Exhibit A - Addendum to FEIR — Menifee City Council, December 6, 2023 (part 8 of 14)

Section 3
· Area ‘D’ – 2 Year - Pre-Development Condition – Unit Hydrograph

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - GOLDEN MEADOWS HYDROLOGY STUDY – AREA ‘D’ EXISTING CONDITION 'OVERALL' UNIT HYDROGRAPH - 2 YEAR 1 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021
BY: BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 60.04(Ac.) = 0.094 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 60.04(Ac.) = 0.094 Sq. Mi.

Length along longest watercourse = 2506.00(Ft.)
Length along longest watercourse measured to centroid = 1300.00(Ft.) Length along longest watercourse = 0.475 Mi.

Length along longest watercourse measured to centroid = 0.246 Mi.

Difference in elevation = 230.00(Ft.)
Slope along watercourse = 484.5970 Ft./Mi.

Average Manning's 'N' = 0.030
Lag time = 0.098 Hr.

Lag time = 5.90 Min.
25% of lag time = 1.48 Min.
40% of lag time = 2.36 Min.

Unit time = 5.00 Min.

Duration of storm = 1 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 0.55 33.02

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 1.30 78.05

STORM EVENT (YEAR) = 2.00
Area Averaged 2-Year Rainfall = 0.550(In)
Area Averaged 100-Year Rainfall = 1.300(In)

Point rain (area averaged) = 0.550(In)
Areal adjustment factor = 99.95 %
Adjusted average point rain = 0.550(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

60.040 73.40 0.000
Total Area Entered = 60.04(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-1 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.083 84.723 14.638 8.857 2 0.167 169.445 45.868 27.755 3 0.250 254.168 18.651 11.285 4 0.333 338.890 7.945 4.808 5 0.417 423.613 4.722 2.857 6 0.500 508.335 2.944 1.781 7 0.583 593.058 2.104 1.273 8 0.667 677.781 1.405 0.850 9 0.750 762.503 0.925 0.560 10 0.833 847.226 0.799 0.483 Sum = 100.000 Sum= 60.509
-----------------------------------------------------------------------

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 3.40 0.224 ( 0.520) 0.202 0.022 2 0.17 4.70 0.310 ( 0.520) 0.279 0.031 3 0.25 4.70 0.310 ( 0.520) 0.279 0.031 4 0.33 5.10 0.336 ( 0.520) 0.303 0.034 5 0.42 5.80 0.383 ( 0.520) 0.344 0.038 6 0.50 5.90 0.389 ( 0.520) 0.350 0.039 7 0.58 7.10 0.468 ( 0.520) 0.422 0.047 8 0.67 8.70 0.574 ( 0.520) 0.516 0.057 9 0.75 13.20 0.871 0.520 ( 0.784) 0.351 10 0.83 29.70 1.959 0.520 ( 1.763) 1.439 11 0.92 7.70 0.508 ( 0.520) 0.457 0.051 12 1.00 4.00 0.264 ( 0.520) 0.237 0.026 (Loss Rate Not Used)
Sum = 100.0 Sum = 2.2 Flood volume = Effective rainfall 0.18(In)
times area 60.0(Ac.)/[(In)/(Ft.)] = 0.9(Ac.Ft) Total soil loss = 0.37(In)
Total soil loss = 1.847(Ac.Ft)
Total rainfall = 0.55(In)
Flood volume = 39341.8 Cubic Feet
Total soil loss = 80462.9 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 44.955(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - GOLDEN MEADOWS HYDROLOGY STUDY – AREA ‘D’ EXISTING CONDITION 'OVERALL' UNIT HYDROGRAPH - 2 YEAR 3 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021
BY: BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 60.04(Ac.) = 0.094 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 60.04(Ac.) = 0.094 Sq. Mi.

Length along longest watercourse = 2506.00(Ft.)
Length along longest watercourse measured to centroid = 1300.00(Ft.) Length along longest watercourse = 0.475 Mi.

Length along longest watercourse measured to centroid = 0.246 Mi.

Difference in elevation = 230.00(Ft.)
Slope along watercourse = 484.5970 Ft./Mi.

Average Manning's 'N' = 0.030
Lag time = 0.098 Hr.

Lag time = 5.90 Min.
25% of lag time = 1.48 Min.
40% of lag time = 2.36 Min.

Unit time = 5.00 Min.

Duration of storm = 3 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 0.85 51.03

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 2.00 120.08

STORM EVENT (YEAR) = 2.00
Area Averaged 2-Year Rainfall = 0.850(In)
Area Averaged 100-Year Rainfall = 2.000(In)

Point rain (area averaged) = 0.850(In)
Areal adjustment factor = 99.97 %
Adjusted average point rain = 0.850(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

60.040 73.40 0.000
Total Area Entered = 60.04(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-1 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 1.30 0.133 ( 0.520) 0.119 0.013 2 0.17 1.30 0.133 ( 0.520) 0.119 0.013 3 0.25 1.10 0.112 ( 0.520) 0.101 0.011 4 0.33 1.50 0.153 ( 0.520) 0.138 0.015 5 0.42 1.50 0.153 ( 0.520) 0.138 0.015 6 0.50 1.80 0.184 ( 0.520) 0.165 0.018 7 0.58 1.50 0.153 ( 0.520) 0.138 0.015 8 0.67 1.80 0.184 ( 0.520) 0.165 0.018 9 0.75 1.80 0.184 ( 0.520) 0.165 0.018 10 0.83 1.50 0.153 ( 0.520) 0.138 0.015 11 0.92 1.60 0.163 ( 0.520) 0.147 0.016 12 1.00 1.80 0.184 ( 0.520) 0.165 0.018 13 1.08 2.20 0.224 ( 0.520) 0.202 0.022 14 1.17 2.20 0.224 ( 0.520) 0.202 0.022 15 1.25 2.20 0.224 ( 0.520) 0.202 0.022 16 1.33 2.00 0.204 ( 0.520) 0.184 0.020 17 1.42 2.60 0.265 ( 0.520) 0.239 0.027 18 1.50 2.70 0.275 ( 0.520) 0.248 0.028 19 1.58 2.40 0.245 ( 0.520) 0.220 0.024 20 1.67 2.70 0.275 ( 0.520) 0.248 0.028 21 1.75 3.30 0.337 ( 0.520) 0.303 0.034 22 1.83 3.10 0.316 ( 0.520) 0.285 0.032 23 1.92 2.90 0.296 ( 0.520) 0.266 0.030 24 2.00 3.00 0.306 ( 0.520) 0.275 0.031 25 2.08 3.10 0.316 ( 0.520) 0.285 0.032 26 2.17 4.20 0.428 ( 0.520) 0.385 0.043 27 2.25 5.00 0.510 ( 0.520) 0.459 0.051 28 2.33 3.50 0.357 ( 0.520) 0.321 0.036 29 2.42 6.80 0.693 0.520 ( 0.624) 0.173 30 2.50 7.30 0.744 0.520 ( 0.670) 0.224 31 2.58 8.20 0.836 0.520 ( 0.753) 0.316 32 2.67 5.90 0.602 0.520 ( 0.541) 0.081 33 2.75 2.00 0.204 ( 0.520) 0.184 0.020 34 2.83 1.80 0.184 ( 0.520) 0.165 0.018 35 2.92 1.80 0.184 ( 0.520) 0.165 0.018 36 3.00 0.60 0.061 ( 0.520) 0.055 0.006 (Loss Rate Not Used)
Sum = 100.0 Sum = 1.5 Flood volume = Effective rainfall 0.13(In)
times area 60.0(Ac.)/[(In)/(Ft.)] = 0.6(Ac.Ft) Total soil loss = 0.72(In)
Total soil loss = 3.615(Ac.Ft)
Total rainfall = 0.85(In)
Flood volume = 27734.9 Cubic Feet
Total soil loss = 157469.9 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 13.167(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - GOLDEN MEADOWS HYDROLOGY STUDY – AREA ‘D’ EXISTING CONDITION 'OVERALL' UNIT HYDROGRAPH - 2 YEAR 6 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021
BY: BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 60.04(Ac.) = 0.094 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 60.04(Ac.) = 0.094 Sq. Mi.

Length along longest watercourse = 2506.00(Ft.)
Length along longest watercourse measured to centroid = 1300.00(Ft.) Length along longest watercourse = 0.475 Mi.

Length along longest watercourse measured to centroid = 0.246 Mi.

Difference in elevation = 230.00(Ft.)
Slope along watercourse = 484.5970 Ft./Mi.

Average Manning's 'N' = 0.030
Lag time = 0.098 Hr.

Lag time = 5.90 Min.
25% of lag time = 1.48 Min.
40% of lag time = 2.36 Min.

Unit time = 5.00 Min.

Duration of storm = 6 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 1.20 72.05

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 3.00 180.12

STORM EVENT (YEAR) = 2.00
Area Averaged 2-Year Rainfall = 1.200(In)
Area Averaged 100-Year Rainfall = 3.000(In)

Point rain (area averaged) = 1.200(In)
Areal adjustment factor = 99.98 %
Adjusted average point rain = 1.200(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

60.040 73.40 0.000
Total Area Entered = 60.04(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-1 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 0.50 0.072 ( 0.520) 0.065 0.007 2 0.17 0.60 0.086 ( 0.520) 0.078 0.009 3 0.25 0.60 0.086 ( 0.520) 0.078 0.009 4 0.33 0.60 0.086 ( 0.520) 0.078 0.009 5 0.42 0.60 0.086 ( 0.520) 0.078 0.009 6 0.50 0.70 0.101 ( 0.520) 0.091 0.010 7 0.58 0.70 0.101 ( 0.520) 0.091 0.010 8 0.67 0.70 0.101 ( 0.520) 0.091 0.010 9 0.75 0.70 0.101 ( 0.520) 0.091 0.010 10 0.83 0.70 0.101 ( 0.520) 0.091 0.010 11 0.92 0.70 0.101 ( 0.520) 0.091 0.010 12 1.00 0.80 0.115 ( 0.520) 0.104 0.012 13 1.08 0.80 0.115 ( 0.520) 0.104 0.012 14 1.17 0.80 0.115 ( 0.520) 0.104 0.012 15 1.25 0.80 0.115 ( 0.520) 0.104 0.012 16 1.33 0.80 0.115 ( 0.520) 0.104 0.012 17 1.42 0.80 0.115 ( 0.520) 0.104 0.012 18 1.50 0.80 0.115 ( 0.520) 0.104 0.012 19 1.58 0.80 0.115 ( 0.520) 0.104 0.012 20 1.67 0.80 0.115 ( 0.520) 0.104 0.012 21 1.75 0.80 0.115 ( 0.520) 0.104 0.012 22 1.83 0.80 0.115 ( 0.520) 0.104 0.012 23 1.92 0.80 0.115 ( 0.520) 0.104 0.012 24 2.00 0.90 0.130 ( 0.520) 0.117 0.013 25 2.08 0.80 0.115 ( 0.520) 0.104 0.012 26 2.17 0.90 0.130 ( 0.520) 0.117 0.013 27 2.25 0.90 0.130 ( 0.520) 0.117 0.013 28 2.33 0.90 0.130 ( 0.520) 0.117 0.013 29 2.42 0.90 0.130 ( 0.520) 0.117 0.013 30 2.50 0.90 0.130 ( 0.520) 0.117 0.013 31 2.58 0.90 0.130 ( 0.520) 0.117 0.013 32 2.67 0.90 0.130 ( 0.520) 0.117 0.013 33 2.75 1.00 0.144 ( 0.520) 0.130 0.014 34 2.83 1.00 0.144 ( 0.520) 0.130 0.014 35 2.92 1.00 0.144 ( 0.520) 0.130 0.014 36 3.00 1.00 0.144 ( 0.520) 0.130 0.014 37 3.08 1.00 0.144 ( 0.520) 0.130 0.014 38 3.17 1.10 0.158 ( 0.520) 0.143 0.016 39 3.25 1.10 0.158 ( 0.520) 0.143 0.016 40 3.33 1.10 0.158 ( 0.520) 0.143 0.016 41 3.42 1.20 0.173 ( 0.520) 0.155 0.017 42 3.50 1.30 0.187 ( 0.520) 0.168 0.019 43 3.58 1.40 0.202 ( 0.520) 0.181 0.020 44 3.67 1.40 0.202 ( 0.520) 0.181 0.020 45 3.75 1.50 0.216 ( 0.520) 0.194 0.022 46 3.83 1.50 0.216 ( 0.520) 0.194 0.022 47 3.92 1.60 0.230 ( 0.520) 0.207 0.023 48 4.00 1.60 0.230 ( 0.520) 0.207 0.023 49 4.08 1.70 0.245 ( 0.520) 0.220 0.024 50 4.17 1.80 0.259 ( 0.520) 0.233 0.026 51 4.25 1.90 0.274 ( 0.520) 0.246 0.027 52 4.33 2.00 0.288 ( 0.520) 0.259 0.029 53 4.42 2.10 0.302 ( 0.520) 0.272 0.030 54 4.50 2.10 0.302 ( 0.520) 0.272 0.030 55 4.58 2.20 0.317 ( 0.520) 0.285 0.032 56 4.67 2.30 0.331 ( 0.520) 0.298 0.033 57 4.75 2.40 0.346 ( 0.520) 0.311 0.035 58 4.83 2.40 0.346 ( 0.520) 0.311 0.035 59 4.92 2.50 0.360 ( 0.520) 0.324 0.036 60 5.00 2.60 0.374 ( 0.520) 0.337 0.037 61 5.08 3.10 0.446 ( 0.520) 0.402 0.045 62 5.17 3.60 0.518 ( 0.520) 0.466 0.052 63 5.25 3.90 0.561 ( 0.520) 0.505 0.056 64 5.33 4.20 0.605 0.520 ( 0.544) 0.084 65 5.42 4.70 0.677 0.520 ( 0.609) 0.156 66 5.50 5.60 0.806 0.520 ( 0.726) 0.286 67 5.58 1.90 0.274 ( 0.520) 0.246 0.027 68 5.67 0.90 0.130 ( 0.520) 0.117 0.013 69 5.75 0.60 0.086 ( 0.520) 0.078 0.009 70 5.83 0.50 0.072 ( 0.520) 0.065 0.007 71 5.92 0.30 0.043 ( 0.520) 0.039 0.004 72 6.00 0.20 0.029 ( 0.520) 0.026 0.003 (Loss Rate Not Used)
Sum = 100.0 Sum = 1.8 Flood volume = Effective rainfall 0.15(In)
times area 60.0(Ac.)/[(In)/(Ft.)] = 0.7(Ac.Ft) Total soil loss = 1.05(In)
Total soil loss = 5.270(Ac.Ft)
Total rainfall = 1.20(In)
Flood volume = 31928.3 Cubic Feet
Total soil loss = 229552.0 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 10.737(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 6 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 5.0 10.0 15.0 20.0 ----------------------------------------------------------------------- 0+ 5 0.0004 0.06 Q | | | | 0+10 0.0023 0.28 Q | | | | 0+15 0.0051 0.40 Q | | | | 0+20 0.0082 0.45 Q | | | | 0+25 0.0115 0.48 Q | | | | 0+30 0.0149 0.51 VQ | | | | 0+35 0.0188 0.56 |Q | | | | 0+40 0.0228 0.58 |Q | | | | 0+45 0.0269 0.59 |Q | | | | 0+50 0.0310 0.60 |Q | | | | 0+55 0.0352 0.61 |Q | | | | 1+ 0 0.0395 0.62 |QV | | | | 1+ 5 0.0440 0.66 |QV | | | | 1+10 0.0487 0.68 |QV | | | | 1+15 0.0534 0.69 |QV | | | | 1+20 0.0582 0.69 |Q V | | | | 1+25 0.0629 0.69 |Q V | | | | 1+30 0.0677 0.69 |Q V | | | | 1+35 0.0725 0.70 |Q V | | | | 1+40 0.0773 0.70 |Q V | | | | 1+45 0.0821 0.70 |Q V | | | | 1+50 0.0869 0.70 |Q V | | | | 1+55 0.0917 0.70 |Q V | | | | 2+ 0 0.0966 0.71 |Q V | | | | 2+ 5 0.1017 0.74 |Q V | | | | 2+10 0.1067 0.73 |Q V | | | | 2+15 0.1119 0.76 |Q V | | | | 2+20 0.1172 0.77 |Q V | | | | 2+25 0.1225 0.78 |Q V | | | | 2+30 0.1279 0.78 |Q V | | | | 2+35 0.1333 0.78 |Q V | | | | 2+40 0.1387 0.78 |Q V | | | | 2+45 0.1442 0.80 |Q V | | | | 2+50 0.1499 0.84 |Q V | | | | 2+55 0.1558 0.85 |Q V | | | | 3+ 0 0.1617 0.86 |Q V | | | | 3+ 5 0.1677 0.86 |Q V| | | | 3+10 0.1737 0.88 |Q V| | | | 3+15 0.1801 0.92 |Q V| | | | 3+20 0.1866 0.94 |Q V | | | 3+25 0.1932 0.96 |Q V | | | 3+30 0.2002 1.02 | Q V | | | 3+35 0.2077 1.09 | Q |V | | | 3+40 0.2156 1.15 | Q |V | | | 3+45 0.2238 1.19 | Q | V | | | 3+50 0.2324 1.25 | Q | V | | | 3+55 0.2413 1.29 | Q | V | | | 4+ 0 0.2505 1.34 | Q | V | | | 4+ 5 0.2600 1.38 | Q | V | | | 4+10 0.2700 1.44 | Q | V | | | 4+15 0.2804 1.52 | Q | V | | | 4+20 0.2914 1.60 | Q | V | | | 4+25 0.3030 1.68 | Q | V | | | 4+30 0.3151 1.75 | Q | V | | | 4+35 0.3275 1.80 | Q | V | | | 4+40 0.3403 1.87 | Q | V | | | 4+45 0.3538 1.95 | Q | V| | | 4+50 0.3677 2.02 | Q | V | | 4+55 0.3819 2.06 | Q | V | | 5+ 0 0.3966 2.13 | Q | |V | | 5+ 5 0.4121 2.26 | Q | | V | | 5+10 0.4297 2.56 | Q | | V | | 5+15 0.4496 2.89 | Q | | V | | 5+20 0.4730 3.39 | Q | | V | | 5+25 0.5069 4.92 | Q| | V | | 5+30 0.5650 8.45 | | Q | V | 5+35 0.6390 10.74 | | |Q | V | 5+40 0.6758 5.34 | Q | | V | 5+45 0.6956 2.88 | Q | | | V | 5+50 0.7085 1.88 | Q | | | V | 5+55 0.7176 1.31 | Q | | | V| 6+ 0 0.7240 0.93 |Q | | | V| 6+ 5 0.7282 0.62 |Q | | | V| 6+10 0.7307 0.36 Q | | | V| 6+15 0.7322 0.21 Q | | | V| 6+20 0.7326 0.05 Q | | | V| 6+25 0.7328 0.03 Q | | | V| 6+30 0.7329 0.02 Q | | | V| 6+35 0.7329 0.01 Q | | | V| 6+40 0.7330 0.00 Q | | | V| 6+45 0.7330 0.00 Q | | | V -----------------------------------------------------------------------

U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD/CIVILDESIGN, 1989 - 2014, Version 9.0 Study date 11/08/21 File: EXD002242.out
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------ Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978
Program License Serial Number 6406
--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used
English Units used in output format
--------------------------------------------------------------------- TRACT 31194 - GOLDEN MEADOWS HYDROLOGY STUDY – AREA ‘D’ EXISTING CONDITION 'OVERALL' UNIT HYDROGRAPH - 2 YEAR HOUR STORM

HUNSAKER & ASSOCIATES,
BY: BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 60.04(Ac.) = 0.094 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 60.04(Ac.) = 0.094 Sq. Mi.

Length along longest watercourse = 2506.00(Ft.)
Length along longest watercourse measured to centroid = 1300.00(Ft.) Length along longest watercourse = 0.475 Mi.

Length along longest watercourse measured to centroid = 0.246 Mi.

Difference in elevation = 230.00(Ft.)
Slope along watercourse = 484.5970 Ft./Mi.

Average Manning's 'N' = 0.030
Lag time = 0.098 Hr.

Lag time = 5.90 Min.
25% of lag time = 1.48 Min.
40% of lag time = 2.36 Min.

Unit time = 15.00 Min.

Duration of storm = 24 Hour(s)
User Entered Base Flow = 0.00(CFS)
2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 2.00 120.08
100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 5.00 300.20
STORM EVENT (YEAR) = 2.00
Area Averaged 2-Year Rainfall = 2.000(In)
Area Averaged 100-Year Rainfall = 5.000(In)
Point rain (area averaged) = 2.000(In)
Areal adjustment factor = 99.99 %
Adjusted average point rain = 2.000(In)
Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

60.040 73.40 0.000
Total Area Entered = 60.04(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-1 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

73.4 55.1 0.520 0.000 0.520 1.000 0.520 Sum (F) = 0.520
Area averaged mean soil loss (F) (In/Hr) = 0.520
Minimum soil loss rate ((In/Hr)) = 0.260
(for 24 hour storm duration)
Soil low loss rate (decimal) = 0.900
--------------------------------------------------------------------- U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.250 254.168 51.434 31.122 2 0.500 508.335 39.798 24.081 3 0.750 762.503 6.885 4.166 4 1.000 1016.671 1.884 1.140 Sum = 100.000 Sum= 60.509
----------------------------------------------------------------------- The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.25 0.20 0.016 ( 0.919) 0.014 0.002 2 0.50 0.30 0.024 ( 0.908) 0.022 0.002 3 0.75 0.30 0.024 ( 0.897) 0.022 0.002 4 1.00 0.40 0.032 ( 0.887) 0.029 0.003 5 1.25 0.30 0.024 ( 0.876) 0.022 0.002 6 1.50 0.30 0.024 ( 0.866) 0.022 0.002 7 1.75 0.30 0.024 ( 0.856) 0.022 0.002 8 2.00 0.40 0.032 ( 0.845) 0.029 0.003 9 2.25 0.40 0.032 ( 0.835) 0.029 0.003 10 2.50 0.40 0.032 ( 0.825) 0.029 0.003 11 2.75 0.50 0.040 ( 0.815) 0.036 0.004 12 3.00 0.50 0.040 ( 0.805) 0.036 0.004 13 3.25 0.50 0.040 ( 0.795) 0.036 0.004 14 3.50 0.50 0.040 ( 0.785) 0.036 0.004 15 3.75 0.50 0.040 ( 0.775) 0.036 0.004 16 4.00 0.60 0.048 ( 0.765) 0.043 0.005 17 4.25 0.60 0.048 ( 0.756) 0.043 0.005 18 4.50 0.70 0.056 ( 0.746) 0.050 0.006 19 4.75 0.70 0.056 ( 0.736) 0.050 0.006 20 5.00 0.80 0.064 ( 0.727) 0.058 0.006 21 5.25 0.60 0.048 ( 0.718) 0.043 0.005 22 5.50 0.70 0.056 ( 0.708) 0.050 0.006 23 5.75 0.80 0.064 ( 0.699) 0.058 0.006 24 6.00 0.80 0.064 ( 0.690) 0.058 0.006 25 6.25 0.90 0.072 ( 0.681) 0.065 0.007 26 6.50 0.90 0.072 ( 0.671) 0.065 0.007 27 6.75 1.00 0.080 ( 0.662) 0.072 0.008 28 7.00 1.00 0.080 ( 0.654) 0.072 0.008 29 7.25 1.00 0.080 ( 0.645) 0.072 0.008 30 7.50 1.10 0.088 ( 0.636) 0.079 0.009 31 7.75 1.20 0.096 ( 0.627) 0.086 0.010 32 8.00 1.30 0.104 ( 0.618) 0.094 0.010 33 8.25 1.50 0.120 ( 0.610) 0.108 0.012 34 8.50 1.50 0.120 ( 0.601) 0.108 0.012 35 8.75 1.60 0.128 ( 0.593) 0.115 0.013 36 9.00 1.70 0.136 ( 0.585) 0.122 0.014 37 9.25 1.90 0.152 ( 0.576) 0.137 0.015 38 9.50 2.00 0.160 ( 0.568) 0.144 0.016 39 9.75 2.10 0.168 ( 0.560) 0.151 0.017 40 10.00 2.20 0.176 ( 0.552) 0.158 0.018 41 10.25 1.50 0.120 ( 0.544) 0.108 0.012 42 10.50 1.50 0.120 ( 0.536) 0.108 0.012 43 10.75 2.00 0.160 ( 0.528) 0.144 0.016 44 11.00 2.00 0.160 ( 0.521) 0.144 0.016 45 11.25 1.90 0.152 ( 0.513) 0.137 0.015 46 11.50 1.90 0.152 ( 0.505) 0.137 0.015 47 11.75 1.70 0.136 ( 0.498) 0.122 0.014 48 12.00 1.80 0.144 ( 0.490) 0.130 0.014 49 12.25 2.50 0.200 ( 0.483) 0.180 0.020 50 12.50 2.60 0.208 ( 0.476) 0.187 0.021 51 12.75 2.80 0.224 ( 0.469) 0.202 0.022 52 13.00 2.90 0.232 ( 0.462) 0.209 0.023 53 13.25 3.40 0.272 ( 0.455) 0.245 0.027 54 13.50 3.40 0.272 ( 0.448) 0.245 0.027 55 13.75 2.30 0.184 ( 0.441) 0.166 0.018 56 14.00 2.30 0.184 ( 0.434) 0.166 0.018 57 14.25 2.70 0.216 ( 0.428) 0.194 0.022 58 14.50 2.60 0.208 ( 0.421) 0.187 0.021 59 14.75 2.60 0.208 ( 0.415) 0.187 0.021 60 15.00 2.50 0.200 ( 0.408) 0.180 0.020 61 15.25 2.40 0.192 ( 0.402) 0.173 0.019 62 15.50 2.30 0.184 ( 0.396) 0.166 0.018 63 15.75 1.90 0.152 ( 0.390) 0.137 0.015 64 16.00 1.90 0.152 ( 0.384) 0.137 0.015 65 16.25 0.40 0.032 ( 0.378) 0.029 0.003 66 16.50 0.40 0.032 ( 0.372) 0.029 0.003 67 16.75 0.30 0.024 ( 0.367) 0.022 0.002 68 17.00 0.30 0.024 ( 0.361) 0.022 0.002 69 17.25 0.50 0.040 ( 0.356) 0.036 0.004 70 17.50 0.50 0.040 ( 0.350) 0.036 0.004 71 17.75 0.50 0.040 ( 0.345) 0.036 0.004 72 18.00 0.40 0.032 ( 0.340) 0.029 0.003 73 18.25 0.40 0.032 ( 0.335) 0.029 0.003 74 18.50 0.40 0.032 ( 0.330) 0.029 0.003 75 18.75 0.30 0.024 ( 0.325) 0.022 0.002 76 19.00 0.20 0.016 ( 0.321) 0.014 0.002 77 19.25 0.30 0.024 ( 0.316) 0.022 0.002 78 19.50 0.40 0.032 ( 0.312) 0.029 0.003 79 19.75 0.30 0.024 ( 0.308) 0.022 0.002 80 20.00 0.20 0.016 ( 0.303) 0.014 0.002 81 20.25 0.30 0.024 ( 0.299) 0.022 0.002 82 20.50 0.30 0.024 ( 0.296) 0.022 0.002 83 20.75 0.30 0.024 ( 0.292) 0.022 0.002 84 21.00 0.20 0.016 ( 0.288) 0.014 0.002 85 21.25 0.30 0.024 ( 0.285) 0.022 0.002 86 21.50 0.20 0.016 ( 0.282) 0.014 0.002 87 21.75 0.30 0.024 ( 0.279) 0.022 0.002 88 22.00 0.20 0.016 ( 0.276) 0.014 0.002 89 22.25 0.30 0.024 ( 0.273) 0.022 0.002 90 22.50 0.20 0.016 ( 0.270) 0.014 0.002 91 22.75 0.20 0.016 ( 0.268) 0.014 0.002 92 23.00 0.20 0.016 ( 0.266) 0.014 0.002 93 23.25 0.20 0.016 ( 0.264) 0.014 0.002 94 23.50 0.20 0.016 ( 0.262) 0.014 0.002 95 23.75 0.20 0.016 ( 0.261) 0.014 0.002 96 24.00 0.20 0.016 ( 0.260) 0.014 0.002 (Loss Rate Not Used)
Sum = 100.0 Sum = 0.8 Flood volume = Effective rainfall 0.20(In)
times area 60.0(Ac.)/[(In)/(Ft.)] = 1.0(Ac.Ft) Total soil loss = 1.80(In)
Total soil loss = 9.005(Ac.Ft)
Total rainfall = 2.00(In)
Flood volume = 43583.9 Cubic Feet
Total soil loss = 392255.4 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 1.624(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 24 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 15 Minute intervals ((CFS))
-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 2.5 5.0 7.5 10.0 ----------------------------------------------------------------------- 0+15 0.0010 0.05 Q | | | | 0+30 0.0034 0.11 Q | | | | 0+45 0.0062 0.14 Q | | | | 1+ 0 0.0097 0.17 Q | | | | 1+15 0.0131 0.16 Q | | | | 1+30 0.0162 0.15 Q | | | | 1+45 0.0192 0.15 Q | | | | 2+ 0 0.0228 0.17 Q | | | | 2+15 0.0267 0.19 QV | | | | 2+30 0.0306 0.19 QV | | | | 2+45 0.0352 0.22 QV | | | | 3+ 0 0.0401 0.24 QV | | | | 3+15 0.0451 0.24 QV | | | | 3+30 0.0501 0.24 Q V | | | | 3+45 0.0551 0.24 Q V | | | | 4+ 0 0.0606 0.27 |QV | | | | 4+15 0.0665 0.29 |QV | | | | 4+30 0.0730 0.31 |QV | | | | 4+45 0.0799 0.33 |Q V | | | | 5+ 0 0.0874 0.36 |Q V | | | | 5+15 0.0943 0.33 |Q V | | | | 5+30 0.1010 0.32 |Q V | | | | 5+45 0.1084 0.36 |Q V | | | | 6+ 0 0.1163 0.38 |Q V | | | | 6+15 0.1248 0.41 |Q V | | | | 6+30 0.1338 0.43 |Q V | | | | 6+45 0.1433 0.46 |Q V | | | | 7+ 0 0.1532 0.48 |Q V | | | | 7+15 0.1632 0.48 |Q V | | | | 7+30 0.1737 0.51 | Q V | | | | 7+45 0.1851 0.55 | Q V | | | | 8+ 0 0.1975 0.60 | Q V | | | | 8+15 0.2115 0.67 | Q V | | | | 8+30 0.2263 0.72 | Q V| | | | 8+45 0.2418 0.75 | Q V| | | | 9+ 0 0.2582 0.80 | Q V | | | 9+15 0.2761 0.87 | Q V | | | 9+30 0.2955 0.94 | Q |V | | | 9+45 0.3159 0.99 | Q | V | | | 10+ 0 0.3373 1.04 | Q | V | | | 10+15 0.3556 0.89 | Q | V | | | 10+30 0.3712 0.76 | Q | V | | | 10+45 0.3889 0.86 | Q | V | | | 11+ 0 0.4085 0.95 | Q | V | | | 11+15 0.4279 0.94 | Q | V | | | 11+30 0.4470 0.92 | Q | V | | | 11+45 0.4650 0.87 | Q | V | | | 12+ 0 0.4827 0.86 | Q | V| | | 12+15 0.5042 1.04 | Q | V | | 12+30 0.5291 1.20 | Q | V | | 12+45 0.5560 1.30 | Q | | V | | 13+ 0 0.5843 1.37 | Q | | V | | 13+15 0.6158 1.52 | Q | | V | | 13+30 0.6493 1.62 | Q | | V | | 13+45 0.6776 1.37 | Q | | V | | 14+ 0 0.7016 1.16 | Q | | V | | 14+15 0.7268 1.22 | Q | | V| | 14+30 0.7530 1.27 | Q | | V | 14+45 0.7790 1.26 | Q | | V | 15+ 0 0.8045 1.24 | Q | | | V | 15+15 0.8291 1.19 | Q | | | V | 15+30 0.8527 1.14 | Q | | | V | 15+45 0.8738 1.02 | Q | | | V | 16+ 0 0.8932 0.94 | Q | | | V | 16+15 0.9045 0.55 | Q | | | V | 16+30 0.9098 0.26 |Q | | | V | 16+45 0.9136 0.18 Q | | | V | 17+ 0 0.9167 0.15 Q | | | V | 17+15 0.9208 0.20 Q | | | V | 17+30 0.9256 0.23 Q | | | V | 17+45 0.9305 0.24 Q | | | V | 18+ 0 0.9350 0.22 Q | | | V | 18+15 0.9391 0.20 Q | | | V | 18+30 0.9431 0.19 Q | | | V | 18+45 0.9466 0.17 Q | | | V | 19+ 0 0.9492 0.12 Q | | | V | 19+15 0.9518 0.13 Q | | | V | 19+30 0.9553 0.17 Q | | | V | 19+45 0.9587 0.16 Q | | | V | 20+ 0 0.9612 0.12 Q | | | V | 20+15 0.9638 0.13 Q | | | V | 20+30 0.9668 0.14 Q | | | V | 20+45 0.9698 0.14 Q | | | V | 21+ 0 0.9722 0.12 Q | | | V | 21+15 0.9748 0.13 Q | | | V | 21+30 0.9773 0.12 Q | | | V| 21+45 0.9798 0.13 Q | | | V| 22+ 0 0.9823 0.12 Q | | | V| 22+15 0.9849 0.13 Q | | | V| 22+30 0.9873 0.12 Q | | | V| 22+45 0.9893 0.10 Q | | | V| 23+ 0 0.9914 0.10 Q | | | V| 23+15 0.9934 0.10 Q | | | V| 23+30 0.9954 0.10 Q | | | V| 23+45 0.9974 0.10 Q | | | V| 24+ 0 0.9994 0.10 Q | | | V| 24+15 1.0003 0.05 Q | | | V| 24+30 1.0005 0.01 Q | | | V| 24+45 1.0005 0.00 Q | | | V ----------------------------------------------------------------------- Preliminary Hydrology Analysis – Golden Meadows – Tract 31194 – Major Modification

Page 3 ends

Section 3
· Area ‘D’ – 10 Year - Pre-Development Condition – Unit Hydrograph

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - GOLDEN MEADOWS HYDROLOGY STUDY – AREA ‘D’ EXISTING CONDITION 'OVERALL' UNIT HYDROGRAPH - 10 YEAR 1 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021
BY: BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 60.04(Ac.) = 0.094 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 60.04(Ac.) = 0.094 Sq. Mi.

Length along longest watercourse = 2506.00(Ft.)
Length along longest watercourse measured to centroid = 1300.00(Ft.) Length along longest watercourse = 0.475 Mi.

Length along longest watercourse measured to centroid = 0.246 Mi.

Difference in elevation = 230.00(Ft.)
Slope along watercourse = 484.5970 Ft./Mi.

Average Manning's 'N' = 0.030
Lag time = 0.098 Hr.

Lag time = 5.90 Min.
25% of lag time = 1.48 Min.
40% of lag time = 2.36 Min.

Unit time = 5.00 Min.

Duration of storm = 1 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 0.55 33.02

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 1.30 78.05

STORM EVENT (YEAR) = 10.00
Area Averaged 2-Year Rainfall = 0.550(In)
Area Averaged 100-Year Rainfall = 1.300(In)

Point rain (area averaged) = 0.859(In)
Areal adjustment factor = 99.95 %
Adjusted average point rain = 0.858(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

60.040 73.40 0.000
Total Area Entered = 60.04(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-2 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 3.40 0.350 ( 0.322) 0.315 0.035 2 0.17 4.70 0.484 0.322 ( 0.436) 0.162 3 0.25 4.70 0.484 0.322 ( 0.436) 0.162 4 0.33 5.10 0.525 0.322 ( 0.473) 0.203 5 0.42 5.80 0.597 0.322 ( 0.538) 0.275 6 0.50 5.90 0.608 0.322 ( 0.547) 0.286 7 0.58 7.10 0.731 0.322 ( 0.658) 0.409 8 0.67 8.70 0.896 0.322 ( 0.806) 0.574 9 0.75 13.20 1.359 0.322 ( 1.223) 1.037 10 0.83 29.70 3.058 0.322 ( 2.752) 2.736 11 0.92 7.70 0.793 0.322 ( 0.714) 0.471 12 1.00 4.00 0.412 0.322 ( 0.371) 0.090 (Loss Rate Not Used)
Sum = 100.0 Sum = 6.4 Flood volume = Effective rainfall 0.54(In)
times area 60.0(Ac.)/[(In)/(Ft.)] = 2.7(Ac.Ft) Total soil loss = 0.32(In)
Total soil loss = 1.608(Ac.Ft)
Total rainfall = 0.86(In)
Flood volume = 116987.5 Cubic Feet
Total soil loss = 70028.9 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 97.004(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - GOLDEN MEADOWS HYDROLOGY STUDY – AREA ‘D’ EXISTING CONDITION 'OVERALL' UNIT HYDROGRAPH - 10 YEAR 3 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021
BY: BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 60.04(Ac.) = 0.094 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 60.04(Ac.) = 0.094 Sq. Mi.

Length along longest watercourse = 2506.00(Ft.)
Length along longest watercourse measured to centroid = 1300.00(Ft.) Length along longest watercourse = 0.475 Mi.

Length along longest watercourse measured to centroid = 0.246 Mi.

Difference in elevation = 230.00(Ft.)
Slope along watercourse = 484.5970 Ft./Mi.

Average Manning's 'N' = 0.030
Lag time = 0.098 Hr.

Lag time = 5.90 Min.
25% of lag time = 1.48 Min.
40% of lag time = 2.36 Min.

Unit time = 5.00 Min.

Duration of storm = 3 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 0.85 51.03

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 2.00 120.08

STORM EVENT (YEAR) = 10.00
Area Averaged 2-Year Rainfall = 0.850(In)
Area Averaged 100-Year Rainfall = 2.000(In)

Point rain (area averaged) = 1.323(In)
Areal adjustment factor = 99.97 %
Adjusted average point rain = 1.323(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

60.040 73.40 0.000
Total Area Entered = 60.04(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-2 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 1.30 0.206 ( 0.322) 0.186 0.021 2 0.17 1.30 0.206 ( 0.322) 0.186 0.021 3 0.25 1.10 0.175 ( 0.322) 0.157 0.017 4 0.33 1.50 0.238 ( 0.322) 0.214 0.024 5 0.42 1.50 0.238 ( 0.322) 0.214 0.024 6 0.50 1.80 0.286 ( 0.322) 0.257 0.029 7 0.58 1.50 0.238 ( 0.322) 0.214 0.024 8 0.67 1.80 0.286 ( 0.322) 0.257 0.029 9 0.75 1.80 0.286 ( 0.322) 0.257 0.029 10 0.83 1.50 0.238 ( 0.322) 0.214 0.024 11 0.92 1.60 0.254 ( 0.322) 0.229 0.025 12 1.00 1.80 0.286 ( 0.322) 0.257 0.029 13 1.08 2.20 0.349 ( 0.322) 0.314 0.035 14 1.17 2.20 0.349 ( 0.322) 0.314 0.035 15 1.25 2.20 0.349 ( 0.322) 0.314 0.035 16 1.33 2.00 0.317 ( 0.322) 0.286 0.032 17 1.42 2.60 0.413 0.322 ( 0.371) 0.091 18 1.50 2.70 0.429 0.322 ( 0.386) 0.107 19 1.58 2.40 0.381 0.322 ( 0.343) 0.059 20 1.67 2.70 0.429 0.322 ( 0.386) 0.107 21 1.75 3.30 0.524 0.322 ( 0.471) 0.202 22 1.83 3.10 0.492 0.322 ( 0.443) 0.170 23 1.92 2.90 0.460 0.322 ( 0.414) 0.138 24 2.00 3.00 0.476 0.322 ( 0.429) 0.154 25 2.08 3.10 0.492 0.322 ( 0.443) 0.170 26 2.17 4.20 0.667 0.322 ( 0.600) 0.345 27 2.25 5.00 0.794 0.322 ( 0.714) 0.472 28 2.33 3.50 0.556 0.322 ( 0.500) 0.234 29 2.42 6.80 1.079 0.322 ( 0.971) 0.758 30 2.50 7.30 1.159 0.322 ( 1.043) 0.837 31 2.58 8.20 1.302 0.322 ( 1.171) 0.980 32 2.67 5.90 0.937 0.322 ( 0.843) 0.615 33 2.75 2.00 0.317 ( 0.322) 0.286 0.032 34 2.83 1.80 0.286 ( 0.322) 0.257 0.029 35 2.92 1.80 0.286 ( 0.322) 0.257 0.029 36 3.00 0.60 0.095 ( 0.322) 0.086 0.010 (Loss Rate Not Used)
Sum = 100.0 Sum = 6.0 Flood volume = Effective rainfall 0.50(In)
times area 60.0(Ac.)/[(In)/(Ft.)] = 2.5(Ac.Ft) Total soil loss = 0.83(In)
Total soil loss = 4.131(Ac.Ft)
Total rainfall = 1.32(In)
Flood volume = 108354.4 Cubic Feet
Total soil loss = 179937.3 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 47.992(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - GOLDEN MEADOWS HYDROLOGY STUDY – AREA ‘D’ EXISTING CONDITION 'OVERALL' UNIT HYDROGRAPH - 10 YEAR 6 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021
BY: BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 60.04(Ac.) = 0.094 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 60.04(Ac.) = 0.094 Sq. Mi.

Length along longest watercourse = 2506.00(Ft.)
Length along longest watercourse measured to centroid = 1300.00(Ft.) Length along longest watercourse = 0.475 Mi.

Length along longest watercourse measured to centroid = 0.246 Mi.

Difference in elevation = 230.00(Ft.)
Slope along watercourse = 484.5970 Ft./Mi.

Average Manning's 'N' = 0.030
Lag time = 0.098 Hr.

Lag time = 5.90 Min.
25% of lag time = 1.48 Min.
40% of lag time = 2.36 Min.

Unit time = 5.00 Min.

Duration of storm = 6 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 1.20 72.05

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 3.00 180.12

STORM EVENT (YEAR) = 10.00
Area Averaged 2-Year Rainfall = 1.200(In)
Area Averaged 100-Year Rainfall = 3.000(In)

Point rain (area averaged) = 1.941(In)
Areal adjustment factor = 99.98 %
Adjusted average point rain = 1.940(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

60.040 73.40 0.000
Total Area Entered = 60.04(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-2 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 0.50 0.116 ( 0.322) 0.105 0.012 2 0.17 0.60 0.140 ( 0.322) 0.126 0.014 3 0.25 0.60 0.140 ( 0.322) 0.126 0.014 4 0.33 0.60 0.140 ( 0.322) 0.126 0.014 5 0.42 0.60 0.140 ( 0.322) 0.126 0.014 6 0.50 0.70 0.163 ( 0.322) 0.147 0.016 7 0.58 0.70 0.163 ( 0.322) 0.147 0.016 8 0.67 0.70 0.163 ( 0.322) 0.147 0.016 9 0.75 0.70 0.163 ( 0.322) 0.147 0.016 10 0.83 0.70 0.163 ( 0.322) 0.147 0.016 11 0.92 0.70 0.163 ( 0.322) 0.147 0.016 12 1.00 0.80 0.186 ( 0.322) 0.168 0.019 13 1.08 0.80 0.186 ( 0.322) 0.168 0.019 14 1.17 0.80 0.186 ( 0.322) 0.168 0.019 15 1.25 0.80 0.186 ( 0.322) 0.168 0.019 16 1.33 0.80 0.186 ( 0.322) 0.168 0.019 17 1.42 0.80 0.186 ( 0.322) 0.168 0.019 18 1.50 0.80 0.186 ( 0.322) 0.168 0.019 19 1.58 0.80 0.186 ( 0.322) 0.168 0.019 20 1.67 0.80 0.186 ( 0.322) 0.168 0.019 21 1.75 0.80 0.186 ( 0.322) 0.168 0.019 22 1.83 0.80 0.186 ( 0.322) 0.168 0.019 23 1.92 0.80 0.186 ( 0.322) 0.168 0.019 24 2.00 0.90 0.210 ( 0.322) 0.189 0.021 25 2.08 0.80 0.186 ( 0.322) 0.168 0.019 26 2.17 0.90 0.210 ( 0.322) 0.189 0.021 27 2.25 0.90 0.210 ( 0.322) 0.189 0.021 28 2.33 0.90 0.210 ( 0.322) 0.189 0.021 29 2.42 0.90 0.210 ( 0.322) 0.189 0.021 30 2.50 0.90 0.210 ( 0.322) 0.189 0.021 31 2.58 0.90 0.210 ( 0.322) 0.189 0.021 32 2.67 0.90 0.210 ( 0.322) 0.189 0.021 33 2.75 1.00 0.233 ( 0.322) 0.210 0.023 34 2.83 1.00 0.233 ( 0.322) 0.210 0.023 35 2.92 1.00 0.233 ( 0.322) 0.210 0.023 36 3.00 1.00 0.233 ( 0.322) 0.210 0.023 37 3.08 1.00 0.233 ( 0.322) 0.210 0.023 38 3.17 1.10 0.256 ( 0.322) 0.230 0.026 39 3.25 1.10 0.256 ( 0.322) 0.230 0.026 40 3.33 1.10 0.256 ( 0.322) 0.230 0.026 41 3.42 1.20 0.279 ( 0.322) 0.251 0.028 42 3.50 1.30 0.303 ( 0.322) 0.272 0.030 43 3.58 1.40 0.326 ( 0.322) 0.293 0.033 44 3.67 1.40 0.326 ( 0.322) 0.293 0.033 45 3.75 1.50 0.349 ( 0.322) 0.314 0.035 46 3.83 1.50 0.349 ( 0.322) 0.314 0.035 47 3.92 1.60 0.373 0.322 ( 0.335) 0.051 48 4.00 1.60 0.373 0.322 ( 0.335) 0.051 49 4.08 1.70 0.396 0.322 ( 0.356) 0.074 50 4.17 1.80 0.419 0.322 ( 0.377) 0.097 51 4.25 1.90 0.442 0.322 ( 0.398) 0.120 52 4.33 2.00 0.466 0.322 ( 0.419) 0.144 53 4.42 2.10 0.489 0.322 ( 0.440) 0.167 54 4.50 2.10 0.489 0.322 ( 0.440) 0.167 55 4.58 2.20 0.512 0.322 ( 0.461) 0.190 56 4.67 2.30 0.535 0.322 ( 0.482) 0.214 57 4.75 2.40 0.559 0.322 ( 0.503) 0.237 58 4.83 2.40 0.559 0.322 ( 0.503) 0.237 59 4.92 2.50 0.582 0.322 ( 0.524) 0.260 60 5.00 2.60 0.605 0.322 ( 0.545) 0.283 61 5.08 3.10 0.722 0.322 ( 0.650) 0.400 62 5.17 3.60 0.838 0.322 ( 0.754) 0.516 63 5.25 3.90 0.908 0.322 ( 0.817) 0.586 64 5.33 4.20 0.978 0.322 ( 0.880) 0.656 65 5.42 4.70 1.094 0.322 ( 0.985) 0.772 66 5.50 5.60 1.304 0.322 ( 1.173) 0.982 67 5.58 1.90 0.442 0.322 ( 0.398) 0.120 68 5.67 0.90 0.210 ( 0.322) 0.189 0.021 69 5.75 0.60 0.140 ( 0.322) 0.126 0.014 70 5.83 0.50 0.116 ( 0.322) 0.105 0.012 71 5.92 0.30 0.070 ( 0.322) 0.063 0.007 72 6.00 0.20 0.047 ( 0.322) 0.042 0.005 (Loss Rate Not Used)
Sum = 100.0 Sum = 7.3 Flood volume = Effective rainfall 0.61(In)
times area 60.0(Ac.)/[(In)/(Ft.)] = 3.1(Ac.Ft) Total soil loss = 1.33(In)
Total soil loss = 6.645(Ac.Ft)
Total rainfall = 1.94(In)
Flood volume = 133391.9 Cubic Feet
Total soil loss = 289451.0 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 43.816(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 6 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 12.5 25.0 37.5 50.0 ----------------------------------------------------------------------- 0+ 5 0.0007 0.10 Q | | | | 0+10 0.0038 0.45 Q | | | | 0+15 0.0082 0.64 Q | | | | 0+20 0.0132 0.73 Q | | | | 0+25 0.0185 0.77 Q | | | | 0+30 0.0241 0.82 Q | | | | 0+35 0.0304 0.90 Q | | | | 0+40 0.0368 0.94 Q | | | | 0+45 0.0435 0.96 Q | | | | 0+50 0.0502 0.97 Q | | | | 0+55 0.0569 0.98 Q | | | | 1+ 0 0.0638 1.00 Q | | | | 1+ 5 0.0712 1.07 Q | | | | 1+10 0.0787 1.10 QV | | | | 1+15 0.0864 1.11 QV | | | | 1+20 0.0941 1.12 QV | | | | 1+25 0.1018 1.12 QV | | | | 1+30 0.1095 1.12 QV | | | | 1+35 0.1173 1.13 QV | | | | 1+40 0.1250 1.13 QV | | | | 1+45 0.1328 1.13 QV | | | | 1+50 0.1405 1.13 QV | | | | 1+55 0.1483 1.13 QV | | | | 2+ 0 0.1562 1.15 Q V | | | | 2+ 5 0.1644 1.19 Q V | | | | 2+10 0.1725 1.17 Q V | | | | 2+15 0.1810 1.22 Q V | | | | 2+20 0.1895 1.25 Q V | | | | 2+25 0.1982 1.25 |QV | | | | 2+30 0.2068 1.26 |QV | | | | 2+35 0.2155 1.26 |QV | | | | 2+40 0.2243 1.27 |QV | | | | 2+45 0.2331 1.29 |Q V | | | | 2+50 0.2424 1.35 |Q V | | | | 2+55 0.2520 1.38 |Q V | | | | 3+ 0 0.2615 1.39 |Q V | | | | 3+ 5 0.2712 1.40 |Q V | | | | 3+10 0.2810 1.42 |Q V | | | | 3+15 0.2912 1.49 |Q V | | | | 3+20 0.3017 1.52 |Q V | | | | 3+25 0.3124 1.55 |Q V | | | | 3+30 0.3237 1.64 |Q V | | | | 3+35 0.3358 1.76 |Q V | | | | 3+40 0.3487 1.87 |Q V | | | | 3+45 0.3620 1.93 |Q V | | | | 3+50 0.3759 2.02 |Q V | | | | 3+55 0.3911 2.20 |Q V | | | | 4+ 0 0.4094 2.66 | Q V | | | | 4+ 5 0.4304 3.05 | Q V | | | | 4+10 0.4579 3.99 | Q V | | | | 4+15 0.4934 5.16 | Q V | | | | 4+20 0.5376 6.42 | Q V | | | | 4+25 0.5908 7.73 | QV | | | | 4+30 0.6519 8.87 | QV | | | | 4+35 0.7181 9.60 | Q V| | | | 4+40 0.7920 10.73 | Q V | | | 4+45 0.8747 12.02 | Q|V | | | 4+50 0.9653 13.16 | Q V | | | 4+55 1.0609 13.88 | |Q V | | | 5+ 0 1.1642 14.99 | |Q V | | | 5+ 5 1.2819 17.10 | | Q V | | | 5+10 1.4323 21.84 | | QV | | | 5+15 1.6199 27.24 | | |Q | | 5+20 1.8392 31.83 | | | VQ | | 5+25 2.0911 36.58 | | | V Q| | 5+30 2.3899 43.39 | | | |V Q | 5+35 2.6917 43.82 | | | | Q | 5+40 2.8469 22.53 | | Q | | V | 5+45 2.9275 11.71 | Q| | | V | 5+50 2.9779 7.31 | Q | | | V | 5+55 3.0113 4.86 | Q | | | V| 6+ 0 3.0338 3.27 | Q | | | V| 6+ 5 3.0481 2.08 |Q | | | V| 6+10 3.0564 1.20 Q | | | V| 6+15 3.0608 0.64 Q | | | V| 6+20 3.0616 0.12 Q | | | V| 6+25 3.0619 0.05 Q | | | V| 6+30 3.0621 0.03 Q | | | V| 6+35 3.0622 0.01 Q | | | V| 6+40 3.0622 0.01 Q | | | V| 6+45 3.0623 0.00 Q | | | V -----------------------------------------------------------------------

U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD/CIVILDESIGN, 1989 - 2014, Version 9.0 Study date 11/08/21 File: EXD0102410.out
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------ Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978
Program License Serial Number 6406
--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used
English Units used in output format
--------------------------------------------------------------------- TRACT 31194 - GOLDEN MEADOWS HYDROLOGY STUDY – AREA ‘D’ EXISTING CONDITION 'OVERALL' UNIT HYDROGRAPH - 10 YEAR HOUR STORM

HUNSAKER & ASSOCIATES,
BY: BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 60.04(Ac.) = 0.094 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 60.04(Ac.) = 0.094 Sq. Mi.

Length along longest watercourse = 2506.00(Ft.)
Length along longest watercourse measured to centroid = 1300.00(Ft.) Length along longest watercourse = 0.475 Mi.

Length along longest watercourse measured to centroid = 0.246 Mi.

Difference in elevation = 230.00(Ft.)
Slope along watercourse = 484.5970 Ft./Mi.

Average Manning's 'N' = 0.030
Lag time = 0.098 Hr.

Lag time = 5.90 Min.
25% of lag time = 1.48 Min.
40% of lag time = 2.36 Min.

Unit time = 15.00 Min.

Duration of storm = 24 Hour(s)
User Entered Base Flow = 0.00(CFS)
2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 2.00 120.08
100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 5.00 300.20
STORM EVENT (YEAR) = 10.00
Area Averaged 2-Year Rainfall = 2.000(In)
Area Averaged 100-Year Rainfall = 5.000(In)
Point rain (area averaged) = 3.234(In)
Areal adjustment factor = 99.99 %
Adjusted average point rain = 3.234(In)
Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

60.040 73.40 0.000
Total Area Entered = 60.04(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-2 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

73.4 73.4 0.322 0.000 0.322 1.000 0.322 Sum (F) = 0.322
Area averaged mean soil loss (F) (In/Hr) = 0.322
Minimum soil loss rate ((In/Hr)) = 0.161
(for 24 hour storm duration)
Soil low loss rate (decimal) = 0.900
--------------------------------------------------------------------- U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.250 254.168 51.434 31.122 2 0.500 508.335 39.798 24.081 3 0.750 762.503 6.885 4.166 4 1.000 1016.671 1.884 1.140 Sum = 100.000 Sum= 60.509
----------------------------------------------------------------------- The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.25 0.20 0.026 ( 0.568) 0.023 0.003 2 0.50 0.30 0.039 ( 0.562) 0.035 0.004 3 0.75 0.30 0.039 ( 0.555) 0.035 0.004 4 1.00 0.40 0.052 ( 0.549) 0.047 0.005 5 1.25 0.30 0.039 ( 0.542) 0.035 0.004 6 1.50 0.30 0.039 ( 0.536) 0.035 0.004 7 1.75 0.30 0.039 ( 0.529) 0.035 0.004 8 2.00 0.40 0.052 ( 0.523) 0.047 0.005 9 2.25 0.40 0.052 ( 0.517) 0.047 0.005 10 2.50 0.40 0.052 ( 0.510) 0.047 0.005 11 2.75 0.50 0.065 ( 0.504) 0.058 0.006 12 3.00 0.50 0.065 ( 0.498) 0.058 0.006 13 3.25 0.50 0.065 ( 0.492) 0.058 0.006 14 3.50 0.50 0.065 ( 0.486) 0.058 0.006 15 3.75 0.50 0.065 ( 0.480) 0.058 0.006 16 4.00 0.60 0.078 ( 0.474) 0.070 0.008 17 4.25 0.60 0.078 ( 0.468) 0.070 0.008 18 4.50 0.70 0.091 ( 0.462) 0.081 0.009 19 4.75 0.70 0.091 ( 0.456) 0.081 0.009 20 5.00 0.80 0.103 ( 0.450) 0.093 0.010 21 5.25 0.60 0.078 ( 0.444) 0.070 0.008 22 5.50 0.70 0.091 ( 0.438) 0.081 0.009 23 5.75 0.80 0.103 ( 0.432) 0.093 0.010 24 6.00 0.80 0.103 ( 0.427) 0.093 0.010 25 6.25 0.90 0.116 ( 0.421) 0.105 0.012 26 6.50 0.90 0.116 ( 0.415) 0.105 0.012 27 6.75 1.00 0.129 ( 0.410) 0.116 0.013 28 7.00 1.00 0.129 ( 0.404) 0.116 0.013 29 7.25 1.00 0.129 ( 0.399) 0.116 0.013 30 7.50 1.10 0.142 ( 0.393) 0.128 0.014 31 7.75 1.20 0.155 ( 0.388) 0.140 0.016 32 8.00 1.30 0.168 ( 0.383) 0.151 0.017 33 8.25 1.50 0.194 ( 0.377) 0.175 0.019 34 8.50 1.50 0.194 ( 0.372) 0.175 0.019 35 8.75 1.60 0.207 ( 0.367) 0.186 0.021 36 9.00 1.70 0.220 ( 0.362) 0.198 0.022 37 9.25 1.90 0.246 ( 0.357) 0.221 0.025 38 9.50 2.00 0.259 ( 0.352) 0.233 0.026 39 9.75 2.10 0.272 ( 0.347) 0.244 0.027 40 10.00 2.20 0.285 ( 0.342) 0.256 0.028 41 10.25 1.50 0.194 ( 0.337) 0.175 0.019 42 10.50 1.50 0.194 ( 0.332) 0.175 0.019 43 10.75 2.00 0.259 ( 0.327) 0.233 0.026 44 11.00 2.00 0.259 ( 0.322) 0.233 0.026 45 11.25 1.90 0.246 ( 0.317) 0.221 0.025 46 11.50 1.90 0.246 ( 0.313) 0.221 0.025 47 11.75 1.70 0.220 ( 0.308) 0.198 0.022 48 12.00 1.80 0.233 ( 0.303) 0.210 0.023 49 12.25 2.50 0.323 ( 0.299) 0.291 0.032 50 12.50 2.60 0.336 0.294 ( 0.303) 0.042 51 12.75 2.80 0.362 0.290 ( 0.326) 0.072 52 13.00 2.90 0.375 0.286 ( 0.338) 0.089 53 13.25 3.40 0.440 0.281 ( 0.396) 0.158 54 13.50 3.40 0.440 0.277 ( 0.396) 0.163 55 13.75 2.30 0.298 ( 0.273) 0.268 0.030 56 14.00 2.30 0.298 ( 0.269) 0.268 0.030 57 14.25 2.70 0.349 0.265 ( 0.314) 0.085 58 14.50 2.60 0.336 0.261 ( 0.303) 0.076 59 14.75 2.60 0.336 0.257 ( 0.303) 0.080 60 15.00 2.50 0.323 0.253 ( 0.291) 0.071 61 15.25 2.40 0.310 0.249 ( 0.279) 0.062 62 15.50 2.30 0.298 0.245 ( 0.268) 0.052 63 15.75 1.90 0.246 ( 0.241) 0.221 0.025 64 16.00 1.90 0.246 ( 0.238) 0.221 0.025 65 16.25 0.40 0.052 ( 0.234) 0.047 0.005 66 16.50 0.40 0.052 ( 0.230) 0.047 0.005 67 16.75 0.30 0.039 ( 0.227) 0.035 0.004 68 17.00 0.30 0.039 ( 0.223) 0.035 0.004 69 17.25 0.50 0.065 ( 0.220) 0.058 0.006 70 17.50 0.50 0.065 ( 0.217) 0.058 0.006 71 17.75 0.50 0.065 ( 0.214) 0.058 0.006 72 18.00 0.40 0.052 ( 0.210) 0.047 0.005 73 18.25 0.40 0.052 ( 0.207) 0.047 0.005 74 18.50 0.40 0.052 ( 0.204) 0.047 0.005 75 18.75 0.30 0.039 ( 0.201) 0.035 0.004 76 19.00 0.20 0.026 ( 0.198) 0.023 0.003 77 19.25 0.30 0.039 ( 0.196) 0.035 0.004 78 19.50 0.40 0.052 ( 0.193) 0.047 0.005 79 19.75 0.30 0.039 ( 0.190) 0.035 0.004 80 20.00 0.20 0.026 ( 0.188) 0.023 0.003 81 20.25 0.30 0.039 ( 0.185) 0.035 0.004 82 20.50 0.30 0.039 ( 0.183) 0.035 0.004 83 20.75 0.30 0.039 ( 0.181) 0.035 0.004 84 21.00 0.20 0.026 ( 0.178) 0.023 0.003 85 21.25 0.30 0.039 ( 0.176) 0.035 0.004 86 21.50 0.20 0.026 ( 0.174) 0.023 0.003 87 21.75 0.30 0.039 ( 0.172) 0.035 0.004 88 22.00 0.20 0.026 ( 0.171) 0.023 0.003 89 22.25 0.30 0.039 ( 0.169) 0.035 0.004 90 22.50 0.20 0.026 ( 0.167) 0.023 0.003 91 22.75 0.20 0.026 ( 0.166) 0.023 0.003 92 23.00 0.20 0.026 ( 0.165) 0.023 0.003 93 23.25 0.20 0.026 ( 0.163) 0.023 0.003 94 23.50 0.20 0.026 ( 0.162) 0.023 0.003 95 23.75 0.20 0.026 ( 0.162) 0.023 0.003 96 24.00 0.20 0.026 ( 0.161) 0.023 0.003 (Loss Rate Not Used)
Sum = 100.0 Sum = 1.9 Flood volume = Effective rainfall 0.46(In)
times area 60.0(Ac.)/[(In)/(Ft.)] = 2.3(Ac.Ft) Total soil loss = 2.77(In)
Total soil loss = 13.863(Ac.Ft)
Total rainfall = 3.23(In)
Flood volume = 100922.1 Cubic Feet
Total soil loss = 603878.9 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 9.338(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 24 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 15 Minute intervals ((CFS))
-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 2.5 5.0 7.5 10.0 ----------------------------------------------------------------------- 0+15 0.0017 0.08 Q | | | | 0+30 0.0054 0.18 Q | | | | 0+45 0.0101 0.23 Q | | | | 1+ 0 0.0158 0.27 VQ | | | | 1+15 0.0213 0.27 VQ | | | | 1+30 0.0262 0.24 Q | | | | 1+45 0.0311 0.24 Q | | | | 2+ 0 0.0368 0.28 VQ | | | | 2+15 0.0431 0.31 VQ | | | | 2+30 0.0496 0.31 VQ | | | | 2+45 0.0569 0.35 VQ | | | | 3+ 0 0.0648 0.38 |Q | | | | 3+15 0.0729 0.39 |Q | | | | 3+30 0.0810 0.39 |Q | | | | 3+45 0.0891 0.39 |Q | | | | 4+ 0 0.0980 0.43 |Q | | | | 4+15 0.1075 0.46 |Q | | | | 4+30 0.1181 0.51 | Q | | | | 4+45 0.1292 0.54 | Q | | | | 5+ 0 0.1414 0.59 | Q | | | | 5+15 0.1525 0.54 | Q | | | | 5+30 0.1633 0.52 | Q | | | | 5+45 0.1754 0.58 | QV | | | | 6+ 0 0.1881 0.62 | QV | | | | 6+15 0.2019 0.67 | QV | | | | 6+30 0.2163 0.70 | QV | | | | 6+45 0.2317 0.74 | QV | | | | 7+ 0 0.2477 0.78 | QV | | | | 7+15 0.2639 0.78 | QV | | | | 7+30 0.2809 0.82 | QV | | | | 7+45 0.2994 0.89 | Q V | | | | 8+ 0 0.3194 0.97 | Q V | | | | 8+15 0.3420 1.09 | QV | | | | 8+30 0.3659 1.16 | Q V | | | | 8+45 0.3910 1.21 | Q V | | | | 9+ 0 0.4175 1.29 | Q V | | | | 9+15 0.4465 1.40 | Q V | | | | 9+30 0.4778 1.51 | Q V | | | | 9+45 0.5108 1.60 | Q V | | | | 10+ 0 0.5454 1.68 | Q V| | | | 10+15 0.5750 1.43 | Q V| | | | 10+30 0.6003 1.22 | Q V | | | 10+45 0.6289 1.39 | Q V | | | 11+ 0 0.6605 1.53 | Q |V | | | 11+15 0.6919 1.52 | Q |V | | | 11+30 0.7228 1.49 | Q | V | | | 11+45 0.7519 1.41 | Q | V | | | 12+ 0 0.7805 1.39 | Q | V | | | 12+15 0.8154 1.69 | Q | V | | | 12+30 0.8609 2.20 | Q | V | | | 12+45 0.9315 3.42 | | Q V | | | 13+ 0 1.0293 4.73 | | VQ | | | 13+15 1.1830 7.44 | | V Q| | 13+30 1.3759 9.34 | | | V | Q | 13+45 1.4918 5.61 | | | Q V | | 14+ 0 1.5435 2.50 | Q | V | | 14+15 1.6191 3.66 | | Q | V | | 14+30 1.7132 4.55 | | Q | V| | 14+45 1.8102 4.69 | | Q | V | 15+ 0 1.9038 4.53 | | Q | | V | 15+15 1.9873 4.04 | | Q | | V | 15+30 2.0597 3.50 | | Q | | V | 15+45 2.1086 2.37 | Q| | | V | 16+ 0 2.1427 1.65 | Q | | | V | 16+15 2.1616 0.92 | Q | | | V | 16+30 2.1702 0.42 |Q | | | V | 16+45 2.1763 0.30 |Q | | | V | 17+ 0 2.1813 0.24 Q | | | V | 17+15 2.1878 0.32 |Q | | | V | 17+30 2.1956 0.38 |Q | | | V | 17+45 2.2037 0.39 |Q | | | V | 18+ 0 2.2109 0.35 |Q | | | V | 18+15 2.2175 0.32 |Q | | | V | 18+30 2.2240 0.31 |Q | | | V | 18+45 2.2297 0.27 |Q | | | V | 19+ 0 2.2338 0.20 Q | | | V | 19+15 2.2381 0.21 Q | | | V | 19+30 2.2436 0.27 |Q | | | V | 19+45 2.2491 0.26 |Q | | | V | 20+ 0 2.2532 0.20 Q | | | V | 20+15 2.2575 0.21 Q | | | V | 20+30 2.2622 0.23 Q | | | V| 20+45 2.2671 0.23 Q | | | V| 21+ 0 2.2711 0.19 Q | | | V| 21+15 2.2753 0.20 Q | | | V| 21+30 2.2792 0.19 Q | | | V| 21+45 2.2834 0.20 Q | | | V| 22+ 0 2.2873 0.19 Q | | | V| 22+15 2.2915 0.20 Q | | | V| 22+30 2.2954 0.19 Q | | | V| 22+45 2.2987 0.16 Q | | | V| 23+ 0 2.3020 0.16 Q | | | V| 23+15 2.3052 0.16 Q | | | V| 23+30 2.3085 0.16 Q | | | V| 23+45 2.3117 0.16 Q | | | V| 24+ 0 2.3149 0.16 Q | | | V| 24+15 2.3165 0.08 Q | | | V| 24+30 2.3168 0.01 Q | | | V| 24+45 2.3169 0.00 Q | | | V| ----------------------------------------------------------------------- Preliminary Hydrology Analysis – Golden Meadows – Tract 31194 – Major Modification

Page 3 ends

Section 3
· Area ‘D’ – 100 Year - Pre-Development Condition – Unit Hydrograph

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - GOLDEN MEADOWS HYDROLOGY STUDY – AREA ‘D’ EXISTING CONDITION 'OVERALL' UNIT HYDROGRAPH - 100 YEAR 1 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021
BY: BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 60.04(Ac.) = 0.094 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 60.04(Ac.) = 0.094 Sq. Mi.

Length along longest watercourse = 2506.00(Ft.)
Length along longest watercourse measured to centroid = 1300.00(Ft.) Length along longest watercourse = 0.475 Mi.

Length along longest watercourse measured to centroid = 0.246 Mi.

Difference in elevation = 230.00(Ft.)
Slope along watercourse = 484.5970 Ft./Mi.

Average Manning's 'N' = 0.030
Lag time = 0.098 Hr.

Lag time = 5.90 Min.
25% of lag time = 1.48 Min.
40% of lag time = 2.36 Min.

Unit time = 5.00 Min.

Duration of storm = 1 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 0.55 33.02

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 1.30 78.05

STORM EVENT (YEAR) = 100.00
Area Averaged 2-Year Rainfall = 0.550(In)
Area Averaged 100-Year Rainfall = 1.300(In)

Point rain (area averaged) = 1.300(In)
Areal adjustment factor = 99.95 %
Adjusted average point rain = 1.299(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

60.040 73.40 0.000
Total Area Entered = 60.04(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-3 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 3.40 0.530 0.164 ( 0.477) 0.366 2 0.17 4.70 0.733 0.164 ( 0.660) 0.569 3 0.25 4.70 0.733 0.164 ( 0.660) 0.569 4 0.33 5.10 0.795 0.164 ( 0.716) 0.631 5 0.42 5.80 0.904 0.164 ( 0.814) 0.741 6 0.50 5.90 0.920 0.164 ( 0.828) 0.756 7 0.58 7.10 1.107 0.164 ( 0.996) 0.943 8 0.67 8.70 1.356 0.164 ( 1.221) 1.193 9 0.75 13.20 2.058 0.164 ( 1.852) 1.894 10 0.83 29.70 4.631 0.164 ( 4.168) 4.467 11 0.92 7.70 1.201 0.164 ( 1.080) 1.037 12 1.00 4.00 0.624 0.164 ( 0.561) 0.460 (Loss Rate Not Used)
Sum = 100.0 Sum = 13.6 Flood volume = Effective rainfall 1.14(In)
times area 60.0(Ac.)/[(In)/(Ft.)] = 5.7(Ac.Ft) Total soil loss = 0.16(In)
Total soil loss = 0.819(Ac.Ft)
Total rainfall = 1.30(In)
Flood volume = 247487.4 Cubic Feet
Total soil loss = 35687.2 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 166.474(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 50.0 100.0 150.0 200.0 ----------------------------------------------------------------------- 0+ 5 0.0224 3.25 Q | | | | 0+10 0.1272 15.22 V Q | | | | 0+15 0.2992 24.98 | V Q | | | | 0+20 0.5030 29.59 | V Q | | | | 0+25 0.7392 34.31 | VQ | | | | 0+30 1.0107 39.41 | Q | | | | 0+35 1.3127 43.86 | QV| | | | 0+40 1.6758 52.72 | QV | | | 0+45 2.1500 68.85 | | Q V | | | 0+50 2.9452 115.46 | | V Q | | 0+55 4.0917 166.47 | | | V | Q | 1+ 0 4.7785 99.73 | | Q| | V | 1+ 5 5.1647 56.07 | |Q | | V | 1+10 5.3673 29.43 | Q | | | V | 1+15 5.4876 17.46 | Q | | | V | 1+20 5.5674 11.59 | Q | | | V| 1+25 5.6196 7.58 |Q | | | V| 1+30 5.6532 4.88 Q | | | V| 1+35 5.6748 3.13 Q | | | V| 1+40 5.6800 0.76 Q | | | V| 1+45 5.6815 0.22 Q | | | V -----------------------------------------------------------------------

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - GOLDEN MEADOWS HYDROLOGY STUDY – AREA ‘D’ EXISTING CONDITION 'OVERALL' UNIT HYDROGRAPH - 100 YEAR 3 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021
BY: BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 60.04(Ac.) = 0.094 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 60.04(Ac.) = 0.094 Sq. Mi.

Length along longest watercourse = 2506.00(Ft.)
Length along longest watercourse measured to centroid = 1300.00(Ft.) Length along longest watercourse = 0.475 Mi.

Length along longest watercourse measured to centroid = 0.246 Mi.

Difference in elevation = 230.00(Ft.)
Slope along watercourse = 484.5970 Ft./Mi.

Average Manning's 'N' = 0.030
Lag time = 0.098 Hr.

Lag time = 5.90 Min.
25% of lag time = 1.48 Min.
40% of lag time = 2.36 Min.

Unit time = 5.00 Min.

Duration of storm = 3 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 0.85 51.03

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 2.00 120.08

STORM EVENT (YEAR) = 100.00
Area Averaged 2-Year Rainfall = 0.850(In)
Area Averaged 100-Year Rainfall = 2.000(In)

Point rain (area averaged) = 2.000(In)
Areal adjustment factor = 99.97 %
Adjusted average point rain = 1.999(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

60.040 73.40 0.000
Total Area Entered = 60.04(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-3 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 1.30 0.312 0.164 ( 0.281) 0.148 2 0.17 1.30 0.312 0.164 ( 0.281) 0.148 3 0.25 1.10 0.264 0.164 ( 0.238) 0.100 4 0.33 1.50 0.360 0.164 ( 0.324) 0.196 5 0.42 1.50 0.360 0.164 ( 0.324) 0.196 6 0.50 1.80 0.432 0.164 ( 0.389) 0.268 7 0.58 1.50 0.360 0.164 ( 0.324) 0.196 8 0.67 1.80 0.432 0.164 ( 0.389) 0.268 9 0.75 1.80 0.432 0.164 ( 0.389) 0.268 10 0.83 1.50 0.360 0.164 ( 0.324) 0.196 11 0.92 1.60 0.384 0.164 ( 0.346) 0.220 12 1.00 1.80 0.432 0.164 ( 0.389) 0.268 13 1.08 2.20 0.528 0.164 ( 0.475) 0.364 14 1.17 2.20 0.528 0.164 ( 0.475) 0.364 15 1.25 2.20 0.528 0.164 ( 0.475) 0.364 16 1.33 2.00 0.480 0.164 ( 0.432) 0.316 17 1.42 2.60 0.624 0.164 ( 0.561) 0.460 18 1.50 2.70 0.648 0.164 ( 0.583) 0.484 19 1.58 2.40 0.576 0.164 ( 0.518) 0.412 20 1.67 2.70 0.648 0.164 ( 0.583) 0.484 21 1.75 3.30 0.792 0.164 ( 0.713) 0.628 22 1.83 3.10 0.744 0.164 ( 0.669) 0.580 23 1.92 2.90 0.696 0.164 ( 0.626) 0.532 24 2.00 3.00 0.720 0.164 ( 0.648) 0.556 25 2.08 3.10 0.744 0.164 ( 0.669) 0.580 26 2.17 4.20 1.008 0.164 ( 0.907) 0.844 27 2.25 5.00 1.200 0.164 ( 1.080) 1.036 28 2.33 3.50 0.840 0.164 ( 0.756) 0.676 29 2.42 6.80 1.632 0.164 ( 1.468) 1.468 30 2.50 7.30 1.752 0.164 ( 1.576) 1.588 31 2.58 8.20 1.967 0.164 ( 1.771) 1.804 32 2.67 5.90 1.416 0.164 ( 1.274) 1.252 33 2.75 2.00 0.480 0.164 ( 0.432) 0.316 34 2.83 1.80 0.432 0.164 ( 0.389) 0.268 35 2.92 1.80 0.432 0.164 ( 0.389) 0.268 36 3.00 0.60 0.144 ( 0.164) 0.130 0.014 (Loss Rate Not Used)
Sum = 100.0 Sum = 18.1 Flood volume = Effective rainfall 1.51(In)
times area 60.0(Ac.)/[(In)/(Ft.)] = 7.6(Ac.Ft) Total soil loss = 0.49(In)
Total soil loss = 2.444(Ac.Ft)
Total rainfall = 2.00(In)
Flood volume = 329335.0 Cubic Feet
Total soil loss = 106440.9 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 92.086(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 25.0 50.0 75.0 100.0 ----------------------------------------------------------------------- 0+ 5 0.0090 1.31 Q | | | | 0+10 0.0464 5.43 V Q | | | | 0+15 0.0924 6.68 V Q | | | | 0+20 0.1400 6.91 V Q | | | | 0+25 0.2051 9.45 |V Q | | | | 0+30 0.2823 11.21 |V Q | | | | 0+35 0.3724 13.08 |V Q | | | | 0+40 0.4608 12.85 | V Q | | | | 0+45 0.5612 14.57 | V Q | | | | 0+50 0.6629 14.76 | V Q | | | | 0+55 0.7545 13.30 | V Q | | | | 1+ 0 0.8493 13.78 | VQ | | | | 1+ 5 0.9597 16.03 | VQ | | | | 1+10 1.0921 19.22 | V Q | | | | 1+15 1.2335 20.53 | V Q | | | | 1+20 1.3757 20.66 | VQ | | | | 1+25 1.5201 20.96 | Q | | | | 1+30 1.6912 24.85 | VQ| | | | 1+35 1.8731 26.41 | VQ | | | 1+40 2.0521 26.00 | Q | | | 1+45 2.2517 28.98 | |Q | | | 1+50 2.4812 33.32 | | Q | | | 1+55 2.7120 33.52 | | QV | | | 2+ 0 2.9376 32.75 | | Q V | | | 2+ 5 3.1675 33.38 | | Q V | | | 2+10 3.4200 36.66 | | Q V | | | 2+15 3.7373 46.07 | | QV| | | 2+20 4.0910 51.36 | | QV | | 2+25 4.4488 51.94 | | Q V | | 2+30 4.9493 72.68 | | | V Q| | 2+35 5.5427 86.16 | | | V| Q | 2+40 6.1769 92.09 | | | | V Q | 2+45 6.6838 73.60 | | | Q| V | 2+50 6.9842 43.62 | | Q | | V | 2+55 7.1965 30.83 | | Q | | V | 3+ 0 7.3554 23.07 | Q| | | V | 3+ 5 7.4425 12.65 | Q | | | V| 3+10 7.4942 7.51 | Q | | | V| 3+15 7.5256 4.56 |Q | | | V| 3+20 7.5442 2.70 |Q | | | V| 3+25 7.5537 1.38 Q | | | V| 3+30 7.5575 0.55 Q | | | V| 3+35 7.5595 0.29 Q | | | V| 3+40 7.5604 0.14 Q | | | V| 3+45 7.5605 0.01 Q | | | V -----------------------------------------------------------------------

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - GOLDEN MEADOWS HYDROLOGY STUDY – AREA ‘D’ EXISTING CONDITION 'OVERALL' UNIT HYDROGRAPH - 100 YEAR 6 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021
BY: BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 60.04(Ac.) = 0.094 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 60.04(Ac.) = 0.094 Sq. Mi.

Length along longest watercourse = 2506.00(Ft.)
Length along longest watercourse measured to centroid = 1300.00(Ft.) Length along longest watercourse = 0.475 Mi.

Length along longest watercourse measured to centroid = 0.246 Mi.

Difference in elevation = 230.00(Ft.)
Slope along watercourse = 484.5970 Ft./Mi.

Average Manning's 'N' = 0.030
Lag time = 0.098 Hr.

Lag time = 5.90 Min.
25% of lag time = 1.48 Min.
40% of lag time = 2.36 Min.

Unit time = 5.00 Min.

Duration of storm = 6 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 1.20 72.05

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 3.00 180.12

STORM EVENT (YEAR) = 100.00
Area Averaged 2-Year Rainfall = 1.200(In)
Area Averaged 100-Year Rainfall = 3.000(In)

Point rain (area averaged) = 3.000(In)
Areal adjustment factor = 99.98 %
Adjusted average point rain = 2.999(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

60.040 73.40 0.000
Total Area Entered = 60.04(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-3 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 0.50 0.180 ( 0.164) 0.162 0.018 2 0.17 0.60 0.216 0.164 ( 0.194) 0.052 3 0.25 0.60 0.216 0.164 ( 0.194) 0.052 4 0.33 0.60 0.216 0.164 ( 0.194) 0.052 5 0.42 0.60 0.216 0.164 ( 0.194) 0.052 6 0.50 0.70 0.252 0.164 ( 0.227) 0.088 7 0.58 0.70 0.252 0.164 ( 0.227) 0.088 8 0.67 0.70 0.252 0.164 ( 0.227) 0.088 9 0.75 0.70 0.252 0.164 ( 0.227) 0.088 10 0.83 0.70 0.252 0.164 ( 0.227) 0.088 11 0.92 0.70 0.252 0.164 ( 0.227) 0.088 12 1.00 0.80 0.288 0.164 ( 0.259) 0.124 13 1.08 0.80 0.288 0.164 ( 0.259) 0.124 14 1.17 0.80 0.288 0.164 ( 0.259) 0.124 15 1.25 0.80 0.288 0.164 ( 0.259) 0.124 16 1.33 0.80 0.288 0.164 ( 0.259) 0.124 17 1.42 0.80 0.288 0.164 ( 0.259) 0.124 18 1.50 0.80 0.288 0.164 ( 0.259) 0.124 19 1.58 0.80 0.288 0.164 ( 0.259) 0.124 20 1.67 0.80 0.288 0.164 ( 0.259) 0.124 21 1.75 0.80 0.288 0.164 ( 0.259) 0.124 22 1.83 0.80 0.288 0.164 ( 0.259) 0.124 23 1.92 0.80 0.288 0.164 ( 0.259) 0.124 24 2.00 0.90 0.324 0.164 ( 0.292) 0.160 25 2.08 0.80 0.288 0.164 ( 0.259) 0.124 26 2.17 0.90 0.324 0.164 ( 0.292) 0.160 27 2.25 0.90 0.324 0.164 ( 0.292) 0.160 28 2.33 0.90 0.324 0.164 ( 0.292) 0.160 29 2.42 0.90 0.324 0.164 ( 0.292) 0.160 30 2.50 0.90 0.324 0.164 ( 0.292) 0.160 31 2.58 0.90 0.324 0.164 ( 0.292) 0.160 32 2.67 0.90 0.324 0.164 ( 0.292) 0.160 33 2.75 1.00 0.360 0.164 ( 0.324) 0.196 34 2.83 1.00 0.360 0.164 ( 0.324) 0.196 35 2.92 1.00 0.360 0.164 ( 0.324) 0.196 36 3.00 1.00 0.360 0.164 ( 0.324) 0.196 37 3.08 1.00 0.360 0.164 ( 0.324) 0.196 38 3.17 1.10 0.396 0.164 ( 0.356) 0.232 39 3.25 1.10 0.396 0.164 ( 0.356) 0.232 40 3.33 1.10 0.396 0.164 ( 0.356) 0.232 41 3.42 1.20 0.432 0.164 ( 0.389) 0.268 42 3.50 1.30 0.468 0.164 ( 0.421) 0.304 43 3.58 1.40 0.504 0.164 ( 0.454) 0.340 44 3.67 1.40 0.504 0.164 ( 0.454) 0.340 45 3.75 1.50 0.540 0.164 ( 0.486) 0.376 46 3.83 1.50 0.540 0.164 ( 0.486) 0.376 47 3.92 1.60 0.576 0.164 ( 0.518) 0.412 48 4.00 1.60 0.576 0.164 ( 0.518) 0.412 49 4.08 1.70 0.612 0.164 ( 0.551) 0.448 50 4.17 1.80 0.648 0.164 ( 0.583) 0.484 51 4.25 1.90 0.684 0.164 ( 0.615) 0.520 52 4.33 2.00 0.720 0.164 ( 0.648) 0.556 53 4.42 2.10 0.756 0.164 ( 0.680) 0.592 54 4.50 2.10 0.756 0.164 ( 0.680) 0.592 55 4.58 2.20 0.792 0.164 ( 0.713) 0.628 56 4.67 2.30 0.828 0.164 ( 0.745) 0.664 57 4.75 2.40 0.864 0.164 ( 0.777) 0.700 58 4.83 2.40 0.864 0.164 ( 0.777) 0.700 59 4.92 2.50 0.900 0.164 ( 0.810) 0.736 60 5.00 2.60 0.936 0.164 ( 0.842) 0.772 61 5.08 3.10 1.116 0.164 ( 1.004) 0.952 62 5.17 3.60 1.296 0.164 ( 1.166) 1.132 63 5.25 3.90 1.404 0.164 ( 1.263) 1.240 64 5.33 4.20 1.512 0.164 ( 1.361) 1.348 65 5.42 4.70 1.692 0.164 ( 1.522) 1.528 66 5.50 5.60 2.016 0.164 ( 1.814) 1.852 67 5.58 1.90 0.684 0.164 ( 0.615) 0.520 68 5.67 0.90 0.324 0.164 ( 0.292) 0.160 69 5.75 0.60 0.216 0.164 ( 0.194) 0.052 70 5.83 0.50 0.180 ( 0.164) 0.162 0.018 71 5.92 0.30 0.108 ( 0.164) 0.097 0.011 72 6.00 0.20 0.072 ( 0.164) 0.065 0.007 (Loss Rate Not Used)
Sum = 100.0 Sum = 24.4 Flood volume = Effective rainfall 2.03(In)
times area 60.0(Ac.)/[(In)/(Ft.)] = 10.2(Ac.Ft) Total soil loss = 0.97(In)
Total soil loss = 4.845(Ac.Ft)
Total rainfall = 3.00(In)
Flood volume = 442648.1 Cubic Feet
Total soil loss = 211052.5 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 87.950(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 6 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 22.5 45.0 67.5 90.0 ----------------------------------------------------------------------- 0+ 5 0.0011 0.16 Q | | | | 0+10 0.0077 0.96 Q | | | | 0+15 0.0223 2.12 Q | | | | 0+20 0.0401 2.59 VQ | | | | 0+25 0.0594 2.80 VQ | | | | 0+30 0.0818 3.25 VQ | | | | 0+35 0.1117 4.34 VQ | | | | 0+40 0.1448 4.80 V Q | | | | 0+45 0.1793 5.01 V Q | | | | 0+50 0.2148 5.15 V Q | | | | 0+55 0.2508 5.23 V Q | | | | 1+ 0 0.2893 5.59 |VQ | | | | 1+ 5 0.3349 6.62 |VQ | | | | 1+10 0.3834 7.05 |V Q | | | | 1+15 0.4332 7.24 |V Q | | | | 1+20 0.4838 7.34 |V Q | | | | 1+25 0.5348 7.40 | VQ | | | | 1+30 0.5861 7.45 | VQ | | | | 1+35 0.6376 7.48 | VQ | | | | 1+40 0.6893 7.50 | VQ | | | | 1+45 0.7411 7.52 | VQ | | | | 1+50 0.7929 7.52 | Q | | | | 1+55 0.8446 7.52 | Q | | | | 2+ 0 0.8986 7.84 | Q | | | | 2+ 5 0.9573 8.52 | Q | | | | 2+10 1.0141 8.24 | Q | | | | 2+15 1.0761 9.01 | Q | | | | 2+20 1.1405 9.35 | Q | | | | 2+25 1.2058 9.48 | Q | | | | 2+30 1.2717 9.57 | QV | | | | 2+35 1.3379 9.61 | QV | | | | 2+40 1.4043 9.65 | QV | | | | 2+45 1.4732 10.00 | QV | | | | 2+50 1.5489 11.00 | Q V | | | | 2+55 1.6276 11.42 | QV | | | | 3+ 0 1.7075 11.60 | QV | | | | 3+ 5 1.7880 11.70 | Q V | | | | 3+10 1.8712 12.08 | Q V | | | | 3+15 1.9617 13.13 | Q V | | | | 3+20 2.0551 13.56 | Q V | | | | 3+25 2.1520 14.08 | Q V | | | | 3+30 2.2589 15.52 | Q V | | | | 3+35 2.3780 17.30 | Q V| | | | 3+40 2.5084 18.93 | QV| | | | 3+45 2.6459 19.96 | Q V | | | 3+50 2.7927 21.32 | QV | | | 3+55 2.9461 22.28 | Q|V | | | 4+ 0 3.1086 23.59 | Q V | | | 4+ 5 3.2774 24.51 | Q V | | | 4+10 3.4574 26.14 | |Q V | | | 4+15 3.6506 28.05 | | Q V | | | 4+20 3.8576 30.06 | | Q V | | | 4+25 4.0789 32.13 | | Q V | | | 4+30 4.3125 33.92 | | QV | | | 4+35 4.5539 35.05 | | Q V | | | 4+40 4.8074 36.80 | | Q V | | | 4+45 5.0746 38.79 | | Q V| | | 4+50 5.3538 40.55 | | Q |V | | 4+55 5.6408 41.67 | | Q | V | | 5+ 0 5.9396 43.39 | | Q| V | | 5+ 5 6.2609 46.64 | | Q V | | 5+10 6.6326 53.97 | | | Q V | | 5+15 7.0619 62.33 | | | Q | | 5+20 7.5400 69.42 | | | VQ | 5+25 8.0686 76.76 | | | |V Q | 5+30 8.6698 87.30 | | | | V Q | 5+35 9.2755 87.95 | | | | V Q| 5+40 9.6421 53.22 | | | Q | V | 5+45 9.8481 29.91 | | Q | | V | 5+50 9.9707 17.80 | Q | | | V| 5+55 10.0470 11.08 | Q | | | V| 6+ 0 10.0967 7.22 | Q | | | V| 6+ 5 10.1283 4.59 | Q | | | V| 6+10 10.1469 2.70 |Q | | | V| 6+15 10.1571 1.49 Q | | | V| 6+20 10.1602 0.45 Q | | | V| 6+25 10.1612 0.15 Q | | | V| 6+30 10.1616 0.05 Q | | | V| 6+35 10.1617 0.02 Q | | | V| 6+40 10.1618 0.01 Q | | | V| 6+45 10.1618 0.00 Q | | | V| -----------------------------------------------------------------------

U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD/CIVILDESIGN, 1989 - 2014, Version 9.0 Study date 11/08/21 File: EXD10024100.out
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------ Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978
Program License Serial Number 6406
--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used
English Units used in output format
--------------------------------------------------------------------- TRACT 31194 - GOLDEN MEADOWS HYDROLOGY STUDY – AREA ‘D’ EXISTING CONDITION 'OVERALL' UNIT HYDROGRAPH - 100 YEAR HOUR STORM

HUNSAKER & ASSOCIATES,
BY: BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 60.04(Ac.) = 0.094 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 60.04(Ac.) = 0.094 Sq. Mi.

Length along longest watercourse = 2506.00(Ft.)
Length along longest watercourse measured to centroid = 1300.00(Ft.) Length along longest watercourse = 0.475 Mi.

Length along longest watercourse measured to centroid = 0.246 Mi.

Difference in elevation = 230.00(Ft.)
Slope along watercourse = 484.5970 Ft./Mi.

Average Manning's 'N' = 0.030
Lag time = 0.098 Hr.

Lag time = 5.90 Min.
25% of lag time = 1.48 Min.
40% of lag time = 2.36 Min.

Unit time = 15.00 Min.

Duration of storm = 24 Hour(s)
User Entered Base Flow = 0.00(CFS)
2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 2.00 120.08
100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

60.04 5.00 300.20
STORM EVENT (YEAR) = 100.00
Area Averaged 2-Year Rainfall = 2.000(In)
Area Averaged 100-Year Rainfall = 5.000(In)
Point rain (area averaged) = 5.000(In)
Areal adjustment factor = 99.99 %
Adjusted average point rain = 4.999(In)
Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

60.040 73.40 0.000
Total Area Entered = 60.04(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-3 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

73.4 87.0 0.164 0.000 0.164 1.000 0.164 Sum (F) = 0.164
Area averaged mean soil loss (F) (In/Hr) = 0.164
Minimum soil loss rate ((In/Hr)) = 0.082
(for 24 hour storm duration)
Soil low loss rate (decimal) = 0.900
--------------------------------------------------------------------- U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.250 254.168 51.434 31.122 2 0.500 508.335 39.798 24.081 3 0.750 762.503 6.885 4.166 4 1.000 1016.671 1.884 1.140 Sum = 100.000 Sum= 60.509
----------------------------------------------------------------------- The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.25 0.20 0.040 ( 0.289) 0.036 0.004 2 0.50 0.30 0.060 ( 0.286) 0.054 0.006 3 0.75 0.30 0.060 ( 0.282) 0.054 0.006 4 1.00 0.40 0.080 ( 0.279) 0.072 0.008 5 1.25 0.30 0.060 ( 0.276) 0.054 0.006 6 1.50 0.30 0.060 ( 0.273) 0.054 0.006 7 1.75 0.30 0.060 ( 0.269) 0.054 0.006 8 2.00 0.40 0.080 ( 0.266) 0.072 0.008 9 2.25 0.40 0.080 ( 0.263) 0.072 0.008 10 2.50 0.40 0.080 ( 0.260) 0.072 0.008 11 2.75 0.50 0.100 ( 0.256) 0.090 0.010 12 3.00 0.50 0.100 ( 0.253) 0.090 0.010 13 3.25 0.50 0.100 ( 0.250) 0.090 0.010 14 3.50 0.50 0.100 ( 0.247) 0.090 0.010 15 3.75 0.50 0.100 ( 0.244) 0.090 0.010 16 4.00 0.60 0.120 ( 0.241) 0.108 0.012 17 4.25 0.60 0.120 ( 0.238) 0.108 0.012 18 4.50 0.70 0.140 ( 0.235) 0.126 0.014 19 4.75 0.70 0.140 ( 0.232) 0.126 0.014 20 5.00 0.80 0.160 ( 0.229) 0.144 0.016 21 5.25 0.60 0.120 ( 0.226) 0.108 0.012 22 5.50 0.70 0.140 ( 0.223) 0.126 0.014 23 5.75 0.80 0.160 ( 0.220) 0.144 0.016 24 6.00 0.80 0.160 ( 0.217) 0.144 0.016 25 6.25 0.90 0.180 ( 0.214) 0.162 0.018 26 6.50 0.90 0.180 ( 0.211) 0.162 0.018 27 6.75 1.00 0.200 ( 0.209) 0.180 0.020 28 7.00 1.00 0.200 ( 0.206) 0.180 0.020 29 7.25 1.00 0.200 ( 0.203) 0.180 0.020 30 7.50 1.10 0.220 ( 0.200) 0.198 0.022 31 7.75 1.20 0.240 0.197 ( 0.216) 0.043 32 8.00 1.30 0.260 0.195 ( 0.234) 0.065 33 8.25 1.50 0.300 0.192 ( 0.270) 0.108 34 8.50 1.50 0.300 0.189 ( 0.270) 0.111 35 8.75 1.60 0.320 0.187 ( 0.288) 0.133 36 9.00 1.70 0.340 0.184 ( 0.306) 0.156 37 9.25 1.90 0.380 0.181 ( 0.342) 0.199 38 9.50 2.00 0.400 0.179 ( 0.360) 0.221 39 9.75 2.10 0.420 0.176 ( 0.378) 0.244 40 10.00 2.20 0.440 0.174 ( 0.396) 0.266 41 10.25 1.50 0.300 0.171 ( 0.270) 0.129 42 10.50 1.50 0.300 0.169 ( 0.270) 0.131 43 10.75 2.00 0.400 0.166 ( 0.360) 0.234 44 11.00 2.00 0.400 0.164 ( 0.360) 0.236 45 11.25 1.90 0.380 0.161 ( 0.342) 0.218 46 11.50 1.90 0.380 0.159 ( 0.342) 0.221 47 11.75 1.70 0.340 0.157 ( 0.306) 0.183 48 12.00 1.80 0.360 0.154 ( 0.324) 0.206 49 12.25 2.50 0.500 0.152 ( 0.450) 0.348 50 12.50 2.60 0.520 0.150 ( 0.468) 0.370 51 12.75 2.80 0.560 0.148 ( 0.504) 0.412 52 13.00 2.90 0.580 0.145 ( 0.522) 0.435 53 13.25 3.40 0.680 0.143 ( 0.612) 0.537 54 13.50 3.40 0.680 0.141 ( 0.612) 0.539 55 13.75 2.30 0.460 0.139 ( 0.414) 0.321 56 14.00 2.30 0.460 0.137 ( 0.414) 0.323 57 14.25 2.70 0.540 0.135 ( 0.486) 0.405 58 14.50 2.60 0.520 0.133 ( 0.468) 0.387 59 14.75 2.60 0.520 0.131 ( 0.468) 0.389 60 15.00 2.50 0.500 0.129 ( 0.450) 0.371 61 15.25 2.40 0.480 0.127 ( 0.432) 0.353 62 15.50 2.30 0.460 0.125 ( 0.414) 0.335 63 15.75 1.90 0.380 0.123 ( 0.342) 0.257 64 16.00 1.90 0.380 0.121 ( 0.342) 0.259 65 16.25 0.40 0.080 ( 0.119) 0.072 0.008 66 16.50 0.40 0.080 ( 0.117) 0.072 0.008 67 16.75 0.30 0.060 ( 0.115) 0.054 0.006 68 17.00 0.30 0.060 ( 0.114) 0.054 0.006 69 17.25 0.50 0.100 ( 0.112) 0.090 0.010 70 17.50 0.50 0.100 ( 0.110) 0.090 0.010 71 17.75 0.50 0.100 ( 0.109) 0.090 0.010 72 18.00 0.40 0.080 ( 0.107) 0.072 0.008 73 18.25 0.40 0.080 ( 0.105) 0.072 0.008 74 18.50 0.40 0.080 ( 0.104) 0.072 0.008 75 18.75 0.30 0.060 ( 0.102) 0.054 0.006 76 19.00 0.20 0.040 ( 0.101) 0.036 0.004 77 19.25 0.30 0.060 ( 0.100) 0.054 0.006 78 19.50 0.40 0.080 ( 0.098) 0.072 0.008 79 19.75 0.30 0.060 ( 0.097) 0.054 0.006 80 20.00 0.20 0.040 ( 0.096) 0.036 0.004 81 20.25 0.30 0.060 ( 0.094) 0.054 0.006 82 20.50 0.30 0.060 ( 0.093) 0.054 0.006 83 20.75 0.30 0.060 ( 0.092) 0.054 0.006 84 21.00 0.20 0.040 ( 0.091) 0.036 0.004 85 21.25 0.30 0.060 ( 0.090) 0.054 0.006 86 21.50 0.20 0.040 ( 0.089) 0.036 0.004 87 21.75 0.30 0.060 ( 0.088) 0.054 0.006 88 22.00 0.20 0.040 ( 0.087) 0.036 0.004 89 22.25 0.30 0.060 ( 0.086) 0.054 0.006 90 22.50 0.20 0.040 ( 0.085) 0.036 0.004 91 22.75 0.20 0.040 ( 0.084) 0.036 0.004 92 23.00 0.20 0.040 ( 0.084) 0.036 0.004 93 23.25 0.20 0.040 ( 0.083) 0.036 0.004 94 23.50 0.20 0.040 ( 0.083) 0.036 0.004 95 23.75 0.20 0.040 ( 0.082) 0.036 0.004 96 24.00 0.20 0.040 ( 0.082) 0.036 0.004 (Loss Rate Not Used)
Sum = 100.0 Sum = 9.7 Flood volume = Effective rainfall 2.42(In)
times area 60.0(Ac.)/[(In)/(Ft.)] = 12.1(Ac.Ft) Total soil loss = 2.57(In)
Total soil loss = 12.883(Ac.Ft)
Total rainfall = 5.00(In)
Flood volume = 528434.0 Cubic Feet
Total soil loss = 561164.2 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 31.997(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 24 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 15 Minute intervals ((CFS))
-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 10.0 20.0 30.0 40.0 ----------------------------------------------------------------------- 0+15 0.0026 0.12 Q | | | | 0+30 0.0084 0.28 Q | | | | 0+45 0.0156 0.35 Q | | | | 1+ 0 0.0244 0.42 Q | | | | 1+15 0.0329 0.41 Q | | | | 1+30 0.0405 0.37 Q | | | | 1+45 0.0481 0.37 Q | | | | 2+ 0 0.0569 0.43 Q | | | | 2+15 0.0667 0.47 Q | | | | 2+30 0.0766 0.48 Q | | | | 2+45 0.0879 0.55 Q | | | | 3+ 0 0.1002 0.59 Q | | | | 3+15 0.1127 0.60 Q | | | | 3+30 0.1252 0.61 Q | | | | 3+45 0.1377 0.61 Q | | | | 4+ 0 0.1515 0.67 Q | | | | 4+15 0.1663 0.72 Q | | | | 4+30 0.1825 0.79 Q | | | | 4+45 0.1998 0.84 Q | | | | 5+ 0 0.2185 0.91 Q | | | | 5+15 0.2358 0.83 Q | | | | 5+30 0.2524 0.81 Q | | | | 5+45 0.2711 0.90 Q | | | | 6+ 0 0.2909 0.96 Q | | | | 6+15 0.3121 1.03 Q | | | | 6+30 0.3344 1.08 |Q | | | | 6+45 0.3582 1.15 |Q | | | | 7+ 0 0.3830 1.20 |Q | | | | 7+15 0.4079 1.21 |Q | | | | 7+30 0.4342 1.27 |Q | | | | 7+45 0.4747 1.96 |Q | | | | 8+ 0 0.5403 3.17 |V Q | | | | 8+15 0.6464 5.14 | V Q | | | | 8+30 0.7780 6.37 | V Q | | | | 8+45 0.9297 7.34 | V Q | | | | 9+ 0 1.1084 8.65 | V Q | | | | 9+15 1.3279 10.62 | V Q | | | 9+30 1.5855 12.47 | V | Q | | | 9+45 1.8731 13.92 | V | Q | | | 10+ 0 2.1894 15.31 | V | Q | | | 10+15 2.4309 11.69 | V |Q | | | 10+30 2.6081 8.57 | Q | | | | 10+45 2.8411 11.28 | V|Q | | | 11+ 0 3.1236 13.67 | V Q | | | 11+15 3.4049 13.62 | V Q | | | 11+30 3.6816 13.39 | | VQ | | | 11+45 3.9338 12.21 | | Q | | | 12+ 0 4.1815 11.99 | |Q V | | | 12+15 4.5286 16.80 | | V Q | | | 12+30 4.9619 20.97 | | V Q | | 12+45 5.4462 23.44 | | V | Q | | 13+ 0 5.9712 25.41 | | V| Q | | 13+15 6.5771 29.33 | | V Q| | 13+30 7.2382 32.00 | | | V |Q | 13+45 7.7696 25.72 | | | Q | | 14+ 0 8.1964 20.66 | | Q V | | 14+15 8.6584 22.36 | | | Q V | | 14+30 9.1448 23.54 | | | Q V | 14+45 9.6307 23.52 | | | Q V | 15+ 0 10.1064 23.02 | | | Q | V | 15+15 10.5612 22.02 | | | Q | V | 15+30 10.9940 20.95 | | Q | V | 15+45 11.3656 17.98 | | Q | | V | 16+ 0 11.6975 16.07 | | Q | | V | 16+15 11.8617 7.95 | Q | | | V| 16+30 11.8992 1.82 |Q | | | V| 16+45 11.9138 0.71 Q | | | V| 17+ 0 11.9216 0.37 Q | | | V| 17+15 11.9317 0.49 Q | | | V| 17+30 11.9438 0.58 Q | | | V| 17+45 11.9562 0.60 Q | | | V| 18+ 0 11.9674 0.54 Q | | | V| 18+15 11.9776 0.49 Q | | | V| 18+30 11.9877 0.49 Q | | | V| 18+45 11.9964 0.42 Q | | | V| 19+ 0 12.0028 0.31 Q | | | V| 19+15 12.0094 0.32 Q | | | V| 19+30 12.0180 0.42 Q | | | V| 19+45 12.0265 0.41 Q | | | V| 20+ 0 12.0328 0.31 Q | | | V| 20+15 12.0394 0.32 Q | | | V| 20+30 12.0467 0.35 Q | | | V| 20+45 12.0542 0.36 Q | | | V| 21+ 0 12.0604 0.30 Q | | | V| 21+15 12.0669 0.32 Q | | | V| 21+30 12.0730 0.29 Q | | | V| 21+45 12.0794 0.31 Q | | | V| 22+ 0 12.0855 0.29 Q | | | V| 22+15 12.0919 0.31 Q | | | V| 22+30 12.0980 0.29 Q | | | V| 22+45 12.1032 0.25 Q | | | V| 23+ 0 12.1082 0.24 Q | | | V| 23+15 12.1132 0.24 Q | | | V| 23+30 12.1182 0.24 Q | | | V| 23+45 12.1232 0.24 Q | | | V| 24+ 0 12.1282 0.24 Q | | | V| 24+15 12.1306 0.12 Q | | | V| 24+30 12.1311 0.02 Q | | | V| 24+45 12.1312 0.00 Q | | | V ----------------------------------------------------------------------- Preliminary Hydrology Analysis – Golden Meadows – Tract 31194 – Major Modification

Page 3 ends

Section 3
· Area ‘D’ – 2 Year - Post-Development Condition – Unit Hydrograph

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - 'GOLDEN MEADOWS' MAJOR MODIFICATION
PRELIMINARY HYDROLOGY STUDY – AREA ‘D’
PROPOSED CONDITION UNIT HYDROGRAPH - 2 YEAR 1 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021, BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 55.84(Ac.) = 0.087 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 55.84(Ac.) = 0.087 Sq. Mi.

Length along longest watercourse = 4101.00(Ft.)
Length along longest watercourse measured to centroid = 1105.00(Ft.) Length along longest watercourse = 0.777 Mi.

Length along longest watercourse measured to centroid = 0.209 Mi.

Difference in elevation = 49.10(Ft.)
Slope along watercourse = 63.2158 Ft./Mi.

Average Manning's 'N' = 0.015
Lag time = 0.082 Hr.

Lag time = 4.93 Min.
25% of lag time = 1.23 Min.
40% of lag time = 1.97 Min.

Unit time = 5.00 Min.

Duration of storm = 1 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 0.55 30.71

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 1.30 72.59

STORM EVENT (YEAR) = 2.00
Area Averaged 2-Year Rainfall = 0.550(In)
Area Averaged 100-Year Rainfall = 1.300(In)

Point rain (area averaged) = 0.550(In)
Areal adjustment factor = 99.95 %
Adjusted average point rain = 0.550(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

55.840 65.70 0.500
Total Area Entered = 55.84(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-1 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.083 101.508 19.663 11.066 2 0.167 203.015 48.509 27.299 3 0.250 304.523 15.411 8.673 4 0.333 406.031 6.983 3.930 5 0.417 507.539 3.915 2.203 6 0.500 609.046 2.530 1.424 7 0.583 710.554 1.553 0.874 8 0.667 812.062 1.435 0.808 Sum = 100.000 Sum= 56.276
-----------------------------------------------------------------------

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 3.40 0.224 ( 0.337) 0.112 0.112 2 0.17 4.70 0.310 ( 0.337) 0.155 0.155 3 0.25 4.70 0.310 ( 0.337) 0.155 0.155 4 0.33 5.10 0.336 ( 0.337) 0.168 0.168 5 0.42 5.80 0.383 ( 0.337) 0.191 0.191 6 0.50 5.90 0.389 ( 0.337) 0.195 0.195 7 0.58 7.10 0.468 ( 0.337) 0.234 0.234 8 0.67 8.70 0.574 ( 0.337) 0.287 0.287 9 0.75 13.20 0.871 0.337 ( 0.435) 0.534 10 0.83 29.70 1.959 0.337 ( 0.980) 1.622 11 0.92 7.70 0.508 ( 0.337) 0.254 0.254 12 1.00 4.00 0.264 ( 0.337) 0.132 0.132 (Loss Rate Not Used)
Sum = 100.0 Sum = 4.0 Flood volume = Effective rainfall 0.34(In)
times area 55.8(Ac.)/[(In)/(Ft.)] = 1.6(Ac.Ft) Total soil loss = 0.21(In)
Total soil loss = 0.992(Ac.Ft)
Total rainfall = 0.55(In)
Flood volume = 68229.7 Cubic Feet
Total soil loss = 43198.4 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 53.975(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - 'GOLDEN MEADOWS' MAJOR MODIFICATION
PRELIMINARY HYDROLOGY STUDY – AREA ‘D’
PROPOSED CONDITION UNIT HYDROGRAPH - 2 YEAR 3 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021, BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 55.84(Ac.) = 0.087 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 55.84(Ac.) = 0.087 Sq. Mi.

Length along longest watercourse = 4101.00(Ft.)
Length along longest watercourse measured to centroid = 1105.00(Ft.) Length along longest watercourse = 0.777 Mi.

Length along longest watercourse measured to centroid = 0.209 Mi.

Difference in elevation = 49.10(Ft.)
Slope along watercourse = 63.2158 Ft./Mi.

Average Manning's 'N' = 0.015
Lag time = 0.082 Hr.

Lag time = 4.93 Min.
25% of lag time = 1.23 Min.
40% of lag time = 1.97 Min.

Unit time = 5.00 Min.

Duration of storm = 3 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 0.85 47.46

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 2.00 111.68

STORM EVENT (YEAR) = 2.00
Area Averaged 2-Year Rainfall = 0.850(In)
Area Averaged 100-Year Rainfall = 2.000(In)

Point rain (area averaged) = 0.850(In)
Areal adjustment factor = 99.98 %
Adjusted average point rain = 0.850(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

55.840 65.70 0.500
Total Area Entered = 55.84(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-1 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.083 101.508 19.663 11.066 2 0.167 203.015 48.509 27.299 3 0.250 304.523 15.411 8.673 4 0.333 406.031 6.983 3.930 5 0.417 507.539 3.915 2.203 6 0.500 609.046 2.530 1.424 7 0.583 710.554 1.553 0.874 8 0.667 812.062 1.435 0.808 Sum = 100.000 Sum= 56.276
-----------------------------------------------------------------------

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 1.30 0.133 ( 0.337) 0.066 0.066 2 0.17 1.30 0.133 ( 0.337) 0.066 0.066 3 0.25 1.10 0.112 ( 0.337) 0.056 0.056 4 0.33 1.50 0.153 ( 0.337) 0.076 0.076 5 0.42 1.50 0.153 ( 0.337) 0.076 0.076 6 0.50 1.80 0.184 ( 0.337) 0.092 0.092 7 0.58 1.50 0.153 ( 0.337) 0.076 0.076 8 0.67 1.80 0.184 ( 0.337) 0.092 0.092 9 0.75 1.80 0.184 ( 0.337) 0.092 0.092 10 0.83 1.50 0.153 ( 0.337) 0.076 0.076 11 0.92 1.60 0.163 ( 0.337) 0.082 0.082 12 1.00 1.80 0.184 ( 0.337) 0.092 0.092 13 1.08 2.20 0.224 ( 0.337) 0.112 0.112 14 1.17 2.20 0.224 ( 0.337) 0.112 0.112 15 1.25 2.20 0.224 ( 0.337) 0.112 0.112 16 1.33 2.00 0.204 ( 0.337) 0.102 0.102 17 1.42 2.60 0.265 ( 0.337) 0.133 0.133 18 1.50 2.70 0.275 ( 0.337) 0.138 0.138 19 1.58 2.40 0.245 ( 0.337) 0.122 0.122 20 1.67 2.70 0.275 ( 0.337) 0.138 0.138 21 1.75 3.30 0.337 ( 0.337) 0.168 0.168 22 1.83 3.10 0.316 ( 0.337) 0.158 0.158 23 1.92 2.90 0.296 ( 0.337) 0.148 0.148 24 2.00 3.00 0.306 ( 0.337) 0.153 0.153 25 2.08 3.10 0.316 ( 0.337) 0.158 0.158 26 2.17 4.20 0.428 ( 0.337) 0.214 0.214 27 2.25 5.00 0.510 ( 0.337) 0.255 0.255 28 2.33 3.50 0.357 ( 0.337) 0.178 0.178 29 2.42 6.80 0.693 0.337 ( 0.347) 0.356 30 2.50 7.30 0.744 0.337 ( 0.372) 0.407 31 2.58 8.20 0.836 0.337 ( 0.418) 0.499 32 2.67 5.90 0.602 ( 0.337) 0.301 0.301 33 2.75 2.00 0.204 ( 0.337) 0.102 0.102 34 2.83 1.80 0.184 ( 0.337) 0.092 0.092 35 2.92 1.80 0.184 ( 0.337) 0.092 0.092 36 3.00 0.60 0.061 ( 0.337) 0.031 0.031 (Loss Rate Not Used)
Sum = 100.0 Sum = 5.2 Flood volume = Effective rainfall 0.44(In)
times area 55.8(Ac.)/[(In)/(Ft.)] = 2.0(Ac.Ft) Total soil loss = 0.41(In)
Total soil loss = 1.928(Ac.Ft)
Total rainfall = 0.85(In)
Flood volume = 88253.7 Cubic Feet
Total soil loss = 83998.5 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 22.973(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 7.5 15.0 22.5 30.0 ----------------------------------------------------------------------- 0+ 5 0.0051 0.73 Q | | | | 0+10 0.0226 2.54 V Q | | | | 0+15 0.0433 3.01 V Q | | | | 0+20 0.0654 3.21 |V Q | | | | 0+25 0.0918 3.83 |V Q | | | | 0+30 0.1209 4.23 | V Q | | | | 0+35 0.1526 4.59 | V Q | | | | 0+40 0.1840 4.56 | V Q | | | | 0+45 0.2179 4.93 | V Q | | | | 0+50 0.2515 4.87 | V Q | | | | 0+55 0.2830 4.58 | VQ | | | | 1+ 0 0.3155 4.72 | Q | | | | 1+ 5 0.3516 5.23 | Q | | | | 1+10 0.3919 5.86 | Q | | | | 1+15 0.4338 6.08 | Q | | | | 1+20 0.4756 6.07 | QV| | | | 1+25 0.5182 6.18 | Q V | | | 1+30 0.5666 7.02 | Q|V | | | 1+35 0.6165 7.25 | Q| V | | | 1+40 0.6657 7.16 | Q| V | | | 1+45 0.7198 7.85 | Q V | | | 1+50 0.7797 8.69 | |Q V | | | 1+55 0.8391 8.62 | |Q V | | | 2+ 0 0.8974 8.47 | |Q V | | | 2+ 5 0.9567 8.62 | |Q V | | | 2+10 1.0215 9.40 | | Q V | | 2+15 1.1004 11.45 | | Q |V | | 2+20 1.1847 12.24 | | Q | V | | 2+25 1.2721 12.70 | | Q | V | | 2+30 1.3944 17.75 | | | Q V | | 2+35 1.5430 21.58 | | | Q V | 2+40 1.7012 22.97 | | | Q V | 2+45 1.8163 16.71 | | | Q | V | 2+50 1.8861 10.14 | | Q | | V | 2+55 1.9394 7.73 | Q | | V | 3+ 0 1.9811 6.06 | Q | | | V| 3+ 5 2.0046 3.41 | Q | | | V| 3+10 2.0159 1.64 | Q | | | V| 3+15 2.0213 0.79 |Q | | | V| 3+20 2.0238 0.36 Q | | | V| 3+25 2.0252 0.20 Q | | | V| 3+30 2.0259 0.10 Q | | | V| 3+35 2.0260 0.02 Q | | | V| -----------------------------------------------------------------------

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - 'GOLDEN MEADOWS' MAJOR MODIFICATION
PRELIMINARY HYDROLOGY STUDY – AREA ‘D’
PROPOSED CONDITION UNIT HYDROGRAPH - 2 YEAR 6 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021, BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 55.84(Ac.) = 0.087 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 55.84(Ac.) = 0.087 Sq. Mi.

Length along longest watercourse = 4101.00(Ft.)
Length along longest watercourse measured to centroid = 1105.00(Ft.) Length along longest watercourse = 0.777 Mi.

Length along longest watercourse measured to centroid = 0.209 Mi.

Difference in elevation = 49.10(Ft.)
Slope along watercourse = 63.2158 Ft./Mi.

Average Manning's 'N' = 0.015
Lag time = 0.082 Hr.

Lag time = 4.93 Min.
25% of lag time = 1.23 Min.
40% of lag time = 1.97 Min.

Unit time = 5.00 Min.

Duration of storm = 6 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 1.20 67.01

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 3.00 167.52

STORM EVENT (YEAR) = 2.00
Area Averaged 2-Year Rainfall = 1.200(In)
Area Averaged 100-Year Rainfall = 3.000(In)

Point rain (area averaged) = 1.200(In)
Areal adjustment factor = 99.98 %
Adjusted average point rain = 1.200(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

55.840 65.70 0.500
Total Area Entered = 55.84(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-1 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.083 101.508 19.663 11.066 2 0.167 203.015 48.509 27.299 3 0.250 304.523 15.411 8.673 4 0.333 406.031 6.983 3.930 5 0.417 507.539 3.915 2.203 6 0.500 609.046 2.530 1.424 7 0.583 710.554 1.553 0.874 8 0.667 812.062 1.435 0.808 Sum = 100.000 Sum= 56.276
-----------------------------------------------------------------------

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 0.50 0.072 ( 0.337) 0.036 0.036 2 0.17 0.60 0.086 ( 0.337) 0.043 0.043 3 0.25 0.60 0.086 ( 0.337) 0.043 0.043 4 0.33 0.60 0.086 ( 0.337) 0.043 0.043 5 0.42 0.60 0.086 ( 0.337) 0.043 0.043 6 0.50 0.70 0.101 ( 0.337) 0.050 0.050 7 0.58 0.70 0.101 ( 0.337) 0.050 0.050 8 0.67 0.70 0.101 ( 0.337) 0.050 0.050 9 0.75 0.70 0.101 ( 0.337) 0.050 0.050 10 0.83 0.70 0.101 ( 0.337) 0.050 0.050 11 0.92 0.70 0.101 ( 0.337) 0.050 0.050 12 1.00 0.80 0.115 ( 0.337) 0.058 0.058 13 1.08 0.80 0.115 ( 0.337) 0.058 0.058 14 1.17 0.80 0.115 ( 0.337) 0.058 0.058 15 1.25 0.80 0.115 ( 0.337) 0.058 0.058 16 1.33 0.80 0.115 ( 0.337) 0.058 0.058 17 1.42 0.80 0.115 ( 0.337) 0.058 0.058 18 1.50 0.80 0.115 ( 0.337) 0.058 0.058 19 1.58 0.80 0.115 ( 0.337) 0.058 0.058 20 1.67 0.80 0.115 ( 0.337) 0.058 0.058 21 1.75 0.80 0.115 ( 0.337) 0.058 0.058 22 1.83 0.80 0.115 ( 0.337) 0.058 0.058 23 1.92 0.80 0.115 ( 0.337) 0.058 0.058 24 2.00 0.90 0.130 ( 0.337) 0.065 0.065 25 2.08 0.80 0.115 ( 0.337) 0.058 0.058 26 2.17 0.90 0.130 ( 0.337) 0.065 0.065 27 2.25 0.90 0.130 ( 0.337) 0.065 0.065 28 2.33 0.90 0.130 ( 0.337) 0.065 0.065 29 2.42 0.90 0.130 ( 0.337) 0.065 0.065 30 2.50 0.90 0.130 ( 0.337) 0.065 0.065 31 2.58 0.90 0.130 ( 0.337) 0.065 0.065 32 2.67 0.90 0.130 ( 0.337) 0.065 0.065 33 2.75 1.00 0.144 ( 0.337) 0.072 0.072 34 2.83 1.00 0.144 ( 0.337) 0.072 0.072 35 2.92 1.00 0.144 ( 0.337) 0.072 0.072 36 3.00 1.00 0.144 ( 0.337) 0.072 0.072 37 3.08 1.00 0.144 ( 0.337) 0.072 0.072 38 3.17 1.10 0.158 ( 0.337) 0.079 0.079 39 3.25 1.10 0.158 ( 0.337) 0.079 0.079 40 3.33 1.10 0.158 ( 0.337) 0.079 0.079 41 3.42 1.20 0.173 ( 0.337) 0.086 0.086 42 3.50 1.30 0.187 ( 0.337) 0.094 0.094 43 3.58 1.40 0.202 ( 0.337) 0.101 0.101 44 3.67 1.40 0.202 ( 0.337) 0.101 0.101 45 3.75 1.50 0.216 ( 0.337) 0.108 0.108 46 3.83 1.50 0.216 ( 0.337) 0.108 0.108 47 3.92 1.60 0.230 ( 0.337) 0.115 0.115 48 4.00 1.60 0.230 ( 0.337) 0.115 0.115 49 4.08 1.70 0.245 ( 0.337) 0.122 0.122 50 4.17 1.80 0.259 ( 0.337) 0.130 0.130 51 4.25 1.90 0.274 ( 0.337) 0.137 0.137 52 4.33 2.00 0.288 ( 0.337) 0.144 0.144 53 4.42 2.10 0.302 ( 0.337) 0.151 0.151 54 4.50 2.10 0.302 ( 0.337) 0.151 0.151 55 4.58 2.20 0.317 ( 0.337) 0.158 0.158 56 4.67 2.30 0.331 ( 0.337) 0.166 0.166 57 4.75 2.40 0.346 ( 0.337) 0.173 0.173 58 4.83 2.40 0.346 ( 0.337) 0.173 0.173 59 4.92 2.50 0.360 ( 0.337) 0.180 0.180 60 5.00 2.60 0.374 ( 0.337) 0.187 0.187 61 5.08 3.10 0.446 ( 0.337) 0.223 0.223 62 5.17 3.60 0.518 ( 0.337) 0.259 0.259 63 5.25 3.90 0.561 ( 0.337) 0.281 0.281 64 5.33 4.20 0.605 ( 0.337) 0.302 0.302 65 5.42 4.70 0.677 0.337 ( 0.338) 0.340 66 5.50 5.60 0.806 0.337 ( 0.403) 0.469 67 5.58 1.90 0.274 ( 0.337) 0.137 0.137 68 5.67 0.90 0.130 ( 0.337) 0.065 0.065 69 5.75 0.60 0.086 ( 0.337) 0.043 0.043 70 5.83 0.50 0.072 ( 0.337) 0.036 0.036 71 5.92 0.30 0.043 ( 0.337) 0.022 0.022 72 6.00 0.20 0.029 ( 0.337) 0.014 0.014 (Loss Rate Not Used)
Sum = 100.0 Sum = 7.3 Flood volume = Effective rainfall 0.61(In)
times area 55.8(Ac.)/[(In)/(Ft.)] = 2.8(Ac.Ft) Total soil loss = 0.59(In)
Total soil loss = 2.765(Ac.Ft)
Total rainfall = 1.20(In)
Flood volume = 122734.9 Cubic Feet
Total soil loss = 120457.5 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 19.801(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 6 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 5.0 10.0 15.0 20.0 ----------------------------------------------------------------------- 0+ 5 0.0027 0.40 Q | | | | 0+10 0.0128 1.46 V Q | | | | 0+15 0.0264 1.97 V Q | | | | 0+20 0.0414 2.17 V Q | | | | 0+25 0.0571 2.28 V Q | | | | 0+30 0.0738 2.43 |V Q | | | | 0+35 0.0922 2.67 |V Q | | | | 0+40 0.1112 2.76 |V Q | | | | 0+45 0.1305 2.80 |V Q | | | | 0+50 0.1499 2.81 | V Q | | | | 0+55 0.1693 2.83 | V Q | | | | 1+ 0 0.1894 2.91 | V Q | | | | 1+ 5 0.2108 3.11 | V Q | | | | 1+10 0.2327 3.18 | V Q | | | | 1+15 0.2548 3.20 | V Q | | | | 1+20 0.2769 3.22 | V Q | | | | 1+25 0.2992 3.23 | V Q | | | | 1+30 0.3215 3.24 | V Q | | | | 1+35 0.3438 3.24 | V Q | | | | 1+40 0.3661 3.24 | VQ | | | | 1+45 0.3885 3.24 | VQ | | | | 1+50 0.4108 3.24 | VQ | | | | 1+55 0.4331 3.24 | Q | | | | 2+ 0 0.4560 3.32 | Q | | | | 2+ 5 0.4797 3.44 | Q | | | | 2+10 0.5030 3.38 | QV | | | | 2+15 0.5274 3.55 | Q | | | | 2+20 0.5522 3.60 | Q | | | | 2+25 0.5771 3.62 | QV | | | | 2+30 0.6022 3.63 | QV | | | | 2+35 0.6272 3.64 | QV | | | | 2+40 0.6523 3.64 | Q V| | | | 2+45 0.6780 3.73 | Q V| | | | 2+50 0.7050 3.92 | Q V | | | 2+55 0.7325 3.99 | Q V | | | 3+ 0 0.7601 4.01 | Q V | | | 3+ 5 0.7879 4.03 | Q |V | | | 3+10 0.8163 4.12 | Q |V | | | 3+15 0.8460 4.32 | Q | V | | | 3+20 0.8763 4.39 | Q | V | | | 3+25 0.9073 4.50 | Q | V | | | 3+30 0.9403 4.79 | Q| V | | | 3+35 0.9757 5.14 | Q V | | | 3+40 1.0131 5.43 | Q V | | | 3+45 1.0519 5.63 | |Q V | | | 3+50 1.0924 5.88 | |Q V | | | 3+55 1.1340 6.05 | | Q V | | | 4+ 0 1.1774 6.30 | | Q V | | | 4+ 5 1.2220 6.47 | | Q V | | | 4+10 1.2688 6.79 | | Q V | | | 4+15 1.3180 7.15 | | Q V | | | 4+20 1.3699 7.53 | | Q V| | | 4+25 1.4245 7.92 | | Q V | | 4+30 1.4813 8.24 | | Q |V | | 4+35 1.5394 8.45 | | Q |V | | 4+40 1.6000 8.79 | | Q | V | | 4+45 1.6631 9.17 | | Q | V | | 4+50 1.7284 9.48 | | Q | V | | 4+55 1.7950 9.67 | | Q| V | | 5+ 0 1.8639 10.01 | | Q V | | 5+ 5 1.9376 10.70 | | |Q V | | 5+10 2.0216 12.20 | | | Q V | | 5+15 2.1166 13.79 | | | Q V | 5+20 2.2206 15.10 | | | QV | 5+25 2.3344 16.53 | | | | Q | 5+30 2.4680 19.40 | | | | V Q | 5+35 2.6044 19.80 | | | | V Q| 5+40 2.6824 11.33 | | | Q | V | 5+45 2.7300 6.91 | | Q | | V | 5+50 2.7623 4.69 | Q| | | V| 5+55 2.7855 3.36 | Q | | | V| 6+ 0 2.8010 2.25 | Q | | | V| 6+ 5 2.8107 1.41 | Q | | | V| 6+10 2.8143 0.52 |Q | | | V| 6+15 2.8160 0.25 Q | | | V| 6+20 2.8168 0.13 Q | | | V| 6+25 2.8173 0.07 Q | | | V| 6+30 2.8175 0.03 Q | | | V| 6+35 2.8176 0.01 Q | | | V -----------------------------------------------------------------------

U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD/CIVILDESIGN, 1989 - 2014, Version 9.0 Study date 11/08/21 File: PRD002242.out
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------ Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978
Program License Serial Number 6406
--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used
English Units used in output format
--------------------------------------------------------------------- TRACT 31194 - 'GOLDEN MEADOWS' MAJOR MODIFICATION
PRELIMINARY HYDROLOGY STUDY – AREA ‘D’
PROPOSED CONDITION UNIT HYDROGRAPH - 2 YEAR HOUR STORM

HUNSAKER & ASSOCIATES, BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 55.84(Ac.) = 0.087 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 55.84(Ac.) = 0.087 Sq. Mi.

Length along longest watercourse = 4101.00(Ft.)
Length along longest watercourse measured to centroid = 1105.00(Ft.) Length along longest watercourse = 0.777 Mi.

Length along longest watercourse measured to centroid = 0.209 Mi.

Difference in elevation = 49.10(Ft.)
Slope along watercourse = 63.2158 Ft./Mi.

Average Manning's 'N' = 0.015
Lag time = 0.082 Hr.

Lag time = 4.93 Min.
25% of lag time = 1.23 Min.
40% of lag time = 1.97 Min.

Unit time = 15.00 Min.

Duration of storm = 24 Hour(s)
User Entered Base Flow = 0.00(CFS)
2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 2.00 111.68
100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 5.00 279.20
STORM EVENT (YEAR) = 2.00
Area Averaged 2-Year Rainfall = 2.000(In)
Area Averaged 100-Year Rainfall = 5.000(In)
Point rain (area averaged) = 2.000(In)
Areal adjustment factor = 99.99 %
Adjusted average point rain = 2.000(In)
Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

55.840 65.70 0.500
Total Area Entered = 55.84(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-1 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

65.7 45.8 0.613 0.500 0.337 1.000 0.337 Sum (F) = 0.337
Area averaged mean soil loss (F) (In/Hr) = 0.337
Minimum soil loss rate ((In/Hr)) = 0.169
(for 24 hour storm duration)
Soil low loss rate (decimal) = 0.500
--------------------------------------------------------------------- U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.250 304.523 57.140 32.156 2 0.500 609.046 36.881 20.755 3 0.750 913.570 5.980 3.365 Sum = 100.000 Sum= 56.276
----------------------------------------------------------------------- The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.25 0.20 0.016 ( 0.595) 0.008 0.008 2 0.50 0.30 0.024 ( 0.588) 0.012 0.012 3 0.75 0.30 0.024 ( 0.581) 0.012 0.012 4 1.00 0.40 0.032 ( 0.575) 0.016 0.016 5 1.25 0.30 0.024 ( 0.568) 0.012 0.012 6 1.50 0.30 0.024 ( 0.561) 0.012 0.012 7 1.75 0.30 0.024 ( 0.554) 0.012 0.012 8 2.00 0.40 0.032 ( 0.548) 0.016 0.016 9 2.25 0.40 0.032 ( 0.541) 0.016 0.016 10 2.50 0.40 0.032 ( 0.534) 0.016 0.016 11 2.75 0.50 0.040 ( 0.528) 0.020 0.020 12 3.00 0.50 0.040 ( 0.521) 0.020 0.020 13 3.25 0.50 0.040 ( 0.515) 0.020 0.020 14 3.50 0.50 0.040 ( 0.509) 0.020 0.020 15 3.75 0.50 0.040 ( 0.502) 0.020 0.020 16 4.00 0.60 0.048 ( 0.496) 0.024 0.024 17 4.25 0.60 0.048 ( 0.490) 0.024 0.024 18 4.50 0.70 0.056 ( 0.483) 0.028 0.028 19 4.75 0.70 0.056 ( 0.477) 0.028 0.028 20 5.00 0.80 0.064 ( 0.471) 0.032 0.032 21 5.25 0.60 0.048 ( 0.465) 0.024 0.024 22 5.50 0.70 0.056 ( 0.459) 0.028 0.028 23 5.75 0.80 0.064 ( 0.453) 0.032 0.032 24 6.00 0.80 0.064 ( 0.447) 0.032 0.032 25 6.25 0.90 0.072 ( 0.441) 0.036 0.036 26 6.50 0.90 0.072 ( 0.435) 0.036 0.036 27 6.75 1.00 0.080 ( 0.429) 0.040 0.040 28 7.00 1.00 0.080 ( 0.423) 0.040 0.040 29 7.25 1.00 0.080 ( 0.418) 0.040 0.040 30 7.50 1.10 0.088 ( 0.412) 0.044 0.044 31 7.75 1.20 0.096 ( 0.406) 0.048 0.048 32 8.00 1.30 0.104 ( 0.401) 0.052 0.052 33 8.25 1.50 0.120 ( 0.395) 0.060 0.060 34 8.50 1.50 0.120 ( 0.390) 0.060 0.060 35 8.75 1.60 0.128 ( 0.384) 0.064 0.064 36 9.00 1.70 0.136 ( 0.379) 0.068 0.068 37 9.25 1.90 0.152 ( 0.373) 0.076 0.076 38 9.50 2.00 0.160 ( 0.368) 0.080 0.080 39 9.75 2.10 0.168 ( 0.363) 0.084 0.084 40 10.00 2.20 0.176 ( 0.358) 0.088 0.088 41 10.25 1.50 0.120 ( 0.352) 0.060 0.060 42 10.50 1.50 0.120 ( 0.347) 0.060 0.060 43 10.75 2.00 0.160 ( 0.342) 0.080 0.080 44 11.00 2.00 0.160 ( 0.337) 0.080 0.080 45 11.25 1.90 0.152 ( 0.332) 0.076 0.076 46 11.50 1.90 0.152 ( 0.327) 0.076 0.076 47 11.75 1.70 0.136 ( 0.323) 0.068 0.068 48 12.00 1.80 0.144 ( 0.318) 0.072 0.072 49 12.25 2.50 0.200 ( 0.313) 0.100 0.100 50 12.50 2.60 0.208 ( 0.308) 0.104 0.104 51 12.75 2.80 0.224 ( 0.304) 0.112 0.112 52 13.00 2.90 0.232 ( 0.299) 0.116 0.116 53 13.25 3.40 0.272 ( 0.295) 0.136 0.136 54 13.50 3.40 0.272 ( 0.290) 0.136 0.136 55 13.75 2.30 0.184 ( 0.286) 0.092 0.092 56 14.00 2.30 0.184 ( 0.281) 0.092 0.092 57 14.25 2.70 0.216 ( 0.277) 0.108 0.108 58 14.50 2.60 0.208 ( 0.273) 0.104 0.104 59 14.75 2.60 0.208 ( 0.269) 0.104 0.104 60 15.00 2.50 0.200 ( 0.265) 0.100 0.100 61 15.25 2.40 0.192 ( 0.261) 0.096 0.096 62 15.50 2.30 0.184 ( 0.257) 0.092 0.092 63 15.75 1.90 0.152 ( 0.253) 0.076 0.076 64 16.00 1.90 0.152 ( 0.249) 0.076 0.076 65 16.25 0.40 0.032 ( 0.245) 0.016 0.016 66 16.50 0.40 0.032 ( 0.241) 0.016 0.016 67 16.75 0.30 0.024 ( 0.238) 0.012 0.012 68 17.00 0.30 0.024 ( 0.234) 0.012 0.012 69 17.25 0.50 0.040 ( 0.230) 0.020 0.020 70 17.50 0.50 0.040 ( 0.227) 0.020 0.020 71 17.75 0.50 0.040 ( 0.224) 0.020 0.020 72 18.00 0.40 0.032 ( 0.220) 0.016 0.016 73 18.25 0.40 0.032 ( 0.217) 0.016 0.016 74 18.50 0.40 0.032 ( 0.214) 0.016 0.016 75 18.75 0.30 0.024 ( 0.211) 0.012 0.012 76 19.00 0.20 0.016 ( 0.208) 0.008 0.008 77 19.25 0.30 0.024 ( 0.205) 0.012 0.012 78 19.50 0.40 0.032 ( 0.202) 0.016 0.016 79 19.75 0.30 0.024 ( 0.199) 0.012 0.012 80 20.00 0.20 0.016 ( 0.197) 0.008 0.008 81 20.25 0.30 0.024 ( 0.194) 0.012 0.012 82 20.50 0.30 0.024 ( 0.191) 0.012 0.012 83 20.75 0.30 0.024 ( 0.189) 0.012 0.012 84 21.00 0.20 0.016 ( 0.187) 0.008 0.008 85 21.25 0.30 0.024 ( 0.185) 0.012 0.012 86 21.50 0.20 0.016 ( 0.182) 0.008 0.008 87 21.75 0.30 0.024 ( 0.180) 0.012 0.012 88 22.00 0.20 0.016 ( 0.179) 0.008 0.008 89 22.25 0.30 0.024 ( 0.177) 0.012 0.012 90 22.50 0.20 0.016 ( 0.175) 0.008 0.008 91 22.75 0.20 0.016 ( 0.174) 0.008 0.008 92 23.00 0.20 0.016 ( 0.172) 0.008 0.008 93 23.25 0.20 0.016 ( 0.171) 0.008 0.008 94 23.50 0.20 0.016 ( 0.170) 0.008 0.008 95 23.75 0.20 0.016 ( 0.169) 0.008 0.008 96 24.00 0.20 0.016 ( 0.169) 0.008 0.008 (Loss Rate Not Used)
Sum = 100.0 Sum = 4.0 Flood volume = Effective rainfall 1.00(In)
times area 55.8(Ac.)/[(In)/(Ft.)] = 4.7(Ac.Ft) Total soil loss = 1.00(In)
Total soil loss = 4.653(Ac.Ft)
Total rainfall = 2.00(In)
Flood volume = 202677.1 Cubic Feet
Total soil loss = 202677.1 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 7.589(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 24 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 15 Minute intervals ((CFS))
-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 2.5 5.0 7.5 10.0 ----------------------------------------------------------------------- 0+15 0.0053 0.26 VQ | | | | 0+30 0.0167 0.55 V Q | | | | 0+45 0.0304 0.66 V Q | | | | 1+ 0 0.0470 0.80 V Q | | | | 1+15 0.0627 0.76 V Q | | | | 1+30 0.0769 0.69 V Q | | | | 1+45 0.0909 0.68 V Q | | | | 2+ 0 0.1075 0.80 V Q | | | | 2+15 0.1258 0.89 V Q | | | | 2+30 0.1445 0.90 |V Q | | | | 2+45 0.1657 1.03 |V Q | | | | 3+ 0 0.1887 1.11 |V Q | | | | 3+15 0.2120 1.13 |V Q | | | | 3+30 0.2352 1.13 | V Q | | | | 3+45 0.2585 1.13 | V Q | | | | 4+ 0 0.2844 1.25 | V Q | | | | 4+15 0.3121 1.34 | V Q | | | | 4+30 0.3426 1.48 | V Q | | | | 4+45 0.3749 1.56 | V Q | | | | 5+ 0 0.4102 1.71 | V Q | | | | 5+15 0.4418 1.53 | V Q | | | | 5+30 0.4729 1.51 | V Q | | | | 5+45 0.5079 1.69 | V Q | | | | 6+ 0 0.5448 1.79 | V Q | | | | 6+15 0.5847 1.93 | V Q | | | | 6+30 0.6263 2.01 | V Q | | | | 6+45 0.6708 2.16 | V Q | | | | 7+ 0 0.7171 2.24 | V Q | | | | 7+15 0.7636 2.25 | V Q| | | | 7+30 0.8128 2.38 | V Q| | | | 7+45 0.8664 2.59 | V Q | | | 8+ 0 0.9246 2.82 | V |Q | | | 8+15 0.9901 3.17 | V | Q | | | 8+30 1.0593 3.35 | V| Q | | | 8+45 1.1318 3.51 | V| Q | | | 9+ 0 1.2086 3.72 | V Q | | | 9+15 1.2927 4.07 | V Q | | | 9+30 1.3832 4.38 | |V Q | | | 9+45 1.4787 4.62 | | V Q | | | 10+ 0 1.5788 4.84 | | V Q| | | 10+15 1.6622 4.04 | | V Q | | | 10+30 1.7340 3.47 | | QV | | | 10+45 1.8171 4.02 | | VQ | | | 11+ 0 1.9087 4.44 | | VQ | | | 11+15 1.9991 4.38 | | Q | | | 11+30 2.0878 4.29 | | Q | | | 11+45 2.1709 4.02 | | Q V | | | 12+ 0 2.2532 3.98 | | Q V| | | 12+15 2.3553 4.94 | | QV | | 12+30 2.4723 5.66 | | VQ | | 12+45 2.5983 6.10 | | | V Q | | 13+ 0 2.7307 6.41 | | | V Q | | 13+15 2.8787 7.16 | | | V Q | | 13+30 3.0355 7.59 | | | V Q | 13+45 3.1644 6.24 | | | Q V | | 14+ 0 3.2745 5.33 | | |Q V | | 14+15 3.3922 5.69 | | | Q V| | 14+30 3.5140 5.90 | | | Q V | 14+45 3.6353 5.87 | | | Q V | 15+ 0 3.7536 5.73 | | | Q | V | 15+15 3.8675 5.51 | | | Q | V | 15+30 3.9768 5.29 | | |Q | V | 15+45 4.0735 4.68 | | Q | | V | 16+ 0 4.1630 4.33 | | Q | | V | 16+15 4.2115 2.35 | Q| | | V | 16+30 4.2343 1.10 | Q | | | V | 16+45 4.2502 0.77 | Q | | | V | 17+ 0 4.2645 0.69 | Q | | | V | 17+15 4.2838 0.93 | Q | | | V | 17+30 4.3065 1.10 | Q | | | V | 17+45 4.3297 1.13 | Q | | | V | 18+ 0 4.3503 1.00 | Q | | | V | 18+15 4.3692 0.91 | Q | | | V | 18+30 4.3878 0.90 | Q | | | V | 18+45 4.4038 0.77 | Q | | | V | 19+ 0 4.4154 0.56 | Q | | | V | 19+15 4.4276 0.59 | Q | | | V | 19+30 4.4439 0.79 | Q | | | V | 19+45 4.4596 0.76 | Q | | | V | 20+ 0 4.4712 0.56 | Q | | | V | 20+15 4.4834 0.59 | Q | | | V | 20+30 4.4971 0.66 | Q | | | V | 20+45 4.5111 0.68 | Q | | | V | 21+ 0 4.5224 0.55 | Q | | | V | 21+15 4.5346 0.59 | Q | | | V | 21+30 4.5456 0.53 | Q | | | V| 21+45 4.5579 0.59 | Q | | | V| 22+ 0 4.5689 0.53 | Q | | | V| 22+15 4.5811 0.59 | Q | | | V| 22+30 4.5922 0.53 | Q | | | V| 22+45 4.6018 0.46 |Q | | | V| 23+ 0 4.6111 0.45 |Q | | | V| 23+15 4.6204 0.45 |Q | | | V| 23+30 4.6297 0.45 |Q | | | V| 23+45 4.6390 0.45 |Q | | | V| 24+ 0 4.6483 0.45 |Q | | | V| 24+15 4.6523 0.19 Q | | | V| 24+30 4.6528 0.03 Q | | | V ----------------------------------------------------------------------- Preliminary Hydrology Analysis – Golden Meadows – Tract 31194 – Major Modification

Page 3 ends

Section 3
· Area ‘D’ – 10 Year Post-Development Condition – Unit Hydrograph

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - 'GOLDEN MEADOWS' MAJOR MODIFICATION
PRELIMINARY HYDROLOGY STUDY – AREA ‘D’
PROPOSED CONDITION UNIT HYDROGRAPH - 10 YEAR 1 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021, BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 55.84(Ac.) = 0.087 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 55.84(Ac.) = 0.087 Sq. Mi.

Length along longest watercourse = 4101.00(Ft.)
Length along longest watercourse measured to centroid = 1105.00(Ft.) Length along longest watercourse = 0.777 Mi.

Length along longest watercourse measured to centroid = 0.209 Mi.

Difference in elevation = 49.10(Ft.)
Slope along watercourse = 63.2158 Ft./Mi.

Average Manning's 'N' = 0.015
Lag time = 0.082 Hr.

Lag time = 4.93 Min.
25% of lag time = 1.23 Min.
40% of lag time = 1.97 Min.

Unit time = 5.00 Min.

Duration of storm = 1 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 0.55 30.71

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 1.30 72.59

STORM EVENT (YEAR) = 10.00
Area Averaged 2-Year Rainfall = 0.550(In)
Area Averaged 100-Year Rainfall = 1.300(In)

Point rain (area averaged) = 0.859(In)
Areal adjustment factor = 99.95 %
Adjusted average point rain = 0.858(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

55.840 65.70 0.500
Total Area Entered = 55.84(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-2 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.083 101.508 19.663 11.066 2 0.167 203.015 48.509 27.299 3 0.250 304.523 15.411 8.673 4 0.333 406.031 6.983 3.930 5 0.417 507.539 3.915 2.203 6 0.500 609.046 2.530 1.424 7 0.583 710.554 1.553 0.874 8 0.667 812.062 1.435 0.808 Sum = 100.000 Sum= 56.276
-----------------------------------------------------------------------

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 3.40 0.350 ( 0.225) 0.175 0.175 2 0.17 4.70 0.484 0.225 ( 0.242) 0.259 3 0.25 4.70 0.484 0.225 ( 0.242) 0.259 4 0.33 5.10 0.525 0.225 ( 0.263) 0.301 5 0.42 5.80 0.597 0.225 ( 0.299) 0.373 6 0.50 5.90 0.608 0.225 ( 0.304) 0.383 7 0.58 7.10 0.731 0.225 ( 0.366) 0.506 8 0.67 8.70 0.896 0.225 ( 0.448) 0.671 9 0.75 13.20 1.359 0.225 ( 0.680) 1.135 10 0.83 29.70 3.058 0.225 ( 1.529) 2.834 11 0.92 7.70 0.793 0.225 ( 0.396) 0.568 12 1.00 4.00 0.412 ( 0.225) 0.206 0.206 (Loss Rate Not Used)
Sum = 100.0 Sum = 7.7 Flood volume = Effective rainfall 0.64(In)
times area 55.8(Ac.)/[(In)/(Ft.)] = 3.0(Ac.Ft) Total soil loss = 0.22(In)
Total soil loss = 1.019(Ac.Ft)
Total rainfall = 0.86(In)
Flood volume = 129559.1 Cubic Feet
Total soil loss = 44381.4 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 98.404(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - 'GOLDEN MEADOWS' MAJOR MODIFICATION
PRELIMINARY HYDROLOGY STUDY – AREA ‘D’
PROPOSED CONDITION UNIT HYDROGRAPH - 10 YEAR 3 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021, BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 55.84(Ac.) = 0.087 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 55.84(Ac.) = 0.087 Sq. Mi.

Length along longest watercourse = 4101.00(Ft.)
Length along longest watercourse measured to centroid = 1105.00(Ft.) Length along longest watercourse = 0.777 Mi.

Length along longest watercourse measured to centroid = 0.209 Mi.

Difference in elevation = 49.10(Ft.)
Slope along watercourse = 63.2158 Ft./Mi.

Average Manning's 'N' = 0.015
Lag time = 0.082 Hr.

Lag time = 4.93 Min.
25% of lag time = 1.23 Min.
40% of lag time = 1.97 Min.

Unit time = 5.00 Min.

Duration of storm = 3 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 0.85 47.46

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 2.00 111.68

STORM EVENT (YEAR) = 10.00
Area Averaged 2-Year Rainfall = 0.850(In)
Area Averaged 100-Year Rainfall = 2.000(In)

Point rain (area averaged) = 1.323(In)
Areal adjustment factor = 99.98 %
Adjusted average point rain = 1.323(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

55.840 65.70 0.500
Total Area Entered = 55.84(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-2 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.083 101.508 19.663 11.066 2 0.167 203.015 48.509 27.299 3 0.250 304.523 15.411 8.673 4 0.333 406.031 6.983 3.930 5 0.417 507.539 3.915 2.203 6 0.500 609.046 2.530 1.424 7 0.583 710.554 1.553 0.874 8 0.667 812.062 1.435 0.808 Sum = 100.000 Sum= 56.276
-----------------------------------------------------------------------

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 1.30 0.206 ( 0.225) 0.103 0.103 2 0.17 1.30 0.206 ( 0.225) 0.103 0.103 3 0.25 1.10 0.175 ( 0.225) 0.087 0.087 4 0.33 1.50 0.238 ( 0.225) 0.119 0.119 5 0.42 1.50 0.238 ( 0.225) 0.119 0.119 6 0.50 1.80 0.286 ( 0.225) 0.143 0.143 7 0.58 1.50 0.238 ( 0.225) 0.119 0.119 8 0.67 1.80 0.286 ( 0.225) 0.143 0.143 9 0.75 1.80 0.286 ( 0.225) 0.143 0.143 10 0.83 1.50 0.238 ( 0.225) 0.119 0.119 11 0.92 1.60 0.254 ( 0.225) 0.127 0.127 12 1.00 1.80 0.286 ( 0.225) 0.143 0.143 13 1.08 2.20 0.349 ( 0.225) 0.175 0.175 14 1.17 2.20 0.349 ( 0.225) 0.175 0.175 15 1.25 2.20 0.349 ( 0.225) 0.175 0.175 16 1.33 2.00 0.317 ( 0.225) 0.159 0.159 17 1.42 2.60 0.413 ( 0.225) 0.206 0.206 18 1.50 2.70 0.429 ( 0.225) 0.214 0.214 19 1.58 2.40 0.381 ( 0.225) 0.190 0.190 20 1.67 2.70 0.429 ( 0.225) 0.214 0.214 21 1.75 3.30 0.524 0.225 ( 0.262) 0.299 22 1.83 3.10 0.492 0.225 ( 0.246) 0.267 23 1.92 2.90 0.460 0.225 ( 0.230) 0.236 24 2.00 3.00 0.476 0.225 ( 0.238) 0.252 25 2.08 3.10 0.492 0.225 ( 0.246) 0.267 26 2.17 4.20 0.667 0.225 ( 0.333) 0.442 27 2.25 5.00 0.794 0.225 ( 0.397) 0.569 28 2.33 3.50 0.556 0.225 ( 0.278) 0.331 29 2.42 6.80 1.079 0.225 ( 0.540) 0.855 30 2.50 7.30 1.159 0.225 ( 0.579) 0.934 31 2.58 8.20 1.302 0.225 ( 0.651) 1.077 32 2.67 5.90 0.937 0.225 ( 0.468) 0.712 33 2.75 2.00 0.317 ( 0.225) 0.159 0.159 34 2.83 1.80 0.286 ( 0.225) 0.143 0.143 35 2.92 1.80 0.286 ( 0.225) 0.143 0.143 36 3.00 0.60 0.095 ( 0.225) 0.048 0.048 (Loss Rate Not Used)
Sum = 100.0 Sum = 9.7 Flood volume = Effective rainfall 0.81(In)
times area 55.8(Ac.)/[(In)/(Ft.)] = 3.8(Ac.Ft) Total soil loss = 0.51(In)
Total soil loss = 2.390(Ac.Ft)
Total rainfall = 1.32(In)
Flood volume = 164008.6 Cubic Feet
Total soil loss = 104121.1 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 50.907(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 15.0 30.0 45.0 60.0 ----------------------------------------------------------------------- 0+ 5 0.0079 1.14 Q | | | | 0+10 0.0351 3.96 V Q | | | | 0+15 0.0674 4.68 V Q | | | | 0+20 0.1018 5.00 |V Q | | | | 0+25 0.1429 5.96 |V Q | | | | 0+30 0.1882 6.58 |V Q | | | | 0+35 0.2375 7.15 | V Q | | | | 0+40 0.2864 7.10 | VQ | | | | 0+45 0.3392 7.67 | V Q | | | | 0+50 0.3915 7.59 | VQ | | | | 0+55 0.4405 7.13 | Q | | | | 1+ 0 0.4912 7.35 | QV | | | | 1+ 5 0.5472 8.14 | Q | | | | 1+10 0.6101 9.13 | Q | | | | 1+15 0.6753 9.47 | QV | | | | 1+20 0.7404 9.44 | QV | | | | 1+25 0.8066 9.62 | Q V | | | | 1+30 0.8819 10.93 | Q V| | | | 1+35 0.9596 11.28 | Q V | | | 1+40 1.0363 11.14 | Q |V | | | 1+45 1.1233 12.64 | Q |V | | | 1+50 1.2252 14.79 | Q| V | | | 1+55 1.3242 14.39 | Q| V | | | 2+ 0 1.4194 13.82 | Q| V | | | 2+ 5 1.5174 14.23 | Q| V | | | 2+10 1.6322 16.67 | |Q V | | | 2+15 1.7907 23.02 | | Q V| | | 2+20 1.9661 25.46 | | Q V | | 2+25 2.1489 26.55 | | Q | V | | 2+30 2.4283 40.56 | | | V Q | | 2+35 2.7621 48.48 | | | V| Q | 2+40 3.1127 50.91 | | | | Q | 2+45 3.3705 37.43 | | | Q | V | 2+50 3.5107 20.36 | | Q | | V | 2+55 3.6097 14.38 | Q| | | V | 3+ 0 3.6848 10.90 | Q | | | V| 3+ 5 3.7273 6.16 | Q | | | V| 3+10 3.7480 3.01 | Q | | | V| 3+15 3.7578 1.42 Q | | | V| 3+20 3.7617 0.56 Q | | | V| 3+25 3.7638 0.31 Q | | | V| 3+30 3.7649 0.16 Q | | | V| 3+35 3.7651 0.04 Q | | | V -----------------------------------------------------------------------

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - 'GOLDEN MEADOWS' MAJOR MODIFICATION
PRELIMINARY HYDROLOGY STUDY – AREA ‘D’
PROPOSED CONDITION UNIT HYDROGRAPH - 10 YEAR 6 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021, BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 55.84(Ac.) = 0.087 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 55.84(Ac.) = 0.087 Sq. Mi.

Length along longest watercourse = 4101.00(Ft.)
Length along longest watercourse measured to centroid = 1105.00(Ft.) Length along longest watercourse = 0.777 Mi.

Length along longest watercourse measured to centroid = 0.209 Mi.

Difference in elevation = 49.10(Ft.)
Slope along watercourse = 63.2158 Ft./Mi.

Average Manning's 'N' = 0.015
Lag time = 0.082 Hr.

Lag time = 4.93 Min.
25% of lag time = 1.23 Min.
40% of lag time = 1.97 Min.

Unit time = 5.00 Min.

Duration of storm = 6 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 1.20 67.01

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 3.00 167.52

STORM EVENT (YEAR) = 10.00
Area Averaged 2-Year Rainfall = 1.200(In)
Area Averaged 100-Year Rainfall = 3.000(In)

Point rain (area averaged) = 1.941(In)
Areal adjustment factor = 99.98 %
Adjusted average point rain = 1.940(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

55.840 65.70 0.500
Total Area Entered = 55.84(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-2 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.083 101.508 19.663 11.066 2 0.167 203.015 48.509 27.299 3 0.250 304.523 15.411 8.673 4 0.333 406.031 6.983 3.930 5 0.417 507.539 3.915 2.203 6 0.500 609.046 2.530 1.424 7 0.583 710.554 1.553 0.874 8 0.667 812.062 1.435 0.808 Sum = 100.000 Sum= 56.276
-----------------------------------------------------------------------

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 0.50 0.116 ( 0.225) 0.058 0.058 2 0.17 0.60 0.140 ( 0.225) 0.070 0.070 3 0.25 0.60 0.140 ( 0.225) 0.070 0.070 4 0.33 0.60 0.140 ( 0.225) 0.070 0.070 5 0.42 0.60 0.140 ( 0.225) 0.070 0.070 6 0.50 0.70 0.163 ( 0.225) 0.081 0.081 7 0.58 0.70 0.163 ( 0.225) 0.081 0.081 8 0.67 0.70 0.163 ( 0.225) 0.081 0.081 9 0.75 0.70 0.163 ( 0.225) 0.081 0.081 10 0.83 0.70 0.163 ( 0.225) 0.081 0.081 11 0.92 0.70 0.163 ( 0.225) 0.081 0.081 12 1.00 0.80 0.186 ( 0.225) 0.093 0.093 13 1.08 0.80 0.186 ( 0.225) 0.093 0.093 14 1.17 0.80 0.186 ( 0.225) 0.093 0.093 15 1.25 0.80 0.186 ( 0.225) 0.093 0.093 16 1.33 0.80 0.186 ( 0.225) 0.093 0.093 17 1.42 0.80 0.186 ( 0.225) 0.093 0.093 18 1.50 0.80 0.186 ( 0.225) 0.093 0.093 19 1.58 0.80 0.186 ( 0.225) 0.093 0.093 20 1.67 0.80 0.186 ( 0.225) 0.093 0.093 21 1.75 0.80 0.186 ( 0.225) 0.093 0.093 22 1.83 0.80 0.186 ( 0.225) 0.093 0.093 23 1.92 0.80 0.186 ( 0.225) 0.093 0.093 24 2.00 0.90 0.210 ( 0.225) 0.105 0.105 25 2.08 0.80 0.186 ( 0.225) 0.093 0.093 26 2.17 0.90 0.210 ( 0.225) 0.105 0.105 27 2.25 0.90 0.210 ( 0.225) 0.105 0.105 28 2.33 0.90 0.210 ( 0.225) 0.105 0.105 29 2.42 0.90 0.210 ( 0.225) 0.105 0.105 30 2.50 0.90 0.210 ( 0.225) 0.105 0.105 31 2.58 0.90 0.210 ( 0.225) 0.105 0.105 32 2.67 0.90 0.210 ( 0.225) 0.105 0.105 33 2.75 1.00 0.233 ( 0.225) 0.116 0.116 34 2.83 1.00 0.233 ( 0.225) 0.116 0.116 35 2.92 1.00 0.233 ( 0.225) 0.116 0.116 36 3.00 1.00 0.233 ( 0.225) 0.116 0.116 37 3.08 1.00 0.233 ( 0.225) 0.116 0.116 38 3.17 1.10 0.256 ( 0.225) 0.128 0.128 39 3.25 1.10 0.256 ( 0.225) 0.128 0.128 40 3.33 1.10 0.256 ( 0.225) 0.128 0.128 41 3.42 1.20 0.279 ( 0.225) 0.140 0.140 42 3.50 1.30 0.303 ( 0.225) 0.151 0.151 43 3.58 1.40 0.326 ( 0.225) 0.163 0.163 44 3.67 1.40 0.326 ( 0.225) 0.163 0.163 45 3.75 1.50 0.349 ( 0.225) 0.175 0.175 46 3.83 1.50 0.349 ( 0.225) 0.175 0.175 47 3.92 1.60 0.373 ( 0.225) 0.186 0.186 48 4.00 1.60 0.373 ( 0.225) 0.186 0.186 49 4.08 1.70 0.396 ( 0.225) 0.198 0.198 50 4.17 1.80 0.419 ( 0.225) 0.210 0.210 51 4.25 1.90 0.442 ( 0.225) 0.221 0.221 52 4.33 2.00 0.466 0.225 ( 0.233) 0.241 53 4.42 2.10 0.489 0.225 ( 0.244) 0.264 54 4.50 2.10 0.489 0.225 ( 0.244) 0.264 55 4.58 2.20 0.512 0.225 ( 0.256) 0.288 56 4.67 2.30 0.535 0.225 ( 0.268) 0.311 57 4.75 2.40 0.559 0.225 ( 0.279) 0.334 58 4.83 2.40 0.559 0.225 ( 0.279) 0.334 59 4.92 2.50 0.582 0.225 ( 0.291) 0.357 60 5.00 2.60 0.605 0.225 ( 0.303) 0.381 61 5.08 3.10 0.722 0.225 ( 0.361) 0.497 62 5.17 3.60 0.838 0.225 ( 0.419) 0.614 63 5.25 3.90 0.908 0.225 ( 0.454) 0.683 64 5.33 4.20 0.978 0.225 ( 0.489) 0.753 65 5.42 4.70 1.094 0.225 ( 0.547) 0.870 66 5.50 5.60 1.304 0.225 ( 0.652) 1.079 67 5.58 1.90 0.442 ( 0.225) 0.221 0.221 68 5.67 0.90 0.210 ( 0.225) 0.105 0.105 69 5.75 0.60 0.140 ( 0.225) 0.070 0.070 70 5.83 0.50 0.116 ( 0.225) 0.058 0.058 71 5.92 0.30 0.070 ( 0.225) 0.035 0.035 72 6.00 0.20 0.047 ( 0.225) 0.023 0.023 (Loss Rate Not Used)
Sum = 100.0 Sum = 13.6 Flood volume = Effective rainfall 1.13(In)
times area 55.8(Ac.)/[(In)/(Ft.)] = 5.3(Ac.Ft) Total soil loss = 0.81(In)
Total soil loss = 3.758(Ac.Ft)
Total rainfall = 1.94(In)
Flood volume = 229578.2 Cubic Feet
Total soil loss = 163691.1 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 47.605(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 6 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 12.5 25.0 37.5 50.0 ----------------------------------------------------------------------- 0+ 5 0.0044 0.64 Q | | | | 0+10 0.0207 2.36 VQ | | | | 0+15 0.0427 3.19 V Q | | | | 0+20 0.0669 3.52 V Q | | | | 0+25 0.0923 3.69 V Q | | | | 0+30 0.1193 3.93 V Q | | | | 0+35 0.1490 4.31 |V Q | | | | 0+40 0.1798 4.47 |V Q | | | | 0+45 0.2110 4.53 |V Q | | | | 0+50 0.2424 4.55 |V Q | | | | 0+55 0.2738 4.57 | VQ | | | | 1+ 0 0.3062 4.71 | VQ | | | | 1+ 5 0.3409 5.03 | V Q | | | | 1+10 0.3763 5.14 | V Q | | | | 1+15 0.4120 5.18 | VQ | | | | 1+20 0.4478 5.21 | VQ | | | | 1+25 0.4838 5.22 | VQ | | | | 1+30 0.5199 5.23 | VQ | | | | 1+35 0.5560 5.24 | Q | | | | 1+40 0.5921 5.24 | Q | | | | 1+45 0.6282 5.24 | Q | | | | 1+50 0.6643 5.24 | QV | | | | 1+55 0.7004 5.24 | QV | | | | 2+ 0 0.7374 5.37 | QV | | | | 2+ 5 0.7757 5.56 | QV | | | | 2+10 0.8134 5.47 | Q V | | | | 2+15 0.8529 5.74 | Q V | | | | 2+20 0.8930 5.82 | Q V | | | | 2+25 0.9333 5.85 | Q V | | | | 2+30 0.9738 5.87 | Q V | | | | 2+35 1.0143 5.89 | Q V | | | | 2+40 1.0549 5.89 | Q V | | | | 2+45 1.0964 6.03 | Q V | | | | 2+50 1.1401 6.35 | Q V | | | | 2+55 1.1845 6.45 | Q V | | | | 3+ 0 1.2292 6.49 | Q V| | | | 3+ 5 1.2741 6.52 | Q V| | | | 3+10 1.3200 6.66 | Q V | | | 3+15 1.3681 6.99 | Q V | | | 3+20 1.4171 7.10 | Q V | | | 3+25 1.4672 7.28 | Q |V | | | 3+30 1.5206 7.75 | Q |V | | | 3+35 1.5778 8.31 | Q |V | | | 3+40 1.6383 8.79 | Q | V | | | 3+45 1.7010 9.10 | Q | V | | | 3+50 1.7665 9.51 | Q | V | | | 3+55 1.8339 9.79 | Q | V | | | 4+ 0 1.9040 10.19 | Q | V | | | 4+ 5 1.9761 10.46 | Q | V | | | 4+10 2.0517 10.98 | Q | V | | | 4+15 2.1314 11.57 | Q| V | | | 4+20 2.2159 12.28 | Q| V | | | 4+25 2.3072 13.26 | Q V | | | 4+30 2.4048 14.16 | |Q V | | | 4+35 2.5064 14.75 | |Q V| | | 4+40 2.6153 15.82 | | Q V| | | 4+45 2.7325 17.01 | | Q V | | 4+50 2.8564 18.00 | | Q |V | | 4+55 2.9848 18.64 | | Q | V | | 5+ 0 3.1207 19.73 | | Q | V | | 5+ 5 3.2719 21.96 | | Q | V | | 5+10 3.4565 26.80 | | |Q V | | 5+15 3.6765 31.94 | | | Q V | | 5+20 3.9257 36.19 | | | QV| | 5+25 4.2065 40.76 | | | |VQ | 5+30 4.5343 47.60 | | | | V Q | 5+35 4.8480 45.55 | | | | Q | 5+40 5.0103 23.56 | | Q | | V | 5+45 5.1059 13.88 | |Q | | V | 5+50 5.1690 9.16 | Q | | | V| 5+55 5.2129 6.39 | Q | | | V| 6+ 0 5.2418 4.18 | Q | | | V| 6+ 5 5.2592 2.54 | Q | | | V| 6+10 5.2650 0.84 Q | | | V| 6+15 5.2677 0.40 Q | | | V| 6+20 5.2692 0.21 Q | | | V| 6+25 5.2699 0.11 Q | | | V| 6+30 5.2703 0.05 Q | | | V| 6+35 5.2704 0.02 Q | | | V -----------------------------------------------------------------------

U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD/CIVILDESIGN, 1989 - 2014, Version 9.0 Study date 11/08/21 File: PRD0102410.out
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------ Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978
Program License Serial Number 6406
--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used
English Units used in output format
--------------------------------------------------------------------- TRACT 31194 - 'GOLDEN MEADOWS' MAJOR MODIFICATION
PRELIMINARY HYDROLOGY STUDY – AREA ‘D’
PROPOSED CONDITION UNIT HYDROGRAPH - 10 YEAR HOUR STORM

HUNSAKER & ASSOCIATES, BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 55.84(Ac.) = 0.087 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 55.84(Ac.) = 0.087 Sq. Mi.

Length along longest watercourse = 4101.00(Ft.)
Length along longest watercourse measured to centroid = 1105.00(Ft.) Length along longest watercourse = 0.777 Mi.

Length along longest watercourse measured to centroid = 0.209 Mi.

Difference in elevation = 49.10(Ft.)
Slope along watercourse = 63.2158 Ft./Mi.

Average Manning's 'N' = 0.015
Lag time = 0.082 Hr.

Lag time = 4.93 Min.
25% of lag time = 1.23 Min.
40% of lag time = 1.97 Min.

Unit time = 15.00 Min.

Duration of storm = 24 Hour(s)
User Entered Base Flow = 0.00(CFS)
2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 2.00 111.68
100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 5.00 279.20
STORM EVENT (YEAR) = 10.00
Area Averaged 2-Year Rainfall = 2.000(In)
Area Averaged 100-Year Rainfall = 5.000(In)
Point rain (area averaged) = 3.234(In)
Areal adjustment factor = 99.99 %
Adjusted average point rain = 3.234(In)
Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

55.840 65.70 0.500
Total Area Entered = 55.84(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-2 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

65.7 65.7 0.408 0.500 0.225 1.000 0.225 Sum (F) = 0.225
Area averaged mean soil loss (F) (In/Hr) = 0.225
Minimum soil loss rate ((In/Hr)) = 0.112
(for 24 hour storm duration)
Soil low loss rate (decimal) = 0.500
--------------------------------------------------------------------- U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.250 304.523 57.140 32.156 2 0.500 609.046 36.881 20.755 3 0.750 913.570 5.980 3.365 Sum = 100.000 Sum= 56.276
----------------------------------------------------------------------- The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.25 0.20 0.026 ( 0.397) 0.013 0.013 2 0.50 0.30 0.039 ( 0.392) 0.019 0.019 3 0.75 0.30 0.039 ( 0.388) 0.019 0.019 4 1.00 0.40 0.052 ( 0.383) 0.026 0.026 5 1.25 0.30 0.039 ( 0.378) 0.019 0.019 6 1.50 0.30 0.039 ( 0.374) 0.019 0.019 7 1.75 0.30 0.039 ( 0.369) 0.019 0.019 8 2.00 0.40 0.052 ( 0.365) 0.026 0.026 9 2.25 0.40 0.052 ( 0.361) 0.026 0.026 10 2.50 0.40 0.052 ( 0.356) 0.026 0.026 11 2.75 0.50 0.065 ( 0.352) 0.032 0.032 12 3.00 0.50 0.065 ( 0.348) 0.032 0.032 13 3.25 0.50 0.065 ( 0.343) 0.032 0.032 14 3.50 0.50 0.065 ( 0.339) 0.032 0.032 15 3.75 0.50 0.065 ( 0.335) 0.032 0.032 16 4.00 0.60 0.078 ( 0.331) 0.039 0.039 17 4.25 0.60 0.078 ( 0.326) 0.039 0.039 18 4.50 0.70 0.091 ( 0.322) 0.045 0.045 19 4.75 0.70 0.091 ( 0.318) 0.045 0.045 20 5.00 0.80 0.103 ( 0.314) 0.052 0.052 21 5.25 0.60 0.078 ( 0.310) 0.039 0.039 22 5.50 0.70 0.091 ( 0.306) 0.045 0.045 23 5.75 0.80 0.103 ( 0.302) 0.052 0.052 24 6.00 0.80 0.103 ( 0.298) 0.052 0.052 25 6.25 0.90 0.116 ( 0.294) 0.058 0.058 26 6.50 0.90 0.116 ( 0.290) 0.058 0.058 27 6.75 1.00 0.129 ( 0.286) 0.065 0.065 28 7.00 1.00 0.129 ( 0.282) 0.065 0.065 29 7.25 1.00 0.129 ( 0.278) 0.065 0.065 30 7.50 1.10 0.142 ( 0.275) 0.071 0.071 31 7.75 1.20 0.155 ( 0.271) 0.078 0.078 32 8.00 1.30 0.168 ( 0.267) 0.084 0.084 33 8.25 1.50 0.194 ( 0.263) 0.097 0.097 34 8.50 1.50 0.194 ( 0.260) 0.097 0.097 35 8.75 1.60 0.207 ( 0.256) 0.103 0.103 36 9.00 1.70 0.220 ( 0.252) 0.110 0.110 37 9.25 1.90 0.246 ( 0.249) 0.123 0.123 38 9.50 2.00 0.259 ( 0.245) 0.129 0.129 39 9.75 2.10 0.272 ( 0.242) 0.136 0.136 40 10.00 2.20 0.285 ( 0.238) 0.142 0.142 41 10.25 1.50 0.194 ( 0.235) 0.097 0.097 42 10.50 1.50 0.194 ( 0.232) 0.097 0.097 43 10.75 2.00 0.259 ( 0.228) 0.129 0.129 44 11.00 2.00 0.259 ( 0.225) 0.129 0.129 45 11.25 1.90 0.246 ( 0.222) 0.123 0.123 46 11.50 1.90 0.246 ( 0.218) 0.123 0.123 47 11.75 1.70 0.220 ( 0.215) 0.110 0.110 48 12.00 1.80 0.233 ( 0.212) 0.116 0.116 49 12.25 2.50 0.323 ( 0.209) 0.162 0.162 50 12.50 2.60 0.336 ( 0.206) 0.168 0.168 51 12.75 2.80 0.362 ( 0.202) 0.181 0.181 52 13.00 2.90 0.375 ( 0.199) 0.188 0.188 53 13.25 3.40 0.440 0.196 ( 0.220) 0.243 54 13.50 3.40 0.440 0.193 ( 0.220) 0.246 55 13.75 2.30 0.298 ( 0.190) 0.149 0.149 56 14.00 2.30 0.298 ( 0.188) 0.149 0.149 57 14.25 2.70 0.349 ( 0.185) 0.175 0.175 58 14.50 2.60 0.336 ( 0.182) 0.168 0.168 59 14.75 2.60 0.336 ( 0.179) 0.168 0.168 60 15.00 2.50 0.323 ( 0.176) 0.162 0.162 61 15.25 2.40 0.310 ( 0.174) 0.155 0.155 62 15.50 2.30 0.298 ( 0.171) 0.149 0.149 63 15.75 1.90 0.246 ( 0.168) 0.123 0.123 64 16.00 1.90 0.246 ( 0.166) 0.123 0.123 65 16.25 0.40 0.052 ( 0.163) 0.026 0.026 66 16.50 0.40 0.052 ( 0.161) 0.026 0.026 67 16.75 0.30 0.039 ( 0.158) 0.019 0.019 68 17.00 0.30 0.039 ( 0.156) 0.019 0.019 69 17.25 0.50 0.065 ( 0.154) 0.032 0.032 70 17.50 0.50 0.065 ( 0.151) 0.032 0.032 71 17.75 0.50 0.065 ( 0.149) 0.032 0.032 72 18.00 0.40 0.052 ( 0.147) 0.026 0.026 73 18.25 0.40 0.052 ( 0.145) 0.026 0.026 74 18.50 0.40 0.052 ( 0.143) 0.026 0.026 75 18.75 0.30 0.039 ( 0.141) 0.019 0.019 76 19.00 0.20 0.026 ( 0.139) 0.013 0.013 77 19.25 0.30 0.039 ( 0.137) 0.019 0.019 78 19.50 0.40 0.052 ( 0.135) 0.026 0.026 79 19.75 0.30 0.039 ( 0.133) 0.019 0.019 80 20.00 0.20 0.026 ( 0.131) 0.013 0.013 81 20.25 0.30 0.039 ( 0.129) 0.019 0.019 82 20.50 0.30 0.039 ( 0.128) 0.019 0.019 83 20.75 0.30 0.039 ( 0.126) 0.019 0.019 84 21.00 0.20 0.026 ( 0.124) 0.013 0.013 85 21.25 0.30 0.039 ( 0.123) 0.019 0.019 86 21.50 0.20 0.026 ( 0.122) 0.013 0.013 87 21.75 0.30 0.039 ( 0.120) 0.019 0.019 88 22.00 0.20 0.026 ( 0.119) 0.013 0.013 89 22.25 0.30 0.039 ( 0.118) 0.019 0.019 90 22.50 0.20 0.026 ( 0.117) 0.013 0.013 91 22.75 0.20 0.026 ( 0.116) 0.013 0.013 92 23.00 0.20 0.026 ( 0.115) 0.013 0.013 93 23.25 0.20 0.026 ( 0.114) 0.013 0.013 94 23.50 0.20 0.026 ( 0.113) 0.013 0.013 95 23.75 0.20 0.026 ( 0.113) 0.013 0.013 96 24.00 0.20 0.026 ( 0.112) 0.013 0.013 (Loss Rate Not Used)
Sum = 100.0 Sum = 6.5 Flood volume = Effective rainfall 1.63(In)
times area 55.8(Ac.)/[(In)/(Ft.)] = 7.6(Ac.Ft) Total soil loss = 1.60(In)
Total soil loss = 7.466(Ac.Ft)
Total rainfall = 3.23(In)
Flood volume = 330287.5 Cubic Feet
Total soil loss = 325215.7 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 13.614(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 24 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 15 Minute intervals ((CFS))
-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 5.0 10.0 15.0 20.0 ----------------------------------------------------------------------- 0+15 0.0086 0.42 Q | | | | 0+30 0.0270 0.89 VQ | | | | 0+45 0.0492 1.07 V Q | | | | 1+ 0 0.0760 1.30 V Q | | | | 1+15 0.1014 1.23 V Q | | | | 1+30 0.1244 1.11 V Q | | | | 1+45 0.1470 1.09 V Q | | | | 2+ 0 0.1739 1.30 V Q | | | | 2+15 0.2035 1.43 VQ | | | | 2+30 0.2336 1.46 |VQ | | | | 2+45 0.2680 1.66 |V Q | | | | 3+ 0 0.3052 1.80 |V Q | | | | 3+15 0.3428 1.82 |V Q | | | | 3+30 0.3804 1.82 | VQ | | | | 3+45 0.4180 1.82 | VQ | | | | 4+ 0 0.4599 2.03 | V Q | | | | 4+15 0.5046 2.16 | V Q | | | | 4+30 0.5541 2.39 | V Q | | | | 4+45 0.6063 2.53 | V Q | | | | 5+ 0 0.6633 2.76 | V Q | | | | 5+15 0.7144 2.48 | VQ | | | | 5+30 0.7648 2.44 | Q | | | | 5+45 0.8213 2.74 | VQ | | | | 6+ 0 0.8810 2.89 | VQ | | | | 6+15 0.9455 3.12 | V Q | | | | 6+30 1.0128 3.26 | VQ | | | | 6+45 1.0848 3.49 | VQ | | | | 7+ 0 1.1596 3.62 | VQ | | | | 7+15 1.2348 3.64 | VQ | | | | 7+30 1.3144 3.85 | VQ | | | | 7+45 1.4010 4.19 | VQ | | | | 8+ 0 1.4951 4.56 | V Q| | | | 8+15 1.6011 5.13 | V Q | | | 8+30 1.7131 5.42 | VQ | | | 8+45 1.8302 5.67 | V|Q | | | 9+ 0 1.9544 6.01 | V Q | | | 9+15 2.0905 6.59 | V Q | | | 9+30 2.2369 7.08 | |V Q | | | 9+45 2.3912 7.47 | | V Q | | | 10+ 0 2.5531 7.83 | | V Q | | | 10+15 2.6880 6.53 | | QV | | | 10+30 2.8041 5.61 | |Q V | | | 10+45 2.9384 6.50 | | Q V | | | 11+ 0 3.0866 7.17 | | Q V | | | 11+15 3.2328 7.08 | | Q V | | | 11+30 3.3762 6.94 | | Q V | | | 11+45 3.5106 6.50 | | Q V | | | 12+ 0 3.6437 6.44 | | Q V| | | 12+15 3.8088 7.99 | | Q V | | 12+30 3.9980 9.16 | | Q V | | 12+45 4.2018 9.86 | | Q| V | | 13+ 0 4.4159 10.36 | | Q V | | 13+15 4.6708 12.34 | | | Q | | 13+30 4.9521 13.61 | | | VQ | | 13+45 5.1736 10.72 | | |Q V | | 14+ 0 5.3535 8.70 | | Q | V | | 14+15 5.5437 9.21 | | Q | V| | 14+30 5.7408 9.54 | | Q| V | 14+45 5.9368 9.49 | | Q | V | 15+ 0 6.1282 9.26 | | Q | | V | 15+15 6.3124 8.92 | | Q | | V | 15+30 6.4892 8.55 | | Q | | V | 15+45 6.6455 7.57 | | Q | | V | 16+ 0 6.7902 7.01 | | Q | | V | 16+15 6.8687 3.80 | Q | | | V | 16+30 6.9055 1.78 | Q | | | V | 16+45 6.9313 1.25 | Q | | | V | 17+ 0 6.9544 1.11 | Q | | | V | 17+15 6.9855 1.51 | Q | | | V | 17+30 7.0222 1.78 | Q | | | V | 17+45 7.0599 1.82 | Q | | | V | 18+ 0 7.0932 1.61 | Q | | | V | 18+15 7.1237 1.48 | Q | | | V | 18+30 7.1538 1.46 | Q | | | V | 18+45 7.1796 1.25 | Q | | | V | 19+ 0 7.1984 0.91 |Q | | | V | 19+15 7.2181 0.96 |Q | | | V | 19+30 7.2446 1.28 | Q | | | V | 19+45 7.2699 1.23 | Q | | | V | 20+ 0 7.2886 0.91 |Q | | | V | 20+15 7.3084 0.96 |Q | | | V | 20+30 7.3306 1.07 | Q | | | V | 20+45 7.3531 1.09 | Q | | | V | 21+ 0 7.3714 0.88 |Q | | | V | 21+15 7.3912 0.96 |Q | | | V | 21+30 7.4090 0.86 |Q | | | V| 21+45 7.4288 0.96 |Q | | | V| 22+ 0 7.4466 0.86 |Q | | | V| 22+15 7.4664 0.96 |Q | | | V| 22+30 7.4843 0.86 |Q | | | V| 22+45 7.4998 0.75 |Q | | | V| 23+ 0 7.5148 0.73 |Q | | | V| 23+15 7.5299 0.73 |Q | | | V| 23+30 7.5449 0.73 |Q | | | V| 23+45 7.5600 0.73 |Q | | | V| 24+ 0 7.5750 0.73 |Q | | | V| 24+15 7.5815 0.31 Q | | | V| 24+30 7.5824 0.04 Q | | | V ----------------------------------------------------------------------- Preliminary Hydrology Analysis – Golden Meadows – Tract 31194 – Major Modification

Page 3 ends

Section 3
· Area ‘D’ – 100 Year - Post-Development Condition – Unit Hydrograph

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - 'GOLDEN MEADOWS' MAJOR MODIFICATION
PRELIMINARY HYDROLOGY STUDY – AREA ‘D’
PROPOSED CONDITION UNIT HYDROGRAPH - 100 YEAR 1 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021, BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 55.84(Ac.) = 0.087 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 55.84(Ac.) = 0.087 Sq. Mi.

Length along longest watercourse = 4101.00(Ft.)
Length along longest watercourse measured to centroid = 1105.00(Ft.) Length along longest watercourse = 0.777 Mi.

Length along longest watercourse measured to centroid = 0.209 Mi.

Difference in elevation = 49.10(Ft.)
Slope along watercourse = 63.2158 Ft./Mi.

Average Manning's 'N' = 0.015
Lag time = 0.082 Hr.

Lag time = 4.93 Min.
25% of lag time = 1.23 Min.
40% of lag time = 1.97 Min.

Unit time = 5.00 Min.

Duration of storm = 1 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 0.55 30.71

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 1.30 72.59

STORM EVENT (YEAR) = 100.00
Area Averaged 2-Year Rainfall = 0.550(In)
Area Averaged 100-Year Rainfall = 1.300(In)

Point rain (area averaged) = 1.300(In)
Areal adjustment factor = 99.95 %
Adjusted average point rain = 1.299(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

55.840 65.70 0.500
Total Area Entered = 55.84(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-3 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.083 101.508 19.663 11.066 2 0.167 203.015 48.509 27.299 3 0.250 304.523 15.411 8.673 4 0.333 406.031 6.983 3.930 5 0.417 507.539 3.915 2.203 6 0.500 609.046 2.530 1.424 7 0.583 710.554 1.553 0.874 8 0.667 812.062 1.435 0.808 Sum = 100.000 Sum= 56.276
-----------------------------------------------------------------------

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 3.40 0.530 0.119 ( 0.265) 0.411 2 0.17 4.70 0.733 0.119 ( 0.366) 0.614 3 0.25 4.70 0.733 0.119 ( 0.366) 0.614 4 0.33 5.10 0.795 0.119 ( 0.398) 0.676 5 0.42 5.80 0.904 0.119 ( 0.452) 0.785 6 0.50 5.90 0.920 0.119 ( 0.460) 0.801 7 0.58 7.10 1.107 0.119 ( 0.554) 0.988 8 0.67 8.70 1.357 0.119 ( 0.678) 1.237 9 0.75 13.20 2.058 0.119 ( 1.029) 1.939 10 0.83 29.70 4.631 0.119 ( 2.315) 4.512 11 0.92 7.70 1.201 0.119 ( 0.600) 1.082 12 1.00 4.00 0.624 0.119 ( 0.312) 0.505 (Loss Rate Not Used)
Sum = 100.0 Sum = 14.2 Flood volume = Effective rainfall 1.18(In)
times area 55.8(Ac.)/[(In)/(Ft.)] = 5.5(Ac.Ft) Total soil loss = 0.12(In)
Total soil loss = 0.554(Ac.Ft)
Total rainfall = 1.30(In)
Flood volume = 239249.0 Cubic Feet
Total soil loss = 24126.6 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 161.451(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 50.0 100.0 150.0 200.0 ----------------------------------------------------------------------- 0+ 5 0.0313 4.55 Q | | | | 0+10 0.1555 18.02 |V Q | | | | 0+15 0.3423 27.13 | V Q | | | | 0+20 0.5571 31.19 | V Q | | | | 0+25 0.8038 35.81 | V Q | | | | 0+30 1.0829 40.54 | VQ | | | | 0+35 1.3920 44.87 | Q V | | | 0+40 1.7636 53.96 | Q V | | | 0+45 2.2506 70.72 | | Q V | | | 0+50 3.0875 121.51 | | | V Q | | 0+55 4.1994 161.45 | | | V Q | 1+ 0 4.8012 87.37 | | Q | | V | 1+ 5 5.1349 48.46 | Q| | | V | 1+10 5.2948 23.22 | Q | | | V | 1+15 5.3877 13.49 | Q | | | V| 1+20 5.4440 8.16 |Q | | | V| 1+25 5.4805 5.31 |Q | | | V| 1+30 5.4896 1.32 Q | | | V| 1+35 5.4924 0.41 Q | | | V -----------------------------------------------------------------------

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - 'GOLDEN MEADOWS' MAJOR MODIFICATION
PRELIMINARY HYDROLOGY STUDY – AREA ‘D’
PROPOSED CONDITION UNIT HYDROGRAPH - 100 YEAR 3 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021, BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 55.84(Ac.) = 0.087 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 55.84(Ac.) = 0.087 Sq. Mi.

Length along longest watercourse = 4101.00(Ft.)
Length along longest watercourse measured to centroid = 1105.00(Ft.) Length along longest watercourse = 0.777 Mi.

Length along longest watercourse measured to centroid = 0.209 Mi.

Difference in elevation = 49.10(Ft.)
Slope along watercourse = 63.2158 Ft./Mi.

Average Manning's 'N' = 0.015
Lag time = 0.082 Hr.

Lag time = 4.93 Min.
25% of lag time = 1.23 Min.
40% of lag time = 1.97 Min.

Unit time = 5.00 Min.

Duration of storm = 3 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 0.85 47.46

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 2.00 111.68

STORM EVENT (YEAR) = 100.00
Area Averaged 2-Year Rainfall = 0.850(In)
Area Averaged 100-Year Rainfall = 2.000(In)

Point rain (area averaged) = 2.000(In)
Areal adjustment factor = 99.98 %
Adjusted average point rain = 2.000(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

55.840 65.70 0.500
Total Area Entered = 55.84(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-3 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.083 101.508 19.663 11.066 2 0.167 203.015 48.509 27.299 3 0.250 304.523 15.411 8.673 4 0.333 406.031 6.983 3.930 5 0.417 507.539 3.915 2.203 6 0.500 609.046 2.530 1.424 7 0.583 710.554 1.553 0.874 8 0.667 812.062 1.435 0.808 Sum = 100.000 Sum= 56.276
-----------------------------------------------------------------------

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 1.30 0.312 0.119 ( 0.156) 0.193 2 0.17 1.30 0.312 0.119 ( 0.156) 0.193 3 0.25 1.10 0.264 0.119 ( 0.132) 0.145 4 0.33 1.50 0.360 0.119 ( 0.180) 0.241 5 0.42 1.50 0.360 0.119 ( 0.180) 0.241 6 0.50 1.80 0.432 0.119 ( 0.216) 0.313 7 0.58 1.50 0.360 0.119 ( 0.180) 0.241 8 0.67 1.80 0.432 0.119 ( 0.216) 0.313 9 0.75 1.80 0.432 0.119 ( 0.216) 0.313 10 0.83 1.50 0.360 0.119 ( 0.180) 0.241 11 0.92 1.60 0.384 0.119 ( 0.192) 0.265 12 1.00 1.80 0.432 0.119 ( 0.216) 0.313 13 1.08 2.20 0.528 0.119 ( 0.264) 0.409 14 1.17 2.20 0.528 0.119 ( 0.264) 0.409 15 1.25 2.20 0.528 0.119 ( 0.264) 0.409 16 1.33 2.00 0.480 0.119 ( 0.240) 0.361 17 1.42 2.60 0.624 0.119 ( 0.312) 0.505 18 1.50 2.70 0.648 0.119 ( 0.324) 0.529 19 1.58 2.40 0.576 0.119 ( 0.288) 0.457 20 1.67 2.70 0.648 0.119 ( 0.324) 0.529 21 1.75 3.30 0.792 0.119 ( 0.396) 0.673 22 1.83 3.10 0.744 0.119 ( 0.372) 0.625 23 1.92 2.90 0.696 0.119 ( 0.348) 0.577 24 2.00 3.00 0.720 0.119 ( 0.360) 0.601 25 2.08 3.10 0.744 0.119 ( 0.372) 0.625 26 2.17 4.20 1.008 0.119 ( 0.504) 0.889 27 2.25 5.00 1.200 0.119 ( 0.600) 1.081 28 2.33 3.50 0.840 0.119 ( 0.420) 0.721 29 2.42 6.80 1.632 0.119 ( 0.816) 1.513 30 2.50 7.30 1.752 0.119 ( 0.876) 1.633 31 2.58 8.20 1.968 0.119 ( 0.984) 1.848 32 2.67 5.90 1.416 0.119 ( 0.708) 1.297 33 2.75 2.00 0.480 0.119 ( 0.240) 0.361 34 2.83 1.80 0.432 0.119 ( 0.216) 0.313 35 2.92 1.80 0.432 0.119 ( 0.216) 0.313 36 3.00 0.60 0.144 ( 0.119) 0.072 0.072 (Loss Rate Not Used)
Sum = 100.0 Sum = 19.8 Flood volume = Effective rainfall 1.65(In)
times area 55.8(Ac.)/[(In)/(Ft.)] = 7.7(Ac.Ft) Total soil loss = 0.35(In)
Total soil loss = 1.643(Ac.Ft)
Total rainfall = 2.00(In)
Flood volume = 333714.2 Cubic Feet
Total soil loss = 71585.1 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 89.368(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

U n i t H y d r o g r a p h A n a l y s i s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------

Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978

Program License Serial Number 6407

--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used

English Units used in output format

--------------------------------------------------------------------- TRACT 31194 - 'GOLDEN MEADOWS' MAJOR MODIFICATION
PRELIMINARY HYDROLOGY STUDY – AREA ‘D’
PROPOSED CONDITION UNIT HYDROGRAPH - 100 YEAR 6 HOUR STORM HUNSAKER & ASSOCIATES, MAY 2021, BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 55.84(Ac.) = 0.087 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 55.84(Ac.) = 0.087 Sq. Mi.

Length along longest watercourse = 4101.00(Ft.)
Length along longest watercourse measured to centroid = 1105.00(Ft.) Length along longest watercourse = 0.777 Mi.

Length along longest watercourse measured to centroid = 0.209 Mi.

Difference in elevation = 49.10(Ft.)
Slope along watercourse = 63.2158 Ft./Mi.

Average Manning's 'N' = 0.015
Lag time = 0.082 Hr.

Lag time = 4.93 Min.
25% of lag time = 1.23 Min.
40% of lag time = 1.97 Min.

Unit time = 5.00 Min.

Duration of storm = 6 Hour(s)
User Entered Base Flow = 0.00(CFS)

2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 1.20 67.01

100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 3.00 167.52

STORM EVENT (YEAR) = 100.00
Area Averaged 2-Year Rainfall = 1.200(In)
Area Averaged 100-Year Rainfall = 3.000(In)

Point rain (area averaged) = 3.000(In)
Areal adjustment factor = 99.98 %
Adjusted average point rain = 2.999(In)

Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

55.840 65.70 0.500
Total Area Entered = 55.84(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-3 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.083 101.508 19.663 11.066 2 0.167 203.015 48.509 27.299 3 0.250 304.523 15.411 8.673 4 0.333 406.031 6.983 3.930 5 0.417 507.539 3.915 2.203 6 0.500 609.046 2.530 1.424 7 0.583 710.554 1.553 0.874 8 0.667 812.062 1.435 0.808 Sum = 100.000 Sum= 56.276
-----------------------------------------------------------------------

The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value

Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.08 0.50 0.180 ( 0.119) 0.090 0.090 2 0.17 0.60 0.216 ( 0.119) 0.108 0.108 3 0.25 0.60 0.216 ( 0.119) 0.108 0.108 4 0.33 0.60 0.216 ( 0.119) 0.108 0.108 5 0.42 0.60 0.216 ( 0.119) 0.108 0.108 6 0.50 0.70 0.252 0.119 ( 0.126) 0.133 7 0.58 0.70 0.252 0.119 ( 0.126) 0.133 8 0.67 0.70 0.252 0.119 ( 0.126) 0.133 9 0.75 0.70 0.252 0.119 ( 0.126) 0.133 10 0.83 0.70 0.252 0.119 ( 0.126) 0.133 11 0.92 0.70 0.252 0.119 ( 0.126) 0.133 12 1.00 0.80 0.288 0.119 ( 0.144) 0.169 13 1.08 0.80 0.288 0.119 ( 0.144) 0.169 14 1.17 0.80 0.288 0.119 ( 0.144) 0.169 15 1.25 0.80 0.288 0.119 ( 0.144) 0.169 16 1.33 0.80 0.288 0.119 ( 0.144) 0.169 17 1.42 0.80 0.288 0.119 ( 0.144) 0.169 18 1.50 0.80 0.288 0.119 ( 0.144) 0.169 19 1.58 0.80 0.288 0.119 ( 0.144) 0.169 20 1.67 0.80 0.288 0.119 ( 0.144) 0.169 21 1.75 0.80 0.288 0.119 ( 0.144) 0.169 22 1.83 0.80 0.288 0.119 ( 0.144) 0.169 23 1.92 0.80 0.288 0.119 ( 0.144) 0.169 24 2.00 0.90 0.324 0.119 ( 0.162) 0.205 25 2.08 0.80 0.288 0.119 ( 0.144) 0.169 26 2.17 0.90 0.324 0.119 ( 0.162) 0.205 27 2.25 0.90 0.324 0.119 ( 0.162) 0.205 28 2.33 0.90 0.324 0.119 ( 0.162) 0.205 29 2.42 0.90 0.324 0.119 ( 0.162) 0.205 30 2.50 0.90 0.324 0.119 ( 0.162) 0.205 31 2.58 0.90 0.324 0.119 ( 0.162) 0.205 32 2.67 0.90 0.324 0.119 ( 0.162) 0.205 33 2.75 1.00 0.360 0.119 ( 0.180) 0.241 34 2.83 1.00 0.360 0.119 ( 0.180) 0.241 35 2.92 1.00 0.360 0.119 ( 0.180) 0.241 36 3.00 1.00 0.360 0.119 ( 0.180) 0.241 37 3.08 1.00 0.360 0.119 ( 0.180) 0.241 38 3.17 1.10 0.396 0.119 ( 0.198) 0.277 39 3.25 1.10 0.396 0.119 ( 0.198) 0.277 40 3.33 1.10 0.396 0.119 ( 0.198) 0.277 41 3.42 1.20 0.432 0.119 ( 0.216) 0.313 42 3.50 1.30 0.468 0.119 ( 0.234) 0.349 43 3.58 1.40 0.504 0.119 ( 0.252) 0.385 44 3.67 1.40 0.504 0.119 ( 0.252) 0.385 45 3.75 1.50 0.540 0.119 ( 0.270) 0.421 46 3.83 1.50 0.540 0.119 ( 0.270) 0.421 47 3.92 1.60 0.576 0.119 ( 0.288) 0.457 48 4.00 1.60 0.576 0.119 ( 0.288) 0.457 49 4.08 1.70 0.612 0.119 ( 0.306) 0.493 50 4.17 1.80 0.648 0.119 ( 0.324) 0.529 51 4.25 1.90 0.684 0.119 ( 0.342) 0.565 52 4.33 2.00 0.720 0.119 ( 0.360) 0.601 53 4.42 2.10 0.756 0.119 ( 0.378) 0.637 54 4.50 2.10 0.756 0.119 ( 0.378) 0.637 55 4.58 2.20 0.792 0.119 ( 0.396) 0.673 56 4.67 2.30 0.828 0.119 ( 0.414) 0.709 57 4.75 2.40 0.864 0.119 ( 0.432) 0.745 58 4.83 2.40 0.864 0.119 ( 0.432) 0.745 59 4.92 2.50 0.900 0.119 ( 0.450) 0.781 60 5.00 2.60 0.936 0.119 ( 0.468) 0.817 61 5.08 3.10 1.116 0.119 ( 0.558) 0.997 62 5.17 3.60 1.296 0.119 ( 0.648) 1.177 63 5.25 3.90 1.404 0.119 ( 0.702) 1.285 64 5.33 4.20 1.512 0.119 ( 0.756) 1.393 65 5.42 4.70 1.692 0.119 ( 0.846) 1.573 66 5.50 5.60 2.016 0.119 ( 1.008) 1.897 67 5.58 1.90 0.684 0.119 ( 0.342) 0.565 68 5.67 0.90 0.324 0.119 ( 0.162) 0.205 69 5.75 0.60 0.216 ( 0.119) 0.108 0.108 70 5.83 0.50 0.180 ( 0.119) 0.090 0.090 71 5.92 0.30 0.108 ( 0.119) 0.054 0.054 72 6.00 0.20 0.072 ( 0.119) 0.036 0.036 (Loss Rate Not Used)
Sum = 100.0 Sum = 27.7 Flood volume = Effective rainfall 2.31(In)
times area 55.8(Ac.)/[(In)/(Ft.)] = 10.7(Ac.Ft) Total soil loss = 0.69(In)
Total soil loss = 3.222(Ac.Ft)
Total rainfall = 3.00(In)
Flood volume = 467636.7 Cubic Feet
Total soil loss = 140344.2 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 86.447(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 6 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 5 Minute intervals ((CFS))

-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 22.5 45.0 67.5 90.0 ----------------------------------------------------------------------- 0+ 5 0.0069 1.00 Q | | | | 0+10 0.0320 3.65 VQ | | | | 0+15 0.0659 4.93 V Q | | | | 0+20 0.1034 5.44 V Q | | | | 0+25 0.1427 5.70 V Q | | | | 0+30 0.1850 6.15 V Q | | | | 0+35 0.2328 6.93 V Q | | | | 0+40 0.2826 7.24 |V Q | | | | 0+45 0.3333 7.35 |V Q | | | | 0+50 0.3843 7.41 |V Q | | | | 0+55 0.4355 7.44 |V Q | | | | 1+ 0 0.4897 7.86 |V Q | | | | 1+ 5 0.5507 8.87 | VQ | | | | 1+10 0.6140 9.18 | V Q | | | | 1+15 0.6781 9.32 | V Q | | | | 1+20 0.7429 9.40 | V Q | | | | 1+25 0.8080 9.45 | VQ | | | | 1+30 0.8733 9.48 | VQ | | | | 1+35 0.9388 9.51 | VQ | | | | 1+40 1.0043 9.51 | VQ | | | | 1+45 1.0698 9.51 | VQ | | | | 1+50 1.1353 9.51 | Q | | | | 1+55 1.2008 9.51 | Q | | | | 2+ 0 1.2690 9.91 | Q | | | | 2+ 5 1.3413 10.49 | Q | | | | 2+10 1.4117 10.22 | QV | | | | 2+15 1.4877 11.03 | QV | | | | 2+20 1.5654 11.28 | Q | | | | 2+25 1.6439 11.40 | QV | | | | 2+30 1.7228 11.46 | QV | | | | 2+35 1.8020 11.51 | QV | | | | 2+40 1.8813 11.51 | Q V | | | | 2+45 1.9635 11.94 | Q V | | | | 2+50 2.0525 12.92 | Q V | | | | 2+55 2.1436 13.23 | Q V | | | | 3+ 0 2.2357 13.37 | Q V | | | | 3+ 5 2.3284 13.45 | Q V | | | | 3+10 2.4241 13.90 | Q V| | | | 3+15 2.5268 14.92 | Q V| | | | 3+20 2.6319 15.26 | Q V| | | | 3+25 2.7407 15.80 | Q V | | | 3+30 2.8596 17.26 | Q V | | | 3+35 2.9905 19.00 | Q |V | | | 3+40 3.1315 20.47 | Q|V | | | 3+45 3.2791 21.43 | Q| V | | | 3+50 3.4353 22.69 | Q V | | | 3+55 3.5976 23.56 | Q V | | | 4+ 0 3.7684 24.80 | |Q V | | | 4+ 5 3.9450 25.65 | |Q V | | | 4+10 4.1327 27.25 | | Q V | | | 4+15 4.3328 29.06 | | Q V | | | 4+20 4.5461 30.97 | | Q V | | | 4+25 4.7729 32.92 | | Q V | | | 4+30 5.0106 34.52 | | Q V | | | 4+35 5.2553 35.53 | | Q V| | | 4+40 5.5118 37.24 | | Q V | | 4+45 5.7813 39.13 | | Q |V | | 4+50 6.0614 40.68 | | Q | V | | 4+55 6.3484 41.67 | | Q | V | | 5+ 0 6.6470 43.35 | | Q| V | | 5+ 5 6.9693 46.80 | | Q V | | 5+10 7.3431 54.28 | | | Q V | | 5+15 7.7717 62.23 | | | QV | | 5+20 8.2456 68.80 | | | Q | 5+25 8.7681 75.87 | | | | VQ | 5+30 9.3635 86.45 | | | | V Q | 5+35 9.9366 83.22 | | | | QV | 5+40 10.2608 47.07 | | Q | V | 5+45 10.4445 26.68 | |Q | | V | 5+50 10.5590 16.62 | Q | | | V| 5+55 10.6364 11.25 | Q | | | V| 6+ 0 10.6864 7.26 | Q | | | V| 6+ 5 10.7165 4.36 |Q | | | V| 6+10 10.7269 1.51 Q | | | V| 6+15 10.7313 0.65 Q | | | V| 6+20 10.7336 0.32 Q | | | V| 6+25 10.7347 0.17 Q | | | V| 6+30 10.7353 0.08 Q | | | V| 6+35 10.7355 0.03 Q | | | V -----------------------------------------------------------------------

U n i t H y d r o g r a p h A n a l y s i s
Copyright (c) CIVILCADD/CIVILDESIGN, 1989 - 2014, Version 9.0 Study date 11/08/21 File: PRD10024100.out
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------------------------------------------------ Riverside County Synthetic Unit Hydrology Method
RCFC & WCD Manual date - April 1978
Program License Serial Number 6406
--------------------------------------------------------------------- English (in-lb) Input Units Used
English Rainfall Data (Inches) Input Values Used
English Units used in output format
--------------------------------------------------------------------- TRACT 31194 - 'GOLDEN MEADOWS' MAJOR MODIFICATION
PRELIMINARY HYDROLOGY STUDY – AREA ‘D’
PROPOSED CONDITION UNIT HYDROGRAPH - 100 YEAR HOUR STORM

HUNSAKER & ASSOCIATES, BRIAN LOWELL, PE
-------------------------------------------------------------------- Drainage Area = 55.84(Ac.) = 0.087 Sq. Mi.

Drainage Area for Depth-Area Areal Adjustment = 55.84(Ac.) = 0.087 Sq. Mi.

Length along longest watercourse = 4101.00(Ft.)
Length along longest watercourse measured to centroid = 1105.00(Ft.) Length along longest watercourse = 0.777 Mi.

Length along longest watercourse measured to centroid = 0.209 Mi.

Difference in elevation = 49.10(Ft.)
Slope along watercourse = 63.2158 Ft./Mi.

Average Manning's 'N' = 0.015
Lag time = 0.082 Hr.

Lag time = 4.93 Min.
25% of lag time = 1.23 Min.
40% of lag time = 1.97 Min.

Unit time = 15.00 Min.

Duration of storm = 24 Hour(s)
User Entered Base Flow = 0.00(CFS)
2 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 2.00 111.68
100 YEAR Area rainfall data:

Area(Ac.)[1] Rainfall(In)[2] Weighting[1*2]

55.84 5.00 279.20
STORM EVENT (YEAR) = 100.00
Area Averaged 2-Year Rainfall = 2.000(In)
Area Averaged 100-Year Rainfall = 5.000(In)
Point rain (area averaged) = 5.000(In)
Areal adjustment factor = 99.99 %
Adjusted average point rain = 4.999(In)
Sub-Area Data:

Area(Ac.) Runoff Index Impervious %

55.840 65.70 0.500
Total Area Entered = 55.84(Ac.)

RI RI Infil. Rate Impervious Adj. Infil. Rate Area% F AMC2 AMC-3 (In/Hr) (Dec.%) (In/Hr) (Dec.) (In/Hr)

65.7 82.4 0.216 0.500 0.119 1.000 0.119 Sum (F) = 0.119
Area averaged mean soil loss (F) (In/Hr) = 0.119
Minimum soil loss rate ((In/Hr)) = 0.060
(for 24 hour storm duration)
Soil low loss rate (decimal) = 0.500
--------------------------------------------------------------------- U n i t H y d r o g r a p h
VALLEY S-Curve
-------------------------------------------------------------------- Unit Hydrograph Data
--------------------------------------------------------------------- Unit time period Time % of lag Distribution Unit Hydrograph (hrs) Graph % (CFS) --------------------------------------------------------------------- 1 0.250 304.523 57.140 32.156 2 0.500 609.046 36.881 20.755 3 0.750 913.570 5.980 3.365 Sum = 100.000 Sum= 56.276
----------------------------------------------------------------------- The following loss rate calculations reflect use of the minimum calculated loss rate subtracted from the Storm Rain to produce the maximum Effective Rain value Unit Time Pattern Storm Rain Loss rate(In./Hr) Effective (Hr.) Percent (In/Hr) Max | Low (In/Hr) 1 0.25 0.20 0.040 ( 0.210) 0.020 0.020 2 0.50 0.30 0.060 ( 0.208) 0.030 0.030 3 0.75 0.30 0.060 ( 0.205) 0.030 0.030 4 1.00 0.40 0.080 ( 0.203) 0.040 0.040 5 1.25 0.30 0.060 ( 0.201) 0.030 0.030 6 1.50 0.30 0.060 ( 0.198) 0.030 0.030 7 1.75 0.30 0.060 ( 0.196) 0.030 0.030 8 2.00 0.40 0.080 ( 0.193) 0.040 0.040 9 2.25 0.40 0.080 ( 0.191) 0.040 0.040 10 2.50 0.40 0.080 ( 0.189) 0.040 0.040 11 2.75 0.50 0.100 ( 0.186) 0.050 0.050 12 3.00 0.50 0.100 ( 0.184) 0.050 0.050 13 3.25 0.50 0.100 ( 0.182) 0.050 0.050 14 3.50 0.50 0.100 ( 0.180) 0.050 0.050 15 3.75 0.50 0.100 ( 0.177) 0.050 0.050 16 4.00 0.60 0.120 ( 0.175) 0.060 0.060 17 4.25 0.60 0.120 ( 0.173) 0.060 0.060 18 4.50 0.70 0.140 ( 0.171) 0.070 0.070 19 4.75 0.70 0.140 ( 0.169) 0.070 0.070 20 5.00 0.80 0.160 ( 0.166) 0.080 0.080 21 5.25 0.60 0.120 ( 0.164) 0.060 0.060 22 5.50 0.70 0.140 ( 0.162) 0.070 0.070 23 5.75 0.80 0.160 ( 0.160) 0.080 0.080 24 6.00 0.80 0.160 ( 0.158) 0.080 0.080 25 6.25 0.90 0.180 ( 0.156) 0.090 0.090 26 6.50 0.90 0.180 ( 0.154) 0.090 0.090 27 6.75 1.00 0.200 ( 0.152) 0.100 0.100 28 7.00 1.00 0.200 ( 0.150) 0.100 0.100 29 7.25 1.00 0.200 ( 0.148) 0.100 0.100 30 7.50 1.10 0.220 ( 0.145) 0.110 0.110 31 7.75 1.20 0.240 ( 0.143) 0.120 0.120 32 8.00 1.30 0.260 ( 0.142) 0.130 0.130 33 8.25 1.50 0.300 0.140 ( 0.150) 0.160 34 8.50 1.50 0.300 0.138 ( 0.150) 0.162 35 8.75 1.60 0.320 0.136 ( 0.160) 0.184 36 9.00 1.70 0.340 0.134 ( 0.170) 0.206 37 9.25 1.90 0.380 0.132 ( 0.190) 0.248 38 9.50 2.00 0.400 0.130 ( 0.200) 0.270 39 9.75 2.10 0.420 0.128 ( 0.210) 0.292 40 10.00 2.20 0.440 0.126 ( 0.220) 0.314 41 10.25 1.50 0.300 0.124 ( 0.150) 0.175 42 10.50 1.50 0.300 0.123 ( 0.150) 0.177 43 10.75 2.00 0.400 0.121 ( 0.200) 0.279 44 11.00 2.00 0.400 0.119 ( 0.200) 0.281 45 11.25 1.90 0.380 0.117 ( 0.190) 0.263 46 11.50 1.90 0.380 0.116 ( 0.190) 0.264 47 11.75 1.70 0.340 0.114 ( 0.170) 0.226 48 12.00 1.80 0.360 0.112 ( 0.180) 0.248 49 12.25 2.50 0.500 0.111 ( 0.250) 0.389 50 12.50 2.60 0.520 0.109 ( 0.260) 0.411 51 12.75 2.80 0.560 0.107 ( 0.280) 0.453 52 13.00 2.90 0.580 0.106 ( 0.290) 0.474 53 13.25 3.40 0.680 0.104 ( 0.340) 0.576 54 13.50 3.40 0.680 0.102 ( 0.340) 0.577 55 13.75 2.30 0.460 0.101 ( 0.230) 0.359 56 14.00 2.30 0.460 0.099 ( 0.230) 0.361 57 14.25 2.70 0.540 0.098 ( 0.270) 0.442 58 14.50 2.60 0.520 0.096 ( 0.260) 0.424 59 14.75 2.60 0.520 0.095 ( 0.260) 0.425 60 15.00 2.50 0.500 0.093 ( 0.250) 0.407 61 15.25 2.40 0.480 0.092 ( 0.240) 0.388 62 15.50 2.30 0.460 0.091 ( 0.230) 0.369 63 15.75 1.90 0.380 0.089 ( 0.190) 0.291 64 16.00 1.90 0.380 0.088 ( 0.190) 0.292 65 16.25 0.40 0.080 ( 0.087) 0.040 0.040 66 16.50 0.40 0.080 ( 0.085) 0.040 0.040 67 16.75 0.30 0.060 ( 0.084) 0.030 0.030 68 17.00 0.30 0.060 ( 0.083) 0.030 0.030 69 17.25 0.50 0.100 ( 0.081) 0.050 0.050 70 17.50 0.50 0.100 ( 0.080) 0.050 0.050 71 17.75 0.50 0.100 ( 0.079) 0.050 0.050 72 18.00 0.40 0.080 ( 0.078) 0.040 0.040 73 18.25 0.40 0.080 ( 0.077) 0.040 0.040 74 18.50 0.40 0.080 ( 0.076) 0.040 0.040 75 18.75 0.30 0.060 ( 0.074) 0.030 0.030 76 19.00 0.20 0.040 ( 0.073) 0.020 0.020 77 19.25 0.30 0.060 ( 0.072) 0.030 0.030 78 19.50 0.40 0.080 ( 0.071) 0.040 0.040 79 19.75 0.30 0.060 ( 0.070) 0.030 0.030 80 20.00 0.20 0.040 ( 0.069) 0.020 0.020 81 20.25 0.30 0.060 ( 0.069) 0.030 0.030 82 20.50 0.30 0.060 ( 0.068) 0.030 0.030 83 20.75 0.30 0.060 ( 0.067) 0.030 0.030 84 21.00 0.20 0.040 ( 0.066) 0.020 0.020 85 21.25 0.30 0.060 ( 0.065) 0.030 0.030 86 21.50 0.20 0.040 ( 0.064) 0.020 0.020 87 21.75 0.30 0.060 ( 0.064) 0.030 0.030 88 22.00 0.20 0.040 ( 0.063) 0.020 0.020 89 22.25 0.30 0.060 ( 0.062) 0.030 0.030 90 22.50 0.20 0.040 ( 0.062) 0.020 0.020 91 22.75 0.20 0.040 ( 0.061) 0.020 0.020 92 23.00 0.20 0.040 ( 0.061) 0.020 0.020 93 23.25 0.20 0.040 ( 0.060) 0.020 0.020 94 23.50 0.20 0.040 ( 0.060) 0.020 0.020 95 23.75 0.20 0.040 ( 0.060) 0.020 0.020 96 24.00 0.20 0.040 ( 0.060) 0.020 0.020 (Loss Rate Not Used)
Sum = 100.0 Sum = 13.4 Flood volume = Effective rainfall 3.35(In)
times area 55.8(Ac.)/[(In)/(Ft.)] = 15.6(Ac.Ft) Total soil loss = 1.65(In)
Total soil loss = 7.678(Ac.Ft)
Total rainfall = 5.00(In)
Flood volume = 678914.1 Cubic Feet
Total soil loss = 334471.3 Cubic Feet
-------------------------------------------------------------------- Peak flow rate of this hydrograph = 32.134(CFS)
-------------------------------------------------------------------- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 24 - H O U R S T O R M
R u n o f f H y d r o g r a p h
-------------------------------------------------------------------- Hydrograph in 15 Minute intervals ((CFS))
-------------------------------------------------------------------- Time(h+m) Volume Ac.Ft Q(CFS) 0 10.0 20.0 30.0 40.0 ----------------------------------------------------------------------- 0+15 0.0133 0.64 Q | | | | 0+30 0.0418 1.38 VQ | | | | 0+45 0.0760 1.66 VQ | | | | 1+ 0 0.1176 2.01 V Q | | | | 1+15 0.1567 1.90 VQ | | | | 1+30 0.1923 1.72 VQ | | | | 1+45 0.2272 1.69 VQ | | | | 2+ 0 0.2688 2.01 V Q | | | | 2+15 0.3146 2.22 V Q | | | | 2+30 0.3611 2.25 V Q | | | | 2+45 0.4143 2.57 VQ | | | | 3+ 0 0.4718 2.78 |VQ | | | | 3+15 0.5299 2.81 |VQ | | | | 3+30 0.5881 2.81 |VQ | | | | 3+45 0.6463 2.81 |VQ | | | | 4+ 0 0.7111 3.14 |V Q | | | | 4+15 0.7802 3.34 | VQ | | | | 4+30 0.8566 3.70 | VQ | | | | 4+45 0.9373 3.91 | VQ | | | | 5+ 0 1.0254 4.26 | V Q | | | | 5+15 1.1045 3.83 | VQ | | | | 5+30 1.1823 3.77 | Q | | | | 5+45 1.2697 4.23 | VQ | | | | 6+ 0 1.3620 4.47 | VQ | | | | 6+15 1.4617 4.83 | VQ | | | | 6+30 1.5657 5.03 | VQ | | | | 6+45 1.6771 5.39 | VQ | | | | 7+ 0 1.7927 5.60 | VQ | | | | 7+15 1.9090 5.63 | VQ | | | | 7+30 2.0320 5.95 | Q | | | | 7+45 2.1659 6.48 | VQ | | | | 8+ 0 2.3114 7.04 | V Q | | | | 8+15 2.4822 8.26 | V Q | | | | 8+30 2.6679 8.99 | V Q | | | | 8+45 2.8713 9.84 | V Q| | | | 9+ 0 3.0987 11.01 | V |Q | | | 9+15 3.3649 12.88 | V | Q | | | 9+30 3.6651 14.53 | V| Q | | | 9+45 3.9922 15.83 | V Q | | | 10+ 0 4.3446 17.06 | V Q | | | 10+15 4.6161 13.14 | |V Q | | | 10+30 4.8311 10.40 | Q V | | | 10+45 5.1049 13.25 | | Q | | | 11+ 0 5.4236 15.43 | | V Q | | | 11+15 5.7381 15.22 | | VQ | | | 11+30 6.0460 14.90 | | QV | | | 11+45 6.3279 13.65 | | Q V | | | 12+ 0 6.6080 13.55 | | Q V | | | 12+15 6.9888 18.43 | | VQ | | | 12+30 7.4464 22.14 | | V| Q | | 12+45 7.9507 24.41 | | V Q | | 13+ 0 8.4888 26.04 | | V Q | | 13+15 9.1066 29.90 | | | V Q| | 13+30 9.7705 32.13 | | | V | Q | 13+45 10.2970 25.48 | | | QV | | 14+ 0 10.7309 21.00 | | |Q V | | 14+15 11.2044 22.92 | | | Q V | | 14+30 11.7007 24.02 | | | Q V | 14+45 12.1957 23.96 | | | Q V | 15+ 0 12.6778 23.33 | | | Q | V | 15+15 13.1396 22.35 | | | Q | V | 15+30 13.5799 21.31 | | |Q | V | 15+45 13.9586 18.33 | | Q | | V | 16+ 0 14.3032 16.68 | | Q | | V | 16+15 14.4753 8.33 | Q | | | V | 16+30 14.5394 3.10 | Q | | | V | 16+45 14.5793 1.93 |Q | | | V | 17+ 0 14.6149 1.72 |Q | | | V | 17+15 14.6630 2.33 | Q | | | V | 17+30 14.7198 2.75 | Q | | | V | 17+45 14.7780 2.81 | Q | | | V | 18+ 0 14.8295 2.49 | Q | | | V | 18+15 14.8767 2.29 | Q | | | V | 18+30 14.9232 2.25 | Q | | | V | 18+45 14.9631 1.93 |Q | | | V | 19+ 0 14.9921 1.40 |Q | | | V | 19+15 15.0227 1.48 |Q | | | V | 19+30 15.0635 1.98 |Q | | | V | 19+45 15.1027 1.90 |Q | | | V | 20+ 0 15.1316 1.40 |Q | | | V | 20+15 15.1623 1.48 |Q | | | V | 20+30 15.1965 1.66 |Q | | | V| 20+45 15.2314 1.69 |Q | | | V| 21+ 0 15.2596 1.37 |Q | | | V| 21+15 15.2902 1.48 |Q | | | V| 21+30 15.3178 1.33 |Q | | | V| 21+45 15.3484 1.48 |Q | | | V| 22+ 0 15.3759 1.33 |Q | | | V| 22+15 15.4065 1.48 |Q | | | V| 22+30 15.4341 1.33 |Q | | | V| 22+45 15.4580 1.16 |Q | | | V| 23+ 0 15.4813 1.13 |Q | | | V| 23+15 15.5046 1.13 |Q | | | V| 23+30 15.5278 1.13 |Q | | | V| 23+45 15.5511 1.13 |Q | | | V| 24+ 0 15.5744 1.13 |Q | | | V| 24+15 15.5843 0.48 Q | | | V| 24+30 15.5857 0.07 Q | | | V| ----------------------------------------------------------------------- Preliminary Hydrology Analysis – Golden Meadows – Tract 31194 – Major Modification

Page 4 ends

Menifee City CouncilDecember 6, 2023

Menifee City Council
December 6, 2023