pipe = 25.30(In.)
Critical Depth = 25.29(In.)
Pipe flow velocity = 9.63(Ft/s)
Travel time through pipe = 0.19 min.

Time of concentration (TC) = 14.85 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 129.000 to Point/Station 135.100 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 1
Stream flow area = 59.770(Ac.)
Runoff from this stream = 39.029(CFS)
Time of concentration = 14.85 min.

Rainfall intensity = 1.153(In/Hr)
Program is now starting with Main Stream No. 2

Page 28 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 136.000 to Point/Station 137.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 616.000(Ft.)
Top (of initial area) elevation = 1515.100(Ft.)
Bottom (of initial area) elevation = 1506.700(Ft.)
Difference in elevation = 8.400(Ft.)
Slope = 0.01364 s(percent)= 1.36
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 12.021 min.

Rainfall intensity = 1.289(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.521
Decimal fraction soil group A = 1.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 16.20
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 1.202(CFS)
Total initial stream area = 1.790(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 137.000 to Point/Station 138.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1498.900(Ft.)
Downstream point/station elevation = 1498.400(Ft.)
Pipe length = 47.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 1.202(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow = 1.202(CFS)
Normal flow depth in pipe = 5.57(In.)
Flow top width inside pipe = 8.74(In.)
Critical Depth = 6.05(In.)
Pipe flow velocity = 4.18(Ft/s)
Travel time through pipe = 0.19 min.

Time of concentration (TC) = 12.21 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 137.000 to Point/Station 138.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 2 in normal stream number 1
Stream flow area = 1.790(Ac.)
Runoff from this stream = 1.202(CFS)
Time of concentration = 12.21 min.

Rainfall intensity = 1.279(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 139.000 to Point/Station 140.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 701.000(Ft.)
Top (of initial area) elevation = 1512.200(Ft.)
Bottom (of initial area) elevation = 1506.700(Ft.)
Difference in elevation = 5.500(Ft.)
Slope = 0.00785 s(percent)= 0.78

Page 29 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 14.139 min.

Rainfall intensity = 1.183(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.600
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 36.00
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 1.675(CFS)
Total initial stream area = 2.360(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 140.000 to Point/Station 138.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1498.600(Ft.)
Downstream point/station elevation = 1498.400(Ft.)
Pipe length = 10.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 1.675(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow = 1.675(CFS)
Normal flow depth in pipe = 5.63(In.)
Flow top width inside pipe = 8.71(In.)
Critical Depth = 7.14(In.)
Pipe flow velocity = 5.76(Ft/s)
Travel time through pipe = 0.03 min.

Time of concentration (TC) = 14.17 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 140.000 to Point/Station 138.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 2 in normal stream number 2
Stream flow area = 2.360(Ac.)
Runoff from this stream = 1.675(CFS)
Time of concentration = 14.17 min.

Rainfall intensity = 1.182(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 1.202 12.21 1.279
2 1.675 14.17 1.182
Largest stream flow has longer time of concentration
Qp = 1.675 + sum of
Qb Ia/Ib

1.202 * 0.924 = 1.111
Qp = 2.786

Total of 2 streams to confluence:

Flow rates before confluence point:

1.202 1.675
Area of streams before confluence:

1.790 2.360
Results of confluence:

Page 30 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Total flow rate = 2.786(CFS)
Time of concentration = 14.168 min.

Effective stream area after confluence = 4.150(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 138.000 to Point/Station 135.200 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1498.400(Ft.)
Downstream point/station elevation = 1498.000(Ft.)
Pipe length = 40.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 2.786(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 2.786(CFS)
Normal flow depth in pipe = 7.98(In.)
Flow top width inside pipe = 11.33(In.)
Critical Depth = 8.59(In.)
Pipe flow velocity = 5.02(Ft/s)
Travel time through pipe = 0.13 min.

Time of concentration (TC) = 14.30 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 138.000 to Point/Station 135.200 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 2
Stream flow area = 4.150(Ac.)
Runoff from this stream = 2.786(CFS)
Time of concentration = 14.30 min.

Rainfall intensity = 1.176(In/Hr)
Program is now starting with Main Stream No. 3

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 146.000 to Point/Station 147.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 1000.000(Ft.)
Top (of initial area) elevation = 1744.000(Ft.)
Bottom (of initial area) elevation = 1579.000(Ft.)
Difference in elevation = 165.000(Ft.)
Slope = 0.16500 s(percent)= 16.50
TC = k(0.530)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 12.044 min.

Rainfall intensity = 1.288(In/Hr) for a 2.0 year storm UNDEVELOPED (poor cover) subarea
Runoff Coefficient = 0.538
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 60.60
Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 2.959(CFS)
Total initial stream area = 4.270(Ac.)
Pervious area fraction = 1.000

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 147.000 to Point/Station 148.000

Page 31 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx **** IMPROVED CHANNEL TRAVEL TIME ****
______________________________________________________________________ Upstream point elevation = 1579.000(Ft.)
Downstream point elevation = 1568.000(Ft.)
Channel length thru subarea = 185.000(Ft.)
Channel base width = 0.000(Ft.)
Slope or 'Z' of left channel bank = 1.000
Slope or 'Z' of right channel bank = 1.000
Estimated mean flow rate at midpoint of channel = 3.196(CFS) Manning's 'N' = 0.013
Maximum depth of channel = 1.500(Ft.)
Flow(q) thru subarea = 3.196(CFS)
Depth of flow = 0.576(Ft.), Average velocity = 9.644(Ft/s) Channel flow top width = 1.151(Ft.)
Flow Velocity = 9.64(Ft/s)
Travel time = 0.32 min.

Time of concentration = 12.36 min.

Sub-Channel No. 1 Critical depth = 0.914(Ft.)
' ' ' Critical flow top width = 1.828(Ft.) ' ' ' Critical flow velocity= 3.826(Ft/s) ' ' ' Critical flow area = 0.836(Sq.Ft)

Adding area flow to channel
UNDEVELOPED (fair cover) subarea
Runoff Coefficient = 0.437
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 49.80
Pervious area fraction = 1.000; Impervious fraction = 0.000 Rainfall intensity = 1.270(In/Hr) for a 2.0 year storm Subarea runoff = 0.422(CFS) for 0.760(Ac.)
Total runoff = 3.381(CFS) Total area = 5.030(Ac.) Depth of flow = 0.588(Ft.), Average velocity = 9.781(Ft/s)

Sub-Channel No. 1 Critical depth = 0.938(Ft.)
' ' ' Critical flow top width = 1.875(Ft.) ' ' ' Critical flow velocity= 3.847(Ft/s) ' ' ' Critical flow area = 0.879(Sq.Ft)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 147.000 to Point/Station 148.000 **** SUBAREA FLOW ADDITION ****
______________________________________________________________________ UNDEVELOPED (poor cover) subarea
Runoff Coefficient = 0.535
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 60.60
Pervious area fraction = 1.000; Impervious fraction = 0.000 Time of concentration = 12.36 min.

Rainfall intensity = 1.270(In/Hr) for a 2.0 year storm Subarea runoff = 1.631(CFS) for 2.400(Ac.)
Total runoff = 5.012(CFS) Total area = 7.430(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Page 32 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Process from Point/Station 148.000 to Point/Station 149.000 **** IMPROVED CHANNEL TRAVEL TIME ****
______________________________________________________________________ Upstream point elevation = 1568.000(Ft.)
Downstream point elevation = 1560.000(Ft.)
Channel length thru subarea = 220.000(Ft.)
Channel base width = 0.000(Ft.)
Slope or 'Z' of left channel bank = 1.000
Slope or 'Z' of right channel bank = 1.000
Estimated mean flow rate at midpoint of channel = 5.147(CFS) Manning's 'N' = 0.013
Maximum depth of channel = 1.500(Ft.)
Flow(q) thru subarea = 5.147(CFS)
Depth of flow = 0.755(Ft.), Average velocity = 9.035(Ft/s) Channel flow top width = 1.510(Ft.)
Flow Velocity = 9.04(Ft/s)
Travel time = 0.41 min.

Time of concentration = 12.77 min.

Sub-Channel No. 1 Critical depth = 1.102(Ft.)
' ' ' Critical flow top width = 2.203(Ft.) ' ' ' Critical flow velocity= 4.242(Ft/s) ' ' ' Critical flow area = 1.213(Sq.Ft)

Adding area flow to channel
UNDEVELOPED (fair cover) subarea
Runoff Coefficient = 0.433
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 49.80
Pervious area fraction = 1.000; Impervious fraction = 0.000 Rainfall intensity = 1.249(In/Hr) for a 2.0 year storm Subarea runoff = 0.217(CFS) for 0.400(Ac.)
Total runoff = 5.229(CFS) Total area = 7.830(Ac.) Depth of flow = 0.759(Ft.), Average velocity = 9.071(Ft/s)

Sub-Channel No. 1 Critical depth = 1.109(Ft.)
' ' ' Critical flow top width = 2.219(Ft.) ' ' ' Critical flow velocity= 4.249(Ft/s) ' ' ' Critical flow area = 1.231(Sq.Ft)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 149.000 to Point/Station 150.000 **** IMPROVED CHANNEL TRAVEL TIME ****
______________________________________________________________________ Upstream point elevation = 1560.000(Ft.)
Downstream point elevation = 1555.000(Ft.)
Channel length thru subarea = 190.000(Ft.)
Channel base width = 0.000(Ft.)
Slope or 'Z' of left channel bank = 1.000
Slope or 'Z' of right channel bank = 1.000
Estimated mean flow rate at midpoint of channel = 5.531(CFS) Manning's 'N' = 0.013
Maximum depth of channel = 1.500(Ft.)
Flow(q) thru subarea = 5.531(CFS)
Depth of flow = 0.824(Ft.), Average velocity = 8.148(Ft/s) Channel flow top width = 1.648(Ft.)
Flow Velocity = 8.15(Ft/s)
Travel time = 0.39 min.

Page 33 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Time of concentration = 13.16 min.

Sub-Channel No. 1 Critical depth = 1.141(Ft.)
' ' ' Critical flow top width = 2.281(Ft.) ' ' ' Critical flow velocity= 4.251(Ft/s) ' ' ' Critical flow area = 1.301(Sq.Ft)

Adding area flow to channel
UNDEVELOPED (fair cover) subarea
Runoff Coefficient = 0.430
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 49.80
Pervious area fraction = 1.000; Impervious fraction = 0.000 Rainfall intensity = 1.229(In/Hr) for a 2.0 year storm Subarea runoff = 0.534(CFS) for 1.010(Ac.)
Total runoff = 5.763(CFS) Total area = 8.840(Ac.) Depth of flow = 0.837(Ft.), Average velocity = 8.232(Ft/s)

Sub-Channel No. 1 Critical depth = 1.156(Ft.)
' ' ' Critical flow top width = 2.313(Ft.) ' ' ' Critical flow velocity= 4.310(Ft/s) ' ' ' Critical flow area = 1.337(Sq.Ft)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 149.000 to Point/Station 150.000 **** SUBAREA FLOW ADDITION ****
______________________________________________________________________ UNDEVELOPED (poor cover) subarea
Runoff Coefficient = 0.528
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 60.60
Pervious area fraction = 1.000; Impervious fraction = 0.000 Time of concentration = 13.16 min.

Rainfall intensity = 1.229(In/Hr) for a 2.0 year storm Subarea runoff = 2.206(CFS) for 3.400(Ac.)
Total runoff = 7.968(CFS) Total area = 12.240(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 150.000 to Point/Station 151.000 **** IMPROVED CHANNEL TRAVEL TIME ****
______________________________________________________________________ Upstream point elevation = 1555.000(Ft.)
Downstream point elevation = 1536.000(Ft.)
Channel length thru subarea = 330.000(Ft.)
Channel base width = 0.000(Ft.)
Slope or 'Z' of left channel bank = 1.000
Slope or 'Z' of right channel bank = 1.000
Estimated mean flow rate at midpoint of channel = 8.131(CFS) Manning's 'N' = 0.013
Maximum depth of channel = 1.500(Ft.)
Flow(q) thru subarea = 8.131(CFS)
Depth of flow = 0.822(Ft.), Average velocity = 12.034(Ft/s) Channel flow top width = 1.644(Ft.)
Flow Velocity = 12.03(Ft/s)

Page 34 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Travel time = 0.46 min.

Time of concentration = 13.62 min.

Sub-Channel No. 1 Critical depth = 1.328(Ft.)
' ' ' Critical flow top width = 2.656(Ft.) ' ' ' Critical flow velocity= 4.610(Ft/s) ' ' ' Critical flow area = 1.764(Sq.Ft)

Adding area flow to channel
UNDEVELOPED (fair cover) subarea
Runoff Coefficient = 0.426
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 49.80
Pervious area fraction = 1.000; Impervious fraction = 0.000 Rainfall intensity = 1.207(In/Hr) for a 2.0 year storm Subarea runoff = 0.257(CFS) for 0.500(Ac.)
Total runoff = 8.225(CFS) Total area = 12.740(Ac.) Depth of flow = 0.826(Ft.), Average velocity = 12.069(Ft/s)

Sub-Channel No. 1 Critical depth = 1.328(Ft.)
' ' ' Critical flow top width = 2.656(Ft.) ' ' ' Critical flow velocity= 4.663(Ft/s) ' ' ' Critical flow area = 1.764(Sq.Ft)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 151.000 to Point/Station 152.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1534.000(Ft.)
Downstream point/station elevation = 1533.000(Ft.)
Pipe length = 104.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 8.225(CFS)
Nearest computed pipe diameter = 18.00(In.)
Calculated individual pipe flow = 8.225(CFS)
Normal flow depth in pipe = 12.16(In.)
Flow top width inside pipe = 16.85(In.)
Critical Depth = 13.33(In.)
Pipe flow velocity = 6.47(Ft/s)
Travel time through pipe = 0.27 min.

Time of concentration (TC) = 13.88 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 151.000 to Point/Station 152.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 3 in normal stream number 1
Stream flow area = 12.740(Ac.)
Runoff from this stream = 8.225(CFS)
Time of concentration = 13.88 min.

Rainfall intensity = 1.195(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 153.000 to Point/Station 152.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 727.000(Ft.)

Page 35 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Top (of initial area) elevation = 1707.000(Ft.)
Bottom (of initial area) elevation = 1537.000(Ft.)
Difference in elevation = 170.000(Ft.)
Slope = 0.23384 s(percent)= 23.38
TC = k(0.530)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 9.888 min.

Rainfall intensity = 1.430(In/Hr) for a 2.0 year storm UNDEVELOPED (poor cover) subarea
Runoff Coefficient = 0.625
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.500
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.500
RI index for soil(AMC 1) = 67.90
Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 3.037(CFS)
Total initial stream area = 3.400(Ac.)
Pervious area fraction = 1.000

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 153.000 to Point/Station 152.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 3 in normal stream number 2
Stream flow area = 3.400(Ac.)
Runoff from this stream = 3.037(CFS)
Time of concentration = 9.89 min.

Rainfall intensity = 1.430(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 8.225 13.88 1.195
2 3.037 9.89 1.430
Largest stream flow has longer time of concentration
Qp = 8.225 + sum of
Qb Ia/Ib

3.037 * 0.835 = 2.537
Qp = 10.763

Total of 2 streams to confluence:

Flow rates before confluence point:

8.225 3.037
Area of streams before confluence:

12.740 3.400
Results of confluence:

Total flow rate = 10.763(CFS)
Time of concentration = 13.883 min.

Effective stream area after confluence = 16.140(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 152.000 to Point/Station 154.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1533.000(Ft.)
Downstream point/station elevation = 1519.500(Ft.)
Pipe length = 440.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 10.763(CFS)
Nearest computed pipe diameter = 15.00(In.)

Page 36 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Calculated individual pipe flow = 10.763(CFS)
Normal flow depth in pipe = 11.70(In.)
Flow top width inside pipe = 12.43(In.)
Critical depth could not be calculated.

Pipe flow velocity = 10.49(Ft/s)
Travel time through pipe = 0.70 min.

Time of concentration (TC) = 14.58 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 152.000 to Point/Station 154.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 3 in normal stream number 1
Stream flow area = 16.140(Ac.)
Runoff from this stream = 10.763(CFS)
Time of concentration = 14.58 min.

Rainfall intensity = 1.164(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 155.000 to Point/Station 156.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 320.000(Ft.)
Top (of initial area) elevation = 1575.000(Ft.)
Bottom (of initial area) elevation = 1528.000(Ft.)
Difference in elevation = 47.000(Ft.)
Slope = 0.14688 s(percent)= 14.69
TC = k(0.710)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 10.470 min.

Rainfall intensity = 1.387(In/Hr) for a 2.0 year storm UNDEVELOPED (fair cover) subarea
Runoff Coefficient = 0.625
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
RI index for soil(AMC 1) = 68.60
Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 0.477(CFS)
Total initial stream area = 0.550(Ac.)
Pervious area fraction = 1.000

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 156.000 to Point/Station 154.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1528.000(Ft.)
Downstream point/station elevation = 1519.500(Ft.)
Pipe length = 36.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 0.477(CFS)
Nearest computed pipe diameter = 6.00(In.)
Calculated individual pipe flow = 0.477(CFS)
Normal flow depth in pipe = 1.70(In.)
Flow top width inside pipe = 5.41(In.)
Critical Depth = 4.22(In.)
Pipe flow velocity = 10.44(Ft/s)
Travel time through pipe = 0.06 min.

Time of concentration (TC) = 10.53 min.

Page 37 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 156.000 to Point/Station 154.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 3 in normal stream number 2
Stream flow area = 0.550(Ac.)
Runoff from this stream = 0.477(CFS)
Time of concentration = 10.53 min.

Rainfall intensity = 1.383(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 10.763 14.58 1.164
2 0.477 10.53 1.383
Largest stream flow has longer time of concentration
Qp = 10.763 + sum of
Qb Ia/Ib

0.477 * 0.841 = 0.401
Qp = 11.164

Total of 2 streams to confluence:

Flow rates before confluence point:

10.763 0.477
Area of streams before confluence:

16.140 0.550
Results of confluence:

Total flow rate = 11.164(CFS)
Time of concentration = 14.582 min.

Effective stream area after confluence = 16.690(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 154.000 to Point/Station 157.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1519.500(Ft.)
Downstream point/station elevation = 1509.800(Ft.)
Pipe length = 660.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 11.164(CFS)
Nearest computed pipe diameter = 18.00(In.)
Calculated individual pipe flow = 11.164(CFS)
Normal flow depth in pipe = 13.05(In.)
Flow top width inside pipe = 16.07(In.)
Critical Depth = 15.34(In.)
Pipe flow velocity = 8.13(Ft/s)
Travel time through pipe = 1.35 min.

Time of concentration (TC) = 15.94 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 154.000 to Point/Station 157.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 3 in normal stream number 1
Stream flow area = 16.690(Ac.)
Runoff from this stream = 11.164(CFS)
Time of concentration = 15.94 min.

Rainfall intensity = 1.111(In/Hr)

Page 38 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 158.000 to Point/Station 159.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 442.000(Ft.)
Top (of initial area) elevation = 1640.000(Ft.)
Bottom (of initial area) elevation = 1535.000(Ft.)
Difference in elevation = 105.000(Ft.)
Slope = 0.23756 s(percent)= 23.76
TC = k(0.530)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 8.078 min.

Rainfall intensity = 1.592(In/Hr) for a 2.0 year storm UNDEVELOPED (poor cover) subarea
Runoff Coefficient = 0.676
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 1.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 71.60
Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 2.205(CFS)
Total initial stream area = 2.050(Ac.)
Pervious area fraction = 1.000

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 159.000 to Point/Station 157.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1533.000(Ft.)
Downstream point/station elevation = 1509.800(Ft.)
Pipe length = 65.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 2.205(CFS)
Nearest computed pipe diameter = 6.00(In.)
Calculated individual pipe flow = 2.205(CFS)
Normal flow depth in pipe = 3.55(In.)
Flow top width inside pipe = 5.90(In.)
Critical depth could not be calculated.

Pipe flow velocity = 18.22(Ft/s)
Travel time through pipe = 0.06 min.

Time of concentration (TC) = 8.14 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 159.000 to Point/Station 157.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 3 in normal stream number 2
Stream flow area = 2.050(Ac.)
Runoff from this stream = 2.205(CFS)
Time of concentration = 8.14 min.

Rainfall intensity = 1.586(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 11.164 15.94 1.111
2 2.205 8.14 1.586
Largest stream flow has longer time of concentration
Qp = 11.164 + sum of
Qb Ia/Ib

Page 39 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx

2.205 * 0.700 = 1.544
Qp = 12.708

Total of 2 streams to confluence:

Flow rates before confluence point:

11.164 2.205
Area of streams before confluence:

16.690 2.050
Results of confluence:

Total flow rate = 12.708(CFS)
Time of concentration = 15.936 min.

Effective stream area after confluence = 18.740(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 157.000 to Point/Station 160.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1509.800(Ft.)
Downstream point/station elevation = 1503.800(Ft.)
Pipe length = 307.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 12.708(CFS)
Nearest computed pipe diameter = 18.00(In.)
Calculated individual pipe flow = 12.708(CFS)
Normal flow depth in pipe = 12.94(In.)
Flow top width inside pipe = 16.19(In.)
Critical Depth = 16.10(In.)
Pipe flow velocity = 9.35(Ft/s)
Travel time through pipe = 0.55 min.

Time of concentration (TC) = 16.48 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 157.000 to Point/Station 160.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 3 in normal stream number 1
Stream flow area = 18.740(Ac.)
Runoff from this stream = 12.708(CFS)
Time of concentration = 16.48 min.

Rainfall intensity = 1.091(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 161.000 to Point/Station 162.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 570.000(Ft.)
Top (of initial area) elevation = 1630.000(Ft.)
Bottom (of initial area) elevation = 1535.000(Ft.)
Difference in elevation = 95.000(Ft.)
Slope = 0.16667 s(percent)= 16.67
TC = k(0.530)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 9.600 min.

Rainfall intensity = 1.453(In/Hr) for a 2.0 year storm UNDEVELOPED (poor cover) subarea
Runoff Coefficient = 0.628
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.500
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.500
RI index for soil(AMC 1) = 67.90
Pervious area fraction = 1.000; Impervious fraction = 0.000

Page 40 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Initial subarea runoff = 1.514(CFS)
Total initial stream area = 1.660(Ac.)
Pervious area fraction = 1.000

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 162.000 to Point/Station 160.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1533.000(Ft.)
Downstream point/station elevation = 1503.800(Ft.)
Pipe length = 72.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 1.514(CFS)
Nearest computed pipe diameter = 6.00(In.)
Calculated individual pipe flow = 1.514(CFS)
Normal flow depth in pipe = 2.73(In.)
Flow top width inside pipe = 5.97(In.)
Critical depth could not be calculated.

Pipe flow velocity = 17.45(Ft/s)
Travel time through pipe = 0.07 min.

Time of concentration (TC) = 9.67 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 162.000 to Point/Station 160.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 3 in normal stream number 2
Stream flow area = 1.660(Ac.)
Runoff from this stream = 1.514(CFS)
Time of concentration = 9.67 min.

Rainfall intensity = 1.447(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 12.708 16.48 1.091
2 1.514 9.67 1.447
Largest stream flow has longer time of concentration
Qp = 12.708 + sum of
Qb Ia/Ib

1.514 * 0.754 = 1.141
Qp = 13.849

Total of 2 streams to confluence:

Flow rates before confluence point:

12.708 1.514
Area of streams before confluence:

18.740 1.660
Results of confluence:

Total flow rate = 13.849(CFS)
Time of concentration = 16.483 min.

Effective stream area after confluence = 20.400(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 160.000 to Point/Station 135.200 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1503.800(Ft.)
Downstream point/station elevation = 1498.000(Ft.)

Page 41 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Pipe length = 256.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 13.849(CFS)
Nearest computed pipe diameter = 18.00(In.)
Calculated individual pipe flow = 13.849(CFS)
Normal flow depth in pipe = 13.05(In.)
Flow top width inside pipe = 16.07(In.)
Critical Depth = 16.52(In.)
Pipe flow velocity = 10.09(Ft/s)
Travel time through pipe = 0.42 min.

Time of concentration (TC) = 16.91 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 160.000 to Point/Station 135.200 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 3
Stream flow area = 20.400(Ac.)
Runoff from this stream = 13.849(CFS)
Time of concentration = 16.91 min.

Rainfall intensity = 1.076(In/Hr)
Program is now starting with Main Stream No. 4

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 128.000 to Point/Station 140.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 580.000(Ft.)
Top (of initial area) elevation = 1529.800(Ft.)
Bottom (of initial area) elevation = 1523.300(Ft.)
Difference in elevation = 6.500(Ft.)
Slope = 0.01121 s(percent)= 1.12
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 12.205 min.

Rainfall intensity = 1.279(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.702
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
RI index for soil(AMC 1) = 57.00
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 1.167(CFS)
Total initial stream area = 1.300(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 140.000 to Point/Station 141.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** ______________________________________________________________________ Top of street segment elevation = 1523.300(Ft.)
End of street segment elevation = 1504.000(Ft.)
Length of street segment = 1420.000(Ft.)
Height of curb above gutter flowline = 8.0(In.)
Width of half street (curb to crown) = 38.000(Ft.)
Distance from crown to crossfall grade break = 20.000(Ft.) Slope from gutter to grade break (v/hz) = 0.020
Slope from grade break to crown (v/hz) = 0.020
Street flow is on [1] side(s) of the street

Page 42 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Distance from curb to property line = 40.000(Ft.)
Slope from curb to property line (v/hz) = 0.020
Gutter width = 2.000(Ft.)
Gutter hike from flowline = 2.000(In.)
Manning's N in gutter = 0.0130
Manning's N from gutter to grade break = 0.0130
Manning's N from grade break to crown = 0.0130
Estimated mean flow rate at midpoint of street = 2.142(CFS) Depth of flow = 0.289(Ft.), Average velocity = 2.739(Ft/s) Streetflow hydraulics at midpoint of street travel:

Halfstreet flow width = 8.096(Ft.)
Flow velocity = 2.74(Ft/s)
Travel time = 8.64 min. TC = 20.85 min.

Adding area flow to street
SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.620
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.500
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.500
RI index for soil(AMC 1) = 45.60
Pervious area fraction = 0.500; Impervious fraction = 0.500 Rainfall intensity = 0.963(In/Hr) for a 2.0 year storm Subarea runoff = 1.886(CFS) for 3.160(Ac.)
Total runoff = 3.053(CFS) Total area = 4.460(Ac.) Street flow at end of street = 3.053(CFS)
Half street flow at end of street = 3.053(CFS)
Depth of flow = 0.317(Ft.), Average velocity = 2.962(Ft/s) Flow width (from curb towards crown)= 9.508(Ft.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 141.000 to Point/Station 142.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1498.800(Ft.)
Downstream point/station elevation = 1498.000(Ft.)
Pipe length = 70.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 3.053(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 3.053(CFS)
Normal flow depth in pipe = 8.13(In.)
Flow top width inside pipe = 11.22(In.)
Critical Depth = 8.99(In.)
Pipe flow velocity = 5.39(Ft/s)
Travel time through pipe = 0.22 min.

Time of concentration (TC) = 21.06 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 141.000 to Point/Station 142.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 4 in normal stream number 1
Stream flow area = 4.460(Ac.)
Runoff from this stream = 3.053(CFS)
Time of concentration = 21.06 min.

Rainfall intensity = 0.958(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 117.000 to Point/Station 143.000 **** INITIAL AREA EVALUATION ****

Page 43 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx ______________________________________________________________________ Initial area flow distance = 722.000(Ft.)
Top (of initial area) elevation = 1543.800(Ft.)
Bottom (of initial area) elevation = 1537.300(Ft.)
Difference in elevation = 6.500(Ft.)
Slope = 0.00900 s(percent)= 0.90
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 13.919 min.

Rainfall intensity = 1.193(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.643
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.500
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.500
RI index for soil(AMC 1) = 45.60
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 0.882(CFS)
Total initial stream area = 1.150(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 143.000 to Point/Station 144.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** ______________________________________________________________________ Top of street segment elevation = 1537.300(Ft.)
End of street segment elevation = 1528.600(Ft.)
Length of street segment = 863.000(Ft.)
Height of curb above gutter flowline = 8.0(In.)
Width of half street (curb to crown) = 38.000(Ft.)
Distance from crown to crossfall grade break = 20.000(Ft.) Slope from gutter to grade break (v/hz) = 0.020
Slope from grade break to crown (v/hz) = 0.020
Street flow is on [1] side(s) of the street
Distance from curb to property line = 40.000(Ft.)
Slope from curb to property line (v/hz) = 0.020
Gutter width = 2.000(Ft.)
Gutter hike from flowline = 2.000(In.)
Manning's N in gutter = 0.0130
Manning's N from gutter to grade break = 0.0130
Manning's N from grade break to crown = 0.0130
Estimated mean flow rate at midpoint of street = 1.344(CFS) Depth of flow = 0.266(Ft.), Average velocity = 2.208(Ft/s) Streetflow hydraulics at midpoint of street travel:

Halfstreet flow width = 6.944(Ft.)
Flow velocity = 2.21(Ft/s)
Travel time = 6.52 min. TC = 20.43 min.

Adding area flow to street
SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.661
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.100
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.900
RI index for soil(AMC 1) = 54.72
Pervious area fraction = 0.500; Impervious fraction = 0.500 Rainfall intensity = 0.973(In/Hr) for a 2.0 year storm Subarea runoff = 0.843(CFS) for 1.310(Ac.)
Total runoff = 1.725(CFS) Total area = 2.460(Ac.) Street flow at end of street = 1.725(CFS)
Half street flow at end of street = 1.725(CFS)
Depth of flow = 0.284(Ft.), Average velocity = 2.325(Ft/s)

Page 44 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Flow width (from curb towards crown)= 7.843(Ft.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 144.000 to Point/Station 145.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** ______________________________________________________________________ Top of street segment elevation = 1528.600(Ft.)
End of street segment elevation = 1498.100(Ft.)
Length of street segment = 1850.000(Ft.)
Height of curb above gutter flowline = 8.0(In.)
Width of half street (curb to crown) = 38.000(Ft.)
Distance from crown to crossfall grade break = 20.000(Ft.) Slope from gutter to grade break (v/hz) = 0.020
Slope from grade break to crown (v/hz) = 0.020
Street flow is on [1] side(s) of the street
Distance from curb to property line = 40.000(Ft.)
Slope from curb to property line (v/hz) = 0.020
Gutter width = 2.000(Ft.)
Gutter hike from flowline = 2.000(In.)
Manning's N in gutter = 0.0130
Manning's N from gutter to grade break = 0.0130
Manning's N from grade break to crown = 0.0130
Estimated mean flow rate at midpoint of street = 2.438(CFS) Depth of flow = 0.291(Ft.), Average velocity = 3.038(Ft/s) Streetflow hydraulics at midpoint of street travel:

Halfstreet flow width = 8.220(Ft.)
Flow velocity = 3.04(Ft/s)
Travel time = 10.15 min. TC = 30.58 min.

Adding area flow to street
SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.599
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.500
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.500
RI index for soil(AMC 1) = 45.60
Pervious area fraction = 0.500; Impervious fraction = 0.500 Rainfall intensity = 0.786(In/Hr) for a 2.0 year storm Subarea runoff = 1.342(CFS) for 2.850(Ac.)
Total runoff = 3.066(CFS) Total area = 5.310(Ac.) Street flow at end of street = 3.066(CFS)
Half street flow at end of street = 3.066(CFS)
Depth of flow = 0.309(Ft.), Average velocity = 3.196(Ft/s) Flow width (from curb towards crown)= 9.126(Ft.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 145.000 to Point/Station 142.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1498.600(Ft.)
Downstream point/station elevation = 1498.100(Ft.)
Pipe length = 50.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 3.066(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 3.066(CFS)
Normal flow depth in pipe = 8.58(In.)
Flow top width inside pipe = 10.84(In.)
Critical Depth = 9.01(In.)
Pipe flow velocity = 5.10(Ft/s)
Travel time through pipe = 0.16 min.

Time of concentration (TC) = 30.75 min.

Page 45 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 145.000 to Point/Station 142.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 4 in normal stream number 2
Stream flow area = 5.310(Ac.)
Runoff from this stream = 3.066(CFS)
Time of concentration = 30.75 min.

Rainfall intensity = 0.784(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 3.053 21.06 0.958
2 3.066 30.75 0.784
Largest stream flow has longer time of concentration
Qp = 3.066 + sum of
Qb Ia/Ib

3.053 * 0.818 = 2.499
Qp = 5.565

Total of 2 streams to confluence:

Flow rates before confluence point:

3.053 3.066
Area of streams before confluence:

4.460 5.310
Results of confluence:

Total flow rate = 5.565(CFS)
Time of concentration = 30.746 min.

Effective stream area after confluence = 9.770(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 142.000 to Point/Station 134.400 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1498.100(Ft.)
Downstream point/station elevation = 1496.000(Ft.)
Pipe length = 116.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 5.565(CFS)
Nearest computed pipe diameter = 15.00(In.)
Calculated individual pipe flow = 5.565(CFS)
Normal flow depth in pipe = 8.72(In.)
Flow top width inside pipe = 14.80(In.)
Critical Depth = 11.47(In.)
Pipe flow velocity = 7.51(Ft/s)
Travel time through pipe = 0.26 min.

Time of concentration (TC) = 31.00 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 142.000 to Point/Station 134.400 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 4
Stream flow area = 9.770(Ac.)
Runoff from this stream = 5.565(CFS)
Time of concentration = 31.00 min.

Page 46 of 46 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\02 - pr002.docx Rainfall intensity = 0.780(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 39.029 14.85 1.153
2 2.786 14.30 1.176
3 13.849 16.91 1.076
4 5.565 31.00 0.780
Largest stream flow has longer or shorter time of concentration Qp = 39.029 + sum of
Qb Ia/Ib

2.786 * 0.980 = 2.731
Qa Tb/Ta

13.849 * 0.878 = 12.162
Qa Tb/Ta

5.565 * 0.479 = 2.665
Qp = 56.586

Total of 4 main streams to confluence:

Flow rates before confluence point:

39.029 2.786 13.849 5.565
Area of streams before confluence:

59.770 4.150 20.400 9.770

Results of confluence:

Total flow rate = 56.586(CFS)
Time of concentration = 14.846 min.

Effective stream area after confluence = 94.090(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 142.000 to Point/Station 134.400 **** SUBAREA FLOW ADDITION ****
______________________________________________________________________ UNDEVELOPED (fair cover) subarea
Runoff Coefficient = 0.416
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 49.80
Pervious area fraction = 1.000; Impervious fraction = 0.000 Time of concentration = 14.85 min.

Rainfall intensity = 1.153(In/Hr) for a 2.0 year storm Subarea runoff = 0.858(CFS) for 1.790(Ac.)
Total runoff = 57.444(CFS) Total area = 95.880(Ac.) End of computations, total study area = 95.88 (Ac.) The following figures may
be used for a unit hydrograph study of the same area.

Area averaged pervious area fraction(Ap) = 0.724
Area averaged RI index number = 70.6

Riverside County Rational Hydrology Program

CIVILCADD/CIVILDESIGN Engineering Software,(c) 1989 - 2014 Version 9.0 Rational Hydrology Study Date: 02/07/19 File:EXC002.out ------------------------------------------------------------------------ TRACT 31194 - 'GOLDEN MEADOWS' HYDROLOGY STUDY – AREA ‘C’ EXISTING CONDITION - RATIONAL METHOD - 2 YEAR STORM
HUNSAKER & ASSOCIATES, FEBRUARY 2019
BY: BRIAN LOWELL, PE
------------------------------------------------------------------------ ********* Hydrology Study Control Information **********

English (in-lb) Units used in input data file

------------------------------------------------------------------------

Program License Serial Number 6407

------------------------------------------------------------------------ Rational Method Hydrology Program based on
Riverside County Flood Control & Water Conservation District 1978 hydrology manual

Storm event (year) = 2.00 Antecedent Moisture Condition = 1

2 year, 1 hour precipitation = 0.550(In.)
100 year, 1 hour precipitation = 1.300(In.)

Storm event year = 2.0
Calculated rainfall intensity data:
1 hour intensity = 0.550(In/Hr)
Slope of intensity duration curve = 0.5300

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 301.000 to Point/Station 302.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 756.000(Ft.)
Top (of initial area) elevation = 1719.000(Ft.)
Bottom (of initial area) elevation = 1541.000(Ft.)
Difference in elevation = 178.000(Ft.)
Slope = 0.23545 s(percent)= 23.54
TC = k(0.530)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 10.030 min.

Rainfall intensity = 1.419(In/Hr) for a 2.0 year storm UNDEVELOPED (poor cover) subarea
Runoff Coefficient = 0.585
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.700
Decimal fraction soil group C = 0.300
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 63.56
Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 5.231(CFS)
Total initial stream area = 6.300(Ac.)
Pervious area fraction = 1.000

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 302.000 to Point/Station 303.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION ****
______________________________________________________________________ Top of natural channel elevation = 1548.000(Ft.)
End of natural channel elevation = 1528.000(Ft.)
Length of natural channel = 660.000(Ft.)
Estimated mean flow rate at midpoint of channel = 10.337(CFS)

Natural valley channel type used
L.A. County flood control district formula for channel velocity:

Velocity(ft/s) = (7 + 8(q(English Units)^.352)(slope^0.5) Velocity using mean channel flow = 4.39(Ft/s)

Correction to map slope used on extremely rugged channels with drops and waterfalls (Plate D-6.2)
Normal channel slope = 0.0303
Corrected/adjusted channel slope = 0.0303
Travel time = 2.51 min. TC = 12.54 min.

Adding area flow to channel
UNDEVELOPED (poor cover) subarea
Runoff Coefficient = 0.558
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.800
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.200
RI index for soil(AMC 1) = 63.28
Pervious area fraction = 1.000; Impervious fraction = 0.000 Rainfall intensity = 1.261(In/Hr) for a 2.0 year storm Subarea runoff = 8.652(CFS) for 12.300(Ac.)
Total runoff = 13.882(CFS) Total area = 18.600(Ac.) End of computations, total study area = 18.60 (Ac.) The following figures may
be used for a unit hydrograph study of the same area.

Area averaged pervious area fraction(Ap) = 1.000
Area averaged RI index number = 80.3

Riverside County Rational Hydrology Program

CIVILCADD/CIVILDESIGN Engineering Software,(c) 1989 - 2014 Version 9.0 Rational Hydrology Study Date: 05/18/21 File:PRC002.out ------------------------------------------------------------------------ TRACT 31194 - 'GOLDEN MEADOWS' MAJOR MODIFICATION
PRELIMINARY HYDROLOGY STUDY – AREA ‘C’
DEVELOPED CONDITION RATIONAL METHOD - 2 YEAR STORM
HUNSAKER & ASSOCIATES, MAY 2021, BRIAN LOWELL, PE
------------------------------------------------------------------------ ********* Hydrology Study Control Information **********

English (in-lb) Units used in input data file

------------------------------------------------------------------------

Program License Serial Number 6407

------------------------------------------------------------------------ Rational Method Hydrology Program based on
Riverside County Flood Control & Water Conservation District 1978 hydrology manual

Storm event (year) = 2.00 Antecedent Moisture Condition = 1

2 year, 1 hour precipitation = 0.550(In.)
100 year, 1 hour precipitation = 1.300(In.)

Storm event year = 2.0
Calculated rainfall intensity data:
1 hour intensity = 0.550(In/Hr)
Slope of intensity duration curve = 0.5300

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 300.000 to Point/Station 301.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 500.000(Ft.)
Top (of initial area) elevation = 1566.100(Ft.)
Bottom (of initial area) elevation = 1554.000(Ft.)
Difference in elevation = 12.100(Ft.)
Slope = 0.02420 s(percent)= 2.42
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 9.860 min.

Rainfall intensity = 1.432(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.619
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 36.00
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 1.127(CFS)
Total initial stream area = 1.270(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 301.000 to Point/Station 302.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1546.000(Ft.)
Downstream point/station elevation = 1545.000(Ft.)
Pipe length = 21.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 1.127(CFS)
Nearest computed pipe diameter = 6.00(In.)
Calculated individual pipe flow = 1.127(CFS)
Normal flow depth in pipe = 4.54(In.)
Flow top width inside pipe = 5.15(In.)
Critical depth could not be calculated.

Pipe flow velocity = 7.08(Ft/s)
Travel time through pipe = 0.05 min.

Time of concentration (TC) = 9.91 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 301.000 to Point/Station 302.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 1
Stream flow area = 1.270(Ac.)
Runoff from this stream = 1.127(CFS)
Time of concentration = 9.91 min.

Rainfall intensity = 1.428(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 300.000 to Point/Station 303.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 535.000(Ft.)
Top (of initial area) elevation = 1566.100(Ft.)
Bottom (of initial area) elevation = 1554.000(Ft.)
Difference in elevation = 12.100(Ft.)
Slope = 0.02262 s(percent)= 2.26
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 10.269 min.

Rainfall intensity = 1.402(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.617
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 36.00
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 2.102(CFS)
Total initial stream area = 2.430(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 303.000 to Point/Station 302.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1546.000(Ft.)
Downstream point/station elevation = 1545.000(Ft.)
Pipe length = 30.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 2.102(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow = 2.102(CFS)
Normal flow depth in pipe = 5.53(In.)
Flow top width inside pipe = 8.76(In.)
Critical Depth = 7.85(In.)
Pipe flow velocity = 7.39(Ft/s)
Travel time through pipe = 0.07 min.

Time of concentration (TC) = 10.34 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 303.000 to Point/Station 302.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 2
Stream flow area = 2.430(Ac.)
Runoff from this stream = 2.102(CFS)
Time of concentration = 10.34 min.

Rainfall intensity = 1.397(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 1.127 9.91 1.428
2 2.102 10.34 1.397
Largest stream flow has longer time of concentration
Qp = 2.102 + sum of
Qb Ia/Ib

1.127 * 0.978 = 1.102
Qp = 3.204

Total of 2 streams to confluence:

Flow rates before confluence point:

1.127 2.102
Area of streams before confluence:

1.270 2.430
Results of confluence:

Total flow rate = 3.204(CFS)
Time of concentration = 10.336 min.

Effective stream area after confluence = 3.700(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 302.000 to Point/Station 304.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1545.000(Ft.)
Downstream point/station elevation = 1540.000(Ft.)
Pipe length = 271.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 3.204(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 3.204(CFS)
Normal flow depth in pipe = 7.14(In.)
Flow top width inside pipe = 11.78(In.)
Critical Depth = 9.20(In.)
Pipe flow velocity = 6.59(Ft/s)
Travel time through pipe = 0.69 min.

Time of concentration (TC) = 11.02 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 302.000 to Point/Station 304.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 1
Stream flow area = 3.700(Ac.)
Runoff from this stream = 3.204(CFS)
Time of concentration = 11.02 min.

Rainfall intensity = 1.350(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 303.000 to Point/Station 305.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 215.000(Ft.)
Top (of initial area) elevation = 1554.000(Ft.)
Bottom (of initial area) elevation = 1553.500(Ft.)
Difference in elevation = 0.500(Ft.)
Slope = 0.00233 s(percent)= 0.23
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 11.239 min.

Rainfall intensity = 1.336(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.612
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 36.00
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 1.121(CFS)
Total initial stream area = 1.370(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 305.000 to Point/Station 304.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1540.200(Ft.)
Downstream point/station elevation = 1540.000(Ft.)
Pipe length = 20.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 1.121(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow = 1.121(CFS)
Normal flow depth in pipe = 5.43(In.)
Flow top width inside pipe = 8.81(In.)
Critical Depth = 5.84(In.)
Pipe flow velocity = 4.02(Ft/s)
Travel time through pipe = 0.08 min.

Time of concentration (TC) = 11.32 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 305.000 to Point/Station 304.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 2
Stream flow area = 1.370(Ac.)
Runoff from this stream = 1.121(CFS)
Time of concentration = 11.32 min.

Rainfall intensity = 1.331(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 3.204 11.02 1.350
2 1.121 11.32 1.331
Largest stream flow has longer or shorter time of concentration Qp = 3.204 + sum of
Qa Tb/Ta

1.121 * 0.974 = 1.091
Qp = 4.296

Total of 2 streams to confluence:

Flow rates before confluence point:

3.204 1.121
Area of streams before confluence:

3.700 1.370
Results of confluence:

Total flow rate = 4.296(CFS)
Time of concentration = 11.022 min.

Effective stream area after confluence = 5.070(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 304.000 to Point/Station 306.100 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1540.000(Ft.)
Downstream point/station elevation = 1535.000(Ft.)
Pipe length = 170.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 4.296(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 4.296(CFS)
Normal flow depth in pipe = 7.42(In.)
Flow top width inside pipe = 11.66(In.)
Critical Depth = 10.45(In.)
Pipe flow velocity = 8.42(Ft/s)
Travel time through pipe = 0.34 min.

Time of concentration (TC) = 11.36 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 304.000 to Point/Station 306.100 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 1
Stream flow area = 5.070(Ac.)
Runoff from this stream = 4.296(CFS)
Time of concentration = 11.36 min.

Rainfall intensity = 1.329(In/Hr)
Program is now starting with Main Stream No. 2

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 307.000 to Point/Station 308.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 742.000(Ft.)
Top (of initial area) elevation = 1551.900(Ft.)
Bottom (of initial area) elevation = 1538.600(Ft.)
Difference in elevation = 13.300(Ft.)
Slope = 0.01792 s(percent)= 1.79
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 12.261 min.

Rainfall intensity = 1.276(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.633
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.700
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.300
RI index for soil(AMC 1) = 41.70
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 2.608(CFS)
Total initial stream area = 3.230(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 308.000 to Point/Station 306.200 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1532.000(Ft.)
Downstream point/station elevation = 1531.000(Ft.)
Pipe length = 48.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 2.608(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 2.608(CFS)
Normal flow depth in pipe = 6.05(In.)
Flow top width inside pipe = 12.00(In.)
Critical Depth = 8.31(In.)
Pipe flow velocity = 6.57(Ft/s)
Travel time through pipe = 0.12 min.

Time of concentration (TC) = 12.38 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 308.000 to Point/Station 306.200 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 2
Stream flow area = 3.230(Ac.)
Runoff from this stream = 2.608(CFS)
Time of concentration = 12.38 min.

Rainfall intensity = 1.269(In/Hr)
Program is now starting with Main Stream No. 3

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 309.000 to Point/Station 310.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 647.000(Ft.)
Top (of initial area) elevation = 1719.900(Ft.)
Bottom (of initial area) elevation = 1580.000(Ft.)
Difference in elevation = 139.900(Ft.)
Slope = 0.21623 s(percent)= 21.62
TC = k(0.530)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 9.586 min.

Rainfall intensity = 1.454(In/Hr) for a 2.0 year storm UNDEVELOPED (poor cover) subarea
Runoff Coefficient = 0.629
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.300
Decimal fraction soil group C = 0.700
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 68.04
Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 2.231(CFS)
Total initial stream area = 2.440(Ac.)
Pervious area fraction = 1.000

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 310.000 to Point/Station 306.300 **** IMPROVED CHANNEL TRAVEL TIME ****
______________________________________________________________________ Upstream point elevation = 1580.000(Ft.)
Downstream point elevation = 1535.000(Ft.)
Channel length thru subarea = 532.000(Ft.)
Channel base width = 0.000(Ft.)
Slope or 'Z' of left channel bank = 1.000
Slope or 'Z' of right channel bank = 1.000
Estimated mean flow rate at midpoint of channel = 3.384(CFS) Manning's 'N' = 0.013
Maximum depth of channel = 1.500(Ft.)
Flow(q) thru subarea = 3.384(CFS)
Depth of flow = 0.551(Ft.), Average velocity = 11.166(Ft/s) Channel flow top width = 1.101(Ft.)
Flow Velocity = 11.17(Ft/s)
Travel time = 0.79 min.

Time of concentration = 10.38 min.

Sub-Channel No. 1 Critical depth = 0.938(Ft.)
' ' ' Critical flow top width = 1.875(Ft.) ' ' ' Critical flow velocity= 3.850(Ft/s) ' ' ' Critical flow area = 0.879(Sq.Ft)

Adding area flow to channel
UNDEVELOPED (poor cover) subarea
Runoff Coefficient = 0.601
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.500
Decimal fraction soil group C = 0.500
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 65.80
Pervious area fraction = 1.000; Impervious fraction = 0.000 Rainfall intensity = 1.394(In/Hr) for a 2.0 year storm Subarea runoff = 2.254(CFS) for 2.690(Ac.)
Total runoff = 4.485(CFS) Total area = 5.130(Ac.) Depth of flow = 0.612(Ft.), Average velocity = 11.980(Ft/s)

Sub-Channel No. 1 Critical depth = 1.047(Ft.)
' ' ' Critical flow top width = 2.094(Ft.) ' ' ' Critical flow velocity= 4.092(Ft/s) ' ' ' Critical flow area = 1.096(Sq.Ft)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 310.000 to Point/Station 306.300 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 3
Stream flow area = 5.130(Ac.)
Runoff from this stream = 4.485(CFS)
Time of concentration = 10.38 min.

Rainfall intensity = 1.394(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 4.296 11.36 1.329
2 2.608 12.38 1.269
3 4.485 10.38 1.394
Largest stream flow has longer or shorter time of concentration Qp = 4.485 + sum of
Qa Tb/Ta

4.296 * 0.914 = 3.926
Qa Tb/Ta

2.608 * 0.838 = 2.187
Qp = 10.597

Total of 3 main streams to confluence:

Flow rates before confluence point:

4.296 2.608 4.485
Area of streams before confluence:

5.070 3.230 5.130

Results of confluence:

Total flow rate = 10.597(CFS)
Time of concentration = 10.380 min.

Effective stream area after confluence = 13.430(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 310.000 to Point/Station 306.300 **** SUBAREA FLOW ADDITION ****
______________________________________________________________________ UNDEVELOPED (poor cover) subarea
Runoff Coefficient = 0.620
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.500
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.500
RI index for soil(AMC 1) = 67.90
Pervious area fraction = 1.000; Impervious fraction = 0.000 Time of concentration = 10.38 min.

Rainfall intensity = 1.394(In/Hr) for a 2.0 year storm Subarea runoff = 0.656(CFS) for 0.760(Ac.)
Total runoff = 11.254(CFS) Total area = 14.190(Ac.) End of computations, total study area = 14.19 (Ac.) The following figures may
be used for a unit hydrograph study of the same area.

Area averaged pervious area fraction(Ap) = 0.708
Area averaged RI index number = 68.4

Page 1 of 2 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\05 - EXD002.docx

Riverside County Rational Hydrology Program

CIVILCADD/CIVILDESIGN Engineering Software,(c) 1989 - 2014 Version 9.0 Rational Hydrology Study Date: 04/30/21 File:EXD002.out ------------------------------------------------------------------------ TRACT 31194 - 'GOLDEN MEADOWS' HYDROLOGY STUDY – AREA ‘D’ EXISTING CONDITION - RATIONAL METHOD - 2 YEAR STORM

HUNSAKER & ASSOCIATES,
BY: BRIAN LOWELL, PE
------------------------------------------------------------------------ ********* Hydrology Study Control Information **********

English (in-lb) Units used in input data file

------------------------------------------------------------------------

Program License Serial Number 6406

------------------------------------------------------------------------ Rational Method Hydrology Program based on
Riverside County Flood Control & Water Conservation District 1978 hydrology manual

Storm event (year) = 2.00 Antecedent Moisture Condition = 1

2 year, 1 hour precipitation = 0.550(In.)
100 year, 1 hour precipitation = 1.300(In.)

Storm event year = 2.0
Calculated rainfall intensity data:
1 hour intensity = 0.550(In/Hr)
Slope of intensity duration curve = 0.5300

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 401.000 to Point/Station 402.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 1000.000(Ft.)
Top (of initial area) elevation = 1778.000(Ft.)
Bottom (of initial area) elevation = 1553.000(Ft.)
Difference in elevation = 225.000(Ft.)
Slope = 0.22500 s(percent)= 22.50
TC = k(0.530)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 11.320 min.

Rainfall intensity = 1.331(In/Hr) for a 2.0 year storm UNDEVELOPED (poor cover) subarea
Runoff Coefficient = 0.592
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.500
Decimal fraction soil group C = 0.500
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 65.80
Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 7.879(CFS)

Page 2 of 2 ends

H:\00546\Planning\WQMP - Preliminary\Parts\Appendix 7 - Hydromodification\05 - EXD002.docx Total initial stream area = 10.000(Ac.)
Pervious area fraction = 1.000

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 402.000 to Point/Station 403.000 **** NATURAL CHANNEL TIME + SUBAREA FLOW ADDITION ****
______________________________________________________________________ Top of natural channel elevation = 1553.000(Ft.)
End of natural channel elevation = 1527.000(Ft.)
Length of natural channel = 987.000(Ft.)
Estimated mean flow rate at midpoint of channel = 24.347(CFS)

Natural valley channel type used
L.A. County flood control district formula for channel velocity:

Velocity(ft/s) = (7 + 8(q(English Units)^.352)(slope^0.5) Velocity using mean channel flow = 5.13(Ft/s)

Correction to map slope used on extremely rugged channels with drops and waterfalls (Plate D-6.2)
Normal channel slope = 0.0263
Corrected/adjusted channel slope = 0.0263
Travel time = 3.21 min. TC = 14.53 min.

Adding area flow to channel
UNDEVELOPED (poor cover) subarea
Runoff Coefficient = 0.565
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.500
Decimal fraction soil group C = 0.500
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 65.80
Pervious area fraction = 1.000; Impervious fraction = 0.000 Rainfall intensity = 1.166(In/Hr) for a 2.0 year storm Subarea runoff = 27.525(CFS) for 41.800(Ac.)
Total runoff = 35.404(CFS) Total area = 51.800(Ac.) End of computations, total study area = 51.80 (Ac.) The following figures may
be used for a unit hydrograph study of the same area.

Area averaged pervious area fraction(Ap) = 1.000
Area averaged RI index number = 82.0

Riverside County Rational Hydrology Program

CIVILCADD/CIVILDESIGN Engineering Software,(c) 1989 - 2014 Version 9.0 Rational Hydrology Study Date: 05/18/21 File:PRD002.out ------------------------------------------------------------------------ TRACT 31194 - 'GOLDEN MEADOWS' MAJOR MODIFICATION
PRELIMINARY HYDROLOGY STUDY – AREA ‘D’
DEVELOPED CONDITION RATIONAL METHOD - 2 YEAR STORM
HUNSAKER & ASSOCIATES, MAY 2021, BRIAN LOWELL, PE
------------------------------------------------------------------------ ********* Hydrology Study Control Information **********

English (in-lb) Units used in input data file

------------------------------------------------------------------------

Program License Serial Number 6407

------------------------------------------------------------------------ Rational Method Hydrology Program based on
Riverside County Flood Control & Water Conservation District 1978 hydrology manual

Storm event (year) = 2.00 Antecedent Moisture Condition = 1

2 year, 1 hour precipitation = 0.550(In.)
100 year, 1 hour precipitation = 1.300(In.)

Storm event year = 2.0
Calculated rainfall intensity data:
1 hour intensity = 0.550(In/Hr)
Slope of intensity duration curve = 0.5300

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 470.000 to Point/Station 471.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 1000.000(Ft.)
Top (of initial area) elevation = 1566.100(Ft.)
Bottom (of initial area) elevation = 1546.000(Ft.)
Difference in elevation = 20.100(Ft.)
Slope = 0.02010 s(percent)= 2.01
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 13.503 min.

Rainfall intensity = 1.212(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.602
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 36.00
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 3.826(CFS)
Total initial stream area = 5.240(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 471.000 to Point/Station 439.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1538.000(Ft.)
Downstream point/station elevation = 1533.400(Ft.)
Pipe length = 353.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 3.826(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 3.826(CFS)
Normal flow depth in pipe = 9.26(In.)
Flow top width inside pipe = 10.08(In.)
Critical Depth = 9.98(In.)
Pipe flow velocity = 5.89(Ft/s)
Travel time through pipe = 1.00 min.

Time of concentration (TC) = 14.50 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 471.000 to Point/Station 439.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 1
Stream flow area = 5.240(Ac.)
Runoff from this stream = 3.826(CFS)
Time of concentration = 14.50 min.

Rainfall intensity = 1.167(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 473.000 to Point/Station 443.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 759.000(Ft.)
Top (of initial area) elevation = 1552.000(Ft.)
Bottom (of initial area) elevation = 1539.800(Ft.)
Difference in elevation = 12.200(Ft.)
Slope = 0.01607 s(percent)= 1.61
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 12.646 min.

Rainfall intensity = 1.255(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.606
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 36.00
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 3.141(CFS)
Total initial stream area = 4.130(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 443.000 to Point/Station 439.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1533.800(Ft.)
Downstream point/station elevation = 1533.400(Ft.)
Pipe length = 28.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 3.141(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 3.141(CFS)
Normal flow depth in pipe = 7.66(In.)
Flow top width inside pipe = 11.53(In.)
Critical Depth = 9.11(In.)
Pipe flow velocity = 5.93(Ft/s)
Travel time through pipe = 0.08 min.

Time of concentration (TC) = 12.72 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 443.000 to Point/Station 439.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 2
Stream flow area = 4.130(Ac.)
Runoff from this stream = 3.141(CFS)
Time of concentration = 12.72 min.

Rainfall intensity = 1.251(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 474.000 to Point/Station 441.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 96.000(Ft.)
Top (of initial area) elevation = 1543.200(Ft.)
Bottom (of initial area) elevation = 1539.800(Ft.)
Difference in elevation = 3.400(Ft.)
Slope = 0.03542 s(percent)= 3.54
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Warning: TC computed to be less than 5 min.; program is assuming the time of concentration is 5 minutes.

Initial area time of concentration = 5.000 min.

Rainfall intensity = 2.053(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.752
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
RI index for soil(AMC 1) = 57.00
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 0.154(CFS)
Total initial stream area = 0.100(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 441.000 to Point/Station 439.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1533.800(Ft.)
Downstream point/station elevation = 1533.400(Ft.)
Pipe length = 31.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 0.154(CFS)
Nearest computed pipe diameter = 6.00(In.)
Calculated individual pipe flow = 0.154(CFS)
Normal flow depth in pipe = 2.01(In.)
Flow top width inside pipe = 5.66(In.)
Critical Depth = 2.35(In.)
Pipe flow velocity = 2.67(Ft/s)
Travel time through pipe = 0.19 min.

Time of concentration (TC) = 5.19 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 441.000 to Point/Station 439.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 3
Stream flow area = 0.100(Ac.)
Runoff from this stream = 0.154(CFS)
Time of concentration = 5.19 min.

Rainfall intensity = 2.012(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 3.826 14.50 1.167
2 3.141 12.72 1.251
3 0.154 5.19 2.012
Largest stream flow has longer time of concentration
Qp = 3.826 + sum of
Qb Ia/Ib

3.141 * 0.933 = 2.930
Qb Ia/Ib

0.154 * 0.580 = 0.090
Qp = 6.846

Total of 3 streams to confluence:

Flow rates before confluence point:

3.826 3.141 0.154
Area of streams before confluence:

5.240 4.130 0.100
Results of confluence:

Total flow rate = 6.846(CFS)
Time of concentration = 14.502 min.

Effective stream area after confluence = 9.470(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 439.000 to Point/Station 444.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1533.400(Ft.)
Downstream point/station elevation = 1532.500(Ft.)
Pipe length = 72.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 6.846(CFS)
Nearest computed pipe diameter = 15.00(In.)
Calculated individual pipe flow = 6.846(CFS)
Normal flow depth in pipe = 11.65(In.)
Flow top width inside pipe = 12.50(In.)
Critical Depth = 12.60(In.)
Pipe flow velocity = 6.70(Ft/s)
Travel time through pipe = 0.18 min.

Time of concentration (TC) = 14.68 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 439.000 to Point/Station 444.000 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 1
Stream flow area = 9.470(Ac.)
Runoff from this stream = 6.846(CFS)
Time of concentration = 14.68 min.

Rainfall intensity = 1.160(In/Hr)
Program is now starting with Main Stream No. 2

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 445.000 to Point/Station 446.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 42.000(Ft.)
Top (of initial area) elevation = 1540.500(Ft.)
Bottom (of initial area) elevation = 1539.400(Ft.)
Difference in elevation = 1.100(Ft.)
Slope = 0.02619 s(percent)= 2.62
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Warning: TC computed to be less than 5 min.; program is assuming the time of concentration is 5 minutes.

Initial area time of concentration = 5.000 min.

Rainfall intensity = 2.053(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.659
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 36.00
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 0.081(CFS)
Total initial stream area = 0.060(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 446.000 to Point/Station 447.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1533.800(Ft.)
Downstream point/station elevation = 1533.400(Ft.)
Pipe length = 40.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 0.081(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 0.081(CFS)
Normal flow depth in pipe = 1.13(In.)
Flow top width inside pipe = 8.73(In.)
Critical Depth = 1.25(In.)
Pipe flow velocity = 1.77(Ft/s)
Travel time through pipe = 0.38 min.

Time of concentration (TC) = 5.38 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 446.000 to Point/Station 447.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 2 in normal stream number 1
Stream flow area = 0.060(Ac.)
Runoff from this stream = 0.081(CFS)
Time of concentration = 5.38 min.

Rainfall intensity = 1.975(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 448.000 to Point/Station 449.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 640.000(Ft.)
Top (of initial area) elevation = 1587.200(Ft.)
Bottom (of initial area) elevation = 1540.300(Ft.)
Difference in elevation = 46.900(Ft.)
Slope = 0.07328 s(percent)= 7.33
TC = k(0.710)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 15.876 min.

Rainfall intensity = 1.113(In/Hr) for a 2.0 year storm UNDEVELOPED (fair cover) subarea
Runoff Coefficient = 0.462
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.500
Decimal fraction soil group C = 0.500
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 55.80
Pervious area fraction = 1.000; Impervious fraction = 0.000 Initial subarea runoff = 0.313(CFS)
Total initial stream area = 0.610(Ac.)
Pervious area fraction = 1.000

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 449.000 to Point/Station 447.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1533.800(Ft.)
Downstream point/station elevation = 1533.400(Ft.)
Pipe length = 35.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 0.313(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 0.313(CFS)
Normal flow depth in pipe = 2.07(In.)
Flow top width inside pipe = 11.48(In.)
Critical depth could not be calculated.

Pipe flow velocity = 2.78(Ft/s)
Travel time through pipe = 0.21 min.

Time of concentration (TC) = 16.09 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 449.000 to Point/Station 447.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 2 in normal stream number 2
Stream flow area = 0.610(Ac.)
Runoff from this stream = 0.313(CFS)
Time of concentration = 16.09 min.

Rainfall intensity = 1.105(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 0.081 5.38 1.975
2 0.313 16.09 1.105
Largest stream flow has longer time of concentration
Qp = 0.313 + sum of
Qb Ia/Ib

0.081 * 0.559 = 0.045
Qp = 0.359

Total of 2 streams to confluence:

Flow rates before confluence point:

0.081 0.313
Area of streams before confluence:

0.060 0.610
Results of confluence:

Total flow rate = 0.359(CFS)
Time of concentration = 16.085 min.

Effective stream area after confluence = 0.670(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 447.000 to Point/Station 444.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1533.400(Ft.)
Downstream point/station elevation = 1532.500(Ft.)
Pipe length = 89.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 0.359(CFS)
Given pipe size = 24.00(In.)
Calculated individual pipe flow = 0.359(CFS)
Normal flow depth in pipe = 2.10(In.)
Flow top width inside pipe = 13.57(In.)
Critical depth could not be calculated.

Pipe flow velocity = 2.67(Ft/s)
Travel time through pipe = 0.56 min.

Time of concentration (TC) = 16.64 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 447.000 to Point/Station 444.000 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 2
Stream flow area = 0.670(Ac.)
Runoff from this stream = 0.359(CFS)
Time of concentration = 16.64 min.

Rainfall intensity = 1.085(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 6.846 14.68 1.160
2 0.359 16.64 1.085
Largest stream flow has longer or shorter time of concentration Qp = 6.846 + sum of
Qa Tb/Ta

0.359 * 0.882 = 0.317
Qp = 7.163

Total of 2 main streams to confluence:

Flow rates before confluence point:

6.846 0.359
Area of streams before confluence:

9.470 0.670

Results of confluence:

Total flow rate = 7.163(CFS)
Time of concentration = 14.681 min.

Effective stream area after confluence = 10.140(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 444.000 to Point/Station 450.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1532.500(Ft.)
Downstream point/station elevation = 1532.000(Ft.)
Pipe length = 46.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 7.163(CFS)
Given pipe size = 24.00(In.)
Calculated individual pipe flow = 7.163(CFS)
Normal flow depth in pipe = 9.07(In.)
Flow top width inside pipe = 23.27(In.)
Critical Depth = 11.40(In.)
Pipe flow velocity = 6.58(Ft/s)
Travel time through pipe = 0.12 min.

Time of concentration (TC) = 14.80 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 444.000 to Point/Station 450.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 1
Stream flow area = 10.140(Ac.)
Runoff from this stream = 7.163(CFS)
Time of concentration = 14.80 min.

Rainfall intensity = 1.155(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 451.000 to Point/Station 452.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 388.000(Ft.)
Top (of initial area) elevation = 1543.800(Ft.)
Bottom (of initial area) elevation = 1540.100(Ft.)
Difference in elevation = 3.700(Ft.)
Slope = 0.00954 s(percent)= 0.95
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 10.733 min.

Rainfall intensity = 1.369(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.615
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 1.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 36.00
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 0.219(CFS)
Total initial stream area = 0.260(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 452.000 to Point/Station 450.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1532.700(Ft.)
Downstream point/station elevation = 1532.000(Ft.)
Pipe length = 38.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 0.219(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 0.219(CFS)
Normal flow depth in pipe = 1.56(In.)
Flow top width inside pipe = 10.12(In.)
Critical Depth = 2.05(In.)
Pipe flow velocity = 2.95(Ft/s)
Travel time through pipe = 0.21 min.

Time of concentration (TC) = 10.95 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 452.000 to Point/Station 450.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 2
Stream flow area = 0.260(Ac.)
Runoff from this stream = 0.219(CFS)
Time of concentration = 10.95 min.

Rainfall intensity = 1.355(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 7.163 14.80 1.155
2 0.219 10.95 1.355
Largest stream flow has longer time of concentration
Qp = 7.163 + sum of
Qb Ia/Ib

0.219 * 0.852 = 0.187
Qp = 7.350

Total of 2 streams to confluence:

Flow rates before confluence point:

7.163 0.219
Area of streams before confluence:

10.140 0.260
Results of confluence:

Total flow rate = 7.350(CFS)
Time of concentration = 14.798 min.

Effective stream area after confluence = 10.400(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 450.000 to Point/Station 459.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1532.000(Ft.)
Downstream point/station elevation = 1526.000(Ft.)
Pipe length = 418.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 7.350(CFS)
Given pipe size = 36.00(In.)
Calculated individual pipe flow = 7.350(CFS)
Normal flow depth in pipe = 7.38(In.)
Flow top width inside pipe = 29.06(In.)
Critical Depth = 10.24(In.)
Pipe flow velocity = 7.05(Ft/s)
Travel time through pipe = 0.99 min.

Time of concentration (TC) = 15.79 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 450.000 to Point/Station 459.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 1
Stream flow area = 10.400(Ac.)
Runoff from this stream = 7.350(CFS)
Time of concentration = 15.79 min.

Rainfall intensity = 1.116(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 418.000 to Point/Station 419.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 332.000(Ft.)
Top (of initial area) elevation = 1544.200(Ft.)
Bottom (of initial area) elevation = 1539.000(Ft.)
Difference in elevation = 5.200(Ft.)
Slope = 0.01566 s(percent)= 1.57
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 9.132 min.

Rainfall intensity = 1.492(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.719
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
RI index for soil(AMC 1) = 57.00
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 1.469(CFS)
Total initial stream area = 1.370(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 419.000 to Point/Station 459.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1531.000(Ft.)
Downstream point/station elevation = 1526.000(Ft.)
Pipe length = 54.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 1.469(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 1.469(CFS)
Normal flow depth in pipe = 2.63(In.)
Flow top width inside pipe = 12.71(In.)
Critical Depth = 5.44(In.)
Pipe flow velocity = 9.19(Ft/s)
Travel time through pipe = 0.10 min.

Time of concentration (TC) = 9.23 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 419.000 to Point/Station 459.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 2
Stream flow area = 1.370(Ac.)
Runoff from this stream = 1.469(CFS)
Time of concentration = 9.23 min.

Rainfall intensity = 1.483(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 7.350 15.79 1.116
2 1.469 9.23 1.483
Largest stream flow has longer time of concentration
Qp = 7.350 + sum of
Qb Ia/Ib

1.469 * 0.752 = 1.105
Qp = 8.455

Total of 2 streams to confluence:

Flow rates before confluence point:

7.350 1.469
Area of streams before confluence:

10.400 1.370
Results of confluence:

Total flow rate = 8.455(CFS)
Time of concentration = 15.785 min.

Effective stream area after confluence = 11.770(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 459.000 to Point/Station 420.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1526.000(Ft.)
Downstream point/station elevation = 1523.700(Ft.)
Pipe length = 316.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 8.455(CFS)
Given pipe size = 36.00(In.)
Calculated individual pipe flow = 8.455(CFS)
Normal flow depth in pipe = 9.38(In.)
Flow top width inside pipe = 31.60(In.)
Critical Depth = 11.00(In.)
Pipe flow velocity = 5.77(Ft/s)
Travel time through pipe = 0.91 min.

Time of concentration (TC) = 16.70 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 459.000 to Point/Station 420.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 1
Stream flow area = 11.770(Ac.)
Runoff from this stream = 8.455(CFS)
Time of concentration = 16.70 min.

Rainfall intensity = 1.083(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 421.000 to Point/Station 422.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 508.000(Ft.)
Top (of initial area) elevation = 1541.200(Ft.)
Bottom (of initial area) elevation = 1535.400(Ft.)
Difference in elevation = 5.800(Ft.)
Slope = 0.01142 s(percent)= 1.14
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 11.532 min.

Rainfall intensity = 1.318(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.664
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.400
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.600
RI index for soil(AMC 1) = 47.88
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 2.451(CFS)
Total initial stream area = 2.800(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 422.000 to Point/Station 420.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1528.300(Ft.)
Downstream point/station elevation = 1523.700(Ft.)
Pipe length = 52.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 2.451(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 2.451(CFS)
Normal flow depth in pipe = 3.41(In.)
Flow top width inside pipe = 14.11(In.)
Critical Depth = 7.10(In.)
Pipe flow velocity = 10.53(Ft/s)
Travel time through pipe = 0.08 min.

Time of concentration (TC) = 11.61 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 422.000 to Point/Station 420.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 2
Stream flow area = 2.800(Ac.)
Runoff from this stream = 2.451(CFS)
Time of concentration = 11.61 min.

Rainfall intensity = 1.313(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 8.455 16.70 1.083
2 2.451 11.61 1.313
Largest stream flow has longer time of concentration
Qp = 8.455 + sum of
Qb Ia/Ib

2.451 * 0.825 = 2.022
Qp = 10.477

Total of 2 streams to confluence:

Flow rates before confluence point:

8.455 2.451
Area of streams before confluence:

11.770 2.800
Results of confluence:

Total flow rate = 10.477(CFS)
Time of concentration = 16.697 min.

Effective stream area after confluence = 14.570(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 420.000 to Point/Station 417.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1523.700(Ft.)
Downstream point/station elevation = 1521.000(Ft.)
Pipe length = 350.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 10.477(CFS)
Given pipe size = 36.00(In.)
Calculated individual pipe flow = 10.477(CFS)
Normal flow depth in pipe = 10.31(In.)
Flow top width inside pipe = 32.55(In.)
Critical Depth = 12.29(In.)
Pipe flow velocity = 6.27(Ft/s)
Travel time through pipe = 0.93 min.

Time of concentration (TC) = 17.63 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 420.000 to Point/Station 417.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 1
Stream flow area = 14.570(Ac.)
Runoff from this stream = 10.477(CFS)
Time of concentration = 17.63 min.

Rainfall intensity = 1.053(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 415.000 to Point/Station 416.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 1000.000(Ft.)
Top (of initial area) elevation = 1545.700(Ft.)
Bottom (of initial area) elevation = 1530.400(Ft.)
Difference in elevation = 15.300(Ft.)
Slope = 0.01530 s(percent)= 1.53
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 14.260 min.

Rainfall intensity = 1.178(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.672
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.200
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.800
RI index for soil(AMC 1) = 52.44
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 2.842(CFS)
Total initial stream area = 3.590(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 416.000 to Point/Station 417.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1523.300(Ft.)
Downstream point/station elevation = 1521.000(Ft.)
Pipe length = 26.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 2.842(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 2.842(CFS)
Normal flow depth in pipe = 3.67(In.)
Flow top width inside pipe = 14.50(In.)
Critical Depth = 7.68(In.)
Pipe flow velocity = 11.00(Ft/s)
Travel time through pipe = 0.04 min.

Time of concentration (TC) = 14.30 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 416.000 to Point/Station 417.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 2
Stream flow area = 3.590(Ac.)
Runoff from this stream = 2.842(CFS)
Time of concentration = 14.30 min.

Rainfall intensity = 1.176(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 421.000 to Point/Station 423.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 790.000(Ft.)
Top (of initial area) elevation = 1541.200(Ft.)
Bottom (of initial area) elevation = 1530.400(Ft.)
Difference in elevation = 10.800(Ft.)
Slope = 0.01367 s(percent)= 1.37
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 13.273 min.

Rainfall intensity = 1.224(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.612
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.900
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.100
RI index for soil(AMC 1) = 37.90
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 1.422(CFS)
Total initial stream area = 1.900(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 423.000 to Point/Station 417.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1523.300(Ft.)
Downstream point/station elevation = 1521.000(Ft.)
Pipe length = 24.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 1.422(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 1.422(CFS)
Normal flow depth in pipe = 2.57(In.)
Flow top width inside pipe = 12.58(In.)
Critical Depth = 5.36(In.)
Pipe flow velocity = 9.21(Ft/s)
Travel time through pipe = 0.04 min.

Time of concentration (TC) = 13.32 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 423.000 to Point/Station 417.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 3
Stream flow area = 1.900(Ac.)
Runoff from this stream = 1.422(CFS)
Time of concentration = 13.32 min.

Rainfall intensity = 1.221(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 10.477 17.63 1.053
2 2.842 14.30 1.176
3 1.422 13.32 1.221
Largest stream flow has longer time of concentration
Qp = 10.477 + sum of
Qb Ia/Ib

2.842 * 0.895 = 2.543
Qb Ia/Ib

1.422 * 0.862 = 1.225
Qp = 14.246

Total of 3 streams to confluence:

Flow rates before confluence point:

10.477 2.842 1.422
Area of streams before confluence:

14.570 3.590 1.900
Results of confluence:

Total flow rate = 14.246(CFS)
Time of concentration = 17.628 min.

Effective stream area after confluence = 20.060(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 417.000 to Point/Station 414.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1521.000(Ft.)
Downstream point/station elevation = 1518.500(Ft.)
Pipe length = 388.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 14.246(CFS)
Given pipe size = 48.00(In.)
Calculated individual pipe flow = 14.246(CFS)
Normal flow depth in pipe = 11.39(In.)
Flow top width inside pipe = 40.84(In.)
Critical Depth = 13.24(In.)
Pipe flow velocity = 6.24(Ft/s)
Travel time through pipe = 1.04 min.

Time of concentration (TC) = 18.66 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 417.000 to Point/Station 414.000 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 1
Stream flow area = 20.060(Ac.)
Runoff from this stream = 14.246(CFS)
Time of concentration = 18.66 min.

Rainfall intensity = 1.021(In/Hr)
Program is now starting with Main Stream No. 2

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 400.000 to Point/Station 401.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 490.000(Ft.)
Top (of initial area) elevation = 1545.600(Ft.)
Bottom (of initial area) elevation = 1540.400(Ft.)
Difference in elevation = 5.200(Ft.)
Slope = 0.01061 s(percent)= 1.06
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 11.534 min.

Rainfall intensity = 1.318(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.640
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.500
Decimal fraction soil group C = 0.500
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 42.50
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 1.527(CFS)
Total initial stream area = 1.810(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 401.000 to Point/Station 402.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** ______________________________________________________________________ Top of street segment elevation = 1540.400(Ft.)
End of street segment elevation = 1532.700(Ft.)
Length of street segment = 763.000(Ft.)
Height of curb above gutter flowline = 6.0(In.)
Width of half street (curb to crown) = 18.000(Ft.)
Distance from crown to crossfall grade break = 9.000(Ft.) Slope from gutter to grade break (v/hz) = 0.020
Slope from grade break to crown (v/hz) = 0.020
Street flow is on [1] side(s) of the street
Distance from curb to property line = 10.000(Ft.)
Slope from curb to property line (v/hz) = 0.020
Gutter width = 2.000(Ft.)
Gutter hike from flowline = 1.500(In.)
Manning's N in gutter = 0.0130
Manning's N from gutter to grade break = 0.0130
Manning's N from grade break to crown = 0.0130
Estimated mean flow rate at midpoint of street = 3.277(CFS) Depth of flow = 0.299(Ft.), Average velocity = 2.664(Ft/s) Streetflow hydraulics at midpoint of street travel:

Halfstreet flow width = 10.700(Ft.)
Flow velocity = 2.66(Ft/s)
Travel time = 4.77 min. TC = 16.31 min.

Adding area flow to street
SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.641
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.300
Decimal fraction soil group C = 0.400
Decimal fraction soil group D = 0.300
RI index for soil(AMC 1) = 47.28
Pervious area fraction = 0.500; Impervious fraction = 0.500 Rainfall intensity = 1.097(In/Hr) for a 2.0 year storm Subarea runoff = 3.411(CFS) for 4.850(Ac.)
Total runoff = 4.938(CFS) Total area = 6.660(Ac.) Street flow at end of street = 4.938(CFS)
Half street flow at end of street = 4.938(CFS)
Depth of flow = 0.338(Ft.), Average velocity = 2.939(Ft/s) Flow width (from curb towards crown)= 12.629(Ft.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 402.000 to Point/Station 403.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** ______________________________________________________________________ Top of street segment elevation = 1532.700(Ft.)
End of street segment elevation = 1529.300(Ft.)
Length of street segment = 380.000(Ft.)
Height of curb above gutter flowline = 6.0(In.)
Width of half street (curb to crown) = 18.000(Ft.)
Distance from crown to crossfall grade break = 9.000(Ft.) Slope from gutter to grade break (v/hz) = 0.020
Slope from grade break to crown (v/hz) = 0.020
Street flow is on [1] side(s) of the street
Distance from curb to property line = 10.000(Ft.)
Slope from curb to property line (v/hz) = 0.020
Gutter width = 2.000(Ft.)
Gutter hike from flowline = 1.500(In.)
Manning's N in gutter = 0.0130
Manning's N from gutter to grade break = 0.0130
Manning's N from grade break to crown = 0.0130
Estimated mean flow rate at midpoint of street = 5.471(CFS) Depth of flow = 0.354(Ft.), Average velocity = 2.879(Ft/s) Streetflow hydraulics at midpoint of street travel:

Halfstreet flow width = 13.474(Ft.)
Flow velocity = 2.88(Ft/s)
Travel time = 2.20 min. TC = 18.51 min.

Adding area flow to street
SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.599
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.800
Decimal fraction soil group C = 0.100
Decimal fraction soil group D = 0.100
RI index for soil(AMC 1) = 39.20
Pervious area fraction = 0.500; Impervious fraction = 0.500 Rainfall intensity = 1.026(In/Hr) for a 2.0 year storm Subarea runoff = 1.014(CFS) for 1.650(Ac.)
Total runoff = 5.952(CFS) Total area = 8.310(Ac.) Street flow at end of street = 5.952(CFS)
Half street flow at end of street = 5.952(CFS)
Depth of flow = 0.364(Ft.), Average velocity = 2.938(Ft/s) Flow width (from curb towards crown)= 13.931(Ft.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 403.000 to Point/Station 404.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1522.800(Ft.)
Downstream point/station elevation = 1522.100(Ft.)
Pipe length = 35.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 5.952(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 5.952(CFS)
Normal flow depth in pipe = 7.92(In.)
Flow top width inside pipe = 17.87(In.)
Critical Depth = 11.31(In.)
Pipe flow velocity = 7.94(Ft/s)
Travel time through pipe = 0.07 min.

Time of concentration (TC) = 18.58 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 403.000 to Point/Station 404.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 2 in normal stream number 1
Stream flow area = 8.310(Ac.)
Runoff from this stream = 5.952(CFS)
Time of concentration = 18.58 min.

Rainfall intensity = 1.024(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 400.000 to Point/Station 405.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 530.000(Ft.)
Top (of initial area) elevation = 1545.600(Ft.)
Bottom (of initial area) elevation = 1540.600(Ft.)
Difference in elevation = 5.000(Ft.)
Slope = 0.00943 s(percent)= 0.94
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 12.185 min.

Rainfall intensity = 1.280(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.619
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.800
Decimal fraction soil group C = 0.200
Decimal fraction soil group D = 0.000
RI index for soil(AMC 1) = 38.60
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 2.006(CFS)
Total initial stream area = 2.530(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 405.000 to Point/Station 406.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** ______________________________________________________________________ Top of street segment elevation = 1540.600(Ft.)
End of street segment elevation = 1532.700(Ft.)
Length of street segment = 777.000(Ft.)
Height of curb above gutter flowline = 6.0(In.)
Width of half street (curb to crown) = 18.000(Ft.)
Distance from crown to crossfall grade break = 9.000(Ft.) Slope from gutter to grade break (v/hz) = 0.020
Slope from grade break to crown (v/hz) = 0.020
Street flow is on [1] side(s) of the street
Distance from curb to property line = 10.000(Ft.)
Slope from curb to property line (v/hz) = 0.020
Gutter width = 2.000(Ft.)
Gutter hike from flowline = 1.500(In.)
Manning's N in gutter = 0.0130
Manning's N from gutter to grade break = 0.0130
Manning's N from grade break to crown = 0.0130
Estimated mean flow rate at midpoint of street = 2.843(CFS) Depth of flow = 0.287(Ft.), Average velocity = 2.584(Ft/s) Streetflow hydraulics at midpoint of street travel:

Halfstreet flow width = 10.077(Ft.)
Flow velocity = 2.58(Ft/s)
Travel time = 5.01 min. TC = 17.20 min.

Adding area flow to street
SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.662
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.600
Decimal fraction soil group D = 0.400
RI index for soil(AMC 1) = 52.68
Pervious area fraction = 0.500; Impervious fraction = 0.500 Rainfall intensity = 1.067(In/Hr) for a 2.0 year storm Subarea runoff = 1.624(CFS) for 2.300(Ac.)
Total runoff = 3.630(CFS) Total area = 4.830(Ac.) Street flow at end of street = 3.630(CFS)
Half street flow at end of street = 3.630(CFS)
Depth of flow = 0.308(Ft.), Average velocity = 2.738(Ft/s) Flow width (from curb towards crown)= 11.140(Ft.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 406.000 to Point/Station 407.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** ______________________________________________________________________ Top of street segment elevation = 1532.700(Ft.)
End of street segment elevation = 1529.300(Ft.)
Length of street segment = 343.000(Ft.)
Height of curb above gutter flowline = 6.0(In.)
Width of half street (curb to crown) = 18.000(Ft.)
Distance from crown to crossfall grade break = 9.000(Ft.) Slope from gutter to grade break (v/hz) = 0.020
Slope from grade break to crown (v/hz) = 0.020
Street flow is on [1] side(s) of the street
Distance from curb to property line = 10.000(Ft.)
Slope from curb to property line (v/hz) = 0.020
Gutter width = 2.000(Ft.)
Gutter hike from flowline = 1.500(In.)
Manning's N in gutter = 0.0130
Manning's N from gutter to grade break = 0.0130
Manning's N from grade break to crown = 0.0130
Estimated mean flow rate at midpoint of street = 4.775(CFS) Depth of flow = 0.335(Ft.), Average velocity = 2.896(Ft/s) Streetflow hydraulics at midpoint of street travel:

Halfstreet flow width = 12.506(Ft.)
Flow velocity = 2.90(Ft/s)
Travel time = 1.97 min. TC = 19.17 min.

Adding area flow to street
SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.621
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.500
Decimal fraction soil group C = 0.100
Decimal fraction soil group D = 0.400
RI index for soil(AMC 1) = 44.90
Pervious area fraction = 0.500; Impervious fraction = 0.500 Rainfall intensity = 1.007(In/Hr) for a 2.0 year storm Subarea runoff = 2.234(CFS) for 3.570(Ac.)
Total runoff = 5.864(CFS) Total area = 8.400(Ac.) Street flow at end of street = 5.864(CFS)
Half street flow at end of street = 5.864(CFS)
Depth of flow = 0.356(Ft.), Average velocity = 3.043(Ft/s) Flow width (from curb towards crown)= 13.571(Ft.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 407.000 to Point/Station 404.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1522.800(Ft.)
Downstream point/station elevation = 1522.100(Ft.)
Pipe length = 36.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 5.864(CFS)
Given pipe size = 24.00(In.)
Calculated individual pipe flow = 5.864(CFS)
Normal flow depth in pipe = 7.01(In.)
Flow top width inside pipe = 21.82(In.)
Critical Depth = 10.26(In.)
Pipe flow velocity = 7.68(Ft/s)
Travel time through pipe = 0.08 min.

Time of concentration (TC) = 19.25 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 407.000 to Point/Station 404.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 2 in normal stream number 2
Stream flow area = 8.400(Ac.)
Runoff from this stream = 5.864(CFS)
Time of concentration = 19.25 min.

Rainfall intensity = 1.005(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 408.000 to Point/Station 409.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 395.000(Ft.)
Top (of initial area) elevation = 1533.500(Ft.)
Bottom (of initial area) elevation = 1529.200(Ft.)
Difference in elevation = 4.300(Ft.)
Slope = 0.01089 s(percent)= 1.09
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 10.528 min.

Rainfall intensity = 1.383(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.659
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.500
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.500
RI index for soil(AMC 1) = 45.60
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 0.985(CFS)
Total initial stream area = 1.080(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 409.000 to Point/Station 404.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1522.800(Ft.)
Downstream point/station elevation = 1522.100(Ft.)
Pipe length = 45.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 0.985(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 0.985(CFS)
Normal flow depth in pipe = 3.34(In.)
Flow top width inside pipe = 13.99(In.)
Critical Depth = 4.43(In.)
Pipe flow velocity = 4.36(Ft/s)
Travel time through pipe = 0.17 min.

Time of concentration (TC) = 10.70 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 409.000 to Point/Station 404.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 2 in normal stream number 3
Stream flow area = 1.080(Ac.)
Runoff from this stream = 0.985(CFS)
Time of concentration = 10.70 min.

Rainfall intensity = 1.372(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 5.952 18.58 1.024
2 5.864 19.25 1.005
3 0.985 10.70 1.372
Largest stream flow has longer or shorter time of concentration Qp = 5.952 + sum of
Qa Tb/Ta

5.864 * 0.965 = 5.660
Qb Ia/Ib

0.985 * 0.746 = 0.735
Qp = 12.347

Total of 3 streams to confluence:

Flow rates before confluence point:

5.952 5.864 0.985
Area of streams before confluence:

8.310 8.400 1.080
Results of confluence:

Total flow rate = 12.347(CFS)
Time of concentration = 18.581 min.

Effective stream area after confluence = 17.790(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 404.000 to Point/Station 410.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1522.100(Ft.)
Downstream point/station elevation = 1518.700(Ft.)
Pipe length = 322.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 12.347(CFS)
Given pipe size = 30.00(In.)
Calculated individual pipe flow = 12.347(CFS)
Normal flow depth in pipe = 11.12(In.)
Flow top width inside pipe = 28.98(In.)
Critical Depth = 14.13(In.)
Pipe flow velocity = 7.46(Ft/s)
Travel time through pipe = 0.72 min.

Time of concentration (TC) = 19.30 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 404.000 to Point/Station 410.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 2 in normal stream number 1
Stream flow area = 17.790(Ac.)
Runoff from this stream = 12.347(CFS)
Time of concentration = 19.30 min.

Rainfall intensity = 1.003(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 411.000 to Point/Station 412.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 515.000(Ft.)
Top (of initial area) elevation = 1531.500(Ft.)
Bottom (of initial area) elevation = 1525.700(Ft.)
Difference in elevation = 5.800(Ft.)
Slope = 0.01126 s(percent)= 1.13
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 11.627 min.

Rainfall intensity = 1.312(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.689
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.500
Decimal fraction soil group D = 0.500
RI index for soil(AMC 1) = 53.40
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 1.039(CFS)
Total initial stream area = 1.150(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 412.000 to Point/Station 410.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1518.900(Ft.)
Downstream point/station elevation = 1518.700(Ft.)
Pipe length = 20.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 1.039(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 1.039(CFS)
Normal flow depth in pipe = 3.82(In.)
Flow top width inside pipe = 14.72(In.)
Critical Depth = 4.56(In.)
Pipe flow velocity = 3.79(Ft/s)
Travel time through pipe = 0.09 min.

Time of concentration (TC) = 11.71 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 412.000 to Point/Station 410.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 2 in normal stream number 2
Stream flow area = 1.150(Ac.)
Runoff from this stream = 1.039(CFS)
Time of concentration = 11.71 min.

Rainfall intensity = 1.307(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 407.000 to Point/Station 413.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 311.000(Ft.)
Top (of initial area) elevation = 1528.400(Ft.)
Bottom (of initial area) elevation = 1525.700(Ft.)
Difference in elevation = 2.700(Ft.)
Slope = 0.00868 s(percent)= 0.87
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 10.010 min.

Rainfall intensity = 1.421(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.636
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.800
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.200
RI index for soil(AMC 1) = 39.80
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 1.003(CFS)
Total initial stream area = 1.110(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 413.000 to Point/Station 410.000 **** PIPEFLOW TRAVEL TIME (User specified size) ****
______________________________________________________________________ Upstream point/station elevation = 1518.900(Ft.)
Downstream point/station elevation = 1518.700(Ft.)
Pipe length = 25.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 1.003(CFS)
Given pipe size = 18.00(In.)
Calculated individual pipe flow = 1.003(CFS)
Normal flow depth in pipe = 3.97(In.)
Flow top width inside pipe = 14.93(In.)
Critical Depth = 4.47(In.)
Pipe flow velocity = 3.47(Ft/s)
Travel time through pipe = 0.12 min.

Time of concentration (TC) = 10.13 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 413.000 to Point/Station 410.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 2 in normal stream number 3
Stream flow area = 1.110(Ac.)
Runoff from this stream = 1.003(CFS)
Time of concentration = 10.13 min.

Rainfall intensity = 1.412(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 12.347 19.30 1.003
2 1.039 11.71 1.307
3 1.003 10.13 1.412
Largest stream flow has longer time of concentration
Qp = 12.347 + sum of
Qb Ia/Ib

1.039 * 0.768 = 0.798
Qb Ia/Ib

1.003 * 0.711 = 0.713
Qp = 13.858

Total of 3 streams to confluence:

Flow rates before confluence point:

12.347 1.039 1.003
Area of streams before confluence:

17.790 1.150 1.110
Results of confluence:

Total flow rate = 13.858(CFS)
Time of concentration = 19.300 min.

Effective stream area after confluence = 20.050(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 410.000 to Point/Station 414.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1518.700(Ft.)
Downstream point/station elevation = 1518.500(Ft.)
Pipe length = 55.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 13.858(CFS)
Nearest computed pipe diameter = 24.00(In.)
Calculated individual pipe flow = 13.858(CFS)
Normal flow depth in pipe = 20.02(In.)
Flow top width inside pipe = 17.86(In.)
Critical Depth = 16.09(In.)
Pipe flow velocity = 4.95(Ft/s)
Travel time through pipe = 0.19 min.

Time of concentration (TC) = 19.49 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 410.000 to Point/Station 414.000 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 2
Stream flow area = 20.050(Ac.)
Runoff from this stream = 13.858(CFS)
Time of concentration = 19.49 min.

Rainfall intensity = 0.998(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 14.246 18.66 1.021
2 13.858 19.49 0.998
Largest stream flow has longer or shorter time of concentration Qp = 14.246 + sum of
Qa Tb/Ta

13.858 * 0.958 = 13.273
Qp = 27.519

Total of 2 main streams to confluence:

Flow rates before confluence point:

14.246 13.858
Area of streams before confluence:

20.060 20.050

Results of confluence:

Total flow rate = 27.519(CFS)
Time of concentration = 18.664 min.

Effective stream area after confluence = 40.110(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 414.000 to Point/Station 424.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1518.500(Ft.)
Downstream point/station elevation = 1515.200(Ft.)
Pipe length = 235.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 27.519(CFS)
Nearest computed pipe diameter = 24.00(In.)
Calculated individual pipe flow = 27.519(CFS)
Normal flow depth in pipe = 20.30(In.)
Flow top width inside pipe = 17.34(In.)
Critical Depth = 21.83(In.)
Pipe flow velocity = 9.71(Ft/s)
Travel time through pipe = 0.40 min.

Time of concentration (TC) = 19.07 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 414.000 to Point/Station 424.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 1
Stream flow area = 40.110(Ac.)
Runoff from this stream = 27.519(CFS)
Time of concentration = 19.07 min.

Rainfall intensity = 1.010(In/Hr)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 408.000 to Point/Station 425.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 597.000(Ft.)
Top (of initial area) elevation = 1533.500(Ft.)
Bottom (of initial area) elevation = 1525.600(Ft.)
Difference in elevation = 7.900(Ft.)
Slope = 0.01323 s(percent)= 1.32
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 11.943 min.

Rainfall intensity = 1.294(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.663
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.300
Decimal fraction soil group C = 0.300
Decimal fraction soil group D = 0.400
RI index for soil(AMC 1) = 48.00
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 2.512(CFS)
Total initial stream area = 2.930(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 425.000 to Point/Station 424.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1519.600(Ft.)
Downstream point/station elevation = 1515.200(Ft.)
Pipe length = 63.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 2.512(CFS)
Nearest computed pipe diameter = 9.00(In.)
Calculated individual pipe flow = 2.512(CFS)
Normal flow depth in pipe = 4.89(In.)
Flow top width inside pipe = 8.97(In.)
Critical Depth = 8.32(In.)
Pipe flow velocity = 10.24(Ft/s)
Travel time through pipe = 0.10 min.

Time of concentration (TC) = 12.05 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 425.000 to Point/Station 424.000 **** CONFLUENCE OF MINOR STREAMS ****
______________________________________________________________________ Along Main Stream number: 1 in normal stream number 2
Stream flow area = 2.930(Ac.)
Runoff from this stream = 2.512(CFS)
Time of concentration = 12.05 min.

Rainfall intensity = 1.288(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 27.519 19.07 1.010
2 2.512 12.05 1.288
Largest stream flow has longer time of concentration
Qp = 27.519 + sum of
Qb Ia/Ib

2.512 * 0.784 = 1.969
Qp = 29.489

Total of 2 streams to confluence:

Flow rates before confluence point:

27.519 2.512
Area of streams before confluence:

40.110 2.930
Results of confluence:

Total flow rate = 29.489(CFS)
Time of concentration = 19.068 min.

Effective stream area after confluence = 43.040(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 424.000 to Point/Station 426.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1515.200(Ft.)
Downstream point/station elevation = 1515.100(Ft.)
Pipe length = 20.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 29.489(CFS)
Nearest computed pipe diameter = 30.00(In.)
Calculated individual pipe flow = 29.489(CFS)
Normal flow depth in pipe = 25.08(In.)
Flow top width inside pipe = 22.22(In.)
Critical Depth = 22.22(In.)
Pipe flow velocity = 6.73(Ft/s)
Travel time through pipe = 0.05 min.

Time of concentration (TC) = 19.12 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 424.000 to Point/Station 426.000 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 1
Stream flow area = 43.040(Ac.)
Runoff from this stream = 29.489(CFS)
Time of concentration = 19.12 min.

Rainfall intensity = 1.008(In/Hr)
Program is now starting with Main Stream No. 2

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 416.000 to Point/Station 427.000 **** INITIAL AREA EVALUATION ****
______________________________________________________________________ Initial area flow distance = 708.000(Ft.)
Top (of initial area) elevation = 1530.400(Ft.)
Bottom (of initial area) elevation = 1525.700(Ft.)
Difference in elevation = 4.700(Ft.)
Slope = 0.00664 s(percent)= 0.66
TC = k(0.390)*[(length^3)/(elevation change)]^0.2
Initial area time of concentration = 14.678 min.

Rainfall intensity = 1.160(In/Hr) for a 2.0 year storm SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.640
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.500
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 0.500
RI index for soil(AMC 1) = 45.60
Pervious area fraction = 0.500; Impervious fraction = 0.500 Initial subarea runoff = 3.443(CFS)
Total initial stream area = 4.640(Ac.)
Pervious area fraction = 0.500

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 427.000 to Point/Station 428.000 **** STREET FLOW TRAVEL TIME + SUBAREA FLOW ADDITION **** ______________________________________________________________________ Top of street segment elevation = 1525.700(Ft.)
End of street segment elevation = 1521.200(Ft.)
Length of street segment = 760.000(Ft.)
Height of curb above gutter flowline = 6.0(In.)
Width of half street (curb to crown) = 18.000(Ft.)
Distance from crown to crossfall grade break = 9.000(Ft.) Slope from gutter to grade break (v/hz) = 0.020
Slope from grade break to crown (v/hz) = 0.020
Street flow is on [1] side(s) of the street
Distance from curb to property line = 10.000(Ft.)
Slope from curb to property line (v/hz) = 0.020
Gutter width = 2.000(Ft.)
Gutter hike from flowline = 1.500(In.)
Manning's N in gutter = 0.0130
Manning's N from gutter to grade break = 0.0130
Manning's N from grade break to crown = 0.0130
Estimated mean flow rate at midpoint of street = 4.137(CFS) Depth of flow = 0.347(Ft.), Average velocity = 2.301(Ft/s) Streetflow hydraulics at midpoint of street travel:

Halfstreet flow width = 13.089(Ft.)
Flow velocity = 2.30(Ft/s)
Travel time = 5.51 min. TC = 20.18 min.

Adding area flow to street
SINGLE FAMILY (1/4 Acre Lot)
Runoff Coefficient = 0.672
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
RI index for soil(AMC 1) = 57.00
Pervious area fraction = 0.500; Impervious fraction = 0.500 Rainfall intensity = 0.980(In/Hr) for a 2.0 year storm Subarea runoff = 1.304(CFS) for 1.980(Ac.)
Total runoff = 4.747(CFS) Total area = 6.620(Ac.) Street flow at end of street = 4.747(CFS)
Half street flow at end of street = 4.747(CFS)
Depth of flow = 0.361(Ft.), Average velocity = 2.379(Ft/s) Flow width (from curb towards crown)= 13.823(Ft.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 428.000 to Point/Station 429.000 **** PIPEFLOW TRAVEL TIME (Program estimated size) **** ______________________________________________________________________ Upstream point/station elevation = 1518.000(Ft.)
Downstream point/station elevation = 1515.000(Ft.)
Pipe length = 52.00(Ft.) Manning's N = 0.013
No. of pipes = 1 Required pipe flow = 4.747(CFS)
Nearest computed pipe diameter = 12.00(In.)
Calculated individual pipe flow = 4.747(CFS)
Normal flow depth in pipe = 6.39(In.)
Flow top width inside pipe = 11.98(In.)
Critical Depth = 10.83(In.)
Pipe flow velocity = 11.18(Ft/s)
Travel time through pipe = 0.08 min.

Time of concentration (TC) = 20.26 min.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 428.000 to Point/Station 429.000 **** CONFLUENCE OF MAIN STREAMS ****
______________________________________________________________________ The following data inside Main Stream is listed:

In Main Stream number: 2
Stream flow area = 6.620(Ac.)
Runoff from this stream = 4.747(CFS)
Time of concentration = 20.26 min.

Rainfall intensity = 0.978(In/Hr)
Summary of stream data:

Stream Flow rate TC Rainfall Intensity No. (CFS) (min) (In/Hr)

1 29.489 19.12 1.008
2 4.747 20.26 0.978
Largest stream flow has longer or shorter time of concentration Qp = 29.489 + sum of
Qa Tb/Ta

4.747 * 0.944 = 4.479
Qp = 33.968

Total of 2 main streams to confluence:

Flow rates before confluence point:

29.489 4.747
Area of streams before confluence:

43.040 6.620

Results of confluence:

Total flow rate = 33.968(CFS)
Time of concentration = 19.117 min.

Effective stream area after confluence = 49.660(Ac.)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process from Point/Station 428.000 to Point/Station 429.000 **** SUBAREA FLOW ADDITION ****
______________________________________________________________________ UNDEVELOPED (good cover) subarea
Runoff Coefficient = 0.486
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.300
Decimal fraction soil group D = 0.700
RI index for soil(AMC 1) = 60.84
Pervious area fraction = 1.000; Impervious fraction = 0.000 Time of concentration = 19.12 min.

Rainfall intensity = 1.008(In/Hr) for a 2.0 year storm Subarea runoff = 2.378(CFS) for 4.850(Ac.)
Total runoff = 36.346(CFS) Total area = 54.510(Ac.) End of computations, total study area = 54.51 (Ac.) The following figures may
be used for a unit hydrograph study of the same area.

Area averaged pervious area fraction(Ap) = 0.550
Area averaged RI index number = 65.7

- 37 -

Appendix 8: Source Control
Pollutant Sources/Source Control Checklist

Appendix 8

S T O R M W A T E R P O L L U T A N T S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T 201ϴ SMR WQMP TEMPLATE Appendix 8 – Page 1 of 10
How to use this worksheet (also see instructions in Section + of the 20 SMR WQMP Template):
Review Column 1 and identify which of these potential sources of stormwater pollutants apply to your site. Check each box that applies. Review Column 2 and incorporate all of the corresponding applicable BMPs in your WQMP Exhibit. Review Columns 3 and 4 and incorporate all of the corresponding applicable permanent controls and operational BMPs in your WQMP. Use the format shown in Table +.1oIthis WQMP Template. Describe your specific BMPs in an accompanying narrative, and explain anyspecial conditions or situations that required omitting BMPs or substituting alternative BMPs for those shown here.

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
A. On-site storm drain
inlets
Locations of inlets. Mark all inlets with the words “Only Rain Down the Storm
Drain” or similar. Catch Basin
Markers may be available from the
Riverside County Flood Control
and Water Conservation District,
call 951.955.1200 to verify.
Maintain and periodically repaint or
replace inlet markings.
Provide stormwater pollution
prevention information to new site
owners, lessees, or operators.
See applicable operational BMPs in
Fact Sheet SC-44, “Drainage System
Maintenance,” in the CASQA
Stormwater Quality Handbooks at
www.cabmphandbooks.com
Include the following in lease
agreements: “Tenant shall not allow
anyone to discharge anything to storm
drains or to store or deposit materials
so as to create a potential discharge to
storm drains.”
B. Interior floor drains
and elevator shaft sump
pumps
State that interior floor drains and
elevator shaft sump pumps will be
plumbed to sanitary sewer.
Inspect and maintain drains to prevent
blockages and overflow.
C. Interior parking
garages
State that parking garage floor
drains will be plumbed to the
sanitary sewer.
Inspect and maintain drains to prevent
blockages and overflow.
✔ ✔ ✔ ✔
✔
✔
✔
Appendix 8

S T O R M W A T E R P O L L U T A N T S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T 201ϴSMR WQMP TEMPLATE Appendix 8 – Page 2 of 10

State that final landscape plans will
accomplish all of the following.
Preserve existing native trees,
shrubs, and ground cover to the
maximum extent possible.
Design landscaping to minimize
irrigation and runoff, to promote
surface infiltration where
appropriate, and to minimize the
use of fertilizers and pesticides that
can contribute to stormwater
pollution.
Where landscaped areas are used to
retain or detain stormwater, specify
plants that are tolerant of saturated
soil conditions.
Consider using pest-resistant plants,
especially adjacent to hardscape. To
insure successful establishment,
select plants appropriate to site soils,
slopes, climate, sun, wind, rain, land
use, air movement, ecological
consistency, and plant interactions.
Maintain landscaping using minimum
or no pesticides.
See applicable operational BMPs in
“What you should know
for…..Landscape and Gardening” at

KWWS
ZZZUFZDWHUVKHGRUJDERXW
PDWHULDOVOLEUDU\

EEGG

G
Provide IPM information to new
owners, lessees and operators.
✔ ✔
✔ ✔
✔
✔ ✔
✔
✔
✔
Appendix 8

S T O R M W A T E R P O L L U T A N T S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T 201ϴ SMR WQMP TEMPLATE Appendix 8 – Page 3 of 10

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
E. Pools, spas, ponds,
decorative fountains,
and other water
features.
Show location of water feature and
a sanitary sewer cleanout in an
accessible area within 10 feet.
(Exception: Public pools must be
plumbed according to County
Department of Environmental
Health Guidelines.)
If the Co-Permittee requires pools
to be plumbed to the sanitary
sewer, place a note on the plans
and state in the narrative that this
connection will be made according
to local requirements.
See applicable operational BMPs in
“Guidelines for Maintaining Your
Swimming Pool, Jacuzzi and
Garden Fountain” at

http://
www.rcZDWHUVKHGRUJDERXWPDWHULDOV
OLEUDU\
IIF

F. Food service For restaurants, grocery stores, and other food service operations, show
location (indoors or in a covered
area outdoors) of a floor sink or
other area for cleaning floor mats,
containers, and equipment.
On the drawing, show a note that
this drain will be connected to a
grease interceptor before
discharging to the sanitary sewer.
Describe the location and features
of the designated cleaning area.
Describe the items to be cleaned in
this facility and how it has been
sized to insure that the largest
items can be accommodated.
See the brochure, “The Food Service
Industry Best Management Practices
for: Restaurants, Grocery Stores,
Delicatessens and Bakeries” at
http://
www.rcZDWHUVKHGRUJDERXWPDWHULDOV
OLEUDU\

HDIED

Provide this brochure to new site
owners, lessees, and operators.
G. Refuse areas Show where site refuse and
recycled materials will be handled
and stored for pickup. See local
municipal requirements for sizes
and other details of refuse areas.
If dumpsters or other receptacles
are outdoors, show how the
designated area will be covered,
graded, and paved to prevent run-
on and show locations of berms to
prevent runoff from the area.
Any drains from dumpsters,
compactors, and tallow bin areas
shall be connected to a grease
removal device before discharge to
sanitary sewer.
State how site refuse will be
handled and provide supporting
detail to what is shown on plans.
State that signs will be posted on or
near dumpsters with the words “Do
not dump hazardous materials
here” or similar.
State how the following will be
implemented:

Provide adequate number of
receptacles. Inspect receptacles
regularly; repair or replace leaky
receptacles. Keep receptacles covered.

Prohibit/prevent dumping of liquid or
hazardous wastes. Post “no hazardous
materials” signs. Inspect and pick up
litter daily and clean up spills
immediately. Keep spill control
materials available on-site. See Fact
Sheet SC-34, “Waste Handling and
Disposal” in the CASQA Stormwater
Quality Handbooks at
www.cabmphandbooks.com
✔ ✔ ✔
✔ ✔ ✔
✔
✔
✔
✔
Appendix 8

S T O R M W A T E R P O L L U T A N T S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T 201ϴ SMR WQMP TEMPLATE Appendix 8 – Page 4 of 10

No processes to drain to exterior or
to storm drain system.”
See Fact Sheet SC-10, “Non-
Stormwater Discharges” in the
CASQA Stormwater Quality
Handbooks at
www.cabmphandbooks.com
See the brochure “Industrial &
Commercial Facilities Best Management
Practices for: Industrial, Commercial
Facilities” at
http://www.rcǁĂƚĞƌƐŚĞĚ͘ŽƌŐͬ
ĂďŽƵƚͬŵĂƚĞƌŝĂůƐͲůŝďƌĂƌǇͬ
ηϭϰϱϬϯϴϵϵϮϲϳϲϲͲϲϭĞϴĂĨϬďͲϱϯĂϵ
I. Outdoor storage of
equipment or materials.
(See rows J and K for
source control
measures for vehicle
cleaning, repair, and
maintenance.)
Show any outdoor storage areas,
including how materials will be
covered. Show how areas will be
graded and bermed to prevent run-
on or run-off from area.
Storage of non-hazardous liquids
shall be covered by a roof and/or
drain to the sanitary sewer system,
and be contained by berms, dikes,
liners, or vaults.
Storage of hazardous materials and
wastes must be in compliance with
the local hazardous materials
ordinance and a Hazardous
Materials Management Plan for the
site.
Include a detailed description of
materials to be stored, storage
areas, and structural features to
prevent pollutants from entering
storm drains.

Where appropriate, reference
documentation of compliance with
the requirements of Hazardous
Materials Programs for:
Hazardous Waste Generation
Hazardous Materials Release
Response and Inventory
California Accidental Release
(CalARP)
Aboveground Storage Tank
Uniform Fire Code Article 80
Section 103(b) & (c) 1991
Underground Storage Tank
www.cchealth.org/groups/hazmat/
See the Fact Sheets SC-31, “Outdoor
Liquid Container Storage” and SC-33,
“Outdoor Storage of Raw Materials ”
in the CASQA Stormwater Quality
Handbooks at
www.cabmphandbooks.com
Appendix 8

S T O R M W A T E R P O L L U T A N T S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T 201ϴ SMR WQMP TEMPLATE Appendix 8 – Page 5 of 10

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
J. Vehicle and
Equipment Cleaning
Show on drawings as appropriate:
(1) Commercial/industrial facilities
having vehicle/equipment cleaning
needs shall either provide a
covered, bermed area for washing
activities or discourage
vehicle/equipment washing by
removing hose bibs and installing
signs prohibiting such uses.
(2) Multi-dwelling complexes shall
have a paved, bermed, and covered
car wash area (unless car washing
is prohibited on-site and hoses are
provided with an automatic shut-
off to discourage such use).
(3) Washing areas for cars, vehicles,
and equipment shall be paved,
designed to prevent run-on to or
runoff from the area, and plumbed
to drain to the sanitary sewer.
(4) Commercial car wash facilities
shall be designed such that no
runoff from the facility is
discharged to the storm drain
system. Wastewater from the
facility shall discharge to the
sanitary sewer, or a wastewater
reclamation system shall be
installed.
If a car wash area is not provided,
describe any measures taken to
discourage on-site car washing and
explain how these will be enforced.

Describe operational measures to
implement the following (if
applicable):
Washwater from vehicle and
equipment washing operations shall
not be discharged to the storm drain
system. Refer to “Outdoor Cleaning
Activities and Professional Mobile
Service Providers” for many of the
Potential Sources of Runoff Pollutants
categories below. Brochure can be
found at

http://www.rcǁĂƚĞƌƐŚĞĚ͘ŽƌŐͬ
ĂďŽƵƚͬŵĂƚĞƌŝĂůƐͲůŝďƌĂƌǇͬ
ηϭϰϱϬϯϴϵϵϮϲϳϲϲͲϲϭĞϴĂĨϬďͲϱϯĂϵ
Car dealerships and similar may
rinse cars with water only.

Appendix 8

S T O R M W A T E R P O L L U T A N T S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T 201ϴ SMR WQMP TEMPLATE Appendix 8 – Page 6 of 10

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
K. Vehicle/Equipment
Repair and
Maintenance
Accommodate all vehicle
equipment repair and maintenance
indoors. Or designate an outdoor
work area and design the area to
prevent run-on and runoff of
stormwater.
Show secondary containment for
exterior work areas where motor
oil, brake fluid, gasoline, diesel
fuel, radiator fluid, acid-containing
batteries or other hazardous
materials or hazardous wastes are
used or stored. Drains shall not be
installed within the secondary
containment areas.
Add a note on the plans that states
either (1) there are no floor drains,
or (2) floor drains are connected to
wastewater pretreatment systems
prior to discharge to the sanitary
sewer and an industrial waste
discharge permit will be obtained.
State that no vehicle repair or
maintenance will be done outdoors,
or else describe the required
features of the outdoor work area.
State that there are no floor drains
or if there are floor drains, note the
agency from which an industrial
waste discharge permit will be
obtained and that the design meets
that agency’s requirements.
State that there are no tanks,
containers or sinks to be used for
parts cleaning or rinsing or, if there
are, note the agency from which an
industrial waste discharge permit
will be obtained and that the
design meets that agency’s
requirements.

In the Stormwater Control Plan, note
that all of the following restrictions
apply to use the site:
No person shall dispose of, nor permit
the disposal, directly or indirectly of
vehicle fluids, hazardous materials, or
rinsewater from parts cleaning into
storm drains.
No vehicle fluid removal shall be
performed outside a building, nor on
asphalt or ground surfaces, whether
inside or outside a building, except in
such a manner as to ensure that any
spilled fluid will be in an area of
secondary containment. Leaking
vehicle fluids shall be contained or
drained from the vehicle immediately.
No person shall leave unattended drip
parts or other open containers
containing vehicle fluid, unless such
containers are in use or in an area of
secondary containment.

Refer to “Automotive Maintenance &
Car Care Best Management Practices
for Auto Body Shops, Auto Repair
Shops, Car Dealerships, Gas Stations
and Fleet Service Operations

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✔ ✔ ✔
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Appendix 8

S T O R M W A T E R P O L L U T A N T S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T 201ϴ SMR WQMP TEMPLATE Appendix 8 – Page 7 of 10

1.] The canopy [or
cover] shall not drain onto the
fueling area.
The property owner shall dry sweep
the fueling area routinely.
See the Fact Sheet SD-30 , “Fueling
Areas” in the CASQA Stormwater
Quality Handbooks at
www.cabmphandbooks.com
6 The fueling area shall be defined as the area extending a minimum of 6.5 feet from the corner of each fuel dispenser or the length at which the hose and nozzle assembly may be operated plus a minimum of one foot, whichever is greater.

Appendix 8

S T O R M W A T E R P O L L U T A N T S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T 201ϴ SMR WQMP TEMPLATE Appendix 8 – Page 8 of 10

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
M. Loading Docks Show a preliminary design for the
loading dock area, including
roofing and drainage. Loading
docks shall be covered and/or
graded to minimize run-on to and
runoff from the loading area. Roof
downspouts shall be positioned to
direct stormwater away from the
loading area. Water from loading
dock areas shall be drained to the
sanitary sewer, or diverted and
collected for ultimate discharge to
the sanitary sewer.
Loading dock areas draining
directly to the sanitary sewer shall
be equipped with a spill control
valve or equivalent device, which
shall be kept closed during periods
of operation.
Provide a roof overhang over the
loading area or install door skirts
(cowling) at each bay that enclose
the end of the trailer.
Move loaded and unloaded items
indoors as soon as possible.
See Fact Sheet SC-30, “Outdoor
Loading and Unloading,” in the
CASQA Stormwater Quality
Handbooks at
www.cabmphandbooks.com
Appendix 8

S T O R M W A T E R P O L L U T A N T S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T 201ϴ SMR WQMP TEMPLATE Appendix 8 – Page 9 of 10

IF THESE SOURCES WILL BE
ON THE PROJECT SITE … … THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE 1 Potential Sources of
Runoff Pollutants
2 Permanent Controls—Show on
WQMP Drawings
3 Permanent Controls—List in WQMP
Table and Narrative
4 Operational BMPs—Include in WQMP
Table and Narrative
N. Fire Sprinkler Test
Water
Provide a means to drain fire
sprinkler test water to the sanitary
sewer.
See the note in Fact Sheet SC-41,
“Building and Grounds Maintenance,”
in the CASQA Stormwater Quality
Handbooks at
www.cabmphandbooks.com
O. Miscellaneous Drain
or Wash Wate r or Other
Sources
Boiler drain lines
Condensate drain lines
Rooftop equipment
Drainage sumps
Roofing, gutters, and
trim.
Other sources
Boiler drain lines shall be directly
or indirectly connected to the
sanitary sewer system and may not
discharge to the storm drain
system.
Condensate drain lines may
discharge to landscaped areas if the
flow is small enough that runoff will
not occur. Condensate drain lines
may not discharge to the storm
drain system.
Rooftop equipment with potential
to produce pollutants shall be
roofed and/or have secondary
containment.
Any drainage sumps on-site shall
feature a sediment sump to reduce
the quantity of sediment in pumped
water.
Avoid roofing, gutters, and trim
made of copper or other
unprotected metals that may
leach into runoff.
Include controls for other sources
as specified by local reviewer.
✔ ✔ ✔
✔
✔
Appendix 8

S T O R M W A T E R P O L L U T A N T S O U R C E S / S O U R C E C O N T R O L C H E C K L I S T 201ϴ SMR WQMP TEMPLATE Appendix 8 – Page 10 of 10

Appendix 9: O&M
Operation and Maintenance Plan and Documentation of Finance, Maintenance and Recording Mechanisms

RECORDING REQUESTED BY:

CITY OF MENIFEE
AND WHEN RECORDED MAIL TO:

CITY OF MENIFEE

CITY CLERK
29844 HAUN ROAD
MENIFEE, CA 92586-6540
SPACE ABOVE THIS LINE FOR RECORDER’S USE

WATER QUALITY MANAGEMENT PLAN AND STORMWATER BEST

MANAGEMENT PRACTICES OPERATION, TRANSFER, MAINTENANCE AND

RIGHT OF ENTRY AGREEMENT
PROJECT NAME: _______________________________________________ PROPERTY OWNER NAME: _______________________________________________ PROPERTY ADDRESS: _______________________________________________ _______________________________________________
APN: _______________________________________________ THIS AGREEMENT is made and entered into in
_______________________________________, California, this ___________ day of _______________________________, 202___, by and between ____________________________________________________________, herein after referred to as “Owner”, and the CITY O F MENIFEE, a municipal corporation, located in the County of Riverside, State of California hereinafter referred to as “CITY”; WHEREAS, the City is a Co-Permittee for discharging stormwater from its MS4 facilities pursuant to the Santa Ana Regional Water Quality Control Board Order No. R8-2010-0033, MS4 NPDES Permit No. CAS 618033. Under the terms of the permit the City is required to enforce the provisions of the permit within its jurisdiction. The requirements contained in this agreement are intended to achieve the goals of the MS4 permit; WHEREAS, the Owner owns real property (“Property) in t he City of Menifee, County of Riverside, State of California, more specifically described in Exhibit “A” and depicted in Exhibit “B”, each of which exhibits is attached hereto and incorporated herein by this reference;
WHEREAS, at the time of initial approval of development project known as:
______________________________________________________ within the Property described herein, the City required the project to employ Best Management Practices, hereinafter referred to as “BMPs,” to minimize pollutants in urban runoff; WHEREAS, the Owner has chosen to install and/or implement BMPs as described in the Water Quality Management Plan, on file with the City, hereinafter referred to as “WQMP,” to minimize pollutants in urban runoff and to minimize other adverse impacts of urban runoff; WHEREAS, said WQMP has been certified by the Owner and reviewed and accepted by the City;
WHEREAS, said BMPs, with installation and/or implementation on private property and draining only private property, are part of a private facility with all maintenance or replacement, therefore, the sole responsibility of the Owner in accordance with the terms of this Agreement;
WHEREAS, the Owner is aware that periodic and continuous maintenance, including, but not necessarily limited to, filter material replacement and sediment removal, is required to assure peak performance of all BMPs in the WQMP and that, furthermore, such maintenance activity will require compliance with all Local, State, or Federal laws and regulations, including those pertaining to confined space and waste disposal methods, in effect at the time such maintenance occurs;
NOW THEREFORE, it is mutually stipulated and agreed as follows:

1. Right of Access: Owner hereby provides the City of Menifee designee complete access, of any duration, to the BMPs and their immediate vicinity at any time, upon reasonable notice, or in the event of emergency, as determined by the City’s Engineer, no advance notice, for the purpose of inspection, sampling, testing of the Device, and in case of emergency to direct all necessary repairs or other preventative measures at owner’s expense in accordance with the procedures set forth in paragraph 3 below. City shall make every effort at all times to minimize or avoid interference with Owner’s use of the Property.

2. Responsibility for Operation and Maintenance of BMPs: Owner shall use its best efforts diligently to maintain all BMPs in a manner assuring peak performance at all times. All reasonable precautions shall be exercised by Owner and Owner’s representative or contractor in the removal and extraction of any material(s) from the BMPs and the ultimate disposal of the material(s) in a manner consistent with all relevant laws and regulations in effect at the time. As may be requested from time to time by the City, the Owner shall provide the City with documentation identifying the material(s) removed, the quantity, and disposal destination.

3. City Maintenance at Owner’s Expense : In the event Owner, or its successors or assigns, fails to accomplish the necessary maintenance contemplated by this Agreement, the City may cause such maintenance to be conducted on Owner’s Property at Owner’s expense if Owner does not commence and diligently work to perform the maintenance within five (5) days of receiving written notice from the City, in accordance with paragraph 10 below, of Owner’s failure to comply with the terms of this Agreement. The City may charge the entire cost and expense of any maintenance undertaken by the City, whether performed as a response to an emergency situation or following five (5) day written notice by the City, to the Owner or Owner’s successors or assigns, including administrative costs, attorney’s fees and interest thereon at the maximum rate authorized by the Civil Code from the Date of the notice of expense until paid in full. The City, at its sole election, may take these costs to be a lien upon the property that may be collected at the same time and in the same manner as ordinary municipal taxes as provided in Government Code section 38773.5. Nothing in this section or this Agreement creates an obligation by the City to maintain or repair any BMP, nor does this section prohibit the City from pursuing other legal recourse against Owner.

4. Surety Bond: The City may require the owner to post security in form and for a time period satisfactory to the City to guarantee the performance of the obligations stated herein. Should the Owner fail to perform the obligations under the Agreement, the City may, in the case of a cash bond, act for the Owner using the proceeds from it, or in the case of a surety bond, require the sureties to perform the obligations of the Agreement. As an additional remedy, the City’s Engineer may withdraw any previous stormwater-related approval with respect to the property on which BMPs have been installed and/or implemented until such time as Owner repays to City its reasonable costs incurred in accordance with paragraph 3 above.

5. Recording: This agreement shall be recorded in the Office of the Recorder of Riverside County, California, at the expense of the Owner and shall constitute notice to all successors and assigns of the title to said Property of the obligation herein set forth, and also a lien in such amount as will fully reimburse the City, including interest as herein above set forth, subject to foreclosure in event of default in payment.

6. Attorney’s Fees: In event of legal action occasioned by any default or action of the Owner, or its successors or assigns, then the Owner and its successors or assigns agree(s) to pay all costs incurred by the City in enforcing the terms of this Agreement, including reasonable attorney’s fees and costs, and that the same shall become a part of the lien against said Property.

7. Covenant: It is the intent of the parties hereto that burdens and benefits herein undertaken shall constitute covenants that run with said Property and constitute a lien there against.

8. Binding on Successors: The obligations herein undertaken shall be binding upon the heirs, successors, executors, administrators and assigns of the parties hereto. The term “Owner” shall include not only the present Owner, but also its heirs, successors, executors, administrators, and assigns. Owner shall notify any successor to title of all or part of the Property about the existence of this Agreement. Owner shall provide such notice prior to such successor obtaining an interest in all or part of the Property.

Owner shall provide a copy of such notice to the City at the same time such notice is provided to the successor.

9. Time of the Essence: Time is of the essence in the performance of this Agreement.

10. Notice: Any notice to a party required or called for in this Agreement shall be served in person, or by deposit in the U.S. Mail, first class postage prepaid, to the address set forth below. Notice(s) shall be deemed effective upon receipt, or seventy-two (72) hours after deposit in the U.S. Mail, whichever is earlier. A party may change a notice address only by providing written notice thereof to the other party.

IN WITNESS THEREOF, the parties hereto have affixed their signatures as of the date first written above.

IF TO CITY: IF TO OWNER:

City of Menifee ________________________________
29844 Haun Road ________________________________
Menifee, CA 92586-6540 ________________________________ ________________________________
CITY: OWNER:

By: ___________________________ By:

NAME Armando G. Villa,
City Manager
Title: ____
APPROVED AS TO FORM:

OWNER:
______________________________
Jeffery T. Melching, City Attorney
By:

ATTEST:

NAME
Title:
____________________________ __
Sarah Manwaring, City Clerk

NOTARY ACKNOWLEDGEMENTS ON FOLLOWING PAGE

Page 1 of 1 ends

EXHIBIT “A”
To

COVENANT AND AGREEMENT REGARDING WATER QUALITY MANAGEMENT

PLAN BMP, CONSENT TO INSPECT, MAINTENANCE AND INDEMNIFICATION

For
PORTIONS OF: APN’S 360-300-002; 360-300-003; 360-300-004; 360-300-005; 360-300- 006; 360-300-009; 360-350-001,
Menifee, CA

All that real property located in the City of Menifee, County of Riverside, California, described as follows:

Being a subdivision of a portion of the west half of the northwest quarter of section 15, township 6 south, range 3 west, San Bernardino meridian, together with portions of parcels 2, 3, 5, 6, 8 and lots "b" through and "f", inclusive, of parcel map no. 8433, filed in book 38, page 33 of parcel maps in the office of the Riverside County Recorder, California, lying within sections 15 and 16, township 6 south, range 3 west, San Bernardino meridian

04/16/2021
Brian R. Lowell Date
RCE 74550

HUNSAKER & ASSOCIATESINLAND EMPIRE REGIONIRVINE, INC

HUNSAKERENWS

- 6 -

Appendix 10: Educational Materials
BMP Fact Sheets, Maintenance Guidelines and Other End-User BMP Information

Riverside County - Low Impact Development BMP Design Handbook rev. 2/2012

Page 1 ends

3.1 INFILTRATION BASIN

Description

An Infiltration Basin is a flat earthen basin
designed to capture the design capture volume,
VBMP. The stormwater infiltrates through the
bottom of the basin into the underlying soil over
a 72 hour drawdown period. Flows exceeding
VBMP must discharge to a downstream
conveyance system. Trash and sediment
accumulate within the forebay as stormwater
passes into the basin. Infiltration basins are
highly effective in removing all targeted
pollutants from stormwater runoff.

See Appendix A, and Appendix C, Section 1 of Basin Guidelines, for additional requirements.

Siting Considerations
The use of infiltration basins may be restricted by concerns over ground water contamination, soil permeability, and clogging at the site. See the applicable WQMP for any specific feasibility considerations for using infiltration BMPs. Where this BMP is being used, the soil beneath the basin must be thoroughly evaluated in a geotechnical report since the underlying soils are critical to the basin’s
long term performance. To protect the basin from erosion, the sides and bottom of the basin must be vegetated, preferably with native or low water use plant species.

In addition, these basins may not be appropriate for the following site conditions:
 Industrial sites or locations where spills of toxic materials may occur  Sites with
very low soil infiltration rates
 Sites with high groundwater tables or excessively high soil infiltration rates, where pollutants can affect ground water quality
 Sites with unstabilized soil or construction activity upstream  On steeply sloping terrain
 Infiltration basins located
in a fill condition should refer to Appendix A of this Handbook for details on special requirements/restrictions Type of BMP LID ‐ Infiltration
Treatment Mechanisms Infiltration, Evapotranspiration (when vegetated), Evaporation, and Sedimentation
Maximum Treatment Area 50 acres
Other Names Bioinfiltration Basin
Figure 1 – Infiltration Basin

INFILTRATION BASIN BMP FACT SHEET

Riverside County - Low Impact Development BMP Design Handbook rev. 2/2012

Page 2 ends

Setbacks

Always consult your geotechnical engineer for site specific recommendations regarding setbacks for infiltration trenches. Recommended setbacks are needed to protect buildings, existing trees, walls, onsite or nearby wells, streams, and tanks. Setbacks should be considered early in the design process since they can affect where infiltration facilities may be placed and how deep they ar
e allowed to be. For instance, depth setbacks can dictate fairly shallow facilities that will have a larger footprint and, in some cases, may make an infiltration basin infeasible. In that instance, another BMP must be selected.

Infiltration basins typically must be set back:
 10 feet from the historic high groundwater (meas ured vertically from the bottom of the basin, as shown in Figure 2)
 5 feet from bedrock or impermeable surface layer (measured vertically from the bottom of the basin, as shown in Figure 2)
 From all existing mature tree drip lines as indicated in Figure 2 (to protect their root structure)
 100 feet hori
zontally from wells, tanks or springs
Setbacks to walls and foundations must be included as part of the Geotechnical Report. All other setbacks shall be in accordance with applicable standards of the District’s Basin Guidelines (Appendix C).

Figure 2 – Setback Requirements

INFILTRATION BASIN BMP FACT SHEET

Riverside County - Low Impact Development BMP Design Handbook rev. 2/2012

Page 3 ends

Forebay

A concrete forebay shall be provided to reduce sediment clogging and to reduce erosion. The forebay shall have a design volume of at least 0.5% VBMP and a minimum 1 foot high concrete splashwall / berm. Full height notch‐type weir(s), offset from the line of flow from the basin inlet to prevent short circuiting, shall be used to outlet the forebay. It is recommended that two weirs be used and that they be located on opposite sides of the forebay (see Figure 2).

Overflow

Flows exceeding VBMP must discharge to an acceptable downstream conveyance system. Where an adequate outlet is present, an overflow structure may be used. Where an embankment is present, an emergency spillway may be used instead. Overflows must be placed just above the design water surface for VBMP and be near the outlet of the system. The overflow structure shall be similar to the District’s Standard Drawing CB 110. Additional details may be found in the District’s Basin Guidelines (Appendix C).

Figure 3 – Infiltration Basin

INFILTRATION BASIN BMP FACT SHEET

Riverside County - Low Impact Development BMP Design Handbook rev. 2/2012

Page 4 ends

Landscaping Requirements
Basin vegetation provides erosion protection, improves sediment removal and assists in allowing infiltration to occur. The basin surface and side slopes shall be planted with native grasses. Proper landscape management is also required to ensure that the vegetation does not contribute to water pollution through pesticides, herbicides, or fertilizers. Landscaping shall be in accordance
with County of Riverside Ordinance 859 and the District’s Basin Guidelines (Appendix C), or other guidelines issued by the Engineering Authority.

Maintenance
Normal maintenance of an infiltration basin includes the maintenance of landscaping, debris and trash removal from the surface of the basin, and tending to problems associated with standing water (vectors, odors, etc.). Significant ponding, especially more than 72 hours after an event, may indicate that the basin surface is no longer providing sufficient infiltration and requires aeration. See
the District’s Basin Guidelines (Appendix C) for additional requirements (i.e., fencing, maintenance access, etc.).

Table 1 ‐ Inspection and Maintenance

Schedule Inspection and Maintenance Activity
Ongoing including just
before annual storm
seasons and following
rainfall events.
 Maintain vegetation as needed. Use of fertilizers, pesticides and herbicides should be strenuously avoided to ensure they don’t contribute to water pollution. If appropriate native plant selections and other IPM methods are used, such products shouldn’t be needed. If such projects are used,
o Products shall be applied in accordance with their labeling, especially in relation to application to water, and in areas subjected to flooding. o Fertilizers should not be applied within 15 days before, after, or during the rain season.
 Remove debris and litter from the entire basin to minimize clogging and improve aesthetics.
 Check for obvious problems and repair as needed. Address odor, insects, and overgrowth issues associated with stagnant or standing water in the basin bottom.

There should be no long‐term ponding water.
 Check for erosion and sediment laden areas in the basin. Repair as needed. Clean forebay if needed.
 Revegetate side slopes where needed.

Annually. If possible,
schedule these inspections
within 72 hours after a
significant rainfall.
 Inspection of hydraulic and structural facilities. Examine the inlet for blockage, the embankment and spillway integrity, as well as damage to any structural element.  Check for erosion, slumping and overgrowth. Repair as needed.  Check basin depth for sedime nt build up and reduced total capacity. Scrape bottom as needed and remove sediment. Restore to original cross‐section and infiltration rate. Replant basin vegetation.
 Verify the basin bottom is allowing acceptable infiltration. Use a disc or other method to aerate basin bottom only if there is actual significant loss of infiltrative capa
city, rather than on a routine basis1.
 No water should be present 72 hours after an event. No long term standing water should be present at all. No algae formation should be visible. Correct problem as needed.

1. CA Stormwater BMP Handbook for New Development and Significant Redevelopment

INFILTRATION BASIN BMP FACT SHEET

Riverside County - Low Impact Development BMP Design Handbook rev. 2/2012

Page 5 ends

Table 2 ‐ Design and Sizing Criteria for Infiltration Basins Note: The information contained in this BMP Factsheet is intended to be a summary of design considerations and requirements. Additional information which applies to all detention basins may be found in the District’s Basin Guidelines (Appendix C). In addition, information herein may be superseded by other guidelines issued by the co‐permittee.

INFILTRATION BASIN SIZING PROCEDURE

1. Find the Design Volume, VBMP.
a) Enter the Tributary Area, AT.
b) Enter the Design Volume, VBMP, determined from Section 2.1 of this Handbook.

2. Determine the Maximum Depth.
a) Enter the infiltration rate. The infiltration rate shall be established as described in Appendix A: “Infiltration Testing”.
b) Enter the design Factor of Safety from Table 1 in Appendix A: “Infiltration Testing”. c) The spreadsheet will determine D1, the maximum allowable depth of the basin based on the infiltration rate along with the maximum drawdown time (72 hours) and the Factor of Safety.

D1 = [(t) x (I)] / 12s

Where I = site infiltration rate (in/hr)
s = safety factor
t = drawdown time (maximum 72 hours)
Design Parameter Infiltration Basin
Design Volume VBMP
Forebay Volume 0.5% VBMP
Drawdown time (maximum) 72 hours
Maximum tributary area 50 acres 2
Minimum infiltration rate
Must be sufficient to drain the basin within the
required Drawdown time over the life of the BMP.

The WQMP may include specific requirements for
minimum tested infiltration rates.

Maximum Depth 5 feet
Spillway erosion control Energy dissipators to reduce velocities1 Basin Slope 0%
Freeboard (minimum) 1 foot 1
Historic High Groundwater Setback (max) 10 feet
Bedrock/impermeable layer setback (max) 5 feet
Tree setbacks Mature tree drip line must not overhang the basin Set back from wells, tanks or springs 100 feet
Set back from foundations As recommended in Geotechnical Report

1. Ventura County’s Technical Guidance Manual for Stormwater Quality Control Measures

2. CA Stormwater BMP Handbook for New Development and Significant Redevelopment

INFILTRATION BASIN BMP FACT SHEET

Riverside County - Low Impact Development BMP Design Handbook rev. 2/2012

Page 6 ends

d) Enter the depth of freeboard.
e) Enter the depth to the historic high groundwater level measured from the top of the basin.
f) Enter the depth to the top of bedrock or other impermeable layer measured from the finished grade.
g) The spreadsheet will determine D2, the total basin depth (including freeboard, if used) of the basin, based on restrictions to the depth by groundwater and an impermeable layer.

D 2 = Depth to groundwater – (10 + freeboard) (ft);
or
D 2 = Depth to impermeable layer – (5 + freeboard) (ft) Whichever is least.

h) The spreadsheet will determine the maximum allowable effective depth of basin, DMAX, based on the smallest value between D1 and D2. DMAX is the maximum depth of water only and does not include freeboard. DMAX shall not exceed 5 feet.

3. Basin Geometry

a) Enter the basin side slopes, z (no steeper than 4:1). b) Enter the proposed basin depth, dB excluding freeboard. c) The spreadsheet will determine the minimum required surface area of the basin:

A
s = VBMP / dB

Where As = minimum area required (ft2)
VBMP = volume of the infiltration basin (ft3)
dB= proposed depth not to exceed maximum allowable depth, DMAX (ft)

d) Enter the proposed bottom surface area. This area shall not be less than the minimum required surface area.

4. Forebay
A concrete forebay with a design volume of at least 0.5% V BMP and a minimum 1 foot high
concrete splashwall shall be provided. Full‐height rectangular weir(s) shall be used to outlet the forebay. The weir(s) must be offset from the line of flow from the basin inlet. It is recommended that two weirs be used and that they be located on opposite sides of the forebay
(see Figure 2).

a) The spreadsheet will determine the minimum required forebay volume based on 0.5% VBMP.
b) Enter the proposed depth of the forebay berm/splashwall (1foot minimum). c) The spreadsheet will determine the minimum required forebay surface area. d) Enter the width of rectangular weir to be used (minimum 1.5 inches). Weir width should be established based on a 5 minute drawdown time.

What is stormwater runoff?
Why is stormwater runoff
a problem?
The effects of pollution
Stormwater runoff occurs when precipitation
from rain or snowmelt flows over the ground.

Impervious surfaces like driveways, sidewalks,
and streets prevent stormwater from
naturally soaking into the ground.

Stormwater can pick up debris, chemicals, dirt, and other pollutants and flow into a storm sewer system or directly to a lake, stream, river, wetland, or coastal water. Anything that enters a storm sewer system is discharged untreated into the waterbodies we use for swimming, fishing, and providing drinking water.

Polluted stormwater runoff can have
many adverse effects on plants, fish,
animals, and people.

Sediment can cloud the water
and make it difficult or
impossible for aquatic plants to
grow . Sediment also can
.
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destroy aquatic habitats
Excess nutrients can cause
algae blooms. When algae die,
they sink to the bottom and decompose
in a process that removes oxygen from
the water. Fish and other aquatic
organisms can’t exist in water with low
dissolved oxygen levels.

Bacteria and other pathogens can wash
into swimming areas and create health
hazards, often making beach closures
necessary .

Debris—plastic bags, six-pack rings, bottles, and
cigarette butts—washed into waterbodies can choke, suffocate, or disable aquatic life like ducks, fish, turtles, and birds.

Household hazardous wastes like insecticides, pesticides, paint, solvents, used motor oil, and other auto fluids can poison aquatic life.

Land animals and people can become sick or die from eating diseased fish and shellfish or ingesting polluted water.

Polluted stormwater often
affects drinking water
sources. This, in turn, can
affect human health and
increase drinking water
treatment costs.
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After the Storm
EPA 833-B-03-002
January 2003
For more information contact:
or visit
www.epa.gov/npdes/stormwater
www.epa.gov/nps
A Citizen’s Guide to
Understanding Stormwater

WHEN IT RAINS

IT DRAINS

WHEN IT RAINS

IT DRAINS
Internet Address (URL) HTTP://www.epa.gov
Recycled/Recyclable Printed With Vegetable
Oil Based Inks on 100% Postconsumer,
Process Chlorine Free Recycled Paper
●
●
Auto care
Washing your car and
degreasing auto parts at home
can send detergents and other
contaminants through the
storm sewer system. Dumping
automotive fluids into storm
drains has the same result as
dumping the materials directly
into a waterbody .

Pet waste
Pet waste can be
a major source of
bacteria and
excess nutrients
in local waters.
/c183
When walking
your pet,
remember to pick up the
waste and dispose of it
properly . Flushing pet
waste is the best disposal
method. Leaving pet waste
on the ground increases
public health risks by
allowing harmful bacteria
and nutrients to wash into
the storm drain and
eventually into local
waterbodies.

Septic
systems
Leaking and
poorly
maintained
septic
systems release nutrients and
pathogens (bacteria and
viruses) that can be picked up
by stormwater and discharged
into nearby waterbodies.

Pathogens can cause public
health problems and
environmental concerns.

Lawn care
Excess fertilizers
and pesticides
applied to lawns
and gardens wash
off and pollute
streams. In
addition, yard
clippings and
leaves can wash
into storm drains and contribute
nutrients and organic matter to streams.

Education is essential to changing people's behavior.

Signs and markers near storm drains warn residents
that pollutants entering the drains will be carried
untreated into a local waterbody.

Recycle or properly dispose of household products that
contain chemicals, such as insecticides, pesticides, paint, solvents, and used motor oil and other auto fluids.

Don’t pour them onto the ground or into storm drains.
/c183
/c183
Use a commercial car wash that treats or
recycles its wastewater, or wash your car on
your yard so the water infiltrates into the
ground.

Repair leaks and dispose of used auto fluids
and batteries at designated drop-off or
recycling locations.
/c183
/c183
/c183
/c183
Don’t overwater your lawn. Consider
using a soaker hose instead of a
sprinkler.

Use pesticides and fertilizers
sparingly . When use is necessary , use
these chemicals in the recommended
amounts. Use organic mulch or safer
pest control methods whenever
possible.

Compost or mulch yard waste. Don’t
leave it in the street or sweep it into
storm drains or streams.

Cover piles of dirt or mulch being
used in landscaping projects.
/c183
/c183
Inspect your system every
3 years and pump your
tank as necessary (every 3
to 5 years).

Don't dispose of
household hazardous
waste in sinks or toilets.

Dirt, oil, and debris that collect in
parking lots and paved areas can be
washed into the storm sewer system
and eventually enter local
waterbodies.
/c183
/c183
/c183
Sweep up litter and debris from
sidewalks, driveways and parking lots,
especially around storm drains.

Cover grease storage and dumpsters
and keep them clean to avoid leaks.

Report any chemical spill to the local
hazardous waste cleanup team.

They’ll know the best way to keep
spills from harming the environment.

Erosion controls that aren’t maintained can cause
excessive amounts of sediment and debris to be
carried into the stormwater system. Construction
vehicles can leak fuel, oil, and other harmful fluids
that can be picked up by stormwater and
deposited into local waterbodies.
/c183
/c183
/c183
Divert stormwater away from disturbed or
exposed areas of the construction site.

Install silt fences, vehicle mud removal areas,
vegetative cover, and other sediment and
erosion controls and properly maintain them,
especially after rainstorms.

Prevent soil erosion by minimizing disturbed
areas during construction projects, and seed
and mulch bare areas as soon as possible.

Uncovered fueling stations allow spills to be
washed into storm drains. Cars waiting to be
repaired can leak fuel, oil, and other harmful
fluids that can be picked up by stormwater.
/c183
/c183
/c183
/c183
Clean up spills immediately and properly
dispose of cleanup materials.

Provide cover over fueling stations and
design or retrofit facilities for spill
containment.

Properly maintain fleet vehicles to prevent
oil, gas, and other discharges from being
washed into local waterbodies.

Install and maintain oil/water separators.

Lack of vegetation on streambanks can lead to erosion. Overgrazed pastures can also contribute excessive amounts of sediment to local waterbodies. Excess fertilizers and pesticides can poison aquatic animals and lead to destructive algae blooms. Livestock in streams can contaminate waterways with bacteria, making them unsafe for human contact. /c183
/c183
/c183
/c183
/c183
Keep livestock away from streambanks and provide
them a water source away from waterbodies.

Store and apply manure away from waterbodies and in
accordance with a nutrient management plan.

Vegetate riparian areas along waterways.

Rotate animal grazing to prevent soil erosion in fields.

Apply fertilizers and pesticides according to label
instructions to save money and minimize pollution.

Permeable Pavement
Rain Barrels
Rain Gardens and
Grassy Swales
Vegetated Filter Strips
—Traditional concrete and
asphalt don’t allow water to soak into the ground.

Instead these surfaces rely on storm drains to
divert unwanted water. Permeable pavement
systems allow rain and snowmelt to soak through,
decreasing stormwater runoff.
—You can
collect rainwater from
rooftops in mosquito-
proof containers. The
water can be used later on
lawn or garden areas.
—Specially
designed areas planted
with native plants can provide natural places for
rainwater to collect
and soak into the
ground. Rain from
rooftop areas or paved
areas can be diverted
into these areas rather
than into storm drains.
—Filter strips are areas of
native grass or plants created along roadways or
streams. They trap the pollutants stormwater
picks up as it flows across driveways and streets.

Residential landscaping
Improperly managed logging operations can result in erosion and sedimentation.
/c183
/c183
/c183
/c183
/c183
Conduct preharvest planning to prevent erosion and lower costs.

Use logging methods and equipment that minimize soil disturbance.

Plan and design skid trails, yard areas, and truck access roads to minimize stream crossings and avoid disturbing the forest floor.

Construct stream crossings so that they minimize erosion and physical changes to streams.

Expedite revegetation of cleared areas.

Commercial
Stormwater Pollution Solutions
Construction
Agriculture
Automotive
Facilities
Forestry
Riverside County has two drainage systems - sanitary sewers and storm drains. The storm drain system is designed to help prevent flooding by carrying excess rainwater away from streets. Since the storm drain system does not provide for water treatment, it also serves the function of transporting pollutants directly to our waterways.

Rain and water runoff from automotive shops and
businesses can carry pollutant material into storm
drains. Examples of pollutants include oil and grease
from cars, copper and asbestos from worn brake
linings, zinc from tires, and toxics from spilled fluids.

Since preventing pollution is much easier, and less costly, than cleaning up “after the fact,” the Cities and County of Riverside StormWater/CleanWater Protection Program informs residents and businesses on pollution prevention activities such as the Best Management Practices (BMPs) described in this pamphlet.

The Cities and County of Riverside have adopted ordinances for stormwater management and discharge control. In accordance with state and federal law, these local stormwater ordinances the discharge of wastes into the storm drain system or local surface waters. This includes discharges containing oil, antifreeze, gasoline and other waste materials.

A common stormwater pollution problem associated with
automotive shops and businesses is the hosing down of service bays, parking and other areas. Often, this activity flushes pollutants into the storm drain system. The discharges of pollutants is by local ordinances and state and federal regulations.
unintended
prohibit
strictly prohibited
Unlike sanitary sewers, storm drains
are not connected to a treatment
plant - they flow directly to our
local streams, rivers and lakes.

Stormwater pollution causes as much as 60% of our
water pollution problem. It jeopardizes the quality of
our waterways and poses a threat to groundwater
resources if pollutants percolate through soil.

PLEASE NOTE:

The Cities and County of Riverside
StormWater/CleanWater Protection Program
The Cities and County of Riverside
StormWater/CleanWater Protection Program
What you should know for...

StormWaterPollution StormWaterPollution
Best Management
Practices (BMPS)
for:

StormWater Pollution...What You Should KnowStormWater Pollution...What You Should Know Auto Body Shops
Auto Repair Shops
Car Dealerships
Gas Stations
Fleet Service Operations

AUTOMOTIVE

MAINTENANCE
& CAR CARE
For information on “closed-loop” suppliers
and recycling/disposal vendors, contact:

County of Riverside
Health Services Agency
Department of Environmental Health
at (909) 358-5055.

To order additional brochures or to obtain information
on other pollution prevention activities,
call: (909) 955-1111.

Riverside County gratefully acknowledges the Santa Clara Valley Nonpoint Source Pollution Control Program and the City of Los Angeles Stormwater Management Division for
information provided in this brochure.

SPILLRESPONSEAGENCY:

RECYCLING ANDHAZARDOUSWASTE
DISPOSAL:

TOREPORTILLEGALDUMPING OR A
CLOGGEDSTORMDRAIN:

HAZ-MAT:(909) 358-5055
AFTER5:00P.M.: (909) 358-5245OR911
(909) 358-5055
1-800-506-2555
The Cities and County of Riverside
StormWater/CleanWater Protection Program
1-800-506-2555
StormWater
CleanWater

PROTECTIONPROGRAM
For Information:For Information:

Keep your shop in tune. Follow these Practices to help prevent stormwater pollution . . .Keep your shop in tune. Follow these Practices to help prevent stormwater pollution . . .

1. Changing Automotive Fluids

2. Working on Transmissions, Engines,
and Miscellaneous Repairs

3. Preventing Leaks and Spills

4. Cleaning up Spills
/c108
/c108
/c108
/c108
/c108
/c108
/c108
/c108
/c108
/c108
Designate an area away from storm or
sanitary drains to change automotive fluids.
as a hazardous waste.
flushing fluid that
can be recycled,
and add it to the
waste antifreeze.

Place large pans or an inflatable portable
berm under wrecked cars.

Drain all fluids from wrecked vehicles or
“parts” cars you keep on site.

Collect, separate, and recycle motor oil,
antifreeze, transmission fluid, and gear oil.

Drain brake fluid and other non-recyclables
into a proper container and handle
Use a radiator
Keep a drip pan or a wide low-rimmed
container under vehicles to catch fluids
whenever you unclip hoses, unscrew filters, or
change parts, to contain unexpected leaks.

Avoid spills by emptying and wiping drip pans
when you move them to another vehicle or
when they are half-full.

Routinely check equipment to wipe up spills
and repair leaks.

Clean up small spills
immediately using shop
rags.
/c108
/c108
/c108
/c108
/c108
/c108
/c108
/c108
/c108

5. Identify and Control Wastewater
Discharges

6. Fueling Vehicles

7. Removing and Storing Batteries
/c108
Store batteries indoors, on an open rack.

Return used batteries to a battery vendor.

Contain cracked batteries to prevent
hazardous spills.

Keep dry absorbent materials and/or a
wet/dry vacuum cleaner on hand for mid-sized
spills.

Contain large spills immediately; block or shut
off floor and parking lot drains and notify the
authorities.

Train employees to be familiar with hazardous
spill response plans and emergency
procedures.

Ensure that shop sinks and floor drains are
connected to the sanitary sewer. Check with
the local sewer authority regarding permitting
or other requirements.

Post signs to prevent disposal of liquid wastes
into sanitary drains.

Clean-up minor spills, with a
dry absorbent, rather than
allowing them to evaporate.

Dispose of the absorbent as
a dry hazardous waste.

Use a damp cloth and a
damp mop to keep the area
clean rather than a hose or a
wet mop.

8. Cleaning Parts

9. Metal Grinding and Finishing

10. Storing and Disposing of Waste

11. Selecting and Controlling Inventory
/c108
/c108
/c108
/c108
/c108
/c108
/c108
/c108
/c108
Clean parts in a self-
contained unit, solvent sink,
or parts washer to prevent
solvents and grease from
entering a sewer or storm
drain connection.

Store recyclable and non-recyclable waste
separately.

Place liquid waste (hazardous or otherwise)
within a bermed or secondary containment
area.

Cover outdoor storage areas to prevent
contact with rain water.

Purchase recyclable or non-toxic materials.

Select “closed-loop” suppliers and purchase
supplies in bulk.

Catch metal filings in an enclosed unit or on a
tarpaulin.

Sweep filing area to prevent washing metals
into floor drains.

Collect used parts for delivery to a scrap metal
dealer.

12. Outdoor Parking and Auto
Maintenance

13. Washing Vehicles, Cleaning Engines,
and Other Steam Cleaning

14. Cleaning Work Areas
/c108
/c108
/c108
/c108
/c108
/c108
/c108
/c108
/c108
/c108
Please remember:

Treat outdoor areas as an extension of your
service bays or avoid using altogether.

Sweep-up trash and dirt from outdoor parking
and maintenance areas. Do not hose down
areas. All non-storm water discharges are
prohibited.

Drain work areas to a sanitary drain rather
than a storm drain. Contact the local sewer
authority to determine if pretreatment is
required.

For occasional car exterior cleaning, minimize
the water used and divert runoff to landscaped
areas, keeping it out of the storm drain.

Wash vehicles with biodegradable,
phosphate-free detergent.

Sweep or vacuum the shop floor frequently.

Do not pour mop water into the parking lot,
street, gutter or storm drain.

Use non-toxic cleaning products whenever
possible.

Make sure no wastewater from engine or parts
cleaning or steam cleaning is discharged
where it may flow to a street, gutter, or storm
drain.

Damp mop work areas - do hose down
work areas into the street or gutter.
not

ONLY RAININ THE DRAIN

NO DUMPING

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IN RIVERSIDE COUNTY....Call 1-800-506-2555

TO REPORT ILLEGAL STORMDRAIN DISPOSAL
E-mail: [email protected]
Visit our website: www.floodcontrol.co.riverside.ca.us
Brought to you by the Storm Water/Clean Water Pollution Protection Program.....

REMEMBER, ONLY RAIN IN THE STORMDRAIN!
Maintain your BMPs!
Construction Phasing
www.epa.gov/npdes/menuofbmps
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Riverside County has two drainage systems - sanitary sewers and storm drains. The storm drain system is designed to help prevent flooding by carrying excess rainwater away from streets. Since the storm drain system does not provide for water treatment, it also serves the function of transporting pollutants directly to our waterways.

Waste or washwater generated by the food service
industry often contains materials such as food
wastes, oil, grease, detergents, and degreasers.

These materials can degrade local waters when
allowed to flow into a storm drain system.

The Cities and County of Riverside have adopted ordinances for stormwater management and discharge control. In accordance with state and federal law, these local stormwater ordinances the discharge of wastes into the storm drain system or local surface waters. This includes discharges from the food service industry containing food wastes, oil, grease, detergents, and degreasers.

A common stormwater pollution problem associated with the food service industry is the discharge of washwater into alleys and gutters, and the hosing down of outdoor areas. Often, these activities flush pollutants into the storm drain system. The discharges of pollutants isby local ordinances and state and federal regulations.
unintended
prohibit
strictly prohibited
Unlike sanitary sewers, storm drains
are not connected to a treatment
plant - they flow directly to our
local streams, rivers and lakes.

PLEASE NOTE:

What you should know for...

The Cities and County of Riverside
StormWater/CleanWater Protection Program
The Cities and County of Riverside
StormWater/CleanWater Protection Program
StormWaterPollution StormWaterPollution
Best Management
Practices (BMPS)
for:

StormWater Pollution...What You Should KnowStormWater Pollution...What You Should Know For information on “closed-loop” suppliers
and recycling/disposal vendors, contact:

County of Riverside
Health Services Agency
Department of Environmental Health
at (909) 358-5055.

To order additional brochures or to obtain information
on other pollution prevention activities,
call: (909) 955-1111.

Riverside County gratefully acknowledges the Santa Clara Valley Nonpoint Source Pollution Control Program, Alameda Countywide Clean Water Program and the San Bernardino
County Stormwater Program for information provided in this brochure.

SPILLRESPONSEAGENCY:

HAZARDOUSWASTEDISPOSAL:

RECYCLINGINFORMATION:

HAZ-MAT:(909) 358-5055
AFTER5:00 P.M.: (909) 358-5245OR911
(909) 358-5055
1-800-366-SAVE

TOREPORTILLEGALDUMPING OR ACLOGGED
STORMDRAIN:1-800-506-2555
The Cities and County of Riverside
StormWater/CleanWater Protection Program
1-800-506-2555
Restaurants
Grocery Stores
Delicatessens
Bakeries
THE

FOOD SERVICE

INDUSTRY
For Information:For Information:

What you should know for...

StormWater
CleanWater

PROTECTIONPROGRAM

A Menu of Activities...t oKeep Our Water Clean
Outdoor/Sidewalk
Areas...

You may be
Also,
Please remember:

Sweep up food particles, cigarette butts, and
trash from outdoor dining areas before
rinsing or steam cleaning.

Don’t use toxic bleaches
or detergents when
you pressure wash
outdoor dining
areas, entrances
or surrounding
sidewalk areas.
already implementing of
the BMPs prescribed in this brochure.

However, if you discover any potential
problem areas, please consider using one or
more of the recommended BMPS.
please note that the Riverside County
Environmental Health Department will
monitor potential sources of stormwater
pollution activities during regularly scheduled
inspections of food service facilities. If Health
Department staff observe activities which
may be contributing to stormwater pollution,
suggestions will be provided and/or use of
prescribed BMPS listed in this brochure will
be offered.
many
How ‘Bout That
Dumpster...

Use Water-Friendly
Products...

Keep dumpster and loading dock areas clean.

Control litter by sweeping - don’t hose down
the area. Replace
leaky dumpsters
and keep lids
closed to keep out
rainwater.

Whenever possible, purchase water-based
cleaning products. Look for products
labeled “non-toxic,”
“non-petroleum based,”
“ammonia-free,”
“phosphate-free,”
and “perfume-free,”
or “readily
biodegradable.”
Proper Storage and
Disposal...

Grease and Oil...

General cleaners, floor cleaners, solvents,
and detergents often
contain toxic substances.

Read labels carefully and
store and dispose of these
products properly.

REMEMBER: Don’t throw
toxic waste into the trash
or into a storm drain. To
report toxic spill call 911.

For information on
hazardous waste pick-up
call (909) 358-5055.

Handle and dispose of grease properly. Save
used cooking grease and oil for recycling in
tallow bins or sealed containers. Never pour
grease into a sink, floor drain, dumpster or
storm drain.

Watch out for,
and report to
management,
overflowing
grease
interceptors.

Call (909) 358-5172
for disposal
information.

A Menu of Activities...t oKeep Our Water Clean
Cleanin’ It Right...

Watch Out For Spills...

Pour mop and wash water into the mop sink
or down floor drains...n o tinto gutters,
alleys,
parking lots or
a storm drain.

Wash greasy
equipment only
in designated
wash areas
which are
properly
connected to
the sewer system with an appropriate
oil/water separator. Also, avoid washing
kitchen mats, garbage containers, and other
items in areas where wastewater is likely to
flow into a storm drain.

Use dry methods for spill cleanup. Don’t hose
down outside spills.

Use rags or
absorbents such as
cat litter and then
dispose of in the
garbage, or handle
as hazardous waste
as appropriate. If
necessary, mop the
area with a minimum
amount of water.

Everyone contributes a little to the problem of stormwater pollution. Now it’s time for all of us to become part of the solution!

ONLY RAININ THE DRAIN

NO DUMPING

Riverside County has two drainage systems - sewers and storm drains. The storm drain system was designed to reduce flooding by carrying excess rainwater away from streets and developed areas. Since the storm drain system does not provide for water treatment, it also serves the function of
transporting pollutants directly to our local waterways.

Stormwater runoff is a part of the natural hydrologic process.

However, land development and construction activities can significantly alter natural drainage processes and introduce pollutants into stormwater runoff. Polluted stormwater runoff from construction sites has been identified as a major source of water pollution in California. It jeopardizes the quality of our local waterways and can pose a serious threat to the health of our aquatic ecosystems.

Because preventing pollution is much easier and
less costly than cleaning up “after the fact,” the
Cities and County of Riverside
StormWater/CleanWater Protection Program informs
residents and businesses on pollution prevention activities. This pamphlet describes various Best Management Practices (BMPs) that construction site operators can use to prevent stormwater pollution.

In accordance with applicable federal and state law, the Cities and County of Riverside have adopted ordinances for stormwater management and discharge control that the discharge of pollutants into the storm drain system or local surface water. This includes discharges from construction sites containing sediment, concrete, mortar, paint, solvents, lubricants, vehicle fluids, fuel, pesticides, and construction debris.

The Federal, State and local regulations strictly prohibit the discharge of sediment and pollutants into the streets, the storm drain system or waterways. As an owner, operator or supervisor of a construction site, you may be held financially responsible for any environmental damage caused by your subcontractors or employees. unintended
Unlike sanitary sewers, storm drains are not connected to a wastewater treatment plant – they flow directly to our local streams, rivers and lakes.
prohibit
PLEASE NOTE:

StormWater Pollution...What You Should KnowStormWater Pollution...What You Should Know

STORMWATER POLLUTION
FROM

CONSTRUCTION ACTIVITIES
The two most common sources of
stormwater pollution problems
associated with construction activities are
and . Failure to
maintain adequate erosion and sediment
controls at construction sites often results
in sediment discharges into the storm
drain system, creating multiple problems
once it enters local waterways.

Construction vehicles and heavy
equipment can also track significant
amounts of mud and sediment onto
adjacent streets. Additionally, wind may
transport construction materials and
wastes into streets storm drains, or
directly into our local waterways.
erosion sedimentation
The Cities and County of Riverside
StormWater/CleanWater Protection Program
The Cities and County of Riverside
StormWater/CleanWater Protection Program
What you should know for...

StormWaterPollution StormWaterPollution
Developers
General Contractors
Home Builders
Construction Inspectors
Anyone in the construction
business

GENERAL

CONSTRUCTION &

SITE SUPERVISION
Best Management
Practices (BMPs)
for:

State Water Resources Control Board
Division of Water Quality
1001 I Street
Sacramento CA 95814
(916) 341-5455
Santa Ana Regional Water
Quality Control Board - Region 8
3737 Main Street, Suite 500
Riverside, CA 92501-3348
(909) 782-4130
San Diego Regional Water
Quality Control Board - Region 9
9771 Clairemont Mesa Blvd., Suite A
San Diego, CA 92124
(858) 467-2952
Colorado River Basin Regional Water
Quality Control Board - Region 7
73-720 Fred Waring Drive, Suite 100
Palm Desert, CA 92260
(760) 346-7491
www.swrcb.ca.gov/stormwtr/
www.swrcb.ca.gov/~rwqcb8/
www.swrcb.ca.gov/~rwqcb9/
www.swrcb.ca.gov/~rwqcb7/
Resources
To report a hazardous materials spill,
call:

For recycling and hazardous waste
disposal, call:

To report an illegal dumping or a
clogged storm drain, call:

To order additional brochures or to obtain
information on other pollution prevention
activities, please call (909) 955-1200 or visit the
StormWater/CleanWater Protection Program
website at:

The StormWater/CleanWater Protection Program
gratefully acknowledges the Santa Clara Valley
Nonpoint Pollution Control Program, Alameda
Countywide CleanWater Program and the City of
LosAngeles Stormwater Management Division for
information provided in this brochure.

Riverside County Hazardous Materials
Emergency Response Team
8:00 a.m. – 5:00 p.m.
after 5:00 p.m.

In an emergency call:
(909) 358-5055
(909) 358-5245
911
(909) 358-5055
1-800-506-2555
www.co.riverside.ca.us/depts/flood/waterquality
npdes.asp
StormWater
CleanWater

PROTECTIONPROGRAM

GENERAL CONSTRUCTION ACTIVITIES STORMWATER PERMIT
(Construction Activities General Permit)
The State Water Resources Control Board
(SWRCB) adopted a new Construction
Activities General Permit (WQ Order No. 99-
08DWQ) on August 19, 1999, superseding
the now expired SWRCB statewide General
Permit (WQ Order No. 92-08DWQ). This
permit is administered and enforced by the
SWRCB and the local Regional Water Quality
Control Boards (RWQCB). The updated
Construction Activities General Permit
establishes a number of new stormwater
management requirements for construction
site operator.

Yes, if construction activity results in the
disturbance of five or more acres of total land
area or is part of a common plan of
development that results in the disturbance of
five or more acres.

Obtain the permit package and submit the
completed Notice of Intent (NOI) form to the
Some construction activies
stormwater permits are issued on a regional
basis. Consult your local RWQCB to find out if
your project requires coverage under any of
these permits.

NOTE:

Frequently Asked Questions:

Does my construction site
require coverage under the
Construction Activities General
Permit?
How do I obtain coverage
under the Construction
Activities General Permit?
SWRCB prior to grading or disturbing soil at
the construction site. For ongoing
construction activity involving a change of
ownership, the new owner must submit a new
NOI within 30 days of the date of change of
ownership. The completed NOI along with the
required fee should be mailed to the SWRCB.

Implement BMPs for non-stormwater
discharges year-round.

Prepare and implement a Stormwater
Pollution Prevention Plan (SWPPP) prior
to commencing construction activities.

Keep a copy of the SWPPP at the
construction site for the entire duration of
the project.

Calculate the anticipated stormwater run-
off.

Implement an effective combination of
erosion and sediment control on all soil
disturbed areas.

Conduct site inspections prior to
anticipated storm events, every 24-hours
during extended storm events, and after
actual storm event.

Perform repair and maintenance of BMPs
as soon as possible after storm events
depending upon worker safety.

What must I do to comply with
the requirements of the
Construction Activities General
Permit?
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NOTE:
www.swrcb.ca.gov/stormwtr/
How long is this Construction
Activities General Permit in
effect?
Update the SWPPP as needed, to
manage pollutants or reflect changes in
site conditions.

Include description of post construction
BMPs at the construction site, including
parties responsible for long-term
maintenance.

The Permit coverage stays in effect untilyou
submit a Notice of Termination (NOT) to the
SWRCB. For the purpose of submitting a
NOT, all soil disturbing activities have to be
completed and one of the three following
criteria has to be met:

1. Change of ownership;

2. A uniform vegetative cover with 70
percent coverage has been established;
or,

3. Equivalent stabilization measures such
as the use of reinforced channel liners,
soil cement, fiber matrices, geotextiles,
etc., have been employed.

Please refer to the Construction
Activities General Permit for detailed
information. You may contact the SWRCB,
your local RWQCB, or visit the SWRCB
website at to
obtain a State Construction Activities
Stormwater General Permit packet.

BEST MANAGEMENT PRACTICES
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Protect all storm drain inlets and streams
located near the construction site to
prevent sediment-laden water from
entering the storm drain system.

Limit access to and from the site. Stabilize
construction entrances/exits to minimize
the track out of dirt and mud onto adjacent
streets. Conduct frequent street
sweeping.

Protect stockpiles and construction
materials from winds and rain by storing
them under a roof, secured impermeable
tarp or plastic sheeting.

Avoid storing or stockpiling materials near
storm drain inlets, gullies or streams.

Phase grading operations to limit disturbed
areas and duration of exposure.

Perform major maintenance and repairs
of vehicles and equipment offsite.

Wash out concrete mixers only in
designated washout areas at the
construction site.

Set-up and operate small concrete mixers
on tarps or heavy plastic drop cloths.

Keep construction sites clean by
removing trash, debris, wastes, etc. on a
regular basis.

The following Best Management Practices (BMPs) can significantly reduce pollutant discharges from your construction site. Compliance with stormwater regulations can be as simple as minimizing stormwater contact with potential pollutants by providing covers and secondary containment for construction materials, designating areas away from storm drain systems for storing equipment and materials and implementing good housekeeping practices at the construction site. /c113
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Clean-up spills immediately using dry
clean-up methods (e.g., absorbent
materials such as cat litter, sand or rags
for liquid spills; sweeping for dry spills
such as cement, mortar or fertilizer) and
by removing the contaminated soil from
spills on dirt areas. .

Prevent erosion by implementing any or a
combination of soil stabilization practices
such as mulching, surface roughening,
permanent or temporary seeding.

Maintain all vehicles and equipment in
good working condition. Inspect frequently
for leaks, and repair promptly.

Practice proper waste disposal. Many
construction materials and wastes,
including solvents, water-based paint,
vehicle fluids, broken asphalt and
concrete, wood, and cleared vegetation
can be recycled. Materials that cannot be
recycled must be taken to an appropriate
landfill or disposed of as hazardous
waste.

Cover open dumpsters with secured tarps
or plastic sheeting. Never clean out a
dumpster by washing it down on the
construction site.

Arrange for an adequate debris disposal
schedule to insure that dumpsters do not
overflow.

What Should You Do?
Advance Planning to
Prevent Pollution
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Note: Consult local
drainage policies for more
information.

Remove existing vegetation only as
needed.

Schedule excavation, grading, and
paving operations for dry weather
periods, if possible.

Designate a specific area of the
construction site, well away from
storm drain inlets or watercourses,
for material storage and equipment
maintenance.

Develop and implement an effective
combination of erosion and
sediment controls for the
construction site.

Practice source reduction by
ordering only the amount of
materials that are needed to finish
the project.

Educate your employees and
subcontractors about stormwater
management requirements and
their pollution prevention
responsibilities.

Control the amount of surface runoff
at the construction site by impeding
internally generated flows and using
berms or drainage ditches to direct
incoming offsite flows to go around
the site.

Your community preserves habitat for important native plants and animals. By habitat, we mean homes; food, water, and places with space to live. The habitat is managed as part of a biological conservation easement, a legal agreement that permanently limits its use.

Many conservation easements include a waterway or wetland because plants and animals need clean, fresh water, the most limited resource in our dry Southern California climate. A waterway (also called watercourse, arroyo, wash) conveys a flowing creek, stream, or river, which provides drinking water for local and migrating wildlife.

Not all of our waterways have visible flowing water year-round. Some creeks and streams continue to flow underground, while others flow for a short time after a storm (ephemeral). The small, and often dry washes are important to wildlife because they provide habitat and their periodic flows drain into larger waterways. It's essential that people do not degrade the quality of any water that reaches local waterways.

Water supports an abundance of vegetation and a variety of life, or biodiversity.

Streamside vegetation, along dry or flowing waterways, is referred to as riparian.

Native riparian plants provide native animals with suitable food, shelter, nesting sites and escape-cover from predators.

The purpose of this publication is to
help homeowners become habitat-
friendly neighbors for nearby habitat
lands. The Resources Directory,
inserted inside this booklet, provides
helpful websites and contact
information for agencies,
organizations, gardens, and native
plant nurseries.

Unfortunately, our modern-day
lifestyles have negative impacts on
the environment around us. Human
activity in, or near waterways can damage the capacity of the habitat to support some kinds of plant and animal life, especially species that do not adapt to urban/suburban conditions. Here are some ways to prevent and reduce negative impacts and help restore habitat to healthy conditions.

Gerald & Buff Crosi, California Academy of Sciences
Help Your Wild Next-Door Neighbors
Living on the EdgeLiving on the Edge
Reduce Impacts on Native Wildlife
Prevent light, noise, and
activity in, and adjacent to
wetlands.

CalTIP,
! If you wish to observe wildlife,
please watch from afar,
especially during the breeding
and nesting season, from
March to September. Most
wild animals are naturally
fearful of human contact.

Human activity near a nest or
den may frighten adult
animals away from young and
jeopardize their survival.
! When visiting natural areas,
disturb as little as possible. Avoid walking or riding in a stream course or on channel banks. Heavy foot traffic, horses, and off-road vehicles may cause channel banks to collapse, accelerating erosion and increasing water-born sediment and turbidity. ! Help control entry into habitat areas. Close unessential roadways to prevent access for illegal dumping, trespass, and off-road vehicle use.
! Leave nothing behind.
! Focus necessary lighting downward and inward toward your home, yard, and buildings. ! To report poaching or polluting call Californians Turn In Poachers and Polluters, a confidential secret witness program. The toll free telephone number operates 24 hours a day, 7 days a week. (See the Resources Directory insert for contact information.) Do not allow pets to roam in habitat land
where they will disturb and hunt native
wildlife. Keep pets on a leash and
droppings out of waterways. Cats and dogs
stress or kill wildlife and prevent natural
ecosystems from supporting their own
predators, such as hawks, coyotes, foxes,
and bobcats. Conversely, domesticated
animals face hazards in wild areas. Pets
may be attacked by predators, such as
coyotes and rattlesnakes, or may contract
disease, fleas, and ticks.

Do not release unwanted animals into
the wild. Abandoned cats, dogs, birds,
reptiles and fish can have significant
impacts on populations of native species,
either through disease, predation or
competition for food and space.

USDA Natural Resources Conservation Service
Diana Ruiz

Respect and protect wild animals by keeping them wild. In some instances, being a good neighbor means protecting your living area by excluding certain kinds of wildlife, mainly mammals. The human habitat includes home sites, buildings, yards, gardens, and regularly used outdoor areas. Install fencing around the human habitat portion of your property and secure enclosures to protect children, pets, and farm animals.

! Do not take small animals, such as tortoises, tadpoles, frogs, snakes, birds, lizards or eggs from the wild. Never attempt to “adopt” or domesticate a wild animal. ! Discourage dangerous predators from penetrating human habitat areas. Install fencing that will exclude predators. Place sensors that trigger sprinklers and lights to deter predators and mammals from entering areas of human activity. ! Prevent mammals from living in and near
your home by closing entries, filling holes,
and removing brush, junk, and woodpiles
near buildings.
! Don’t feed human food to wildlife. Do not
leave pet food outside. Prevent garbage from
becoming a food source for wild mammals by
sealing trash can lids. If you compost, use
closed-containers or turn piles regularly.

Compost plant material only; meat scraps
should not be mixed in a compost pile.

Brown-headed Cowbird
Lee Karney/ U.S. Fish and Wildlife Service
R. H. Barrett/ U. S. Fish and Wildlife Service
The endangered Least Bell’s Vireo is
threatened by the Brown-headed Cowbird.

Mark A. Chappell
! Exotic invaders crowd out native species both on land and in water. Do not place fish, frogs, crayfish, turtles, or aquatic plants into
creeks, streams or
lakes. Some non-
native species are not
only able to survive,
but also reproduce
explosively due to a
lack of natural
predators. For
example, the brown-headed cowbird is overwhelming
riparian habitats. The cowbird lays its eggs in another bird’s nest to the detriment of the host’s young.
! Pets are usually unable to survive in wildlands. They starve to death or are eaten. If you cannot find a
home for a pet, contact animal control, your local
animal shelter, or the Humane Society.

For more information, contact the California Department of Fish and Game. (See the Resources Directory insert for contact information.) Diana Ruiz
Reduce Impacts on Native Plants
Remove invasive, non-native plants from
home landscaping and adjacent habitat lands,
especially those that quickly spread through
waterways, displacing important native species.

DO NOT PLANT
Giant reed
Salt Cedar
Tree of Heaven
Red apple, heartleaf iceplant
Fountain grass (yellow)
Castor bean
Periwinkle
Peruvian (Calif.) pepper tree
Brazilian pepper tree
Mexican fan palm
Sweet fennel
Pampas grass/Jubata grass
Common iceplant
Myoporum species
Arundo donax
Tamarix chinensis
Ailanthus altissima
Aptenia cordifolia
Pennisetum setaceum
Ricinus communis
Vinca major
Schinus molle
Schinus terebinthifolius
Washingtonia robusta
Foeniculum vulgare
Cortaderia jubata/selloana
Mesembryanthemum crystallinum
Contact your local Resource Conservation District for help identifying invasive species and for removal of exotic weeds from waterways. Visit the California Invasive Plant Council web site for suggested plants to replace invasives. (See the Resources Directory insert for contact information.)
Protect Water Quality
Make sure that the water that flows off your
property is clean.
! Prevent trash, debris, and waste of any kind
from washing off homesites and streets into
gutters, storm drains, and dry washes. These
drainage-ways empty into streams that flow
to the Santa Ana River, and ultimately, the
ocean.
! Evaluate the flow of runoff over your property.

Place manure, barnyard bedding, and debris
in areas where water does not pool or flow,
or reuse the waste as fertilizer or mulch.

Check with your local municipality for
ordinances concerning the disposal of
manure and bedding.
! Use care when applying fertilizers, pesticides, and herbicides on your property. Read labels “before you buy and before you apply” for directions, application rates, and disposal. Apply the correct amount at the proper time, for example, not during plant dormancy.

Diana Ruiz
Invasive rrundo donax) is
being removed from Temescal Creek.

Giant Reed (A
Dispose of waste in its proper place.
! Read product labels, and dispose of
household hazardous wastes (oil based
paints, pesticides, antifreeze, motor oil,
batteries, flourescent bulbs, etc.) in
prescribed ways and at designated
disposal sites or community collection
events, not on the ground or in a storm
drain inlet. Whenever possible, reduce
the use of hazardous materials in and
around your home. Call the Only Rain
Down the Storm Drain program for
disposal dates and locations. (See the
Resources Directory insert for contact
numbers.) You can also recycle
automotive fluids, tires, and batteries at
car repair businesses.
! Dispose of trash at sanitary landfills.
! Compost yard and other organic wastes.

LacewingLadybird beetlePraying mantis

Better yet:

Reduce,
Reuse,
Recycle.
! Reduce or eliminate the use of pesticides by using “beneficial insects” (ladybugs, praying mantids, lacewings, etc.) If you must use a pesticide, use one with a least- toxic rating, such as insecticidal soaps, horticultural oils, pyrethrin-based insecticides, and insect growth regulators.
! Control erosion to prevent sediment from entering runoff. ! If you have a septic system, inspect and maintain it. Poorly placed and neglected septic systems contaminate groundwater and streams.

Pollutants that flow from residential and urban areas contaminate surface water and the water that percolates into underground water basins (aquifers). Much of our local water supply is pumped from underground aquifers, so keeping runoff clean is essential.

To report any non-emergency crime, such as dumping, please call your City Police or County Sheriff Departments. To report illegal grading or dumping in waterways, contact your City or County Code Enforcement Department. (See the Resources Directory insert for contact numbers.)
Photos by Greg Balmer
Diana Ruiz

Siting Homes Near Waterways
If you are building next to a waterway, leave a buffer
between the waterway and your human habitat area of
graded pads, structures, and ornamental landscaping.

Wildlife habitat land includes areas beyond buildings,
yards, and defensible space (fire safety zones),
generally to be left undisturbed for wildlife. A buffer between the human habitat and a waterway provides
space for habitat, flood waters, and for wildlife escape during high water.

The buffer or “setback” distance will vary according to site conditions, however a minimum 100-foot setback from the top edge of a waterway, not from the water itself, is recom- mended. This allows space for creek/stream meander and high water flows. The banks of creeks and streams “meander”, which means they are constantly “wandering” or relocating.

Meander naturally occurs when flows cause erosion of channel banks and deposition of sediment.

As land is converted to urban uses,
the volume of flow in waterways
increases. Impervious surfaces
from streets, roofs, and parking
lots increase the amount of runoff,
erosion and pollutants that
degrade water quality.

Provide Space for Habitat, Fire, and Flood Protection
Many people are not aware of the vulnerability of natural ecosystems, nor are they aware that it is illegal to grade or alter a waterway without an assessment and permits from resource agencies and municipalities. If you propose an activity that will impact a stream, river, or lake, the California Department of Fish and Game (DFG) requires completion of a Streambed Alteration Agreement.

Depending on the activity you are proposing, you may need to obtain a permit, agreement, or other authorization from one or more government agencies. Notify DFG, U.S. Army Corps of Engineers, and the Santa Ana Regional Water Quality Control Board during early planning, prior to beginning a project that will:
use material from a streambed;
divert, obstruct, or change the natural flow or the bed, channel, or bank of any river, stream, or lake; result in the disposal or deposition of debris, waste, or other natural material where it can pass into any river, stream, or lake.

A Streambed Alteration Agreement is also required for streams that flow intermittently, such as dry washes and waterways with subsurface flow.
!
!
!

A house pad fills an important tributary to an waterway.

Robert Caliva
Frank Heyming
When building homes In fire-prone areas, avoid ridge tops and canyons. Set buildings back from the edge of steep slopes. Create a minimum distance of 100-feet of defensible space, a managed area around a home, where the amount of fuel (dead plants, dry leaves, wood) has been reduced. Consult with your local fire department or the California Department of Forestry and Fire Protection for fire safety and weed abatement information. (Please see Resources Directory insert).

Habitat-friendly Yards
Landscape with Locals. Not just any California native
plant is suitable for landscapes near habitat lands. Local native plants are the safest because they have unique
characteristics that have helped them survive in their
specific environments. Gardening with local flora helps maintain the genetic integrity of local plants and
ecosystems. It helps maintain regional variation in
vegetation and wildlife.

Why is regional variation important? If plants from other areas crossbreed with local natives, scientists fear that local populations would lose some of the unique
characteristics that are important for success in this
region. Their genetic material would no longer be unique and regionally identifiable. Plant interbreeding could reduce biological diversity, biodiversity, in the gene pool. There are important interactions between native plants, microorganisms, and the animals that use them, some of which are critical to the reproduction and survival of native plants and animals.

Create habitat in your yard for urban-adapted wildlife. Even if you live in the heart of a city, consider gardening for urban-adapted wildlife by providing a reliable water source and local native plants that provide food, shelter, and nesting sites. Each small patch of yard provides a stepping-stone of habitat from wildlands across the city. A patchwork of habitat- yards creates an urban ecosystem that more closely mimics our predevelopment, native landscape. When linked together, those patches cumulatively support biodiversity. To host a variety of native birds and butterflies in your yard, select plants that flower and fruit at different times of the year. Prune trees and shrubs in fall and early winter, rather than spring, to avoid destroying bird nests.

It is essential that landowners do not confine, or encroach on waterways. Keep buildings, septic systems, horses, livestock, fencing, agricultural and ornamental plantings out of waterways and away from channel banks.

Len Nunney

Water-wise Landscapes Conserve Water
Reduce water-use by replacing unnecessary lawn areas
with native or drought-tolerant plants and with hardscape (hard surfaces), such as walkways and patios of concrete, brick, stone, decomposed granite, and permeable paving.

For places where you do need a lawn, such as play areas, plant a low water-use turf variety.

When selecting a plant, find out:
! Is it water-thirsty or drought-tolerant?
! When is its growing season; when will it need water?
Most* local native plants are dormant or slow-growing
during the hot, dry summers; their growth occurs
during our rainy season. Once established, many
survive with rainfall alone. This is the opposite for non- native, ornamental landscapes that grow slowly, or not at all during winter, but require irrigation throughout the summer.

! Group plants with similar watering needs together, and install water-saving irrigation systems (drip, micro-sprayers) to apply the correct amount for each hydro-zone or plant grouping. Trees require deep irrigation and may need separate irrigation lines. ! Readjust your irrigation schedule for season and weather conditions. Turn off automatic systems when it’s raining. Don’t run sprinklers when the wind is blowing. Water deeply and only when needed. Water plants in the early morning or evening. Adjust irrigation systems to water soil, not concrete and pavement.
! Apply mulch (bark, compost, sawdust, gravel) to reduce evaporation from the soil surface and to control weeds.

For information about conserving water in landscapes and using native and drought tolerant plants, refer to plant databases, such as the one at be wise.com. The website will also help you create a customized watering schedule for your yard. (See the Resources Directory insert for booklist and websites.)
*Not all native plants are dormant during summer: local riparian plants are the exception. They need water year round, as they are suited for waterways. Streamside vegetation, along dry or flowing waterways, is referred to as riparian.
water
Benefits of landscaping with local native plants:
! Most native plants are drought tolerant, so they require less water. ! Natives rarely require fertilizers.
! Patches of habitat support urban-adapted wildlife, such as birds, bats and insects that help pollinate plants.
! Natives rarely require pesticides. Native plants provide their own natural pest control by attracting beneficial insects that prey on troublesome bugs. ! Local natives help preserve genetic diversity and the integrity of local ecosystems.

Diana Ruiz

Fire-wise Landscaping

Zone 1:
0-30 ft. out from buildings. (
Zone 2:

Lean, Clean and Green
Zone 1 is from See diagram on prior page.)
Grow plants that are small or succulent, such as irrigated lawns or ground covers and low growing, high-moisture shrubs. If you use native plants, use those that can be trimmed back during the dry season or that stay small with little trimming. Native plants that tolerate summer watering (see native plant lists) should be kept well hydrated.* ! Keep plants well hydrated to help them resist fire. Well-trimmed and watered plants are less likely to ignite than desiccated plants that have a buildup of dry stems and leaves. ! Fire needs fuel to burn, so remove any unnecessary plant materials. Prune dead wood and clean the landscape of dead plants, dry leaves, dry brush, firewood, and combustibles.
! Strategically place hard surfaces in your landscape, such as concrete, brick, or stone patios, driveways, pools, walls, and non-flammable decks, to interrupt the spread of fire to buildings.

Create the reduced fuel zone beginning 30 ft. from buildings and extending 100 ft. or more, depending on steepness of slope and type/density of vegetation. ! Selectively remove large shrubby plants and dense groupings. Thin overcrowded plants. Mow grasses and weedy vegetation while they are green. ! Carefully remove excess plants without disturbing the soil; mow instead of disc, to prevent erosion and invasion of non-native plants.
! In chaparral plant communities, after thinning, reduce old, woody growth by cutting plants to their bases every few years, during the summer dormancy. Young plant tissues have higher moisture content and are less flammable. The heavy pruning eliminates mature, highly flammable vegetation but maintains root systems to protect the soil from erosion.
! Low branches and plants growing under trees create “ladders” for fire to climb.

Eliminate ladder fuels, plants that serve as a link between grass and treetops. Prune the lower branches from the lower 1/3 of trees and shrubs. For trees or shrubs taller than 18 feet, prune the lower branches 6 feet above the ground. Remove dead leaves, twigs, and branches.
! In general, remove shrubs that are growing below trees, unless there is a space between the top of the shrub to the lowest branch of the tree that is three times the height of the shrub.

Reduced Fuel
Remove plants that ignite easily and burn hot, such as those with volatile oils (sages) and those that accumulate fine woody branches or many small, dry leaves (chamise). In Zone 1, remove highly volatile plants (partial list below). In Zone 2, remove or widely space volatile plant types, including:

Chamise, Adenostoma fasciculata
Brittlebrush, Encelia farinosa
California buckwheat, Eriogonum fasciculatum
White sage, Salvia apiana
Some Eucalyptus and Acacia
Black sage, Salvia mellifera
Woolly blue curls, Trichostema lanatum
Mountain blue curls, Trichostema parishii
Red Shank, Adenostoma sparsifolium
All Pine, Cypress, Juniper, and Cedar species.
*For best results with native plants, water on overcast days during summer and fall.

Create a minimum distance of 100 ft. of defensible space, a landscape that deprives fire of fuel. Use fire-resistant plants and remove plants that are highly volatile.

Mild to moderate slope
(20% to 40% slope)
Four times (4x) the height of the shrub
(Two shrubs 2’ high should be
spaced 8’ apart)
Moderate to steep slope
(greater than 40% slope)
Six times (6x) the height of the shrub
(Two shrubs 2’ high should be
spaced 12’ apart)
Shrubs
Create Space Between Plants
From edge of one shrub to the edge of the next.

Flat to mild slope
(0% to 20% slope)
Mild to moderate slope
(20% to 40% slope)
Moderate to steep slope
(greater than 40% slope)
Trees
From edge of one tree canopy to the edge of the next.

Prevent erosion and stabilize eroding
areas. If you have exposed soil surfaces,
cover with mulch, and landscape as soon as
possible. (Plants break the impact of falling
rain, and their roots hold soil in place.) Eroding
soil becomes sediment in runoff water, which
pollutes waterways. Disturbed soil also
encourages the growth of non-native weed
species.

Retain thinned, deep-rooted native plants to
anchor the soil and maintain slope stability.

Generally, tall plants have deep, broad root
systems. A goal of fire-wise landscaping is to
maximize rooting depth while minimizing fuel
volume.

For site-specific advice, contact your local Resource Conservation District (RCD) or the USDA Natural Resources Conservation Service (NRCS). For recommendations of native grasses for erosion control, contact the California Native Grasslands Society. (See the Resources Directory insert for contact information.)
Flat to mild slope
(0% to 20% slope)
Two times (2x) the height of the shrub
(Two shrubs 2’ high should be
spaced 4’ apart)
Horizontal clearance information from the California Department of Forestry and Fire Protection.

Diana Ruiz

Shrubs that do not usually tolerate water during summer.

Low shrubs
Tall, deep-rooted shrubs that stay green during summer.

Bladder pod, Isomeris arborea
Bush monkeyflower, Mimulus aurantiacus
Chaparral honeysuckle, Lonicera subspicata
Hollyleaf redberry, Rhamnus illicifolia
Redberry, Rhamnus crocea
Yellow bush-penstemon, Keckiella antirrhinoides
Bigberry manzanita, Arctostaphylos glauca
Thick-leaved lilac, Ceanothus crassifolius
Buck brush, Ceanothus cuneatus
Hairy California lilac, Ceanothus oliganthus
Mountain mahogany, Cercocarpus betuloides
Laurel sumac, Malosma laurina
Scrub oak, Quercus berberidifolia
Sugarbush, Rhus ovata
Lemonade berry, Rhus integrifolia
California Flannel bush, Fremontodendron californicum
Coffeeberry
UDSA-NRCS PLANTS Database
Native Plants for Defensible Space Landscaping in the Inland Empire If you prefer to create a landscape of native, low water-use plants, use these lists to design a yard that is fire-wise. Maintenance is essential; dead and dry plant material must be removed during dry, summer dormancy. Some native plants cannot tolerate irrigation during their summer dormancy, so may die if watered too frequently. Some need only infrequent, deep watering to remain hydrated during the dry summer and fall. The low-growing, low-fuel volume plants are suitable for Zone 1 (0-30 ft.) and beyond.

Larger shrubs and trees, for Zone 2 (30-100+ ft.), must be widely spaced (see diagram on previous page).

Shrubs for Zone 2
Shrubs that need or tolerate water during summer.

Carpenteria, Carpenteria californica
Western redbud, Cercis occidentalis
Toyon, Heteromeles arbutifolia
Nevin’s barberry, Mahonia nevinii
Coffeeberry, Rhamnus californica
Golden current, Ribes aureum.

California wild rose, Rosa californica
Western bridalwreath, Spiraea douglasii
Squawbush, Rhus trilobata
Trees for Zone 2
Trees that tolerate occasional water during summer.

Trees that need water during summer.

Catalina cherry, Prunus illicifolia ssp. Lyonii
Coast live oak, Quercus agrifolia
Valley oak, Quercus lobata
Engelman oak, Quercus engelmannii
Big leaf maple, Acer macrophyllum
White alder, Alnus rombifolia
So. California walnut, Juglans californica
California sycamore, Platanus racemosa
California black oak, Quercus kelloggii
Canyon live oak, Quercus chrysolepis
Willows: Salix laevigata, S. gooddingii
California bay laurel, Umbellularia californica
Sugarbush
Big leaf maple
J. S. Peterson @ UDSA-NRCS
Yellow bush-penstemon
Arlee M.Montalvo Paul Aigner
If you live near conservation easement land or a waterway, there are ways that you can help. Be observant of activities that might be harmful to your nearby habitat lands, or form a habitat-watch group in your neighborhood. Like a neighborhood-watch, property owners help look out for neighborhood habitat and waterways, report illegal activity, and help educate neighbors about human impacts. For help forming a habitat-watch group, contact your local Resource Conservation District or the Riverside Land Conservancy.

Habitat Land Stewards
This publication was developed by the Riverside-Corona
Resource Conservation District. www.RCRCD.com
1-07
All programs and services are provided without regard for race, religion, gender, national origin, and handicap.

Printed on recycled paper
Succulents, Ground Covers, and Low Shrubs
Keep hydrated; if needed, water monthly during summer.

San Diego sedge, Carex spissa
Wild lilac, Ceanothus griseus ‘horizontalis’
California fuchsia, Epilobium canum =Zauschneria
Golden yarrow, Eriophyllum confertiflorum
Lance-leaved live-forever, Dudleya lanceolata
Chalk dudleya, Dudleya pulverulenta
Parry’s nolina, Nolina parryi
Creeping sage, Salvia sonomensis
Creeping snowberry, Symphoricarpos mollis
Chaparral yucca, Yucca whipplei = Hesperoyucca whipplei Valley cholla, Opuntia parryi
Coastal prickly pear, Opuntia littoralis
Annuals or summer-dormant perennials
No need for water during summer. There is little, if any, plant material above ground to burn.

California poppy, Eschscholzia californica
Larkspurs, delphinium, Delphinium parryi, D.cardinale
Wild Canterbury-bell, Phacelia minor
California figwort, Scrophularia californica
Baby blue eyes, Nemophila menziesii
Royal penstemon, Penstemon spectabilis
Lupine, Lupinus species (L. bicolor, L. succulentus,
L. truncatus, L. sparsiflorus)
Perennial herbs that tolerate or need water during summer Yarrow, Achillea millifolium
Columbine, Aquilegia formosa
Douglas iris, Iris douglasiana
Deer grass, Muhlenbergia rigens
Calif. blue-eyed grass, Sisyrinchium bellum
Meadow rue, Thalictrum fendleri var. polycarpum
Yerba mansa, Anemopsis californica
Coral bells, Heuchera ssp.

Common monkey flower, Mimulus guttatus
Scarlet bugler, Penstemon centranthifolius
California goldenrod, Solidago californica
Hedge nettle, Stachys bullata
Slender sedge, Carex praegracilis
Narrow-leaved milkweed, Asclepias fascicularis
Narrow-leaved milkweed
Chaparral yucca
Baby blue eyes
Low-growing, (low fuel volume) Plants for Zones 1 and 2 Arlee M.MontalvoArlee M.MontalvoArlee M.Montalvo
Business/Organization: _______________________________________________

Name: _____________________________________________________________

Address: ___________________________________________________________

City: ___________________________________ Zip: _____________

Phone: _____________________ Fax: _____________________

Email: ______________________________________________________________

# of Total Volunteers: ______ # of Volunteers Under 18: ______ For project information contact Tijana: 951.683.7100 x212, or [email protected] MUST RSVP! SIGN UP NOW TO VOLUNTEER:M UST RSVP! SIGN UP NOW TO VOLUNTEER:MUST RSVP! SIGN UP NOW TO VOLUNTEER:MUST RSVP! SIGN UP NOW TO VOLUNTEER:

Keep Riverside Clean & Beautiful ● 3985 University Ave. ● Riverside, CA 92501 ● fax 951.683.2670 WARD 2 BEAUTIFICATION PROJECT

Volunteer for Litter Cleanups and Graffiti Abatement
B.Y.O.W.B. - Bring Your Own Water Bottle

… KRCB will provide refills, & all project tools

No sandals or flip-flops; must wear long pants

Receive community service hours

LINCOLN PARKLI NCOLN PARKLINCOLN PARKLINCOLN PARK
4261 Park Ave. Riverside, CA 92507
For Connections, Information & Access to Business Opportunities C
ontact the Greater Riverside Chambers of Commerce at: 951.683.7100

Keep Riverside Clean & Beautiful is a community program sponsored by the City of Riverside Public Works Department

and the Greater Riverside Chambers of Commerce

Our Mission… To instill a sense of community pride by creating partnerships that work toward the beautification of the City SATURDAYS ATURDAY SATURDAYSATURDAY •••• FEB 6F EB 6 FEB 6FEB 6 •••• 20102 010 20102010 From 8:00 a.m. to 11:00 a.m.

The primary purpose of storm drains is to carry rain water away from developed areas to prevent flooding. Pollutants discharged to storm drains are transported directly into rivers, lakes and streams. Soaps, degreasers, automotive fluids, litter and a host of materials are washed off buildings, sidewalks, plazas and parking areas. Vehicles and equipment must be properly managed to prevent the pollution of local waterways.

Unintentional spills by mobile service operators
can flow into storm drains and pollute our
waterways. Avoid mishaps. Always have a Spill Response Kit on hand to clean up unintentional spills. Only emergency Mechanical repairs should be done in City streets and use drip pans for spills. Plumbing should be done on private property. Always store chemicals in a leak-proof container and keep covered when not in use. Window/Power Washing waste water shouldn’t be released into the streets, but should be disposed of in a sanitary sewer, landscaped area or in the soil. Soiled Carpet Cleaning wash water should be filtered before being discharged into the sanitary sewer. Dispose of all filter debris properly. Car Washing/Detailing operators should wash cars on private property and use a regulated hose nozzle for water flow control and runoff prevention. Capture and dispose of waste water and chemicals properly. Always prevent runoff water from entering storm drains.

StormWater PollutionStormWater Pollution
Car Washing / Mobile Detailers
Window and Carpet Cleaners
Power Washers
Waterproofers / Street Sweepers
Equipment cleaners or degreasers and
all mobile service providers
Storm drain pollution prevention
information for:

What you should know for...What you should know for...

WATER AGENCY LIST
in Riverside County
City of Banning (951) 922-3130
City of Beaumont (951) 769-8520
City of Blythe (760) 922-6161
City of Coachella (760) 398-3502
Coachella Valley Water District (760) 398-2651
City of Corona (951) 736-2259
Desert Center, CSA #51 (760) 227-3203
Eastern Municipal Water District (951) 928-3777
Elsinore Valley MWD (951) 674-3146
Farm Mutual Water Company (951) 244-4198
City of Hemet (951) 765-3712
Idyllwild Water District (951) 659-2143
Jurupa Community Services District (951) 360-8795
Lake Hemet MWD (951) 658-3241
Lee Lake Water District (951) 277-1414
March Air Force Base (951) 656-7000
Mission Springs Water District (760) 329-6448
City of Palm Springs (760) 323-8253
Rancho Caballero (951) 780-9272
Rancho California Water District (951) 296-6900
Ripley, CSA #62 (760) 922-4951
City of Riverside (951) 351-6170
Rubidoux Services District (951) 684-7580
Silent Valley Club, Inc (951) 849-4501
Valley Sanitary District (760) 347-2356
Western Municipal Water District (951) 789-5000
Yucaipa Valley Water District (909) 797-5117

REPORT ILLEGAL STORM DRAIN DISPOSAL
or online at
Online resources include:

Riverside County Flood Control and Water
Conservation District
California Storm Water Quality Association
State Water Resources Control Board
Power Washers of North America
1-800-506-2555
www.rcflood.org
•
www.rcflood.org
•
www.casqa.org
•
www.swrcb.ca.gov/
•
www.thepwna.org
Helpful telephone numbers and links: Do you know where street flows actually go?Do you know where street flows actually go?

OUTDOOR CLEANING

ACTIVITIES AND

PROFESSIONAL MOBILE

SERVICE PROVIDERS

ONLY RAIN IN THE DRAIN
Storm Drains are NOT connected to sanitary sewer systems and treatment plants!

REPORT ILLEGAL

STORM DRAIN

DISPOSAL
1-800-506-2555
H e l p P r o t e c t O u r W a t e r w a y s !H e l p P r o t e c t O u r W a t e r w a y s ! Use These Guidelines For Outdoor Cleaning Activities and Wash Water Disposal Did you know that disposing of pollutants
into the street, gutter, storm drain or
nearest body of water is PROHIBITED by
law and can bring about stiff penalties.

Waste wash water from Mechanics,
Plumbers, Window/Power Washers, Carpet
Cleaners, Car Washing and Mobile Detailing
activities may contain significant quantities
of motor oil, grease, chemicals, dirt,
detergents, brake pad dust, litter and other
materials.

Best Management Practices, or BMPs as
they are known, are guides to prevent
pollutants from entering the storm drains.

Each of us can do our part to keep storm
water clean by using the suggested BMPs
below:
consider dry cleaning methods first
such as a mop, broom, rag or wire brush.

Always keep a spill response kit on site.
prepare the work area before power
cleaning by using sand bags, rubber mats,
vacuum booms, containment pads or
temporary berms to keep wash water away
from the gutters and storm drains.

use vacuums or other machines to
remove and collect loose debris or litter
before applying water.

Best Management Practices
Simple solutions for both light
and heavy duty jobs:

Do...

Do not let...

Report illegal storm drain disposal,
Call Toll Free
1-800-506-2555
obtain the property owner's
permission to dispose small amounts of
power washing waste water to
landscaped, gravel or unpaved surfaces.
check with your local sanitary sewer
agency's policies on wash water disposal
regulations. (See list on reverse side).
be aware that if discharging to
landscape areas, soapy wash water may
damage landscaping. Residual wash water
may remain on paved surfaces to
evaporate. Sweep up solid residuals and
dispose of properly. Vacuum booms are
another option for capturing and collecting
wash water.
wash or waste water from
sidewalk, plaza or building cleaning go into
a street or storm drain.

Using Cleaning Agents
Think Water Conservation
Try using biodegradable/phosphate-free
products. They are easier on the
environment, but don't confuse them for
being toxic free. Soapy water entering the
storm drain system can impact the delicate
aquatic environment.

When cleaning surfaces with a high-pressure
washer or steam cleaner , additional
precautions should be taken to prevent the
discharge of pollutants into the storm drain
system. These two methods of surface
cleaning can loosen additional material that
can contaminate local waterways.

Minimize water use by using high pressure,
low volume nozzles. Be sure to check all
hoses for leaks.

Screening Wash Water
Drain Inlet Protection & Collection
of Wash Water
•
•
•
•
Equipment and Supplies
•
•
•
•
•
A thorough dry cleanup before washing
exterior surfaces, such as buildings and
decks without loose paint, sidewalks, or plaza
areas should be sufficient to protect receiving
waters. Keep debris from entering the storm
drain after cleaning by first passing the wash
water first through a “20 mesh” or finer
screen to catch the solid materials, then
disposing the mesh in a refuse container.

Prior to any washing, block all storm
drains with an impervious barrier such as
sandbags or berms, or seal the storm
drain with plugs or rubber mats.

Create a containment area with berms
and traps or take advantage of a low spot
to keep wash water contained.

Wash vehicles and equipment on grassy
or gravel areas so that the wash water
can seep into the ground.

Pump or vacuum up all wash water in the
contained area.

For special materials, equipment and
supplies:

New Pig — (800) 468-4647
Lab Safety Supply — (800) 356-0783
C&H — (800) 558-90966
W.W. Grainger — (800) 994-9174
Cleaning Equipment Trade Association
— (800) 441-0111
RY AL IN NO .. .. ..DO NIW AN R DT H ME R S OT
Riverside County has two drainage systems - sanitary sewers and storm drains.

The storm drain system is designed to help prevent flooding by carrying excess rainwater away from streets. Since the storm drain system does not provide for water treatment, it also serves the
function of transporting
pollutants directly to our waterways.

In recent years, awareness of the need
to protect water quality has increased.

As a result, federal, state, and local
programs have been established to
reduce polluted stormwater discharges to
our waterways. The emphasis of these
programs is to prevent stormwater
pollution since it’s much easier, and less
costly, than cleaning up “after the fact.”
unintended
Unlike sanitary sewers, storm
drains are not connected to a
treatment plant - they flow directly
to our local streams, rivers and
lakes.

DIDYOUKNOW...

National Pollutant Discharge Elimination System (NPDES) StormWater Pollution . . . What you should know
Many industrial facilities
and manufacturing operations
must obtain coverage under the
Industrial Activities Storm Water
General Permit

FIND OUT

IF YOUR FACILITY

MUST OBTAIN A PERMIT
StormWater Pollution . . . What you should know
National Pollutant Discharge Elimination System (NPDES) In 1987, the Federal Clean Water Act was amended to establish a framework for regulating industrial stormwater discharges under the NPDES permit program. In California, NPDES permits are issued by the State Water Resources Control Board (SWRCB) and the nine (9) Regional Water Quality Control Boards (RWQCB). In general, certain industrial facilities and manufacturing operations must obtain coverage under the Industrial Activities Storm Water General Permit if the type of facilities or operations falls into one of the several categories described in this brochure.

For more information on the General Industrial
Storm Water Permit contact:

State Water Resources Control Board (SWRCB)
(916) 657-1146 or www.swrcb.ca.gov/ or, at your
Regional Water Quality Control Board (RWQCB).

Santa Ana Region (8)
California Tower
3737 Main Street, Ste. 500
Riverside, CA 92501-3339
(909) 782-4130
San Diego Region (9)
9771 Clairemont Mesa Blvd., Ste. A
San Diego, CA 92124
(619) 467-2952
Colorado River Basin Region (7)
73-720 Fred Waring Dr., Ste. 100
Palm Desert, CA 92260
(760) 346-7491
StormWater
CleanWater

PROTECTIONPROGRAM
SPILLRESPONSEAGENCY:

HAZARDOUSWASTEDISPOSAL:

RECYCLINGINFORMATION:

TOREPORTILLEGALDUMPING OR ACLOGGED
STORMDRAIN:

HAZ-MAT:(909) 358-5055
(909) 358-5055
1-800-366-SAVE
1-800-506-2555
To order additional brochures or to obtain information
on other pollution prevention activities, call:
(909) 955-1111.

Riverside County gratefully acknowledges the State
Water Quality Control Board and the American Public
Works Association, Storm Water Quality Task Force for
the information provided in this brochure.

DIDYOUKNOW...

YOURFACILITYMAY

NEEDASTORMWATER
PERMIT?
For Information:

A BMP is . . .

How Do I Know If I Need A Permit?What are the requirements of the Industrial Activities Storm Water General Permit?
Following areof the
industry categories types that are regulated by the
Industrial Activities Storm Water General Permit.

Contact your local Region Water Quality Control
Board to determine if your facility/operation
requires coverage under the Permit.

Facilities such as cement manufacturing;
feedlots; fertilizer manufacturing; petroleum
refining; phosphate manufacturing; steam electric
power generation; coal mining; mineral mining
and processing; ore mining and dressing; and
asphalt emulsion;
general descriptions
Facilities classified as lumber and wood
products (except wood kitchen cabinets); pulp,
paper, and paperboard mills; chemical producers
(except some pharmaceutical and biological
products); petroleum and coal products; leather
production and products; stone, clay and glass
products; primary metal industries; fabricated
structural metal; ship and boat building and
repairing;
Active or inactive mining operations and
oil and gas exploration, production, processing, or
treatment operations;
Hazardous waste treatment, storage, or
disposal facilities;
/c220
/c220
/c220
/c220
/c220
/c220
/c220
/c220
/c220
/c220
Landfills, land application sites and open
dumps that receive or have received any industrial
waste; unless there is a new overlying land use
such as a golf course, park, etc., and there is no
discharge associated with the landfill;
Facilities involved in the recycling of
materials, including metal scrap yards, battery
reclaimers, salvage yards, and automobile
junkyards;
Steam electric power generating facilities,
facilities that generate steam for electric power by
combustion;
Transportation facilities that have vehicle
maintenance shops, fueling facilities, equipment
cleaning operations, or airport deicing operations.

This includes school bus maintenance facilities
operated by a school district;
Sewage treatment facilities;
Facilities that have areas where material
handling equipment or activities, raw materials,
intermediate products, final products, waste
materials, by-products, or industrial machinery
are exposed to storm water.

How do I obtain coverage under the
Industrial Activities Storm Water General Permit?
Obtain a permit application package from your local Regional Water Quality Control Board listed on the back of this brochure or the State Water Resources Control Board (SWRCB). Submit a completed Notice of Intent (NOI) form, site map and the appropriate fee ($250 or $500) to the SWRCB. Facilities must submit an NOI thirty (30) days prior to beginning operation. Once you submit the NOI, the State Board will send you a letter acknowledging receipt of your NOI and will assign your facility a waste discharge identification number (WDID No.). You will also receive an annual fee billing. These billings should roughly coincide with the date the State Board processed your original NOI submittal.

WARNING: There are significant penalties for non-compliance: a minimum fine of $5,000 for failing to obtain permit coverage, and, up to $10,000 per day, per violation plus $10 per gallon of discharge in excess of 1,000 gallons. any
discharge to a storm drain system that is not
composed entirely of storm water. The following
non-storm water discharges are authorized by the
General Permit: fire hydrant flushing; potable
water sources, including potable water related to
the operation, maintenance, or testing of potable
water systems; drinking fountain water;
atmospheric condensates including refrigeration,
air conditioning, and compressor condensate;
irrigation drainage; landscape watering; springs;
non-contaminated ground water; foundation or
footing drainage; and sea water infiltration where
the sea waters are discharged back into the sea
water source.

A Non-Storm Water Discharge is...

The basic requirements of the Permit are:

The facility must eliminate any non-stormwater discharges or obtain a separate permit for such discharges.

The facility must develop and implement a Storm Water Pollution Prevention Plan (SWPPP). The SWPPP must identify sources of pollutants that may be exposed to stormwater. Once the sources of pollutants have been identified, the facility operator must develop and implement Best Management Practices (BMPs) to minimize or prevent polluted runoff.

The facility must develop and implement a Monitoring Program that includes conducting visual observations and collecting samples of the facility’s storm water discharges associated with industrial activity. The General Permit requires that the analysis be conducted by a laboratory that is certified by the State of California.

The facility must submit to the Regional Board, every July 1, an annual report that includes the results of its monitoring program.

1. 2.

3. 4.

Guidance in preparing a SWPPP is available from a document prepared by the California Storm Water Quality Task Force called the California Storm Water Best Management Practice Handbook. a technique, process, activity,
or structure used to reduce the pollutant content of
a storm water discharge. BMPs may include
simple, non-structural methods such as good
housekeeping, staff training and preventive
maintenance. Additionally, BMPs may include
structural modifications such as the installation of
berms, canopies or treatment control (e.g. setting
basins, oil/water separators, etc.)

Stormwater Pollution
F ound in Y our Area!
This is not a citation.

This is to inform you that our staff found
the following pollutants in the storm
sewer system in your area. This storm
sewer system leads directly to
Motor oil
Oil filters
Antifreeze/
transmission fluid
Paint
Solvent/degreaser
Cooking grease
Detergent
Home improvement waste (concrete,
mortar)
Pet waste
Y ard waste (leaves, grass, mulch)
Excessive dirt and
gravel
Trash
Construction debris
Pesticides and
fertilizers
Other
F or more information or to report
an illegal discharge of
pollutants, please call:

Riverside County Residents, Call . . .
1-800-506-2555 WHEN IT RAINS

IT DRAINS
www.epa.gov/npdes/stormwater
EPA 833-F-03-002
April 2003
.
q
q
q
q
q
q
q
q
q
q
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q
q
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Stormwater runoff is precipitation from rain or
snowmelt that flows over the ground. As it flows,
it can pick up debris,chemicals,dirt,and other
pollutants and deposit them into a storm sewer
system or waterbody .

Anything that enters a storm sewer system is
discharged into the waterbodies we
use for swimming,fishing,and providing
drinking water .

T o keep the stormwater leaving your home or
workplace clean,follow these simple guidelines:

Use
pesticides
and fertilizers
sparingly .

Repair auto
leaks.

Dispose of
household
hazardous waste,used auto fluids
(antifreeze,oil,etc.),and batteries at
designated collection or recycling locations.

Clean up after your pet.

Use a commercial car wash or wash your
car on a lawn or other unpaved surface.

Sweep up yard debris rather than hosing
down areas.Compost or recycle yard waste
when possible.

Clean paint brushes in a sink,not outdoors.

Properly dispose of excess paints through a
household hazardous waste collection
program.

Sweep up and
properly
dispose of
construction
debris like
concrete and
mortar .
untreated
Remember:

Only Rain Down the Drain

for Home and Property Owners
in Riverside C Riverside County ounty

Homeowners living adjacent to streams, lakes and rive rs may be impacted by bank erosion or sediment deposition that can occur due to natu ral processes or man-made causes. Homeowner efforts to mitigate impacts to their property from erosion or sedimentation can negatively affect native plants and animals, lessen a watercourse’s ability to convey storm flows, cause erosion or sedimentation problems on other properties and/ or cause flooding. Below is some guidance regarding actions a homeowner should take before attempting to protect their property:

• In some cases, any alteration of a waterc ourse may be prohibited by local land-use regulations, e.g., a “drainage easement”, “flowage easement”, “floodplain” or “Environmental Constraint Sheet”. You should contact your local City or County building or grading department to determine if these limitations apply to watercourses in or adjacent to your property.
• In some cases, any alteration of a waterc ourse may be prohibited by local land-use regulations, e.g., a “drainage easement”, “flowage easement”, “floodplain” or “Environmental Constraint Sheet”. You should contact your local City or County building or grading department to determine if these limitations apply to watercourses in or adjacent to your property.

• In cases where alterations are not expressly prohibited, grading, filling or otherwise altering a watercourse - even those that flow intermittently, such as dry washes that only flow when it rains – may require approval fro m one or more of the following regulating agencies:
• In cases where alterations are not expressly prohibited, grading, filling or otherwise altering a watercourse - even those that flow intermittently, such as dry washes that only flow when it rains – may require approval fro m one or more of the following regulating agencies:

*Fees may be applicable. *Fees may be applicable.

• Property owners should CONTACT EACH REGULATING AGENCY (listed above) for the necessary approval(s) BEFORE
• Property owners should CONTACT EACH REGULATING AGENCY (listed above) for the necessary approval(s) BEFORE
:

1. Removing soil, rock or plant material from a streambed or the bank of a stream;

REGULATING AGENCY POTENTIAL

REGULATORY
PERMIT

WHERE TO

CONTACT

Local (City, County) land use
authority *
• Grading Permit
• Floodplain Review
White pages under
City/County Government
California Department of
Fish and Game*
• Fish and Game
Section 1602
Agreements
www.dfg.ca.gov
US Army Corps of
Engineers*
• Clean Water Act
Section 404 Permit
www.usace.army.mil
California State Water
Resources Control Board*
• Clean Water Act
Section 401 Water
Quality Certification
or Waste Discharge
Requirements
www.swrcb.ca.gov
(over)
More on Stream Stabilization

2. Placing any waste, material (dirt, rubble) or structures (dams, revetments) on a stream bank or within a stream;

3. Diverting, obstructing, or otherwise modifying the bed, channel, or bank of any river, stream or lake;

4. Dumping or depositing debris, liquid or solid waste, soil, manure or other material that may be conveyed into a wash, stream, river or lake; or

5. Armoring or stabilizing a stream bank against stream bank erosion.

Some other examples of regulated stream a lteration activities include vegetation removal or construction of road crossings or corra ls. Property owners are responsible for obtaining all necessary approvals prior to commencing any of the aforementioned activities.

• The Natural Resources Conservation Service (NRCS) makes onsite recommendations (currently free of charge) to private land owners for effective erosion control. For help in protecting your property from stream erosion please contact:

NATURAL RESOURCES

CONSERVATION SERVICE (NRCS)
CONTACT PHONE NO.

Riverside County (West of the San Jacinto
Mtns.)
Robert Hewitt (951) 654-7139
Beaumont and Banning Area Jim Earsom (909) 799-7407
Desert Area Sam Aslam (760) 347-7658
Blythe Sam Cobb (760) 922-3446

• YOU can help protect water quality:

Prevent trash, debris, manure and waste of any kind from washing off home sites and streets into gutters, storm drains and dry watercourses. During storms, these watercourses can convey pollution into more sensitive streams and rivers.

County-wide Service Information

• Household hazardous wastes (oil-based paints, pesticides, antifreeze, motor oil, batteries and fluorescent bulbs) must never be disposed of in or near watercourses. You may find your nearest household hazardous waste
disposal site by calling (800) 304-2226 or on the web at www.rivcowm.org

• Report illegal grading or dumping in watercourses by
contacting your City or County Code Enforcement
Department, or call (800) 506-2555.

• Report a non-emergency crime such as dumping by
contacting your City Police or County Sherriff’s Department, or call (800) 506-2555.

What you should know...What you should know...

StormWater PollutionStormWater Pollution
lean and healthy creeks,
Criver, lakes and streams are
important to Riverside County.

However, equestrian enthusiasts
and common outdoor equestrian
activities can lead to water
pollution, if owners are not
careful.

Horse waste and equestrian care
products can be washed into
streets and storm drains, when
residents are not careful. Unlike
sanitary sewers (from sinks and
toilets), storm drains flow directly
(untreated) to our creeks, rivers,
lakes and streams.

You would never put animal
waste or products into our
creeks, river, lakes or streams, so
don’t let them enter the storm
drains. Follow these easy tips to
help prevent water pollution while
grooming or feeding horses, or
constructing a stable.

Resources
Contact your city’s storm water
representative for any applicable
local ordinances.

Report a spill, an illegal storm drain
disposal or clogged storm drains.

Obtain pollution prevention information
for Riverside County Residents,
Businesses, Developers, Industries and
Municipalities.

Schedule pollution prevention education
for adults, groups, or school
presentations.

Locate Household Hazardous Waste
Collection Centers.

Riverside County gratefully acknowledges the Orange
County Storm Water Program for the information
provided in this brochure.

For more information,
please call the Riverside County’s
“Only Rain Down the Storm Drain”
1-800-506-2555
or visit the website at
www.rcflood.org
•
•
•
•

FOR SPILL EMERGENCIES,
PLEASE CALL 911

TIPS FOR

HORSE CARE

TIPS FOR

HORSE CARE
RY AL IN NO .. .. ..DO NIW AN R DT H ME R S OT
Environmental responsibility
begins with YOU.

Environmental responsibility
begins with YOU.

Never allow horse waste or care products to
enter the street or storm drain.

Use less-toxic alternatives for grooming.

Even biodegradable products can be
harmful to humans, marine life and the
environment. Follow instructions on the
products and clean up spills.

When washing horses, either allow wash
water to seep into the ground or wash in
an area that is routed to the sanitary
sewer. Do not let wash water enter the
storm drain or any bodies of water.

Conserve water by using a spray nozzle
with an automatic shut-off. Turn off the
water or kink the hose when not in use.

Horse holding areas
should be swept or
shoveled at least
once per day. Never
hose down these
areas! The waste
could end up in a
stream or storm drain.

Grooming
Pasture Management
Paddocks should be cleaned at least
twice per week during the rainy season
and once per week the rest of the year.

Establish healthy and
vigorous pastures with at
least three inches of leafy
material.

During rainfall, consider
indoor feeding, a practice
that keeps manure under
a roof and away from
runoff.

Store animal waste in a sturdy, seepage-
free unit that is enclosed or under cover.

Line waste pits or trenches with an
impermeable layer.

Do not store manure on-site for more than
one week.

Grazing
Collection and Storage
Use and Disposal
Facility Design
Compost soiled bedding and manure.

See http://compostingcouncil.org for
more information.

Donate composted material to local
greenhouses, nurseries and botanical
parks.

Transport manure to topsoil companies or
composting centers.

If you are constructing or re-building a stable,
have your engineer check the County’s
website at www.ocwatersheds.com for
information about facility design.

Remember, good land management protects
horse health and water quality. A horse
property that is managed well can also
prevent disputes with neighbors, attract
wildlife and make horse care more enjoyable.

RY AL IN NO .. .. ..DO NIW AN R DT H ME R S OT

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Appendix G. Geotechnical Plan Review/Addendum

GEOTECHNICAL REVIEW OF
ROUGH GRADING PLANS, TRACT 31194,

MENIFEE, COUNTY OF RIVERSIDE, CALIFORNIA
Prepared For:

WOODSIDE HOMES OF CALIFORNIA
23121 Antonio Parkway, Suite 120
Rancho Santa Margarita, California 92688
January 30,2004
Project No. 110712-002

A LEIGHTON GROUP COMPANY
Leighton and Associates, Inc.

A LEIGHTON GROUP COMPANY
January 30,2004
To: Woodside Homes of California
23 12 1 Antonio Parkway, Suite 120
Rancho Santa Margarita, California 92688
Project No. 110712-002
Attention: Mr. Peter Evans
Subject: Geotechnical Review of Rough Grading Plans, Tract 31194, Menifee, County of Riverside, California.

In accordance with your request and authorization, Leighton and Associates, Inc. (Leighton) has completed a geotechnical review of rough grading plans for Tract 3 1 194. The subject site is located southeast of Evans Road and Garbani Road in Menifee, California (see Figure 1).

Significant geotechnical issues identified include compressible alluvium, hard rock rippability, rockfall hazards, slope stability and seismicity. This report surnrnarizes our findings, conclusions and preliminary recommendations regarding the geotechnical conditions within the subject site.

If you have any questions regarding this report, please do not hesitate to contact this office. We appreciate this opportunity to be of service.

Respectfully submitted,
LEIGHTON AND ASSOCI&l?
Scot Mathis, CEG 2307
Project Geologist
Distribution: (6) Addressee
('2 Adam Terronez, COL\3PU RCE 62
Project Engineer
41715 Enterprise Circle N., Suite 103 rn Temecula, CA 92590-5661 909.296.0530 rn Fax 909.296.0534 ww.leightongeo.com
110712-002
January 30. 2004

TABLE OF CONTENTS
Section Page
11 Purpose and Scope .................................................................................................. 1

1.2 Site Location and Description .................................................................................... 2 ............................................................................................. 1.3 Proposed Development 2

1.4 Project Plans ......................................................................................................... 2

2.0 INVESnGAnON AND LABORATORY TESTING ................................................................. 3

2.1 Test Pits .................................................................................................................. 3

2.2 Soil Borings ............................................................................................................. 3 ................................................................................................... 2.3 Laboratory Testing 3 ....................................................................... 3.0 SUMMARY OF GEOTECHNICAL FINDINGS 4 ....................................................................................... 3.1 Regional Geologic Setting 4

3.2 Site Geologic Units ................................................................................................... 4

3.2.1 Artificial Fill (not a mapped unit) ......................................................................... 4 ................................................................... 3.2.2 Alluvial Deposits (Map Symbol . Qal) 4 . ............................. 3.2.3 Cretaceous-Aged Undifferentiated Granitics (Map Symbol Kgr) 5

3.3 Surface Water and Groundwater ............................................................................... 5

3.4 Landslides and Rockfalls ........................................................................................... 6 . . 3.5 Rippab~l~ty ............................................................................................................... 6

3.6 Faulting .................................................................................................................. 6

3.7 Seismicity ................................................................................................................ 7

3.8 Secondary Seismic Effects ........................................................................................ 8

3.8.1 Lurching and Shallow Ground Rupture ................................................................ 8 ................................................................. 3.8.2 Liquefaction and Dynamic Settlement 8 ........................................................................................................... 3.8.3 Flooding 9 ........................................................................................................... 4.0 CONCLUSIONS 10

5.0 RECOMMENDATIONS .................................................................................................. 12

5.1 General .............................................................................................................. 12

5.2 Site Preparation and Remedial Removals .................................................................. 12

5.3 Cu(/Fill Transition Lots ............................................................................................ 13

5.4 Cut Lots and Streets ...................... ... ................................................................. 13 ........................................................................................................ 5.5 Structural Fills 13 ..................................................................................................... 5.6 Oversized Rock 14

5.7 Shrinkage ..................................................................................................... ............................................................................................. 5.8 Import Soils -i-
Leighton
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TABLE OF CONTENTS (Continued)
........... 5.9 Utility Trenches ... .................................................................................. 15 ........................................................... 5.10 Preliminary Foundation Design Parameters 15 ................................................................................... 5.11 Settlement Considerations 16 ................................................................................................... 5.12 Footing Setback 16 . . ...................................................................................................... 5.13 Slope Stab~l~ty 17

5.14 Retaining Walls .................................................................................................... 17 ..................................................................................... 5.15 Site Drainage and Erosion 17

5.16 Geochemical Characteristics .............................................................................. 18 ............................................................. 5.17 Preliminary Pavement Design Parameters.. 18 ............................................................... ..................... 6.0 GEOTECHNICAL REVIEW ...... 20 .......................................................................................... 6.1 Plans and Specifications 20 ............................................................................................ 6.2 Construction Review.. 20 ........................................................................................................ 7.0 LIMITATIONS 21 Accom~anvina Fiaures, Tables, Plates and A~~endices
Fiaures
Figure 1 - Site Location Map
Figure 2 - Regional Geologic Map
End of Text
End of Text
Tables
Table 1 - Minimum Foundation Design Recommendations for Very Low Expansive Soils
Table 2 - Minimum Foundation Design Recommendations for Low to Medium Expansive Soils
Table 3 - Minimum Post-Tensioned Foundation Design Recommendations For Low to Medium Expansive Soils
Plates
Plate 1 - Geotechnical Map
Ap~endices
Appendix A - References
Appendix B - Geotechnical Boring and Test Pit Logs
Appendix C - Laboratory Testing Procedures and Test Results Appendix D - Seismic Traverse Report
Appendix E - Slope Stability Analysis
Appendix F - General Earthwork and Grading Specifications End of Text
End of Text
End of Text
In Pocket
110712-002
January 30,2004
The purpose of our geotechnical investigation was to summarize the pertinent, readily available geologic and geotechnical data, obtain additional site specific data, and evaluate this data with respect to the proposed development of the subject site, as depicted on the Tract 3 1 194 rough grading plans (Hunsaker and Associates, 2003, Appendix A).

Our scope of services for the current and previous phases of this investigation included the following items:

Review of available geologic and geotechnical information.

Site reconnaissance to observe and document the current surface conditions.

Drilling of 11 hollow stem auger borings to a maximum depth of approximately 20 feet to assess the general engineering characteristics of the subsurface soils, collect samples for laboratory testing, and determine the depth to groundwater, if encountered.

Excavation, logging and sampling of 12 test pits to evaluate the engineering characteristics of existing soils and underlying alluvial soils.

Seismic refraction survey, consisting of 8 seismic lines, to evaluate the excavation characteristics of the on-site rock materials.

Laboratory testing of selected soil samples to determine insitu moisture and density, plasticity index, compaction characteristics (maximum dry density and optimum moisture), direct shear strength, expansion index, consolidation characteristics, and geochemical characteristics (soluble sulfate, chloride, minimum resistivity, and pH).

Analysis of site geotechnical conditions including slope stability, liquefaction potential, dynamic settlement potential and rockfall hazard.

Geotechnical review of Tentative Tract 3 1 194 rough grading plan.

Preparation of this report, presenting our findings and preliminary recommendations with regards to current site conditions, onsite soil types, seismic design parameters, rock rippability, remedial earthwork, general slope stability, residential foundation design, estimated static and seismically induced ground settlement and preliminary pavement design, as needed.

Leighton
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1.2 Site Location and Descri~tion
The subject site is generally located adjacent to the southeast comer of Evans Road and Garbani Road in the Menifee area of Riverside County, California. The location and approximate limits of the site are depicted on the attached Figure 1 (site location map).

During our investigation, several residences and other small buildings were observed to be recently razed in the western portion of the site. The remainder of the site was undeveloped and appeared to be used for agricultural and livestock operations.

Topographically, the central and southeastern portions of the property are relatively flat lying while the northern region of the property is characterized by a steep mountainside. A small, northwest-trending drainage channel extends through the northwestern and central portion of the property. A knoll also exists near the southeast comer of the property. Site elevations range fkom approximately 1,720 feet above mean sea level (msl) in the northeastern comer of the site to approximately 1,500 feet (msl) at the northwestern portion of the site.

Based on the provided rough grading plan (Hunsaker and Associates, 2003) referenced in Appendix A, we understand the proposed development will consist of approximately 492 single-family residences with associated roadways and improvements.

1.4 Proiect Plans
Our investigation and this report are based on the Tract 3 1194 Rough Grading Plan by Hunsaker and Associates Irvine, Inc., as referenced in Appendix A. The plans reviewed by Leighton are 40-scale, plotted December 8, 2004, and consist of 23 sheets. The electronic version of the same plans was used as the base map for the Geotechnical Map (Plate 1) presented in this report. The manner in which the plans are sheeted made it difficult to present the geotechnical data in an understandable way. In order to enhance the accessibility of this report, the Geotechnical Map is presented at 100-scale on a single sheet. The design and topographic information are the same on the 40-scale rough grading plan and the 100-scale Geotechnical Map.
-b
Leighton
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2.0 JNVESnGARON AND LABORATORY TESllNG

2.1 Test Pi@
A backhoe was used on June 6, 2002 to excavate 12 test pits to a maximum depth of approximately 14 feet. The test pits were logged and sampled by a Leighton geologist.

The test pit logs are presented in Appendix B and the test pit locations are depicted on the Geotechnical Map (Plate 1).

2.2 Soil Borinas
On January 12, 2004, 11 hollow-stem auger soil borings (B-1 through B-11) were advanced to a maximum depth of approximately 20 feet. All borings were terminated in dense granitic bedrock. The borings were sampled and logged by a Leighton geologist.

Approximate locations of the borings are depicted on the Geotechnical Map (Plate 1).

Boring logs are included in Appendix B.

During the drilling operation, bulk and relatively undisturbed samples were obtained from the borings for laboratory testing and evaluation. The relatively undisturbed samples were obtained utilizing a modified California drive sampler (2%-inch inside diameter and 3-inch outside diameter) driven 18 inches, where possible, in general accordance with ASTM Test Method D3550. In addition, standard penetration tests (SPT) were performed using a 2-inch outside diameter (1%-inch inside diameter) sampler driven 18 inches, where possible, in general accordance with ASTM Test Method D1586. All samples and SPTs were driven with a 140-pound automatic hammer dropping 30 inches. The number of blows to achieve the last 12 inches of penetration or number of blows with sampling penetration depths was recorded on the boring logs (Appendix B).

2.3 La boratow Testinq
Laboratory tests were performed on representative bulk and relatively undisturbed samples to provide a basis for development of design parameters. Selected samples were tested for insitu moisture and density, plasticity index, compaction characteristics (maximum dry density and optimum moisture), direct shear strength, expansion index, consolidation characteristics, and geotechnical characteristics (soluble sulfate, chloride, minimum resistivity, pH). The results of our laboratory testing, along with brief summaries of the testing procedures, are presented in Appendix C. The results of the in- situ moisture and density determinations are presented on the boring logs (Appendix B).

Leighton
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3.0 SUMMARY OF GEOTECHNICAL FINDINGS
Reaional Geoloaic Settinq
The subject site is located within a prominent natural geomorphic province in southwestern California known as the Peninsular Ranges. The Peninsular Ranges are characterized by steep, elongated ranges and valleys that generally trend northwestward.

Tectonic activity along the numerous faults in the region has created the geomorphology present today.

The subject site is located along the southwestern edge of the relatively stable Penis Block, an eroded mass of Cretaceous and older crystalline and metamorphic rock. Thin sedimentary, metamorphic and volcanic units locally mantle the bedrock with alluvial deposits filling in the lower valley and drainage areas. The Perris Bfock is bounded by the San Jacinto fault zone to the northeast, the Elsinore fault zone to the southwest, the Cucamonga fault zone to the northwest and to the southeast by the Temecula basin which is poorly defined. The region has a complex history, apparently undergoing relative vertical movements of several thousand feet in response to movement on the Elsinore and San Jacinto fault zones.

Site Geoloaic Units
Our field exploration, observations, and review of the pertinent literature (Appendix A) indicate that subsurface materials within the site include several geologic units consisting of various granitic units and alluvial deposits. All of these materials are suitable for re- use as compacted fill, if cleared of debris and organic matter. A general description of each unit follows.

3.2.1 Artificial Fill (not a ma~Ded unit1
Artificial fill was encountered locally throughout the western portion of the site.

The fills were related to existing roadways, residences, and other existing structures. All existing fill is undocumented and is not considered suitable for the support of additional fills or structural improvements. All artificial fill soils should be removed and recompacted in accordance with the recommendations in Section 5.2 of this report.

3.2.2 Alluvial De~osits (M~D Svmbol - Oal]
Existing alluvial soil overlays the majority of the site. As encountered, the alluvial soils generally consist of brown to red- or gray-brown, loose to medium dense, fine to coarse sand to silty sand.

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The alluvium was encountered in the borings to depths ranging fiom about 2.5 feet to approximately 15 feet below grade. The alluvium was similarly encountered in the test pits to depths varying fiom approximately 3.5 to the total excavation depth (approximately 14 feet) in the vicinity of TP-4. Greater depths of alluvium should be anticipated locally between the boring locations.

The near-surface alluvium should be removed from all areas in accordance with Section 5.2 of this report. Removal depths will vary depending upon location, but are anticipated to reach 4 to 10 feet below the existing ground surface in most areas. Some localized deeper removals may be required.

3.2.3 Cretaceous-Aaed Undifferentiated Granitics (M~D Svmbol - Karl The subject site is underlain by Cretaceous-aged granodiorite, tonalite, and gabbro bedrock. In the higher relief regions of the site, the granitic rock is exposed at the ground surface in some locations. The bedrock is typically light to medium gray, weathering to light brown and is generally medium to coarse-grained. Where exposed, the granitic bedrock is generally massive and can be expected to range fkom readily rippable to unrippable depending on the degree of weathering.

Although the granitic rock is anticipated to generate gravel, cobbles and oversize boulders, the weathered bedrock is generally anticipated to be suitable for re-use as compacted fill.

The surface of the site contains numerous granitic boulders. It should be anticipated that site grading will generate a significant number of buried boulders, or floaters. Special placement of oversized material (greater than 12 inches) will be required as described in Section 5.6 of this report.

3.3 Surface Water and Groundwater
A small amount of perched groundwater was encountered in test pit TP-4 at a depth of approximately 12 feet below grade. TP-4 is located in the vicinity of the northwest- trending drainage channel in the central portion of the site. Groundwater was not encountered in any of the borings and no standing water was observed on the ground surface during the time of the investigation.

Based on our observations, we anticipate that limited perched groundwater may be encountered locally during grading of the subject site. We do not anticipate that the water will create a significant constraint to grading operations. However, it should be noted that local perched water conditions may occur in the future, and may fluctuate seasonally, depending on rainfall and irrigation conditions. After grading, seepage may be encountered in the cut slopes along the northeast boundary of the site. These conditions should be addressed on a case-by-case basis, if encountered. -b
Leighton
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3.4 Landslides and Rockfalls
No evidence of on-site landslides was observed during our field investigation. However, the steep, south and west-sloping hillsides on the eastern portion of the site contain numerous loose boulders. The potential for rockfall due to either erosion or seismic ground shaking is significant in this area.

The potential hazard from individual rocks should be assessed during grading. Where possible, rockfall hazards should be removed during grading. In the event that potentially unstable rock cannot be removed, remedial measures such as catchment areas, rock fences, or setbacks may be required. Recommendations should be provided by the geotechnical consultant, based on the actual conditions encountered.

Based on the results of our field investigations, we anticipate that the bedrock in most areas of the subject site wiH generally be rippable to the proposed design grades with conventional heavy earth moving equipment in good operating conditions (Caterpillar D9L or Dl0 with single shank ripper and rock teeth). Localized marginally rippable to unrippable rock may be encountered in the proposed cut slopes in the western and southern portions of the site, as well as in the knolls along the southern site boundary.

Special excavation techniques may be required for grading and utility installation in these areas.

For proposed building pads and utility trenches in marginally rippable to non-rippable rock areas, it may be desirable to overexcavate at least 2 feet below the bottom of proposed utility trenches or 3 to 5 feet below pad grade to facilitate future trenching operations. In addition, due to differential weathering of the granitic bedrock materials, very heavy ripping andlor other specialized excavation techniques may be required to maintain desired excavation rates in some areas.

3.6 Faultinq
No active or inactive fault traces are known to traverse the site (Morton, 2003) and no evidence of onsite faulting was observed during our investigation. As defined by the California Geologic Survey, an active fault is one that has had surface displacement within the Holocene Epoch (roughly the last 11,000 years). The California Geologic Survey has defined a potentially active fault as any fault which has been active during the Quaternary Period (approximately the last 1,600,000 years).

These definitions are used in delineating Earthquake Fault Zones as mandated by the Alquist-Priolo Earthquake Fault Zoning Act. The intent of the act is to require fault investigations on sites located within Earthquake Fault Hazard Zones (Special Studies -b
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Zones) to preclude new construction of certain inhabited structures across the trace of active faults.

The Temecula segment of the active Elsinore Fault Zone is located approximately 6.6 miles (10.6 krn) south of the site (Blake, 2000b). The subject site is not included within an Earthquake Fault Zone as created by the Alquist-Priolo Earthquake Fault Zoning Act (Hart, 1999).

3.7 Seismicity
Our evaluation of the regional seismicity included a deterministic analysis using EQSEARCH and EQFAULT (Blake, 2000a & 2000b) and probabilistic analysis using FRISKSP (Blake, 2000~). As indicated above, the nearest known active fault and source of the design earthquake is considered to be the Elsinore Fault Zone, which is located approximately 6.6 miles south of the subject site. The maximum moment magnitude earthquake is currently estimated to be moment magnitude 6.8Mw (Blake, 2000a).

The Uniform Building Code (UBC) established Seismic Zones (often accepted as minimum standards) based on maps showing ground motion with a 475-year return period, or a 10% probability of exceedance in 50 years. The California Geologic Survey (CGS) Probabilistic Seismic Hazard Model (CGS, 2003) indicates a 10% probability that a peak ground acceleration of up to 0.45g would be exceeded at the subject site in 50 years. This is consistent with Leighton's probabilistic analysis, which was performed with FRISKSP (Blake, 2000~). The design earthquake is therefore considered to be a moment magnitude 6.8Mw event on the Elsinore Fault Zone that would generate a probabilistic peak ground acceleration of 0.45g (Blake, 2000~).

The effect of seismic shaking may be reduced by adhering to the 1997 UBC and seismic design parameters suggested by the Structural Engineers Association of California. The site is located within Seismic Zone 4. Seismic design parameters are presented below:

Seismic Zone = 4
Seismic Source Type = B
Near Source Factor, N, = 1.0
Near Source Factor, Nv = 1.0
Soil Profile Type = Sc
Horizontal Peak Ground Acceleration = 0.45g
(10% probability of exceedance in 50 years)

3.8 Secondarv Seismic Effects
Secondary effects that can be associated with severe ground shaking following a relatively large earthquake include ground lurching, shallow ground rupture, liquefaction, -@
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dynamic settlement, and flooding. These secondary effects of seismic shaking are discussed in the following sections.

3.8.1 Lurchina and Shallow Ground Ru~turq
Soil lurching refers to the rolling motion on the ground surface by the passage of seismic surface waves. Effects of this nature are likely to be most severe where the thickness of soft sediments varies appreciably under structures. The potential for lurching can be reduced if the potentially compressible soils present on the site are removed and properly compacted in accordance with the recommendations of this report.

Ground rupture is generally considered to most likely occur along pre-existing active faults. No fault traces are known to traverse the site (Hart, 1999) and no evidence of onsite faulting was observed during our investigation. The potential for site ground rupture is considered low.

3.8.2 Liauefaction and Dvnamic Settlement
Liquefaction and dynamic settlement of soils can be caused by strong vibratory motion due to earthquakes. Research and historical data indicate that loose granular soils below a near-surface groundwater table are most susceptible to liquefaction, while the stability of most clayey material is not adversely affected by vibratory motion. Liquefaction is characterized by a loss of shear strength in the affected soil layers, thereby causing the soil to act as a viscous liquid. This effect may be manifested at the ground surface by settlement and, possibly, sand boils where insufficient confining overburden is present over liquefied layers. In order for the potential effects of liquefaction to be manifested at the ground surface, the soils generally have to be granular, loose to medium dense, saturated relatively near the ground surface and must be subjected to a sufficient magnitude and duration of ground shaking.

The subject site contains deposits of granular soils; however, these materials are relatively dense and generally unsaturated. Assuming that the loose, near-surface soils will be removed and recompacted in accordance with the recommendations of Section 5.0 of this report, it is our opinion the potential for liquefaction due to the design earthquake event to affect structures at this site is low.

Although the potential for liquefaction is low, ground accelerations generated from a seismic event can produce settlements in sands or granular earth materials both above and below the water table. The potential total seismic densification of the onsite dry to damp alluvial soils due to the design earthquake event may be on Leighton
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the order of % inch. The potential differential seismic densification may be on the order of % inch in 40 feet laterally.

Due to its inland location and distance fkom the nearest major body of water (Diamond Valley Reservoir, approximately 6 miles east of the site), we do not anticipate that the site will be at risk for seismically-induced flooding. 4 Leighton
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4.0 CONCLUSIONS
Based on our preliminary geotechnical evaluation, it is our professional opinion that the proposed development is feasible from a geotechnical standpoint. The following is a summary of the geotechnical factors that may affect development of the site.

The existing onsite soils appear to be suitable for reuse as fill during proposed grading provided they are relatively free of organic material and debris.

Undocumented fill soils (if encountered), topsoil, and the upper 4 to 10 feet of alluvium are considered to be potentially compressible andlor possess a hydrocollapse potential. These materials should be removed and recompacted. Deeper removals will be required locally.

Based on our subsurface explorations, it is our opinion that the on-site earth materials in most areas can be excavated with heavy-duty conventional grading equipment in good working condition. Limited areas of unrippable rock should be anticipated along the hills bordering the site to the south and west.

Site excavations will produce oversize rock (greater than 12 inches) which will require special handling and placement at depths of at least 10 feet below finish grade.

Evidence of active faulting was not identified within or immediately adjacent to the subject site.

Strong ground shaking and/or settlement (seismic densification) may occur at this site due to local earthquake activity.

The design ground motion having a 10 percent probability of being exceeded in 50 years is expected to produce a peak horizontal ground surface acceleration at the site of up to approximately 0.45g.

Numerous large boulders are exposed on the surface of the site, both in the proposed area of development, and on the hillside to the northeast of the proposed development. These boulders present a rockfall hazard. Individual boulders located above the proposed cut slopes should be evaluated during grading and removed if necessary.

Groundwater was not encountered in the soil borings during our investigation. Shallow groundwater may be encountered locally during site grading and construction depending on rainfall. We do not anticipate that groundwater will be a significant constraint during grading.

Perched water may develop in areas of soils with contrasting permeabilities, possibly resulting in saturated fills or seepage from slopes. This condition is often a result of individual homeowners' water use and irrigation practices.

Based on preliminary laboratory results, onsite earth materials are expected to possess a very low to low expansion potential. Moderately expansive soils may be encountered locally -b
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during rough grading. Additional testing should be performed during site grading to verify these observations and limited laboratory data.

Limited laboratory testing (Appendix E) indicates that the on-site soils present a negligible sulfate exposure to concrete. Additional testing should be performed during site grading to verify these observations and limited laboratory data.

Fill and cut slopes are proposed at up to approximately 15 and 38 feet in height, respectively.

Because of remedial grading, the fill portion of the proposed fill-over-cut slopes may increase significantly. Fill and cut slopes up to approximately 30 feet and 45 feet in height, respectively, are expected to be grossly and surficially stable (see Appendix F), assuming that the recommendations of this report are implemented during grading. Cut slopes should be observed during grading for unfavorable conditions, which may require remediation.

Unprotected pads and slope faces will be susceptible to erosion. This risk can be reduced by planting the slopes as soon as possible after grading, and by maintaining proper erosion control measures.
-b
Leighton
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5.0 RECOMMENDATIONS.

5.1 General
Based on the results of the preliminary field and laboratory testing, it is our opinion that the subject site is suitable for residential development from a geotechnical viewpoint.

Grading of the site should be in accordance with our recommendations and the General Earthwork and Grading Specifications in Appendix F and recommendations of future evaluations based on site specific development plans.

5.2 Site Pre~aration and Remedial Removals
Prior to grading, the proposed structural improvement areas (i.e. all structural fill areas, pavement areas, buildings, etc.) of the site should be cleared of surface and subsurface obstructions, heavy vegetation and boulders. Roots and debris should be disposed of offsite. Septic Tanks or seepage pits, if encountered, should be abandoned in accordance with the County of Riverside Department of Health Services guidelines.

The near surface native and undocumented fill soils that exist on site are potentially compressible in their present state and may settle under the surcharge of fills or foundation loading. In areas that will support additional fill soils or structural improvements, these soils should be removed down to competent material.

Competent material is considered to be dense granitic bedrock or undisturbed alluvium with an in-situ dry density of at least 110 pounds per cubic foot and a minimum of 85 percent relative compaction (based on ASTM D1557). Acceptability of all removal bottoms should be reviewed by an engineering geologist with field or laboratory testing under the supervision of a geotechnical engineer. The removal bottom elevations, methodology of testing alluvium and test results of left-in-place alluvium should be documented in the as-graded geotechnical report.

The removal limit should be established by a 1:l projection fiom the edge of fill soils supporting settlement-sensitive structures downward and outward to competent material identified by the geotechnical consultant. The remedial removal depths will vary with location and with the proposed site configuration. The removal depths are generally expected to range from approximately 4 to 10 feet below existing grade, and locally deeper. Removals will also include benching into competent material as the fills rise.

Areas adjacent to existing structures, including roadways, may require special monitoring. Temporary slopes in these areas should be no steeper than %:I (horizonta1:vertical). Friable materials, if encountered, may require additional layback. w
Leighton
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5.3 CutIFill Transition Lots
In order to mitigate the impact of underlying cut/fill transition conditions, we recommend overexcavation of the cut portion of transition lots. Overexcavation should extend to a minimum depth of 3 feet below the bottom of the proposed footings or one-half of the maximum fill thickness on the lot, whichever is deeper. A maximum overexcavation depth of 10 feet is recommended. This overexcavation does not include scarification or preprocessing prior to placement of fill. Overexcavation can encompass the entire lot or extend laterally beyond the building limits a horizontal distance equal to the depth of overexcavation or to a minimum distance of 5 feet, whichever is greater. Overexcavation bottoms should be sloped as needed to prevent the accumulation of subsurface water.

5.4 Cut Lots and Streets
In order to facilitate excavation of footings and trenches in granitic rock, we recommend that cut lots be overexcavated to a minimum depth of 3 feet below finish grades and then capped with compacted fill. Consideration should be given for additional overexcavation of the pad to facilitate onsite utility construction. We further recommend streets be overexcavated to a minimum depth of 2 feet below the deepest utility and then brought back up to design grades with compacted fill.

5.5 Structural Fills
The onsite soils are generally suitable for re-use as compacted fill, provided they are fkee of debris and organic matter. Fills placed within 10 feet of finish pad grades or slope faces should contain no rocks over 12 inches in maximum dimension.

Areas to receive structural fill andlor other surface improvements should be scarified to a minimum depth of 8 inches, conditioned to at least optimum moisture content, and recompacted. Fill soils should be placed at a minimum of 90 percent relative compaction (based on ASTM D1557) and near or above optimum moisture content. Placement and compaction of fill should be performed in accordance with local grading ordinances under the observation and testing of the geotechnical consultant. The optimum lift thickness to produce a uniformly compacted fill will depend on the type and size of compaction equipment used. In general, fill should be placed in uniform lifts not exceeding 8 inches in thickness.

Fill slope keyways will be necessary at the toe of all fill slopes and at fill-over-cut contacts. Keyway schematics, including dimensions and subdrain recommendations, are provided in Appendix F of this report. All keyways should be excavated into dense bedrock or dense alluvium as determined by the geotechnical engineer. The cut portions Leighton
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January 30,2004
of all slope and keyway excavations should be geologically mapped and approved by a geologist prior to fill placement.

Fills placed on slopes steeper than 5:l (horizonta1:vertical) should be benched into dense soils (see Appendix F for benching detail). Benching should be of sufficient depth to remove all loose material. A minimum bench height of 2 feet into approved material should be maintained at all times.

5.6 Oversized Rock
Based on our observations, we anticipate that grading of the subject site will produce a significant amount of oversized rock (greater than 12 inches in maximum dimension).

No rock in excess of 12 inches in maximum dimension may be placed in any fill with 10 feet of finish grade. Oversized rock may be placed in the deeper fill portions of the site, if placed in accordance with the following guidelines and the specifications contained in Appendix F.

Within the upper 5 feet of finish grade, fill soils should not contain rock greater than 8 inches in maximum dimension in order to facilitate foundation and utility trench excavation. For fill soils between 5 and 10 feet below finish grade, the fill may contain rock up to 12 inches in maximum dimension and should be mixed with sufficient soil to eliminate voids. Below a depth of 10 feet, rocks up to a maximum dimension of 36 inches may be incorporated into the fill provided adequate fines to fill all voids are present. Rocks greater than 36 inches in diameter may be placed on a case-by-case basis.

We anticipate that a minimum of approximately 35 to 40 percent coarse grained material will be necessary to adequately fill an voids. Soil used to fill voids in rock fills should be flooded during placement with a sufficient amount of water to wash soil into all voids.

Material filling voids should be compacted to a minimum of 90 percent of the soil's maximum dry density. The outer 20 feet (10 feet vertically) of all fill slopes should not contain rocks greater than 12 inches. Subdrains should be provided at the base of all rock fills to minimize the potential for a build-up of hydrostatic pressure.

The volume change of excavated onsite materials upon recompaction is expected to vary with materials, density, insitu moisture content, location, and compaction effort. The in- place and compacted densities of soil materials vary and accurate overall determination of shrinkage and bulking cannot be made. Therefore, we recommend site grading include, if possible, a balance area or ability to adjust import quantities to accommodate some variation. Based on our experience with similar materials, we anticipate 8 to 12 percent shrinkage in the on-site soils. For planning purposes, we recommend an estimate of 10 percent shrinkage. Due to the generally loose nature of the near surface soils covering most the site, a subsidence value of 0.25 feet should also be applied.

Leighton
110712-002
January 30,2004

5.8 Jmwrt Soils
If import soils are necessary to bring the site up to the proposed grades, these soils should be granular in nature, relatively free of organic material, have an expansion index less than 50 (per ASTM Test Method D4829) and have a low corrosion impact to the proposed improvements. Import soils andor the borrow site should be evaluated by the geotechnical consultant prior to being imported to the site.

5.9 ytilitv Trenches
The onsite soils are generally considered to be suitable as trench backfill provided they are screened of rocks over 6 inches in diameter (or local utility requirements) and organic matter. Trench backfill should be compacted in uniform lifts (not exceeding 8 inches in compacted thickness) by mechanical means to at least 90 percent relative compaction (ASTM Test Method D 1557).

Excavation of utility trenches should be performed in accordance with the project plans, specifications and all applicable OSHA requirements. The contractor should be responsible for providing the "competent person" required by OSHA standards.

Contractors should be advised that sandy or gravelly soils (such as fills generated from the onsite alluvium) can make excavations particularly unsafe if all safety precautions are not taken. In addition, excavations at or near the toe of slopes andlor parallel to slopes may be highly unstable due to the increased driving force and load on the trench wall.

Excavation spoil piles and construction equipment should be kept away from the sides of the trenches.

Due to the nature of the on-site alluvial soils, utility trenches that extend into existing native materials may be unstable, particularly if fkiable soil or gravel layers are exposed.

Utility trenches over 5 feet in depth may require shoringlshielding or layback at 1:l (horizonta1:vertical) or flatter, even after remedial grading has been performed.

5.10 Preliminaw Foundation Desian Parameters
Foundations and slabs should be preliminarily designed in accordance with structural considerations, the seismic parameters of Section 3.7 and the recommendations presented in the 1997 Uniform Building Code (ICBO, 1997). In addition, either post-tension or other stiffened foundationlslab systems may be considered on this site due to the relatively high potential for seismic activity and associated deformation. These foundation systems, combined with the recommended remedial grading, will reduce the potential impact caused by the design level earthquake. -e
Leig hton
110712-002
January 30,2004
We recommend that as grading progresses, each building pad be evaluated for its expansion potential and differential fill thickness. The final footing and slab design for each proposed structure should be designed based on the results of that evaluation.

Foundations and overlying structures should be designed to tolerate the static and dynamic settlement provided in Section 5.1 1 of this report. Dynamic settlements (Section

5.1 1) and peak horizontal ground acceleration (Section 3.7) should be evaluated by the structural engineer for significant effects to the structure.

For budgetary and preliminary planning purposes, foundation design parameters are provided in Table 1 for very low expansive soils (expansion index equal to or less than 20 as classified in accordance with Table 18-I-B of the 1997 UBC). Preliminary foundation design parameters for conventionally reinforced shallow foundations (in accordance with Section 1815 of the UBC) for low to medium expansive soils (expansion index greater than 20) on site are provided in Table 2. Alternatively, low and medium expansive soil subgrades, may utilize a post-tensioned foundation such that Table 3 and the 1997 UBC are followed by design.

5.11 Settlement Considerations
Based on the findings of this limited exploration and analysis, we recommend that the planned residential buildings be designed in anticipation of approximately % inch of total static settlement with '/z inch of static differential settlement across a lateral distance of 40 feet. The majority of the static settlement associated with the building loads (elastic compression) is anticipated to occur during construction as the load is applied.

Additionally, for rough grade design, the architect and structural engineer should utilize % inch in 40 feet as a potential differential settlement effect due to seismic densification.

When available, the rough grading plans should be reviewed by the geotechnical engineer with regard to anticipated settlement.

5.12 Jootina Setback
We recommend a minimum horizontal setback distance from the face of slopes for all structural footings (retaining and decorative walls, building footings, etc.). This distance is measured from the outside bottom edge of the footing horizontally to the slope face (or to the face of a retaining wall) and should be a minimum of W2, where H is the slope height (in feet). The setback should not be less than 7 feet and need not be greater than 10 feet.

Please note that the soils within the structural setback area possess poor lateral stability and improvements (such as retaining walls, pools, decks, sidewalks, fences, pavements, etc.) constructed within this setback area may be subject to lateral movement and/or differential settlement. Potential distress to such improvements may be mitigated by '-r
Leighton
110712-002
January 30,2004
providing a deepened footing or a pier and grade-beam foundation system to support the improvement. The deepened footing should meet the setback as described above.

5.13 Slam Stabilitv
Based on the provided rough grading plans (Hunsaker & Associates, Inc., 2003), we anticipate that fill slopes will be less than 30 feet in height and constructed at a 2:l (horizontal:vertical) inclination. A slope stability analysis has been performed on the estimated maximum fill slopes and is presented in Appendix E. Appropriate laboratory testing was performed to estimate future fill soil strength parameters and is presented in Appendix C. Based on our analysis, 2:l fill slopes up to 30 feet in height are anticipated to be grossly stable for static and pseudostatic cases from a geotechnical standpoint.

Review of the rough-grading plans for surficial and general slope stability should be performed when these plans are available.

Based on the provided rough grading plans (Hunsaker & Associates, Inc., 2003), we anticipate that cut slopes will be less than 45 feet in height and constructed at a 2:l (horizonta1:vertical) inclination. Based on our analysis (Appendix E), 2:l cut slopes up to 45 feet in height in intact granitic are anticipated to be grossly stable for static and pseudostatic cases from a geotechnical standpoint. Cut slopes should be observed by an engineering geologist during grading. If unfavorable jointing, fracture patterns or seepage conditions are encountered, remedial measures may be required.

Slope faces are inherently subject to erosion, particularly if exposed to rainfall and irrigation. Landscaping and slope maintenance should be conducted as soon as possible in order to increase long-term surficial stability.

5.14 Retainina Walls
Due to risk of strong ground shaking, the design of any proposed retaining walls in excess of 5 feet in height should be reviewed by Leighton prior to construction. If walls in excess of 5 feet are planned, wall designs that tolerate the anticipated static and dynamic vertical deformations and incremental dynamic lateral earth pressures should be evaluated.

5.15 Site Drainaae and Erosion
All drainage should be directed away from structures by means of approved permanent or temporary drainage devices. Adequate storm drainage should be provided to avoid siltation of any temporary catch basins. Linear sandbagging of the pads tangential to flow directions in periodic intervals, should reduce erosion potential of runoff over these pads.
w
Leighton
110712-002
January 30,2004
In general, ponding of water should be avoided adjacent to the structures or pavements.

For preliminary planning purposes, positive,drainage may be accomplished by providing a minimum 2 percent gradient away hm the structures for a distance of at least 5 feet.

Protective measures to mitigate excessive site erosion and runoff during construction should also be implemented in accordance with the latest County of Riverside grading ordinances.

5.16 Geochemical Characteristics
Limited laboratory testing indicated a negligible concentration of soluble sulfates in onsite soils for representative samples. The laboratory test results are presented in Appendix E.

Additional corrosion testing should be performed on representative finish grade soils at the completion of rough grading. Concrete foundations in contact with site soils should be designed in accordance with Table 19-A-4 of the Uniform Building Code. A qualified corrosion engineer should be consulted to review the results of laboratory tests and coordinate additional testing if corrosion sensitive materials are to be used.

5.17 Preliminaw Pavement Desian Parameters
In order to provide the following preliminary recommendations, we have assumed an R- value of 30 for preliminary design purposes. These recommendations are intended for planning purposes only. For the final pavement design, appropriate traffic indices should be selected by the project civil engineer or traffic engineering consultant and representative samples of actual subgrade materials should be tested for R-value.

Asphaltic-Concrete (AC) Class 2 Aggregate Base (AB)
The subgrade soils in the upper 6 inches should be properly compacted to at least 95 percent relative compaction (ASTM D1557) and should be moisture-conditioned to near optimum and kept in this condition until the pavement section is constructed. Proof- rolling subgrade to identify localized areas of yielding subgrade (if any) should be .I
Leighton
110712-002
January 30,2004
performed prior to placement of aggregate base and under the observation of the geotechnical consultant.

Minimum relative compaction requirements for aggregate base should be 95 percent of the maximum laboratory density as determined by ASTM D1557. Base rock should conform to the "Standard Specifications for Public Works Construction" (green book) current edition Caltrans Class 2 aggregate base having a minimum R-value of 78.

Asphaltic concrete should be placed on compacted aggregate base and compacted to a minimum 95 percent relative compaction based on the laboratory standards ASTM Dl 561 and D2726.

The preliminary pavement sections provided in this section are meant as minimum, if thinner or highly variable pavement sections are constructed, increased maintenance and repair may be needed.

Leighton
110712-002
January 30,2004
Geotechnical review is of paramount importance in engineering practice. The poor performance of many foundation and earthwork projects have been attributed to inadequate construction review. We recommend that Leighton and Associates be provided the opportunity to review the following items.

6.1 Plans and S~ecifications
Leighton and Associates should review the precise grading and foundation plans and project specifications when they are completed. Such review is necessary to evaluate whether the geotechnical recommendations have been effectively incorporated in plans and other construction documents. Review findings should be reported in writing.

6.2 Construction Review
Observation and testing should be performed by Leighton and Associates representatives during grading and construction. It should be anticipated that the substrata exposed during construction may vary from those encountered in the borings. Reasonably continuous construction observation and review during site grading and foundation installation allows for evaluation of the actual soil conditions and the ability to provide appropriate revisions during construction, if required.

Site preparation, removal of unsuitable soils, approval of imported earth materials, fill placement, foundation installation and other site geotechnically-related operations should be observed and tested by representatives of Leighton and Associates.

Additional laboratory tests of subsurface materials should be performed during or prior to grading to confirm compacted density and moisture content, corrosion potential and expansion potential.

Leighton

110712-002
January 30,2004
TABLE 1
Minimum Foundation Desian Recommendations for Verv Low Ex~ansive Soils Table 1 Notes:
(1) Depth of interior or exterior footing to be measured from lowest adjacent finish grade or drainage swale flowline elevation if less than 5 feet laterally fiom the building foundation. (2) Exterior column footings should be structurally tied in two directions using grade beams and founded at least 18 inches below the lowest adjacent soil grade.
(3) The base of the grade beam should be at the same elevation as that of the adjoining footings. (4) Living area slabs should be tied to the footings as directed by the structural engineer. (5) A 10-mil vapor inhibitor, clean whed rock or line-graded material should be placed beneath slabs in accordance with ASTM El643 and ACI guidelines. All laps and penemtiom in the vapor inhibitor should be sealed (6) Garage slabs should be isolated from stem wall footings with a minimum 318" felt expansion joint. 1-Story Footings All footings 12" deep. Reinforcement for continuous footings: one (See Note 1) No. 4 bar top and bottom.
2-Story Footings All footings 18" deep. Reinforcement for continuous footings: one (See Note 1) No. 4 bar top and bottom.
(7) The recommendations presented above assume that proper maintenance irrigation and drainage are maintained around the structure.

Minimum Footing Width
Garage Door Grade Beam
(See Note 3)
Living Area Floor Slabs
(See Notes 4,5 and 6)
Garage Floor Slabs
(See Notes 5,6 and 7)
Presoaking
Allowable Bearing Capacity
Continuous: 12" for 1-story
Continuous: 15" for 2-story
Isolated column: 24" (18" deep minimum)
A grade beam 12" wide x 12" deep
(18" deep for 2-story) should be provided across the garage entrance.

Minimum 4" thick slab. No. 3 bars at 18 inches on center each way (at midheight).

Minimum 4" thick slab. No, 3 bars at 18 inches on center each way (at midheight). Slab should be quarter-sawn.

Optimum moisture to a depth of 6 inches.
2,000 pounds per square foot
(one-third increase for short term loading)
110712-002
January 30,2004
TABLE 2
Minimum Foundation Desic~n Recommendations for
Low and Medium ExD~~s~v~ Soils
Table 2 Notes:
(1) Concrete floor slabs designed in accordance with UBC Section 1815 should be of sufficient thickness to resist design expansive soil pressures and in accordance with the structural engineers recommendations and the UBC. (2) Exterior column footings should be structurally tied in two directions using grade beams and founded at least 18 inches below the lowest adjacent soil grade.
(3) A 10 mil vapor &bitor; clean crushed rock crusher-run or fine-graded material should be placed beneath slabs in accordance with ASTM El643 and ACI guidelines. All laps and penetrations in the vapor inhibitor should be sealed.
(4) If the concrete slablfloor for the foundation are designed in accordance with Section 1815 of the UBC, a continuous perimeter footing will likely be used including the garage opening. (5) Low to medium expansive soil slabslfoundations designed in accordance with UBC Section 18 15 should be placed monolithically.
(6) Depth of exterior footing to be measured from lowest adjacent finish grade or drainage swale flowline elevation if less than 5 feet laterally from the adjacent exterior footing. (7) Floor slab detailing including crack control joints (if necessary) per the structural engineer's recommendations.

UBC Expansion Index UBC Expansion Index
Low Medium
1 -Story Footing,
Depth of Embedment
2-Story Footing,
Depth of Embedment
1- or 2-Story Isolated
Exterior Column
Footings
Presoaking
Plasticity Index
Be;uing
Capacity
12"
18"
24" width (1 8" deep,
minimum)

1.2 times the optimum
moisture to a depth of 12
inches
20 2,000 pounds per square
foot (one-third increase for
short term loading)
18"
24"
24" width (24" deep,
minimum)

1.3 times the optimum
moisture to a depth of 18
inches
30 2,000 pounds per square
foot (one-third increase for
short term loading)
110712-002
January 30,2004
TABLE 3
Minimum Post-Tensioned Foundation Desian Recommendations For Low to Medium Ex~ansive Soils
Design Criteria
Table 3 Notes:
(1) Concrete floor slabs designed in accordance with UBC Section 1816 should be of sufficient thickness to resist design expansive soil pressures and in accordance with the structural engineers recommendations and the UBC. (2) A 10 mil vapor inhibitor, clean crushed rock or fine-graded material should be placed beneath slabs in accordance with ASTM El643 and ACI guidelines. All laps and penetrations in the vapor inhibitor should be sealed.
(3) Depth of exterior footing to be measured from lowest adjacent finish grade or drainage swale flowline elevation if less than 5 feet laterally from the adjacent exterior footing. (4) Exterior column footings should be structurally tied to the main foundation. (5) Floor slab detailing including crack control joints (if necessary) per the structural engineer's recommendations. (6) Potential total and differential settlement should be included cumulatively with differential swell parameters.

Appendix A
110712-002
January 30,2004
Blake, T.F., 2000a, EQSEARCH, Version 3.00a, A Computer Program for the Estimation of Peak Horizontal Acceleration from Southern California Historical Earthquake Catalogs, Users Manual, 94 pp., with update data, 2000 Version 4.0.

Blake, T. F., 2000b, EQFAULT, Version 3.00b, A Computer Program, for the Deterministic Prediction of Peak Horizontal Acceleration from Digitized California Faults, User's Manual, 77 pp.

Blake, T. F., 2000c, FRISKSP, Version 4.00 Computer Program, for Determining the Probabilistic Horizontal Acceleration, User's Manual, 99 pp.

Blake, T. F., 2000d, UBCSEIS, Version 1.0, User's Manual for Evaluating the Seismic Parameters in accordance with the 1997 UBC, 53 pp.

California Geologic Survey (formerly California Division of Mines and Geology), Probabilistic Seismic Hazard Assessment for the State of California, 1996, Open-File Report 96-08.

Hart, E.W., Bryant, W. A., 1999, Fault-Rupture Hazard Zones in California, Alquist-Priolo Earthquake Fault Zoning with Index to Earthquake Zones Maps: Department of Conservation, Division of Mines and Geology, Special Publication 42. Revised 1997, Supplements 1 and 2 added 1999.

Hunsaker and Associates Irvine, Inc., 2003, Rough Grading plan, Tract 31194, County of Riverside California, 40-scale, 23 sheets, plotted December 8,2003.

International Conference of Building Officials, 1997 Uniform Building Code, Volumes 1-3.

International Conference of Building Officials, 1988, Maps of Known Active Fault-Near Source Zones in California and Adjacent Portions of Nevada.

Morton, D. M., et al., 1999, Preliminary Digital Geologic Map of the Santa Ana 30'X 60' Quadrangle, Southern California, Version 1 .O, USGS Open-File Report 99- 172 Morton, D. M., et al., 2003, Preliminary Geologic Map of the Romoland 7.5' Quadrangle, Riverside County, California, Version 1 .O, USGS Open-File Report 03- 102 Naval Facilities Engineering Command, 1986a, Foundations and earth structures, design manual

7.02, Changes 1: U.S. Navy, September.

Naval Facilities Engineering Command, 1986b, Soil Mechanics, 7.01, Changes 1; U.S. Navy.

WGCEP - Working Group on California Earthquake Probabilities, 1995, Seismic Hazards in Southern California: Probable Earthquake Probabilities, Bulletin of the Seismological Society of America, Vol. 85, No. 2, pp. 379-439.
'fr
Leig hton

GEOTECHNICAL BORING LOG B-1
Date 1-1 2-04 Sheet 1 of 1
Project Woodside Evans & Garboni Project No. 1 1071 2-002 Drilling Co. Cat Pac Type of Rig B-6 1
Hole Diameter 8" Drive Weight 140 Ibs Drop 30"
Elevation Top of Hole +I- 151 4' Location See Map
DESCRIPTION 5 a +

G GRABSAMPLE

C CORESAMPLE
x RDS Remolded DS

GEOTECHNICAL BORING LOG 8-3
Date 1-1 2-04 Sheet 1 of 1
Project Woodside Evans & Garboni Project No. 1 10712-002 Drilling Co. Cal Pac Type of Rig B-6 1
Hole Diameter 8" Drive Weight 140 Ibs Drop 30"
Elevation Top of Hole +I- 1523' Location See Map
c 0 * O Q)s cri-
U) z 5J 3" DESCRIPTION t Q)
Q)
g - A'E: ~1 OE zV! o'!
I-
v-
0 w' t SO 03 Logged By d P o a- AVI &
h
V S Sampled By AVI I-
SM @ 2.5': Brown, damp, medium dense, silty, fine SAND with abundant 108.4 11.1 rootlets
Backfilled with Spoils 1-12-04

R RINGSAMPLE C CORESAMPLE

B BULKSAMPLE

T TUBESAMPLE CR CORROSION RV R-VALUE
GEOTECHNICAL BORING LOG B-4
Date 1-12-04 Sheet 1 of 1
Project Woodside Evans & Garboni Project No. 1 1071 2-002 Drilling Co. Cal Pac Type of Rig B-6 1
Hole Diameter 8" Drive Weight 140 Ibs Drop 30"
Elevation Top of Hole +/- 1507' Location See Map
C 0 0 * 2' '6- z DESCRIPTION +!
* -- " $d $4 aJ
C-
n & HI GO. + 0
5 5
OC =V! 03 Logged By '00 a- AVI
V) n 8
Sampled By V S AVI c
SAWLE TYPES: TYPE OF TESTS: HCO HYDROCOLLAPSE CS CORROSION SUITE

S SPLITSPOON G GRABSAMPLE SU SULFATE HD HYDROMETER MC MOISTURE CONTENT

R RING SAMPLE C CORESAMPLE DS SHEAR SA SINE ANALYSIS SE SAND EQUIVALENT B BULKSAMPLE MD MAXIMUM DENSITY AL ATTERBERG LIMITS -200 200 WASH T TUBESAMPLE CN CONSOLIDATION El WPANSION INDEX RDS Remolded DS

CR CORROSION RV R-VALUE
LEIGHTON AND ASSOCIATES, INC.

A
GEOTECHNICAL BORING LOG B-5
Date 1-1 2-04 Sheet 1 of 1
Project Woodside Evans & Garboni Project No. 1 1071 2-002 Drilling Co. Cat Pac Type of Rig B-6 1
Hole Diameter 8" Drive Weight 140 Ibs Drop 30"
Elevation Top of Hole +I- 151 5' Location See Map
C
88 0,
Z
5-
$8 ,,
@ 5': Brown, damp, medium dense, silty, fine SAND with rootlets HCO common and porous
@ 7.5': Dark brown, moist, med~um dense, silty, fine to medium HCO SAND with few micas I
I
o .-
2'
V S
1490-
,dQ<-
V)
f Z
SAMPLE TYPES: TYPE OF TESTS:

S SPLITSPOON G GRAB SAMPLE SU SULFATE HCO HYDROCOLLAPSE CS CORROSION SUITE

HD HYDROMETER MC MOISTURE CONTENT
R RINGSAMPLE C CORESAMPLE DS DlRECT SHEAR SA SIEVE ANALYSIS SE SAND EQUIVALENT B BULKSAMPLE MD MAXIMUM DENSITY AL ATERBERG LIMITS -200 200 WASH T NBESAMPLE CN CONSOLIDATION El EXPANSION INDEX RDS Remolded DS

CR CORROSION RV R-VALUE
LEIGHTON AND ASSOCIATES, INC.
25 0 z
2 a
5 V)
:

Total Depth 20.3'
No Groundwater Encountered
Backfilled with Spoils 1-12-04
*
e 9
E
V)
ga
a
6 g~
zg OE
=s
ui-
83 ="! 03 a-

DESCRIPTION
Logged By AVI
Sampled By AVI
3 al
I- + 0
a I-

GEOTECHNICAL BORING LOG 8-7
Date 1-1 2-04 Sheet 1 of 1
Project Woodside Evans & Garboni Project No. 1 1 071 2-002 Drilling Co. Cal Pac Type of Rig 6-61
Hole Diameter 8" Drive Weight 140 Ibs Drop 30"
I LEIGHTON AND ASSOCIATES, INC. I
GEOTECHNICAL BORING LOG B-8
LEIGHTON AND ASSOCIATES, INC. I
LEIGHTON AND ASSOCIATES, INC. I
GEOTECHNICAL BORING LOG B-10
Date 1-1 2-04 Sheet I of 1
Project Woodside Evans & Garboni Project No. 1 10712-002 Drilling Co. Cal Pac Type of Rig B-61

DESCRIPTION
No Groundwater Encountered
Backfilled with Spoils 1-12-04
SAMPLE NPES: NPE OF TESTS:

SU SULFATE HCO HYDROCOLLAPSE CS CORROSION SUITE S SPLITSPOON G GRABSAMPLE HD HYDROMETER MC MOISTURE CONTENT R RING SAMPLE C CORESAMPLE DS DlRECT SHEAR SA SIEVE ANALYSIS SE SAND EQUIVALENT B BULKSAMPLE MD MAXlMUMDENSln AL AllERBERG LIMITS -200 200 WASH T NBESAMPLE CN CONSOLIDATION El EXPANSION INDEX RDS Remolded DS

CR CORROSION RV R-VALUE
LEIGHTON AND ASSOCIATES, INC. I

GEOTECHNICAL BORING LOG B-I I
Date 1-1 2-04 Sheet 1 of 1
Project Woodside Evans & Garboni Project No. 110712-002 Drilling Co. Cal Pac Type of Rig B-61
Hole Diameter 8 Drive Weight 140 ibs Drop 30"
Elevation Top of Hole +/- 151 9' Location See Map
3 0)
I-
Y-
0 2i >r
C
Sampled By AVI I-
V S
Surface: Light brown, damp, loose, fine to coarse SAND
@ 5': Dark brown, moist, loose, silty, fine SAND with few rootlets

7.5': Dark brown, moist, very loose, silty, fine SAND with few @ 10': Orange to dark gray, moist, very loose, fine to coarse SAND Backfilled with Spoils 1-12-04

S SPLITSPOON G GRABSAMPLE HD HYDROMETER MC MOISTURE CONTENT

R RING SAMPLE C CORESAMPLE

B BULKSAMPLE
T TUBESAMPLE N El EXPANSION INDEX RDS Remolded DS

RV R-VALUE
LEIGHTON AND ASSOCIATES, INC.
o DESCRIPTION .2* =* --
AVI

APPENDIX B

LOG OF TEST PITS
Project No. 1 10712-001
CLIENT: Woodside - Garbani and Evans Road
LOGGED BY: SER
DATE: 6-6-02
'IZST
PIT#
TP-1
TP-2
TP -3
0 0- 1
1 -4
4-6
0-1
1-4.5

4.5-6.5
0-1
1-12
12-14
DRY

DENSITY
(PCF) ("/.I U.S.C.S.

SM
SM
SM
SM
SM
SMIML

DESCRIPTION
Tilled Zone: Light brown, dry, loose, silty fine to coarse SAND; abundant rootlets Quaternary Alluvium (Qal): Red-brown, damp to moist, medium dense, silty very fine to medium SAND; moderately porous, scattered root hairs
Undifferentiated Granitic Bedrock (Km-1: Gray-brown, very dense, fine to coarse grained GRANITICS; slightly weathered
TD: 6', No Groundwater, No Caving, Backfilled 6-6-02
Tilled Zone: Light brown, dry, loose, silty fine to coarse SAND; abundant rootlets Ouaternarv Alluvium (Qal): Red-brown, damp to moist, medium dense, silty very fine to medium SAND; moderately porous, scattered root hairs (large roots at 4.5') Undifferentiated Granitic Bedrock (Km-): Gray-brown, very dense, fine to coarse grained GRANITICS, slightly to moderately weathered, scattered cobble sized rock TD: 6.5', No Groundwater, No Caving, Backf511ed 6-6-02
Tilled Zone: Light brown, dry, loose, silty fine to coarse SAND; abundant rootlets Ouaternarv Alluvium (Qal): Red-brown to dark brown, moist, medium dense, silty very fine to medium SAND to sandy SILT; moderately porous in upper 6' then becomes slightly porous, scattered root hairs
Undifferentiated Granitic Bedrock (Km-1: Gray-brown, very dense, fine to coarse grained GRANITICS, moderately weathered
TD: 14', No Groundwater, No Caving, Backfilled 6-6-02
Project No. 110712-001
CLIENT: Woodside - Garbani and Evans Road

APPENDIX B

LOG OF TEST PITS
LOGGED BY: SER
DATE: 6-6-02
PIT#
TP-4
TP-5
5 -6 Undifferentiated Granitic Bedrock (Km): Gray-brown to yellow-brown, very dense, fine to coarse grained GRANITICS, moderately weathered
TD: 6', No Groundwater, No Caving, Backfilled 6-6-02
U.S.C.S.

SM
SM
SM/ML
SP
SM
CL
SM

DESCRIPTION
Tilled Zone: Light brown, dry, loose, silty fine to coarse SAND; abundant rootlets Ouaternarv Alluvium (Oall: Red-brown, damp, medium dense, silty very fine to medium SAND; moderately porous, scattered root hairs
Dark red-brown, moist, medium dense, silty very fine to medium SAND to stiff sandy SILT; slightly porous in upper 5'
Light-brown, wet, dense, fine to coarse SAND, highly fiiable TD: 14', Groundwater at 12', No Caving, Backfilled 6-6-02 Tilled Zone: Light brown, dry, loose, silty fine to coarse SAND; abundant rootlets Ouaternaw Alluvium (Qal): Dark brown, moist, stiff CLAY; scattered root hairs, non- porous Red-brown, moist, medium dense, silty very fine to medium SAND; slightly clayey, non-porous, scattered gravel
(FT)
0-1
1-3
3-12
12-14
0- 1
1-3
3-5
DRY

DENSITY
(PCF) (%)

APPENDIX B

LOG OF TEST PITS
Project No. 110712-001 LOGGED BY: SER
CLIENT: Woodside - Garbani and Evans Road DATE: 6-6-02
'IEST
PIT#
TP-6
TP-7
TP-8
DEPTH
(FT)
0-1
1-3.5

3.5-5
0- 1
1 -4
4-7
0-1
1-3.5

3.5-5
DRY

DENSITY
(Pcq (%)
U.S.C.S.

SM
SM
SM
SM
SM
SMISC

DESCRIPTION
Tilled Zone: Light brown, dry, loose, silty fine to coarse SAND; abundant rootlets Ouaternarv Alluvium (Qal): Red-brown, damp, medium dense, silty very fine to medium SAND; moderately porous, scattered rootlets
Undifferentiated Granitic Bedrock (Km): Gray-brown, very dense, fine to coarse grained GRANITICS; slightly weathered
TD: 5', No Groundwater, No Caving, Backfilled 6-6-02
Tilled Zone: Light brown, dry, loose, silty fine to coarse SAND; abundant rootlets Ouaternarv Alluvium (Oal): Brown, damp, medium dense, silty fine to medium SAND; moderately porous, scattered root hairs, few gravels
Undifferentiated Granitic Bedrock Km): Gray-brown to red-brown, very dense, fine to coarse grained GRANITICS, slightly to moderately weathered
TD: 7', No Groundwater, No Caving, Backfilled 6-6-02
Tilled Zone: Light brown, dry, loose, silty fine to coarse SAND; abundant rootlets Ouaternaw Alluvium (Qal): Dark brown, moist, medium dense, silty to clayey SAND; slightly porous, scattered root hairs
Undifferentiated Granitic Bedrock (Ka): Gray-brown, very dense, fine to coarse grained GRANITICS, slightly weathered
TD: 5', No Groundwater, No Caving, Backfilled 6-6-02
I

APPENDIX B

LOG OF TEST PITS
Project No. 1 10712-001
CLIENT: Woodside - Garbani and Evans Road
LOGGED BY: SER
DATE: 6-6-02
TEST
PIT#
TP-9
TP- 1 0
TP-11
DEPTH
(FT)
0- 1
1-3
3 -5
0- 1
1-3
3-5
0-1
1 -4
4-8
8-10
DRY
DENSIn
(PCF)
DESClUPTION
Tilled Zone: Light brown, dry, loose, silty fine to coarse SAND; abundant rootlets Ouatemaw Alluvium (Oal): Dark brown, moist, medium dense, clayey SAND; slightly porous, abundant root hairs
Undifferentiated Granitic Bedrock Em]: Gray-brown, very dense, fine to coarse grained GRANITICS, slightly weathered
TD: 5', No Groundwater, No Caving, BacWlled 6-6-02
Tilled Zone: Light brown, dry, loose, silty fine to coarse SAND; abundant rootlets Quaternarv Alluvium (Oal): Dark brown, damp, medium dense, silty very fine to medium SAND; moderately porous, abundant root hairs
Undifferentiated Granitic Bedrock (Kg): Gray-brown to red-brown, very dense, fine to coarse grained GRANITICS, slightly to moderately weathered
TD: 5', No Groundwater, No Caving, Backfilled 6-6-02
Tilled Zone: Light brown, dry, loose, silty fine to coarse SAND; abundant rootlets Quaternarv Alluvium (Qal): Red-brown, damp, medium dense, silty very fine to medium SAND; moderately porous, few gravel scattered root hairs
Dark brown, moist, medium dense, clayey SAND; slightly porous Undifferentiated Granitic Bedrock Kg-: Gray to olive-brown, moist, dense, fine to medium grained GRANITICS, highly weathered
TD: lo', No Groundwater, No Caving, Backfilled 6-6-02
(%I U.S.C.S.

SM
SC
SM
SM
SM
SM
SC

APPENDIX B

LOG OF TEST PITS
Project No. 110712-001
CLIENT: Woodside - Garbani and Evans Road
LOGGED BY: SER
DATE: 6-6-02
TEST
PIT#
TP- 12
DEPTH
(FT)
0-1.5
SM
5-1 1
Quaternary Alluvium (Qal): Brown, damp, medium dense, silty fine to medium SAND; moderately porous, few gravel, scattered root hairs
SM
DRY

DENSITY
(PCF)
Undifferentiated Granitic Bedrock (Kgr): Red-brown, damp, dense, silty fine to coarse SAND, calcium carbonate faces, non-porous, highly weathered
11-12 Gray-brown, very dense, fine to coarse grained GRANITICS; slightly weathered TD: 12', No Groundwater, No Caving, Backfilled 6-6-02
(%I
U.S.C.S.

DESCRIPTION
Tilled Zone: Light brown, dry, loose, silty fine to coarse SAND; abundant rootlets Appendix C
110712-002
January 30,2004

APPENDIX C
La boratorv Testina Procedures and Test Results
Atterbern Limits: The Atterberg Limits were determined in accordance with ASTM Test Method D423 for engineering classification of the fine-grained materials and presented in the table below:

Moisture and Density Determination Tests: Moisture content and dry density determinations were performed, in general accordance with ASTM test method D2937, on relatively undisturbed samples obtained from the test borings and/or trenches. The results of these tests are presented in the boring and/or trench logs. Where applicable, only moisture content was determined from "undisturbed" or disturbed samples.

Sample Location
Comvaction Characteristics: The maximum dry density and optimum moisture content of typical materials were determined in accordance with ASTM Test Method D 1557. The results of these tests are presented in the table below:

B-6 @ 4' - - NP SM
Liquid Limit (%)
Expansion Index Tests: The expansion potential of selected materials was evaluated by the Expansion Index Test, ASTM D4829. Specimens were molded under a given compactive energy to approximately the optimum moisture content and approximately 50 percent saturation. The prepared 1-inch thick by 4-inch diameter specimens were loaded to an equivalent 144 psf surcharge and inundated with tap water until volumetric equilibrium was reached. The results of these tests are vresented in the table below:

Sample Location Sample Description Maximum Dry Optimum Moisture Density (pcf) Content (%)
Expansion Expansion Sample Location Sample Description 1 ~ndex 1 Potential Plastic
Limit (%)
B-1 @ 0-10'
B-6 @ 5-10'
I B-6 @ 5-10'
I I I
Brown silty sand (SM) 5 Very Low
I TP-7 @ 0-5' 1 Reddish brown silty SAND (SM) 1 8 1 Very Low 11 Plastic
Index (%)
*I
Gray-brown silty SAND (SM)
Brown silty SAND (SM)
USCS Soil
Classification
127.0
134.0

11.0 9.0
110712-002
January 30,2004
La boratow Testina (continued)
Hydrocolla~se Tests: Hydrocollapse tests were performed on selected, relatively undisturbed ring samples. Samples were placed in a consolidometer and loads were applied in geometric progression. The percent hydrocollapse for each load cycle was recorded as the ratio of the amount of vertical compression to the original 1-inch height. The hydrocollapse pressure curves are presented in the test data. Where applicable, time-rates of hydrocollapse were recorded and presented below:

Chloride Content, Sulfate Content, Minimum Resistivity and pH Tests: Chloride content, Sulfate Content, Minimum resistivity and pH tests were performed in general accordance with California Test Method 422,417, and 532. The results are presented in the table below:

Sample
Location
B-5 @ 5'
B-5 @ 7.5'
B-6 @ 5'
B-7 @ 5'
B-11 @ 7.5'
B-11 @ 10'
TP-1 @ 3-4'
TP-4 @ 5-6'
TP-8 @ 3-4'
Sample Description
Brown silty SAND (SM)
Dark brown silty SAND (SM)
Light brown to dark gray silty SAND
(SM)
Red brown silty SAND (SM)
Dark brown silty SAND (SM)
Orange to dark gray silty SAND (SM)
Red brown silty SAND (SM)
Dark red brown silty SAND (SM)
Dark brown silty SAND (SM)
Sample
Location
B-6 @ 5-10'
TP-1 @ 0-3'
TP-7 @ 5-7'
Dry Density
(before test)
(Pcf)
126.4
124.2
117.6
107.8
122.0
112.7
105.3
102.7
109.2
Sample
Description
Red brown silty SAND (SM)
Brown silty SAND (SM)
Light brown silty SAND (SM)
%
Hydrocollapse
-0.80
-0.15
-1.64
-2.40
-0.06
-0.71
-3.53
-0.91
-1.63
Content
(PP~)
30 sulfate
Content (%)
<0.0150
<0.0150
<0.0150
pH

8.64 Minimum
Resistivity
(ohms-cm)
1 1,679
110712-002
January 30,2004
La boratorv Testina (continuedl
Direct Shear Tests: Direct shear tests were performed, in general accordance with ASTM test method D3080, on selected remolded andlor undisturbed samples which were soaked for a minimum of 24 hours under a surcharge equal to the applied normal force during testing. After transfer of the sample to the shear box and reloading the sample, pore pressures set up in the sample due to the transfer were allowed to dissipate for a period of approximately 1 hour prior to application of shearing force. The samples were tested under various normal loads, a motor- driven, strain-controlled, direct-shear testing apparatus at a strain rate of approximately 0.05 inch per minute. The test results are presented in the test data.

Maximum Densitv Tests: A maximum dry density and optimum moisture content of typical materials was determined in accordance with ASTM Test Method D1557. The results of this test are presented in the table below:

Sample Location
B-1, @ 0-10'
B-1, @ 7.5'
TP-8 @ 5-7'
Friction Angle Apparent
Sample Description (degrees) Cohesion (psf)
Peak Relaxed Peak Relaxed
Gray brown silty SAND (SM) 27 Remolded 23 625 500
Yellow gray brown silty
SAND (SM) 48 37 1700 400
Gray brown to red brown silty
SAND (SM), Remolded 44 350 41 350
Sample Location
B-1 @ 0-10'
B-6 @ 5-10'
TP-7 @ 0-5 ft
Maximum Optimum
Sample Description Dry Density Moisture Content
(Pcf) (%)
Gray brown silty SAND, (SM) 127.0 11.0
Light brown silty SAND, (SM) 134.0 9.0
Light brown silty SAND (SM) 133.0 9.0
Appendix D
215 So. Hiahwav 101. Suite 203 P.O. Box 1152 Sslana Beach. CA 92075 Telephone: (858) 481-8949 Facsimile: (858) 481-8998 E mail: [email protected] June 25,2002
Leighton and Associates
4 17 15 Enterprise Circle N., Suite 103
Temecula, CA 92590-566 1
Project No. 02-213
Attn: Scott Richtmyer re: Seismic refraction investigation, Menifee CA This brief letter report is to present the findings of a seismic refiaction survey carried out on a construction site at Garbani Road and Ascot Way in Menifee, California (Fig. 1) on June 3, 2002.

The survey consists of eight lines, each of single spreads. Purposes of the survey were to determine the mechanical properties of the geologic section, layer depths and their thicknesses, and estimate rippability.

A Bison 9024, 24 channel seismograph system, was applied to the task. This instrument has DIFP, digital instantaneous floating point. This translates into a computer-controlled seismograph that records incoming signals at all instrument settings, and these are analyzed by the on-board computer which then outputs optimum, balanced traces with maximum informational content.

Survey Desim - The Line Location Map (Fig. 2) shows the positions and layout directions of the eight refiaction lines. Four of the lines are in relatively flat areas, and four are on the southwest slope of a bedrock ridge. Cut slopes up to 40 feet deep are planned, and the line lengths are designed to investigate to depth in the order of 75 feet.

Geophone interval was 10 feet on all lines; consequently, spread lengths were 250 feet, measured fi-om off end shot to far oBet geophone. Shots were also 10 feet fiom near offset geophones.

In addition to forward and reverse off end shots, a split spread shot was fired between geophones 12 and 1 3. The geophone gap at the split spread position was 20 feet to accommodate the shot.

Source was a heavy duty sledge hammer with an inertial switch. The hammer was slammed onto a metal plate that was coupled to the ground. Because of the relatively short spreads, the sledge hammer source was entirely adequate. Vertical stacking was carried out to build energy and to serve as an effective "noise" abatement strategy in spite of low ambient and cultural noise. With a computer "picking" program that has zoom, filtering, gain, trace isolation and balancing, and other features, there was no di-flEiculty in picking any of the lines.

Elevations of all shot and geophone positions were surveyed in, and then input into the modeling program. Elevation of the forward shot point was arbitrarily taken to be zero feet, and then all other elevations along the given line were relative to this assumed value at the forward shot point. The line positions were then registered to a detailed topographic map (see the line

location map, Fig. 2), and the arbitrary e1evatio.m were converted to absolute. Stakes were planted in the ground at the positions of the off end shots.

Brief Descristion of the Geo~hvsical Method Asslied - Seismic refiaction investigates the subsurface by generating arrival time and offset distance information to determine the path and velocity of an elastic disturbance in the ground. The disturbance is created by shot, hammer, weight drop, or some comparable method for putting impulsive energy into the ground.

Detectors are laid out at regular intervals in a line to measure the first arrival energy and the time of its arrival. The data are plotted in time-distance graphs, from which velocity of, and depth to, layers can be calculated. This is possible because rays (a continuum point on an expanding wave front) of the disturbance wave follows a direct route and is the first arrival energy at the close-in geophones. And the rays are refracted across layer boundaries where there is a difference in elastic and density properties. The critically refracted ray travels along the layer interface, at the speed of the lower layer, and continuously "feeds" energy back to the surface, to be successively detected by the line of geophones.

Shot are normally reversed from one end of the line to the other, to determine whether or not the layering is horizontal or dipping. And the split spread shot gives redundancy to improve the interpretation. The acquired data are computationally int ense. A ray-tracing computer program, SIPT2 in this instance, is used to iteratively honor all refracting surfaces, velocities, and to be able to consider a large number of layers, where they are present. A first energy arrival picking program, with such features as zoom, filtering, time stretching, separation of traces, AGC and balancing of traces, is also applied.

An independent approach to the analysis of seismic refiaction data was applied to several of the spreads. It is referred to as the "Optimized Velocity Model", wherein the subsurface is mapped in terms of velocity classes. It is apparent that highest velocities are associated with the mechanically strongest rocks. The boundaries between velocity classes are determined as the least squares minimum velocity variation for all paths that converge at an array of points, each determined independently in turn. These displays, when compared to the "traditional" seismic sections, strengthen confidence in the interpretation when they converge to a common solution.

Internretation - Monitor records are produced in the field with each shot (Fig. 3). These are prints of the raw data as it comes in to the recorder. They show the quality of the data, so that the operator can determine whether or not the data are pickable, or shots need to be repeated.

Two representative monitor records are illustrated, a mid split spread shot fiom line SL-8, and a fonvard shot from line SL-4. All arrivals are seen to be readily pickable on these raw records, although very minor wind and traffic noise is subtly detectable on the far offset traces.

More of the shooting parameters are listed below the monitor records (Fig. 3).

The first pick information, geophone positions, shot locations and geometry of the spreads are input to a routine that produces a time-distance plot (e.g. line 7 data, Fig. 4). The four curves express the wave arrivals fiom the three shots, forward, reverse, and a split spread. The split spread, however, produces two curves each going in opposite directions. The data, at this location, show slightly irregular plots and a subtly asymmetrical three-layer case, as is apparent fiom the three generalized straight linessuperimposed on the forward curve.

The slight asymmetry and irregularity of the group of curves indicates that the layers are not

uniform and horizontal. Minor undulations in the curves, based on the raw data, are, to some extent, explained by the fact that elevation corrections are not yet applied to the data in the time- distance plot. And some of the irregularity is explained by lateral velocity changes. Minor variations in the positions of the "dog-legs'' in the several curves are mostly an expression of the laterally changing thicknesses of the upper layers.

Models were calculated for the five lines of data (Figs. 5-12). All lines show a three layer case.

The site appears to be on relatively rare basic instrusive rock, within the dominantly granitic Peninsula Ranges batholith. The topmost layer probably consists of some combination of soil and colluviurn essentially undisturbed. Average velocity of the top layer is in the order of 1720 ftlsec, with moderate variation. This value is typical for soiVcolluvia1 materials over the batholith. Average thickness is approximately 9 feet, but the range is fiom feather edge to 15 feet. This is not surprising owing to the relief and the presence of outcrops in the bedrock ridge.

Generally the boundaries tend to mimic the ground surfBce profile. This is to be expected when weathering processes play a sigdicant role in the development of boundaries.

The second layer has an average thickness, where sampled, of approximately 40 feet, but ranges f?om 1 to over 50 feet. Layer 2 appears to be weathered bedrock. Fracturing, relief, facing slope, vegetation, lithology and other factors all contribute to variability of weathering.

Fracturing in crystalline rocks is usually an important factor in that fiacture zones admit air and water to deeper levels, resulting in deeper weathering. Average velocity of layer 2 is near 3780 Wsec, where sampled. The two westmost lines, SL-1 and SL-8, are aberrations, however, with velocities in the 5000 Alsec range. The site is near the apparent boundary between the basic igneous rocks and the granitic clan rocks; possibly, the two anomaIous lines are on granitics.

A third layer is continuous downward, presumably to much greater depths than the depth of investigation, which is approximately 75 feet. Velocity of this material is in the order of 8935 Wsec, with a fairly large range. This may Mer indicate that the site spans the boundary between two rock types. In fact third layer velocities beneath lines SL-1 and SL-8 are abnormally high, similar to layer 2 velocities. The batholith, as aforementioned, is obviously a composite entity, having discrete bodies with somewhat different chemistry, which would, in turn, equate to different mechanical properties and weathering characteristics.

It is highly probable that the geologic interpretations of the topmost and lowest layers detected are correct; that is, the top layer is soiVcolluvium and the deepest layer is unweathered crystalline intrusive rocks. It follows, therefore, that the middle layer is a weathered version of the third layer.

It is clear from the Caterpillar Rippability Chart (Fig. 13) that layer 1 is rippable everywhere, and layer 2 is rippable with heavier equipment. Layer 3 is hard, unweathered, mechanically strong rock, relatively unfiactured where the higher velocities were measured, and should be considered non-rippable everywhere. The Caterpillar Chart is empirical, but is based on thousands of samples of velocity vs rippability in terms of performance of various sized Cats. The chart illustrated is for a D9 Caterpillar.
-8-

SEISMIC REFRACTION DATA
Line Distance and Elevation in Feet
W f L-1 E
Jtl~IIIIItIII~ItIItIttt~1ttttt1tt[t1t1tt1tt
Spread J.
1940 - L
I
st,* I/fil luvium :... ,,..,., Weath. Bedrock [-") Bedrack FIGURE 5
I 1-1 3 1 1 ( ,. ._.....:..... Mypath. BMrod. F-7 Bedrock FIGURE 6
-9-

SEISMIC REFRACTION DATA
Line Distance and Elevation in Feet
1480h1'I"~'lll1~I~II~~I~~*~~~
0 SO 100 150 200 aso rt
I
Key to Lithology:
[-I SSOI 1/n1 IU,,~,,', bk?eth . Bedrock E-9 Bedrock
FIGURE 8
-1 0-
SElSMlC REFRACTION DATA
Line Distance and Elevation in Feet '
I Key to Litholosy:
[TJ Soi l/LI luui~ Weath. Bedrock Bedrock
FIGURE 9
Kw to Lithology:

L-1 sa i lye uu f----J ,..y:,7:e:n$:.f<. Weath. Bedrock F-. Bedrock FIGURE 10
-11-

SEISMIC REFRACTION DATA
Line Distance and Elevation in Feet
Keg trr Litholos~:
-1 1 w @earth. B&roO; e&rock
FIGURE 11
Kew to Lithology:
1-1 so* l,@l l""$",, fl*-*-7 ,:...... ,. .. :...:...:: ., ..., ..: ;: Neath . Bedrock F-I Bedrock FIGURE 12

GLACIAL TILL

IGNEOUS HOCKS
SANllSIONt
MC lAMOIilJ1-IIC i3OCKS
Figure 13. Caterpillar Rippability Chart
Subsurface Surveys professional personnel are trained and experienced and have completed thousands of projects since the company's inception in 1988. It is our policy to work diligently to bring this training and experience to bear to acquire quality data sets, which in turn, can provide clues usefil in formulating our interpretations. Still, non-uniqueness of interpretations, methodological limitations, and non-target interferences are prevailing problems.

Subsurface Surveys makes no guarantee either expressed or implied regarding the accuracy of the interpretations presented. And, in no event will Subsurfice Surveys be liable for any direct, indirect, special, incidental, or consequential damages resulting fiom interpretations and opinions presented herewith.

Conclusions - The seismic data appear to indicate that there are three geologic layers present at the site, namely soillcoliuvium, weathered bedrock and unweathered bedrock of both basic and granitic clan composition. Only the deepest layer, composed of unweathered crystalline rocks, is non-rippable, but the nearest it comes to the surface (where sampled) is approximately 16 feet under line SL-8. Depth to layer 3 is about 65 feet at its maximum under line SL-I. Inasmuch as line SL-8 is located in fairly flat terrain, it does not appear likely that drilling and blasting will be required.

All data acquired in this project are in confidential file in the office. They are available for review by authorized persons at any time. The opportunity to participate in this project is very much appreciated. Please call, if there are questions.

Appendix E
110712-002
January 30,2004

APPENDIX E
Static and Pseudostatic Slo~e Stabilitv Analvsis
Stability of the proposed slopes was evaluated under static and pseudostatic loading conditions using GSTABL7. The GSTABL7 program provides a general solution of the slope stability problems using a two-dimensional limit equilibrium method. For pseudostatic analysis, a static lateral force equivalent to 0.15 times the acceleration due to gravity was used. No correction for increased shear strength under seismic loading was applied for these analyses.

Our analysis utilized shear strength parameters based on shear test data from this investigation (Appendix C) and Leighton's previous experience on similar sites. Shear strength parameters used in the analysis are as follows:

Cohesion (psf) Friction Angle
Weathered Granitic Bedrock 400 37
Artificial Fill ' 380 26
A surficial analysis was also performed for the anticipated 2:l slopes. For this analysis, an assumed Cfoot depth of saturation was utilized along with the fill soil strength parameters indicated above.

Slope Section
Maximum fill slope, 30 A. @ 2:l
Maximum cut slope, 45 A. @ 2: 1
Factor of Safety
Slope Section
Fill slope @ 2: 1
Cut slope @ 2: 1
Gross Stability Static

2.72 2.15
Factor of Safety for
Surficial Stability

2.3 2.6
Gross Stability
Pseudostatic

1.98 1.55
WoodsidelEvans & Earbani 1 1071 2-002 45 ct Cut slope
C:\STEDWIN\TYPICA-1145FTCSL.PL2 Run By: Leighton Consulting Inc. 1/30/2004 3:OlPM

I I I I I I I
Soil Soil Total Saturated Cohesion Friction Piez.

Type Unit Wt. Unit Wt. Intercept Angle Surface
No. (pcfl (pcfl (psf) (deg) No.
1 1 130.0 140.0 400.0 37.0 0
0 I I I I I I I I I I
50 70 90 110 130 150 170 190 21 0 230 250 270
GSTABL7 v.2 FSmin=2.72
Safety Factors Are Calculated By The Simplified Janbu Method for the case of c & phi both > 0 WoodsidelEvans & Earbani 110712-002 45 ct Cut slope
C:\STEDWIN\TYPICA-1\45FTCSL.PL2 Run By: Leighton Consulting Inc. 1/30/2004 3:OOPM I4O
120
, I I 1
pi

I I I I I
Soil Soil Total Saturated Cohesion Friction Piez. Load Value a 1.98 Desc. Type Unit Wt. Unit Wt. Intercept Angle Surface Horiz Eqk 0.150 g< No. (pcf) (pcf) (psf) (deg) No.
1 1 130.0 140.0 400.0 37.0 0
- -
a
100
- -
O
1 80
- -
60 - -
1 40 - -
20 - -
0 I I I I I I 1 I I I
50 70 90 110 130 150 170 190 210 230 250 270
GSTABL7 v.2 FSmin=1.98
Safety Factors Are Calculated By The Simplified Janbu Method for the case of c & phi both > 0

LEIGHTON AND ASSOCIATES
Project No.:

Project:

Case:

Depth of Saturation (ft), Z
Buoyant Unit Weight of Soil (pcf), yb
Total Unit Weight of Soil (pcf), yt
Slope Angle, a
Angle of Internal Friction, 4
Cohesion (psf), c
Force Tending To Cause Movement:

FD = Zy, sin 2a / 2
SURFlClAL SLOPE STABILITY ANALYSIS
1 1 071 2-002
WoodsidelEvans & Garbanit
2:l Fill Slope
Project Name : WoodsidelEvans & Garbani
SURFICIALSTABILITY ProjectNumber: 1 1 071 2-002
DesignedIChecked : AXTIAXT
= 216.20 Iblft
Force Tending To Resist Movement:

F~=z~~cos~~ tan4 +(c)
= 493.24 Iblft
F.S. : 2Zyb cos2 a tan 4 + 2c -
Zyt sin 2a
F.S. = 2.3

LEIGHTON AND ASSOCIATES
SURFlClAL SLOPE STABILITY ANALYSIS
Project No.: 1 1 071 2-002
Project: WoodsidelEvans & Garbanit
Case: 2:1 Cut Slope
Depth of Saturation (ft), Z
Buoyant Unit Weight of Soil (pcf), yb
Total Unit Weight of Soil (pcf), yt
Slope Angle, a
Angle of Internal Friction, +
Cohesion (psf), c
Force Tending To Cause Movement:

FD = Zy, sin 201 / 2
Force Tending To Resist Movement:

F~=z~~cos~~ tan+ +(c)
= 587.01 Iblft
F.S. : 2Zyb cos2 a tan + 2c -
Zyt sin 201
F.S. = 2.6
Project Name : WoodsidelEvans & Garbani
SURFICIAL STABILITY Project Number: 1 1071 2-002
DesignedIChecked : AXTIAXT
= 224.20 Iblft
Appendix F

LEIGHTON AND ASSOCIATES, INC

GENERAL EARTHWORK AND GRADING SPECIFICATIONS FOR ROUGH GRADING

1.0 General

1.1 Intent: These General Earthwork and Grading Specifications are for the grading and earthwork shown on the approved grading plan(s) andor indicated in the geotechnical report(s). These Specifications are a part of the recommendations contained in the geotechnical report(s). In case of conflict, the specific recommendations in the geotechnical report shall supersede these more general Specifications. Observations of the earthwork by the project Geotechnical Consultant during the course of grading may result in new or revised recommendations that could supersede these specifications or the recommendations in the geotechnical report(s).

1.2 The Geotechnical Consultant of Record: Prior to commencement of work, the owner shall employ the Geotechnical Consultant of Record (Geotechnical Consultant). The Geotechnical Consultants shall be responsible for reviewing the approved geotechnical report(s) and accepting the adequacy of the preliminary geotechnical findings, conclusions, and recommendations prior to the commencement of the grading.

Prior to commencement of grading, the Geotechnical Consultant shall review the "work plan" prepared by the Earthwork Contractor (Contractor) and schedule sufficient personnel to perform the appropriate level of observation, mapping, and compaction testing.

During the grading and earthwork operations, the Geotechnical Consultant shall observe, map, and document the subsurface exposures to verify the geotechnical design assumptions. If the observed conditions are found to be significantly different than the interpreted assumptions during the design phase, the Geotechnical Consultant shall inform the owner, recommend appropriate changes in design to accommodate the observed conditions, and notify the review agency where required. Subsurface areas to be geotechnically observed, mapped, elevations recorded, andor tested include natural ground after it has been cleared for receiving fill but before fill is placed, bottoms of all "remedial removal" areas, all key bottoms, and benches made on sloping ground to receive fill.

The Geotechnical Consultant shall observe the moisture-conditioning and processing of the subgrade and fill materials and perform relative compaction testing of fill to determine the attained level of compaction. The' Geotechnical Consultant shall provide the test results to the owner and the Contractor on a routine and frequent basis.

1.3 The Earthwork Contractor: The Earthwork Contractor (Contractor) shall be qualified, experienced, and knowledgeable in earthwork logistics, preparation and processing of ground to receive fill, moisture-conditioning and processing of fill, and compacting fill.

The Contractor shall review and accept the plans, geotechnical report(s), and these Specifications prior to commencement of grading. The Contractor shall be solely responsible for performing the grading in accordance with the plans and specifications.

The Contractor shall prepare and submit to the owner and the Geotechnical Consultant a work plan that indicates the sequence of earthwork grading, the number of "spreads" of Leighton and Associates, Inc.

GENERAL EARTHWORK AND GRADING SPECIFICATIONS

Page 2 of 6 ends

Menifee City CouncilDecember 6, 2023

Menifee City Council
December 6, 2023