Ncil20251210 — Santee City Council, December 10, 2025 (part 13 of 13)

RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .3600 S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 0.96
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 0.90 AVERAGE FLOW DEPTH(FEET) = 0.10 TRAVEL TIME(MIN.) = 6.86 Tc(MIN.) = 14.50
SUBAREA AREA(ACRES) = 1.92 SUBAREA RUNOFF(CFS) = 1.65
AREA-AVERAGE RUNOFF COEFFICIENT = 0.360
TOTAL AREA(ACRES) = 2.0 PEAK FLOW RATE(CFS) = 1.72
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.13 FLOW VELOCITY(FEET/SEC.) = 1.10
LONGEST FLOWPATH FROM NODE 135.00 TO NODE 140.00 = 419.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 140.00 TO NODE 140.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 14.50
RAINFALL INTENSITY(INCH/HR) = 2.39
TOTAL STREAM AREA(ACRES) = 2.00
PEAK FLOW RATE(CFS) AT CONFLUENCE = 1.72
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 4.67 4.69 4.743 1.13
2 1.72 14.50 2.387 2.00

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 5.23 4.69 4.743
2 4.07 14.50 2.387
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 5.23 Tc(MIN.) = 4.69
TOTAL AREA(ACRES) = 3.1
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 140.00 = 469.80 FEET. **************************************************************************** FLOW PROCESS FROM NODE 140.00 TO NODE 144.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 2 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 334.00 DOWNSTREAM ELEVATION(FEET) = 332.20 STREET LENGTH(FEET) = 184.10 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 14.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 9.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0180 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 5.38 ***STREET FLOW SPLITS OVER STREET-CROWN***
FULL DEPTH(FEET) = 0.39 FLOOD WIDTH(FEET) = 14.00
FULL HALF-STREET VELOCITY(FEET/SEC.) = 2.22
SPLIT DEPTH(FEET) = 0.24 SPLIT FLOOD WIDTH(FEET) = 6.86 SPLIT FLOW(CFS) = 0.83 SPLIT VELOCITY(FEET/SEC.) = 1.49 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.39
HALFSTREET FLOOD WIDTH(FEET) = 14.00
AVERAGE FLOW VELOCITY(FEET/SEC.) = 2.22
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.86
STREET FLOW TRAVEL TIME(MIN.) = 1.38 Tc(MIN.) = 6.07
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.186
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.554
SUBAREA AREA(ACRES) = 0.08 SUBAREA RUNOFF(CFS) = 0.30
TOTAL AREA(ACRES) = 3.2 PEAK FLOW RATE(CFS) = 7.44
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.39 HALFSTREET FLOOD WIDTH(FEET) = 14.00 FLOW VELOCITY(FEET/SEC.) = 2.22 DEPTH*VELOCITY(FT*FT/SEC.) = 0.86 LONGEST FLOWPATH FROM NODE 130.00 TO NODE 144.00 = 653.90 FEET. **************************************************************************** FLOW PROCESS FROM NODE 144.00 TO NODE 144.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.186
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5571
SUBAREA AREA(ACRES) = 0.03 SUBAREA RUNOFF(CFS) = 0.11
TOTAL AREA(ACRES) = 3.2 TOTAL RUNOFF(CFS) = 7.56
TC(MIN.) = 6.07
**************************************************************************** FLOW PROCESS FROM NODE 144.00 TO NODE 146.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.64 FLOW LENGTH(FEET) = 36.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 11.7 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.20
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 7.56
PIPE TRAVEL TIME(MIN.) = 0.10 Tc(MIN.) = 6.16
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 146.00 = 689.90 FEET. **************************************************************************** FLOW PROCESS FROM NODE 146.00 TO NODE 146.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.144
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5693
SUBAREA AREA(ACRES) = 0.12 SUBAREA RUNOFF(CFS) = 0.45
TOTAL AREA(ACRES) = 3.4 TOTAL RUNOFF(CFS) = 7.93
TC(MIN.) = 6.16
**************************************************************************** FLOW PROCESS FROM NODE 146.00 TO NODE 150.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.88 FLOW LENGTH(FEET) = 12.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 12.1 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.26
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 7.93
PIPE TRAVEL TIME(MIN.) = 0.03 Tc(MIN.) = 6.20
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 150.00 = 701.90 FEET. **************************************************************************** FLOW PROCESS FROM NODE 150.00 TO NODE 150.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.130
*USER SPECIFIED(SUBAREA):

OFFICE PROFESSIONAL/COMMERCIAL RUNOFF COEFFICIENT = .7900 S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6176
SUBAREA AREA(ACRES) = 0.94 SUBAREA RUNOFF(CFS) = 3.07
TOTAL AREA(ACRES) = 4.3 TOTAL RUNOFF(CFS) = 10.97
TC(MIN.) = 6.20
**************************************************************************** FLOW PROCESS FROM NODE 150.00 TO NODE 199.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 98.10 FLOW LENGTH(FEET) = 190.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 13.3 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.82
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 10.97
PIPE TRAVEL TIME(MIN.) = 0.46 Tc(MIN.) = 6.66
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 199.00 = 891.90 FEET. **************************************************************************** FLOW PROCESS FROM NODE 199.00 TO NODE 199.00 IS CODE = 11 ---------------------------------------------------------------------------- >>>>>CONFLUENCE MEMORY BANK # 1 WITH THE MAIN-STREAM MEMORY<<<<< ============================================================================ ** MAIN STREAM CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 10.97 6.66 3.942 4.30
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 199.00 = 891.90 FEET. ** MEMORY BANK # 1 CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 8.52 6.42 4.036 3.62
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 199.00 = 655.55 FEET. ** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 19.09 6.42 4.036
2 19.29 6.66 3.942
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 19.29 Tc(MIN.) = 6.66
TOTAL AREA(ACRES) = 7.9
============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 7.9 TC(MIN.) = 6.66
PEAK FLOW RATE(CFS) = 19.29
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

____________________________________________________________________________ ****************************************************************************

RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE
Reference: SAN DIEGO COUNTY FLOOD CONTROL DISTRICT
2003,1985,1981 HYDROLOGY MANUAL
(c) Copyright 1982-2014 Advanced Engineering Software (aes) Ver. 21.0 Release Date: 06/01/2014 License ID 1261
Analysis prepared by:

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * SANTEE TOWN CENTER *
* PRE-PROJECT CONDITIONS 50-YEAR EVENT, POC 1 *
* JN-20075 *
************************************************************************** FILE NAME: TC100E50.RAT
TIME/DATE OF STUDY: 10:44 09/09/2025
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 50.00
6-HOUR DURATION PRECIPITATION (INCHES) = 2.400
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.90 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

WIDTH CROSSFALL IN- / OUT-/PARK- HEIGHT WIDTH LIP HIKE FACTOR NO. (FT) (FT) SIDE / SIDE/ WAY (FT) (FT) (FT) (FT) (n)
=== ===== ========= ================= ====== ===== ====== ===== ======= 1 30.0 20.0 0.018/0.018/0.020 0.67 2.00 0.0312 0.167 0.0150 2 14.0 9.0 0.020/0.020/0.020 0.50 1.50 0.0100 0.125 0.0180 GLOBAL STREET FLOW-DEPTH CONSTRAINTS:

1. Relative Flow-Depth = 0.50 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
*SIZE PIPE WITH A FLOW CAPACITY GREATER THAN
OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.*
**************************************************************************** FLOW PROCESS FROM NODE 100.00 TO NODE 102.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .3500 S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 337.40
DOWNSTREAM ELEVATION(FEET) = 337.00
ELEVATION DIFFERENCE(FEET) = 0.40
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 10.283
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.972
SUBAREA RUNOFF(CFS) = 0.11
TOTAL AREA(ACRES) = 0.08 TOTAL RUNOFF(CFS) = 0.11
**************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 105.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 337.00 DOWNSTREAM(FEET) = 331.30 CHANNEL LENGTH THRU SUBAREA(FEET) = 518.55 CHANNEL SLOPE = 0.0110 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 3.000
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 5.00
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.072
*USER SPECIFIED(SUBAREA):

RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .3500 S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.16
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.72 AVERAGE FLOW DEPTH(FEET) = 0.25 TRAVEL TIME(MIN.) = 5.03 Tc(MIN.) = 15.32
SUBAREA AREA(ACRES) = 1.93 SUBAREA RUNOFF(CFS) = 2.07
AREA-AVERAGE RUNOFF COEFFICIENT = 0.350
TOTAL AREA(ACRES) = 2.0 PEAK FLOW RATE(CFS) = 2.16
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.35 FLOW VELOCITY(FEET/SEC.) = 2.05
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 105.00 = 568.55 FEET. **************************************************************************** FLOW PROCESS FROM NODE 105.00 TO NODE 105.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.072
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.3659
SUBAREA AREA(ACRES) = 0.06 SUBAREA RUNOFF(CFS) = 0.17
TOTAL AREA(ACRES) = 2.1 TOTAL RUNOFF(CFS) = 2.33
TC(MIN.) = 15.32
**************************************************************************** FLOW PROCESS FROM NODE 105.00 TO NODE 120.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.60 FLOW LENGTH(FEET) = 40.00 MANNING'S N = 0.013
ESTIMATED PIPE DIAMETER(INCH) INCREASED TO 18.000
DEPTH OF FLOW IN 18.0 INCH PIPE IS 5.9 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 4.60
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 2.33
PIPE TRAVEL TIME(MIN.) = 0.14 Tc(MIN.) = 15.46
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 120.00 = 608.55 FEET. **************************************************************************** FLOW PROCESS FROM NODE 120.00 TO NODE 120.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 15.46
RAINFALL INTENSITY(INCH/HR) = 3.05
TOTAL STREAM AREA(ACRES) = 2.07
PEAK FLOW RATE(CFS) AT CONFLUENCE = 2.33
**************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 112.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .9000 S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 338.00
DOWNSTREAM ELEVATION(FEET) = 337.80
ELEVATION DIFFERENCE(FEET) = 0.20
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.207
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.323
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.46
TOTAL AREA(ACRES) = 0.08 TOTAL RUNOFF(CFS) = 0.46
**************************************************************************** FLOW PROCESS FROM NODE 112.00 TO NODE 120.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 337.80 DOWNSTREAM(FEET) = 331.30 CHANNEL LENGTH THRU SUBAREA(FEET) = 485.57 CHANNEL SLOPE = 0.0134 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.013 MAXIMUM DEPTH(FEET) = 5.00
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.603
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .8500
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 3.83
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.86 AVERAGE FLOW DEPTH(FEET) = 0.12 TRAVEL TIME(MIN.) = 2.82 Tc(MIN.) = 6.03
SUBAREA AREA(ACRES) = 1.39 SUBAREA RUNOFF(CFS) = 6.62
AREA-AVERAGE RUNOFF COEFFICIENT = 0.853
TOTAL AREA(ACRES) = 1.5 PEAK FLOW RATE(CFS) = 7.02
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.16 FLOW VELOCITY(FEET/SEC.) = 3.60
LONGEST FLOWPATH FROM NODE 110.00 TO NODE 120.00 = 535.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 120.00 TO NODE 120.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 6.03
RAINFALL INTENSITY(INCH/HR) = 5.60
TOTAL STREAM AREA(ACRES) = 1.47
PEAK FLOW RATE(CFS) AT CONFLUENCE = 7.02
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 2.33 15.46 3.053 2.07
2 7.02 6.03 5.603 1.47

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 7.93 6.03 5.603
2 6.15 15.46 3.053
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 7.93 Tc(MIN.) = 6.03
TOTAL AREA(ACRES) = 3.5
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 120.00 = 608.55 FEET. **************************************************************************** FLOW PROCESS FROM NODE 120.00 TO NODE 120.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.603
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5754
SUBAREA AREA(ACRES) = 0.08 SUBAREA RUNOFF(CFS) = 0.40
TOTAL AREA(ACRES) = 3.6 TOTAL RUNOFF(CFS) = 11.67
TC(MIN.) = 6.03
**************************************************************************** FLOW PROCESS FROM NODE 120.00 TO NODE 199.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.53 FLOW LENGTH(FEET) = 47.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 13.9 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.91
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 11.67
PIPE TRAVEL TIME(MIN.) = 0.11 Tc(MIN.) = 6.15
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 199.00 = 655.55 FEET. **************************************************************************** FLOW PROCESS FROM NODE 199.00 TO NODE 199.00 IS CODE = 10 ---------------------------------------------------------------------------- >>>>>MAIN-STREAM MEMORY COPIED ONTO MEMORY BANK # 1 <<<<< ============================================================================ **************************************************************************** FLOW PROCESS FROM NODE 130.00 TO NODE 132.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 340.00
DOWNSTREAM ELEVATION(FEET) = 338.20
ELEVATION DIFFERENCE(FEET) = 1.80
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 1.661
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.323
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.40
TOTAL AREA(ACRES) = 0.07 TOTAL RUNOFF(CFS) = 0.40
**************************************************************************** FLOW PROCESS FROM NODE 132.00 TO NODE 140.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 338.20 DOWNSTREAM(FEET) = 334.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 419.80 CHANNEL SLOPE = 0.0100 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.013 MAXIMUM DEPTH(FEET) = 5.00
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.323
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.
*USER SPECIFIED(SUBAREA):

LIMITED INDUSTRIAL RUNOFF COEFFICIENT = .8700
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 3.31
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.48 AVERAGE FLOW DEPTH(FEET) = 0.12 TRAVEL TIME(MIN.) = 2.83 Tc(MIN.) = 4.49
SUBAREA AREA(ACRES) = 1.06 SUBAREA RUNOFF(CFS) = 5.83
AREA-AVERAGE RUNOFF COEFFICIENT = 0.872
TOTAL AREA(ACRES) = 1.1 PEAK FLOW RATE(CFS) = 6.23
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.16 FLOW VELOCITY(FEET/SEC.) = 3.15
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 140.00 = 469.80 FEET. **************************************************************************** FLOW PROCESS FROM NODE 140.00 TO NODE 140.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 4.49
RAINFALL INTENSITY(INCH/HR) = 6.32
TOTAL STREAM AREA(ACRES) = 1.13
PEAK FLOW RATE(CFS) AT CONFLUENCE = 6.23
**************************************************************************** FLOW PROCESS FROM NODE 135.00 TO NODE 137.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .3500 S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 337.20
DOWNSTREAM ELEVATION(FEET) = 337.00
ELEVATION DIFFERENCE(FEET) = 0.20
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 12.027
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.590
SUBAREA RUNOFF(CFS) = 0.10
TOTAL AREA(ACRES) = 0.08 TOTAL RUNOFF(CFS) = 0.10
**************************************************************************** FLOW PROCESS FROM NODE 137.00 TO NODE 140.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 337.00 DOWNSTREAM(FEET) = 334.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 369.00 CHANNEL SLOPE = 0.0081 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 6.00
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.695
*USER SPECIFIED(SUBAREA):

RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .3600 S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.05
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 0.91 AVERAGE FLOW DEPTH(FEET) = 0.10 TRAVEL TIME(MIN.) = 6.73 Tc(MIN.) = 18.76
SUBAREA AREA(ACRES) = 1.92 SUBAREA RUNOFF(CFS) = 1.86
AREA-AVERAGE RUNOFF COEFFICIENT = 0.360
TOTAL AREA(ACRES) = 2.0 PEAK FLOW RATE(CFS) = 1.94
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.15 FLOW VELOCITY(FEET/SEC.) = 1.11
LONGEST FLOWPATH FROM NODE 135.00 TO NODE 140.00 = 419.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 140.00 TO NODE 140.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 18.76
RAINFALL INTENSITY(INCH/HR) = 2.69
TOTAL STREAM AREA(ACRES) = 2.00
PEAK FLOW RATE(CFS) AT CONFLUENCE = 1.94
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 6.23 4.49 6.323 1.13
2 1.94 18.76 2.695 2.00

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 6.69 4.49 6.323
2 4.59 18.76 2.695
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 6.69 Tc(MIN.) = 4.49
TOTAL AREA(ACRES) = 3.1
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 140.00 = 469.80 FEET. **************************************************************************** FLOW PROCESS FROM NODE 140.00 TO NODE 144.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 2 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 334.00 DOWNSTREAM ELEVATION(FEET) = 332.20 STREET LENGTH(FEET) = 184.10 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 14.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 9.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0180 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 6.90 ***STREET FLOW SPLITS OVER STREET-CROWN***
FULL DEPTH(FEET) = 0.39 FLOOD WIDTH(FEET) = 14.00
FULL HALF-STREET VELOCITY(FEET/SEC.) = 2.22
SPLIT DEPTH(FEET) = 0.32 SPLIT FLOOD WIDTH(FEET) = 10.73 SPLIT FLOW(CFS) = 2.35 SPLIT VELOCITY(FEET/SEC.) = 1.90 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.39
HALFSTREET FLOOD WIDTH(FEET) = 14.00
AVERAGE FLOW VELOCITY(FEET/SEC.) = 2.22
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.86
STREET FLOW TRAVEL TIME(MIN.) = 1.38 Tc(MIN.) = 5.87
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.704
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.553
SUBAREA AREA(ACRES) = 0.08 SUBAREA RUNOFF(CFS) = 0.41
TOTAL AREA(ACRES) = 3.2 PEAK FLOW RATE(CFS) = 10.13
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.40 HALFSTREET FLOOD WIDTH(FEET) = 14.00 FLOW VELOCITY(FEET/SEC.) = 2.31 DEPTH*VELOCITY(FT*FT/SEC.) = 0.91 LONGEST FLOWPATH FROM NODE 130.00 TO NODE 144.00 = 653.90 FEET. **************************************************************************** FLOW PROCESS FROM NODE 144.00 TO NODE 144.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.704
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5566
SUBAREA AREA(ACRES) = 0.03 SUBAREA RUNOFF(CFS) = 0.15
TOTAL AREA(ACRES) = 3.2 TOTAL RUNOFF(CFS) = 10.29
TC(MIN.) = 5.87
**************************************************************************** FLOW PROCESS FROM NODE 144.00 TO NODE 146.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.64 FLOW LENGTH(FEET) = 36.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 12.7 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.73
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 10.29
PIPE TRAVEL TIME(MIN.) = 0.09 Tc(MIN.) = 5.96
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 146.00 = 689.90 FEET. **************************************************************************** FLOW PROCESS FROM NODE 146.00 TO NODE 146.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.648
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5689
SUBAREA AREA(ACRES) = 0.12 SUBAREA RUNOFF(CFS) = 0.61
TOTAL AREA(ACRES) = 3.4 TOTAL RUNOFF(CFS) = 10.80
TC(MIN.) = 5.96
**************************************************************************** FLOW PROCESS FROM NODE 146.00 TO NODE 150.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.88 FLOW LENGTH(FEET) = 12.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 13.2 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.80
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 10.80
PIPE TRAVEL TIME(MIN.) = 0.03 Tc(MIN.) = 5.99
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 150.00 = 701.90 FEET. **************************************************************************** FLOW PROCESS FROM NODE 150.00 TO NODE 150.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.631
*USER SPECIFIED(SUBAREA):

OFFICE PROFESSIONAL/COMMERCIAL RUNOFF COEFFICIENT = .7900 S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6172
SUBAREA AREA(ACRES) = 0.94 SUBAREA RUNOFF(CFS) = 4.18
TOTAL AREA(ACRES) = 4.3 TOTAL RUNOFF(CFS) = 14.94
TC(MIN.) = 5.99
**************************************************************************** FLOW PROCESS FROM NODE 150.00 TO NODE 199.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 98.10 FLOW LENGTH(FEET) = 190.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 17.1 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 7.12
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 14.94
PIPE TRAVEL TIME(MIN.) = 0.44 Tc(MIN.) = 6.43
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 199.00 = 891.90 FEET. **************************************************************************** FLOW PROCESS FROM NODE 199.00 TO NODE 199.00 IS CODE = 11 ---------------------------------------------------------------------------- >>>>>CONFLUENCE MEMORY BANK # 1 WITH THE MAIN-STREAM MEMORY<<<<< ============================================================================ ** MAIN STREAM CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 14.94 6.43 5.376 4.30
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 199.00 = 891.90 FEET. ** MEMORY BANK # 1 CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 11.67 6.15 5.536 3.62
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 199.00 = 655.55 FEET. ** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 25.95 6.15 5.536
2 26.28 6.43 5.376
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 26.28 Tc(MIN.) = 6.43
TOTAL AREA(ACRES) = 7.9
============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 7.9 TC(MIN.) = 6.43
PEAK FLOW RATE(CFS) = 26.28
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

____________________________________________________________________________ ****************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * SANTEE TOWN CENTER *
* PRE-PROJECT CONDITIONS 100-YEAR EVENT, POC 1 *
* JN-20075 *
************************************************************************** FILE NAME: TC100E00.RAT
TIME/DATE OF STUDY: 16:45 08/13/2025
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 100.00
6-HOUR DURATION PRECIPITATION (INCHES) = 2.500
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.90 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

1. Relative Flow-Depth = 0.50 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .3500 S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 337.40
DOWNSTREAM ELEVATION(FEET) = 337.00
ELEVATION DIFFERENCE(FEET) = 0.40
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 10.283
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.137
SUBAREA RUNOFF(CFS) = 0.12
TOTAL AREA(ACRES) = 0.08 TOTAL RUNOFF(CFS) = 0.12
**************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 105.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 337.00 DOWNSTREAM(FEET) = 331.30 CHANNEL LENGTH THRU SUBAREA(FEET) = 518.55 CHANNEL SLOPE = 0.0110 CHANNEL BASE(FEET) = 2.00 "Z" FACTOR = 3.000
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 5.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.203
*USER SPECIFIED(SUBAREA):

RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .3500 S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.21
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.73 AVERAGE FLOW DEPTH(FEET) = 0.25 TRAVEL TIME(MIN.) = 5.01 Tc(MIN.) = 15.29
SUBAREA AREA(ACRES) = 1.93 SUBAREA RUNOFF(CFS) = 2.16
AREA-AVERAGE RUNOFF COEFFICIENT = 0.350
TOTAL AREA(ACRES) = 2.0 PEAK FLOW RATE(CFS) = 2.25
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.35 FLOW VELOCITY(FEET/SEC.) = 2.08
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 105.00 = 568.55 FEET. **************************************************************************** FLOW PROCESS FROM NODE 105.00 TO NODE 105.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.203
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.3659
SUBAREA AREA(ACRES) = 0.06 SUBAREA RUNOFF(CFS) = 0.17
TOTAL AREA(ACRES) = 2.1 TOTAL RUNOFF(CFS) = 2.43
TC(MIN.) = 15.29
**************************************************************************** FLOW PROCESS FROM NODE 105.00 TO NODE 120.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.60 FLOW LENGTH(FEET) = 40.00 MANNING'S N = 0.013
ESTIMATED PIPE DIAMETER(INCH) INCREASED TO 18.000
DEPTH OF FLOW IN 18.0 INCH PIPE IS 6.0 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 4.66
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 2.43
PIPE TRAVEL TIME(MIN.) = 0.14 Tc(MIN.) = 15.44
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 120.00 = 608.55 FEET. **************************************************************************** FLOW PROCESS FROM NODE 120.00 TO NODE 120.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 15.44
RAINFALL INTENSITY(INCH/HR) = 3.18
TOTAL STREAM AREA(ACRES) = 2.07
PEAK FLOW RATE(CFS) AT CONFLUENCE = 2.43
**************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 112.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .9000 S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 338.00
DOWNSTREAM ELEVATION(FEET) = 337.80
ELEVATION DIFFERENCE(FEET) = 0.20
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.207
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.587
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.47
TOTAL AREA(ACRES) = 0.08 TOTAL RUNOFF(CFS) = 0.47
**************************************************************************** FLOW PROCESS FROM NODE 112.00 TO NODE 120.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 337.80 DOWNSTREAM(FEET) = 331.30 CHANNEL LENGTH THRU SUBAREA(FEET) = 485.57 CHANNEL SLOPE = 0.0134 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.013 MAXIMUM DEPTH(FEET) = 5.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.886
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .8500
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 4.02
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.95 AVERAGE FLOW DEPTH(FEET) = 0.12 TRAVEL TIME(MIN.) = 2.74 Tc(MIN.) = 5.95
SUBAREA AREA(ACRES) = 1.39 SUBAREA RUNOFF(CFS) = 6.95
AREA-AVERAGE RUNOFF COEFFICIENT = 0.853
TOTAL AREA(ACRES) = 1.5 PEAK FLOW RATE(CFS) = 7.38
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.17 FLOW VELOCITY(FEET/SEC.) = 3.59
LONGEST FLOWPATH FROM NODE 110.00 TO NODE 120.00 = 535.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 120.00 TO NODE 120.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 5.95
RAINFALL INTENSITY(INCH/HR) = 5.89
TOTAL STREAM AREA(ACRES) = 1.47
PEAK FLOW RATE(CFS) AT CONFLUENCE = 7.38
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 2.43 15.44 3.184 2.07
2 7.38 5.95 5.886 1.47

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 8.31 5.95 5.886
2 6.42 15.44 3.184
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 8.31 Tc(MIN.) = 5.95
TOTAL AREA(ACRES) = 3.5
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 120.00 = 608.55 FEET. **************************************************************************** FLOW PROCESS FROM NODE 120.00 TO NODE 120.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.886
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5754
SUBAREA AREA(ACRES) = 0.08 SUBAREA RUNOFF(CFS) = 0.42
TOTAL AREA(ACRES) = 3.6 TOTAL RUNOFF(CFS) = 12.26
TC(MIN.) = 5.95
**************************************************************************** FLOW PROCESS FROM NODE 120.00 TO NODE 199.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.53 FLOW LENGTH(FEET) = 47.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 14.4 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.97
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 12.26
PIPE TRAVEL TIME(MIN.) = 0.11 Tc(MIN.) = 6.06
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 199.00 = 655.55 FEET. **************************************************************************** FLOW PROCESS FROM NODE 199.00 TO NODE 199.00 IS CODE = 10 ---------------------------------------------------------------------------- >>>>>MAIN-STREAM MEMORY COPIED ONTO MEMORY BANK # 1 <<<<< ============================================================================ **************************************************************************** FLOW PROCESS FROM NODE 130.00 TO NODE 132.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 340.00
DOWNSTREAM ELEVATION(FEET) = 338.20
ELEVATION DIFFERENCE(FEET) = 1.80
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 1.661
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.587
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.41
TOTAL AREA(ACRES) = 0.07 TOTAL RUNOFF(CFS) = 0.41
**************************************************************************** FLOW PROCESS FROM NODE 132.00 TO NODE 140.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 338.20 DOWNSTREAM(FEET) = 334.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 419.80 CHANNEL SLOPE = 0.0100 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.013 MAXIMUM DEPTH(FEET) = 5.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.587
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.
*USER SPECIFIED(SUBAREA):

LIMITED INDUSTRIAL RUNOFF COEFFICIENT = .8700
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 3.45
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.53 AVERAGE FLOW DEPTH(FEET) = 0.12 TRAVEL TIME(MIN.) = 2.76 Tc(MIN.) = 4.42
SUBAREA AREA(ACRES) = 1.06 SUBAREA RUNOFF(CFS) = 6.07
AREA-AVERAGE RUNOFF COEFFICIENT = 0.872
TOTAL AREA(ACRES) = 1.1 PEAK FLOW RATE(CFS) = 6.49
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.17 FLOW VELOCITY(FEET/SEC.) = 3.16
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 140.00 = 469.80 FEET. **************************************************************************** FLOW PROCESS FROM NODE 140.00 TO NODE 140.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 4.42
RAINFALL INTENSITY(INCH/HR) = 6.59
TOTAL STREAM AREA(ACRES) = 1.13
PEAK FLOW RATE(CFS) AT CONFLUENCE = 6.49
**************************************************************************** FLOW PROCESS FROM NODE 135.00 TO NODE 137.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .3500 S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 337.20
DOWNSTREAM ELEVATION(FEET) = 337.00
ELEVATION DIFFERENCE(FEET) = 0.20
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 12.027
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.740
SUBAREA RUNOFF(CFS) = 0.10
TOTAL AREA(ACRES) = 0.08 TOTAL RUNOFF(CFS) = 0.10
**************************************************************************** FLOW PROCESS FROM NODE 137.00 TO NODE 140.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 337.00 DOWNSTREAM(FEET) = 334.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 369.00 CHANNEL SLOPE = 0.0081 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 6.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 2.823
*USER SPECIFIED(SUBAREA):

RESIDENTIAL (1. DU/AC OR LESS) RUNOFF COEFFICIENT = .3600 S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.09
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 0.94 AVERAGE FLOW DEPTH(FEET) = 0.10 TRAVEL TIME(MIN.) = 6.57 Tc(MIN.) = 18.60
SUBAREA AREA(ACRES) = 1.92 SUBAREA RUNOFF(CFS) = 1.95
AREA-AVERAGE RUNOFF COEFFICIENT = 0.360
TOTAL AREA(ACRES) = 2.0 PEAK FLOW RATE(CFS) = 2.03
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.15 FLOW VELOCITY(FEET/SEC.) = 1.15
LONGEST FLOWPATH FROM NODE 135.00 TO NODE 140.00 = 419.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 140.00 TO NODE 140.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 18.60
RAINFALL INTENSITY(INCH/HR) = 2.82
TOTAL STREAM AREA(ACRES) = 2.00
PEAK FLOW RATE(CFS) AT CONFLUENCE = 2.03
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 6.49 4.42 6.587 1.13
2 2.03 18.60 2.823 2.00

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 6.97 4.42 6.587
2 4.81 18.60 2.823
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 6.97 Tc(MIN.) = 4.42
TOTAL AREA(ACRES) = 3.1
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 140.00 = 469.80 FEET. **************************************************************************** FLOW PROCESS FROM NODE 140.00 TO NODE 144.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 2 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 334.00 DOWNSTREAM ELEVATION(FEET) = 332.20 STREET LENGTH(FEET) = 184.10 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 14.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 9.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0180 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 7.19 ***STREET FLOW SPLITS OVER STREET-CROWN***
FULL DEPTH(FEET) = 0.39 FLOOD WIDTH(FEET) = 14.00
FULL HALF-STREET VELOCITY(FEET/SEC.) = 2.22
SPLIT DEPTH(FEET) = 0.33 SPLIT FLOOD WIDTH(FEET) = 11.29 SPLIT FLOW(CFS) = 2.64 SPLIT VELOCITY(FEET/SEC.) = 1.94 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.39
HALFSTREET FLOOD WIDTH(FEET) = 14.00
AVERAGE FLOW VELOCITY(FEET/SEC.) = 2.22
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.86
STREET FLOW TRAVEL TIME(MIN.) = 1.38 Tc(MIN.) = 5.80
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.983
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.553
SUBAREA AREA(ACRES) = 0.08 SUBAREA RUNOFF(CFS) = 0.43
TOTAL AREA(ACRES) = 3.2 PEAK FLOW RATE(CFS) = 10.63
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.40 HALFSTREET FLOOD WIDTH(FEET) = 14.00 FLOW VELOCITY(FEET/SEC.) = 2.37 DEPTH*VELOCITY(FT*FT/SEC.) = 0.95 LONGEST FLOWPATH FROM NODE 130.00 TO NODE 144.00 = 653.90 FEET. **************************************************************************** FLOW PROCESS FROM NODE 144.00 TO NODE 144.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.983
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5566
SUBAREA AREA(ACRES) = 0.03 SUBAREA RUNOFF(CFS) = 0.16
TOTAL AREA(ACRES) = 3.2 TOTAL RUNOFF(CFS) = 10.79
TC(MIN.) = 5.80
**************************************************************************** FLOW PROCESS FROM NODE 144.00 TO NODE 146.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.64 FLOW LENGTH(FEET) = 36.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 13.2 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.80
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 10.79
PIPE TRAVEL TIME(MIN.) = 0.09 Tc(MIN.) = 5.89
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 146.00 = 689.90 FEET. **************************************************************************** FLOW PROCESS FROM NODE 146.00 TO NODE 146.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.925
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.5689
SUBAREA AREA(ACRES) = 0.12 SUBAREA RUNOFF(CFS) = 0.64
TOTAL AREA(ACRES) = 3.4 TOTAL RUNOFF(CFS) = 11.33
TC(MIN.) = 5.89
**************************************************************************** FLOW PROCESS FROM NODE 146.00 TO NODE 150.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.88 FLOW LENGTH(FEET) = 12.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 13.6 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.86
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 11.33
PIPE TRAVEL TIME(MIN.) = 0.03 Tc(MIN.) = 5.92
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 150.00 = 701.90 FEET. **************************************************************************** FLOW PROCESS FROM NODE 150.00 TO NODE 150.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.906
*USER SPECIFIED(SUBAREA):

OFFICE PROFESSIONAL/COMMERCIAL RUNOFF COEFFICIENT = .7900 S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.6172
SUBAREA AREA(ACRES) = 0.94 SUBAREA RUNOFF(CFS) = 4.39
TOTAL AREA(ACRES) = 4.3 TOTAL RUNOFF(CFS) = 15.68
TC(MIN.) = 5.92
**************************************************************************** FLOW PROCESS FROM NODE 150.00 TO NODE 199.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 98.10 FLOW LENGTH(FEET) = 190.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 15.2 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 7.46
ESTIMATED PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 15.68
PIPE TRAVEL TIME(MIN.) = 0.42 Tc(MIN.) = 6.35
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 199.00 = 891.90 FEET. **************************************************************************** FLOW PROCESS FROM NODE 199.00 TO NODE 199.00 IS CODE = 11 ---------------------------------------------------------------------------- >>>>>CONFLUENCE MEMORY BANK # 1 WITH THE MAIN-STREAM MEMORY<<<<< ============================================================================ ** MAIN STREAM CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 15.68 6.35 5.648 4.30
LONGEST FLOWPATH FROM NODE 130.00 TO NODE 199.00 = 891.90 FEET. ** MEMORY BANK # 1 CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 12.26 6.06 5.816 3.62
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 199.00 = 655.55 FEET. ** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 27.24 6.06 5.816
2 27.58 6.35 5.648
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 27.58 Tc(MIN.) = 6.35
TOTAL AREA(ACRES) = 7.9
============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 7.9 TC(MIN.) = 6.35
PEAK FLOW RATE(CFS) = 27.58
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

____________________________________________________________________________ ****************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * SANTEE TOWN CENTER *
* PRE-PROJECT CONDITIONS 10-YEAR EVENT, POC 2 *
* JN - 20075 *
************************************************************************** FILE NAME: TC200E10.RAT
TIME/DATE OF STUDY: 10:48 09/09/2025
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 10.00
6-HOUR DURATION PRECIPITATION (INCHES) = 1.800
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.90 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

1. Relative Flow-Depth = 0.50 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
*SIZE PIPE WITH A FLOW CAPACITY GREATER THAN
OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.*
**************************************************************************** FLOW PROCESS FROM NODE 200.00 TO NODE 202.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 335.10
DOWNSTREAM ELEVATION(FEET) = 335.00
ELEVATION DIFFERENCE(FEET) = 0.10
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.207
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.743
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.34
TOTAL AREA(ACRES) = 0.08 TOTAL RUNOFF(CFS) = 0.34
**************************************************************************** FLOW PROCESS FROM NODE 202.00 TO NODE 299.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 335.00 DOWNSTREAM(FEET) = 333.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 170.00 CHANNEL SLOPE = 0.0118 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.013 MAXIMUM DEPTH(FEET) = 5.00
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.743
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.
*USER SPECIFIED(SUBAREA):

OFFICE PROFESSIONAL/COMMERCIAL RUNOFF COEFFICIENT = .7900 S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.22
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.78 AVERAGE FLOW DEPTH(FEET) = 0.06 TRAVEL TIME(MIN.) = 1.60 Tc(MIN.) = 4.80
SUBAREA AREA(ACRES) = 0.47 SUBAREA RUNOFF(CFS) = 1.76
AREA-AVERAGE RUNOFF COEFFICIENT = 0.806
TOTAL AREA(ACRES) = 0.6 PEAK FLOW RATE(CFS) = 2.10
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.09 FLOW VELOCITY(FEET/SEC.) = 2.19
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 299.00 = 220.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 299.00 TO NODE 299.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.743
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.
*USER SPECIFIED(SUBAREA):

OFFICE PROFESSIONAL/COMMERCIAL RUNOFF COEFFICIENT = .8500 S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8234
SUBAREA AREA(ACRES) = 0.36 SUBAREA RUNOFF(CFS) = 1.45
TOTAL AREA(ACRES) = 0.9 TOTAL RUNOFF(CFS) = 3.55
TC(MIN.) = 4.80
============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 0.9 TC(MIN.) = 4.80
PEAK FLOW RATE(CFS) = 3.55
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

____________________________________________________________________________ ****************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * SANTEE TOWN CENTER *
* PRE-PROJECT CONDITIONS 50-YEAR EVENT, POC 2 *
* JN - 20075 *
************************************************************************** FILE NAME: TC200E50.RAT
TIME/DATE OF STUDY: 10:49 09/09/2025
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 50.00
6-HOUR DURATION PRECIPITATION (INCHES) = 2.400
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.90 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

1. Relative Flow-Depth = 0.50 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
*SIZE PIPE WITH A FLOW CAPACITY GREATER THAN
OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.*
**************************************************************************** FLOW PROCESS FROM NODE 200.00 TO NODE 202.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 335.10
DOWNSTREAM ELEVATION(FEET) = 335.00
ELEVATION DIFFERENCE(FEET) = 0.10
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.207
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.323
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.46
TOTAL AREA(ACRES) = 0.08 TOTAL RUNOFF(CFS) = 0.46
**************************************************************************** FLOW PROCESS FROM NODE 202.00 TO NODE 299.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 335.00 DOWNSTREAM(FEET) = 333.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 170.00 CHANNEL SLOPE = 0.0118 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.013 MAXIMUM DEPTH(FEET) = 5.00
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.323
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.
*USER SPECIFIED(SUBAREA):

OFFICE PROFESSIONAL/COMMERCIAL RUNOFF COEFFICIENT = .7900 S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.63
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.04 AVERAGE FLOW DEPTH(FEET) = 0.07 TRAVEL TIME(MIN.) = 1.39 Tc(MIN.) = 4.60
SUBAREA AREA(ACRES) = 0.47 SUBAREA RUNOFF(CFS) = 2.35
AREA-AVERAGE RUNOFF COEFFICIENT = 0.806
TOTAL AREA(ACRES) = 0.6 PEAK FLOW RATE(CFS) = 2.80
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.10 FLOW VELOCITY(FEET/SEC.) = 2.45
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 299.00 = 220.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 299.00 TO NODE 299.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.323
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.
*USER SPECIFIED(SUBAREA):

OFFICE PROFESSIONAL/COMMERCIAL RUNOFF COEFFICIENT = .8500 S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8234
SUBAREA AREA(ACRES) = 0.36 SUBAREA RUNOFF(CFS) = 1.93
TOTAL AREA(ACRES) = 0.9 TOTAL RUNOFF(CFS) = 4.74
TC(MIN.) = 4.60
============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 0.9 TC(MIN.) = 4.60
PEAK FLOW RATE(CFS) = 4.74
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

____________________________________________________________________________ ****************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * SANTEE TOWN CENTER *
* PRE-PROJECT CONDITIONS 100-YEAR EVENT, POC 2 *
* JN - 20075 *
************************************************************************** FILE NAME: TC200E00.RAT
TIME/DATE OF STUDY: 16:55 08/13/2025
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 100.00
6-HOUR DURATION PRECIPITATION (INCHES) = 2.500
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.90 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

1. Relative Flow-Depth = 0.50 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
*SIZE PIPE WITH A FLOW CAPACITY GREATER THAN
OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.*
**************************************************************************** FLOW PROCESS FROM NODE 200.00 TO NODE 202.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 335.10
DOWNSTREAM ELEVATION(FEET) = 335.00
ELEVATION DIFFERENCE(FEET) = 0.10
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.207
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.587
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.47
TOTAL AREA(ACRES) = 0.08 TOTAL RUNOFF(CFS) = 0.47
**************************************************************************** FLOW PROCESS FROM NODE 202.00 TO NODE 299.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 335.00 DOWNSTREAM(FEET) = 333.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 170.00 CHANNEL SLOPE = 0.0118 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.013 MAXIMUM DEPTH(FEET) = 5.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.587
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.
*USER SPECIFIED(SUBAREA):

OFFICE PROFESSIONAL/COMMERCIAL RUNOFF COEFFICIENT = .7900 S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.70
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.12 AVERAGE FLOW DEPTH(FEET) = 0.07 TRAVEL TIME(MIN.) = 1.33 Tc(MIN.) = 4.54
SUBAREA AREA(ACRES) = 0.47 SUBAREA RUNOFF(CFS) = 2.45
AREA-AVERAGE RUNOFF COEFFICIENT = 0.806
TOTAL AREA(ACRES) = 0.6 PEAK FLOW RATE(CFS) = 2.92
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.10 FLOW VELOCITY(FEET/SEC.) = 2.55
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 299.00 = 220.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 299.00 TO NODE 299.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.587
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.
*USER SPECIFIED(SUBAREA):

OFFICE PROFESSIONAL/COMMERCIAL RUNOFF COEFFICIENT = .8500 S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8234
SUBAREA AREA(ACRES) = 0.36 SUBAREA RUNOFF(CFS) = 2.02
TOTAL AREA(ACRES) = 0.9 TOTAL RUNOFF(CFS) = 4.94
TC(MIN.) = 4.54
============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 0.9 TC(MIN.) = 4.54
PEAK FLOW RATE(CFS) = 4.94
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

APPENDIX B
Modified Rational Method Output
[Post-project]
____________________________________________________________________________ ****************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * SANTEE TOWN CENTER *
* POST-PROJECT CONDITIONS 10-YEAR EVENT, POC 1 *
* JN-20075 *
************************************************************************** FILE NAME: TC100P10.RAT
TIME/DATE OF STUDY: 15:29 09/10/2025
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 10.00
6-HOUR DURATION PRECIPITATION (INCHES) = 1.800
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.90 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

1. Relative Flow-Depth = 0.50 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 336.00
DOWNSTREAM ELEVATION(FEET) = 335.75
ELEVATION DIFFERENCE(FEET) = 0.25
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 4.650
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.743
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.38
TOTAL AREA(ACRES) = 0.10 TOTAL RUNOFF(CFS) = 0.38
**************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 104.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 3 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 335.75 DOWNSTREAM ELEVATION(FEET) = 334.50 STREET LENGTH(FEET) = 145.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 26.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 21.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0180 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 0.86 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.25
HALFSTREET FLOOD WIDTH(FEET) = 7.17
AVERAGE FLOW VELOCITY(FEET/SEC.) = 1.44
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.36
STREET FLOW TRAVEL TIME(MIN.) = 1.68 Tc(MIN.) = 6.33
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.072
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.810
SUBAREA AREA(ACRES) = 0.29 SUBAREA RUNOFF(CFS) = 0.96
TOTAL AREA(ACRES) = 0.4 PEAK FLOW RATE(CFS) = 1.29
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.28 HALFSTREET FLOOD WIDTH(FEET) = 8.57
FLOW VELOCITY(FEET/SEC.) = 1.57 DEPTH*VELOCITY(FT*FT/SEC.) = 0.43 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 104.00 = 195.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 104.00 TO NODE 104.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.072
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8100
SUBAREA AREA(ACRES) = 0.29 SUBAREA RUNOFF(CFS) = 0.96
TOTAL AREA(ACRES) = 0.7 TOTAL RUNOFF(CFS) = 2.24
TC(MIN.) = 6.33
**************************************************************************** FLOW PROCESS FROM NODE 104.00 TO NODE 110.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 97.65 FLOW LENGTH(FEET) = 235.00 MANNING'S N = 0.013
ESTIMATED PIPE DIAMETER(INCH) INCREASED TO 18.000
DEPTH OF FLOW IN 18.0 INCH PIPE IS 5.8 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 4.56
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 2.24
PIPE TRAVEL TIME(MIN.) = 0.86 Tc(MIN.) = 7.19
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 110.00 = 430.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 110.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.751
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8100
SUBAREA AREA(ACRES) = 0.23 SUBAREA RUNOFF(CFS) = 0.70
TOTAL AREA(ACRES) = 0.9 TOTAL RUNOFF(CFS) = 2.76
TC(MIN.) = 7.19
**************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 110.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.751
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8200
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8135
SUBAREA AREA(ACRES) = 0.50 SUBAREA RUNOFF(CFS) = 1.54
TOTAL AREA(ACRES) = 1.4 TOTAL RUNOFF(CFS) = 4.30
TC(MIN.) = 7.19
**************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 110.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 7.19
RAINFALL INTENSITY(INCH/HR) = 3.75
TOTAL STREAM AREA(ACRES) = 1.41
PEAK FLOW RATE(CFS) AT CONFLUENCE = 4.30
**************************************************************************** FLOW PROCESS FROM NODE 170.00 TO NODE 172.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 340.00
DOWNSTREAM ELEVATION(FEET) = 338.20
ELEVATION DIFFERENCE(FEET) = 1.80
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 1.661
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.743
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.30
TOTAL AREA(ACRES) = 0.07 TOTAL RUNOFF(CFS) = 0.30
**************************************************************************** FLOW PROCESS FROM NODE 172.00 TO NODE 174.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 338.20 DOWNSTREAM(FEET) = 334.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 416.47 CHANNEL SLOPE = 0.0101 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 10.00
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.700
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .8700
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.53
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.04 AVERAGE FLOW DEPTH(FEET) = 0.11 TRAVEL TIME(MIN.) = 3.41 Tc(MIN.) = 5.07
SUBAREA AREA(ACRES) = 1.08 SUBAREA RUNOFF(CFS) = 4.42
AREA-AVERAGE RUNOFF COEFFICIENT = 0.872
TOTAL AREA(ACRES) = 1.2 PEAK FLOW RATE(CFS) = 4.71
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.16 FLOW VELOCITY(FEET/SEC.) = 2.55
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 174.00 = 466.47 FEET. **************************************************************************** FLOW PROCESS FROM NODE 174.00 TO NODE 110.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 2 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 334.00 DOWNSTREAM ELEVATION(FEET) = 332.20 STREET LENGTH(FEET) = 184.10 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 14.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 9.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0180 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 4.91 ***STREET FLOW SPLITS OVER STREET-CROWN***
FULL DEPTH(FEET) = 0.39 FLOOD WIDTH(FEET) = 14.00
FULL HALF-STREET VELOCITY(FEET/SEC.) = 2.22
SPLIT DEPTH(FEET) = 0.19 SPLIT FLOOD WIDTH(FEET) = 4.48 SPLIT FLOW(CFS) = 0.37 SPLIT VELOCITY(FEET/SEC.) = 1.27 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.39
HALFSTREET FLOOD WIDTH(FEET) = 14.00
AVERAGE FLOW VELOCITY(FEET/SEC.) = 2.22
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.86
STREET FLOW TRAVEL TIME(MIN.) = 1.38 Tc(MIN.) = 6.45
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.024
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.874
SUBAREA AREA(ACRES) = 0.11 SUBAREA RUNOFF(CFS) = 0.40
TOTAL AREA(ACRES) = 1.3 PEAK FLOW RATE(CFS) = 4.71
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.39 HALFSTREET FLOOD WIDTH(FEET) = 14.00 FLOW VELOCITY(FEET/SEC.) = 2.22 DEPTH*VELOCITY(FT*FT/SEC.) = 0.86 LONGEST FLOWPATH FROM NODE 170.00 TO NODE 110.00 = 650.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 110.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.024
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8747
SUBAREA AREA(ACRES) = 0.02 SUBAREA RUNOFF(CFS) = 0.07
TOTAL AREA(ACRES) = 1.3 TOTAL RUNOFF(CFS) = 4.71
TC(MIN.) = 6.45
NOTE: PEAK FLOW RATE DEFAULTED TO UPSTREAM VALUE
**************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 110.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 6.45
RAINFALL INTENSITY(INCH/HR) = 4.02
TOTAL STREAM AREA(ACRES) = 1.28
PEAK FLOW RATE(CFS) AT CONFLUENCE = 4.71
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 4.30 7.19 3.751 1.41
2 4.71 6.45 4.024 1.28

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 8.57 6.45 4.024
2 8.70 7.19 3.751
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 8.70 Tc(MIN.) = 7.19
TOTAL AREA(ACRES) = 2.7
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 110.00 = 650.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 180.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.64 FLOW LENGTH(FEET) = 36.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 13.0 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.36
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 8.70
PIPE TRAVEL TIME(MIN.) = 0.09 Tc(MIN.) = 7.29
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 180.00 = 686.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 180.00 TO NODE 180.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.720
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8451
SUBAREA AREA(ACRES) = 0.12 SUBAREA RUNOFF(CFS) = 0.40
TOTAL AREA(ACRES) = 2.8 TOTAL RUNOFF(CFS) = 8.83
TC(MIN.) = 7.29
**************************************************************************** FLOW PROCESS FROM NODE 180.00 TO NODE 182.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.88 FLOW LENGTH(FEET) = 12.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 13.2 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.38
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 8.83
PIPE TRAVEL TIME(MIN.) = 0.03 Tc(MIN.) = 7.32
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 182.00 = 698.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 182.00 TO NODE 182.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.709
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .7900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8313
SUBAREA AREA(ACRES) = 0.94 SUBAREA RUNOFF(CFS) = 2.75
TOTAL AREA(ACRES) = 3.8 TOTAL RUNOFF(CFS) = 11.56
TC(MIN.) = 7.32
**************************************************************************** FLOW PROCESS FROM NODE 182.00 TO NODE 199.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 98.10 FLOW LENGTH(FEET) = 190.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 13.8 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.90
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 11.56
PIPE TRAVEL TIME(MIN.) = 0.46 Tc(MIN.) = 7.78
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 199.00 = 888.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 199.00 TO NODE 199.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 7.78
RAINFALL INTENSITY(INCH/HR) = 3.57
TOTAL STREAM AREA(ACRES) = 3.75
PEAK FLOW RATE(CFS) AT CONFLUENCE = 11.56
**************************************************************************** FLOW PROCESS FROM NODE 152.00 TO NODE 154.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 338.00
DOWNSTREAM ELEVATION(FEET) = 337.80
ELEVATION DIFFERENCE(FEET) = 0.20
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.207
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.743
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.30
TOTAL AREA(ACRES) = 0.07 TOTAL RUNOFF(CFS) = 0.30
**************************************************************************** FLOW PROCESS FROM NODE 154.00 TO NODE 160.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 337.80 DOWNSTREAM(FEET) = 331.30 CHANNEL LENGTH THRU SUBAREA(FEET) = 485.57 CHANNEL SLOPE = 0.0134 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 10.00
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.940
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .8700
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.74
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.34 AVERAGE FLOW DEPTH(FEET) = 0.10 TRAVEL TIME(MIN.) = 3.46 Tc(MIN.) = 6.66
SUBAREA AREA(ACRES) = 1.40 SUBAREA RUNOFF(CFS) = 4.80
AREA-AVERAGE RUNOFF COEFFICIENT = 0.871
TOTAL AREA(ACRES) = 1.5 PEAK FLOW RATE(CFS) = 5.05
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.15 FLOW VELOCITY(FEET/SEC.) = 2.90
LONGEST FLOWPATH FROM NODE 152.00 TO NODE 160.00 = 535.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 160.00 TO NODE 160.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.940
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8724
SUBAREA AREA(ACRES) = 0.05 SUBAREA RUNOFF(CFS) = 0.18
TOTAL AREA(ACRES) = 1.5 TOTAL RUNOFF(CFS) = 5.22
TC(MIN.) = 6.66
**************************************************************************** FLOW PROCESS FROM NODE 160.00 TO NODE 160.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.940
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8737
SUBAREA AREA(ACRES) = 0.08 SUBAREA RUNOFF(CFS) = 0.28
TOTAL AREA(ACRES) = 1.6 TOTAL RUNOFF(CFS) = 5.51
TC(MIN.) = 6.66
**************************************************************************** FLOW PROCESS FROM NODE 160.00 TO NODE 160.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.940
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8511
SUBAREA AREA(ACRES) = 0.88 SUBAREA RUNOFF(CFS) = 2.81
TOTAL AREA(ACRES) = 2.5 TOTAL RUNOFF(CFS) = 8.32
TC(MIN.) = 6.66
**************************************************************************** FLOW PROCESS FROM NODE 160.00 TO NODE 199.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.53 FLOW LENGTH(FEET) = 47.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 12.6 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.31
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 8.32
PIPE TRAVEL TIME(MIN.) = 0.12 Tc(MIN.) = 6.79
LONGEST FLOWPATH FROM NODE 152.00 TO NODE 199.00 = 582.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 199.00 TO NODE 199.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 6.79
RAINFALL INTENSITY(INCH/HR) = 3.89
TOTAL STREAM AREA(ACRES) = 2.48
PEAK FLOW RATE(CFS) AT CONFLUENCE = 8.32
**************************************************************************** FLOW PROCESS FROM NODE 162.00 TO NODE 164.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 337.00
DOWNSTREAM ELEVATION(FEET) = 336.75
ELEVATION DIFFERENCE(FEET) = 0.25
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 4.650
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.743
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.35
TOTAL AREA(ACRES) = 0.09 TOTAL RUNOFF(CFS) = 0.35
**************************************************************************** FLOW PROCESS FROM NODE 164.00 TO NODE 168.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 3 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 336.75 DOWNSTREAM ELEVATION(FEET) = 333.00 STREET LENGTH(FEET) = 306.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 26.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 21.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0180 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.09 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.25
HALFSTREET FLOOD WIDTH(FEET) = 7.34
AVERAGE FLOW VELOCITY(FEET/SEC.) = 1.74
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.44
STREET FLOW TRAVEL TIME(MIN.) = 2.93 Tc(MIN.) = 7.58
10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.625
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.810
SUBAREA AREA(ACRES) = 0.50 SUBAREA RUNOFF(CFS) = 1.47
TOTAL AREA(ACRES) = 0.6 PEAK FLOW RATE(CFS) = 1.73
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.29 HALFSTREET FLOOD WIDTH(FEET) = 9.06
FLOW VELOCITY(FEET/SEC.) = 1.91 DEPTH*VELOCITY(FT*FT/SEC.) = 0.55 LONGEST FLOWPATH FROM NODE 162.00 TO NODE 168.00 = 356.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 168.00 TO NODE 178.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.07 FLOW LENGTH(FEET) = 93.00 MANNING'S N = 0.013
ESTIMATED PIPE DIAMETER(INCH) INCREASED TO 18.000
DEPTH OF FLOW IN 18.0 INCH PIPE IS 5.1 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 4.24
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 1.73
PIPE TRAVEL TIME(MIN.) = 0.37 Tc(MIN.) = 7.95
LONGEST FLOWPATH FROM NODE 162.00 TO NODE 178.00 = 449.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 178.00 TO NODE 178.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.517
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8100
SUBAREA AREA(ACRES) = 0.24 SUBAREA RUNOFF(CFS) = 0.68
TOTAL AREA(ACRES) = 0.8 TOTAL RUNOFF(CFS) = 2.36
TC(MIN.) = 7.95
**************************************************************************** FLOW PROCESS FROM NODE 178.00 TO NODE 178.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.517
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8100
SUBAREA AREA(ACRES) = 0.36 SUBAREA RUNOFF(CFS) = 1.03
TOTAL AREA(ACRES) = 1.2 TOTAL RUNOFF(CFS) = 3.39
TC(MIN.) = 7.95
**************************************************************************** FLOW PROCESS FROM NODE 178.00 TO NODE 178.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.517
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8100
SUBAREA AREA(ACRES) = 0.59 SUBAREA RUNOFF(CFS) = 1.68
TOTAL AREA(ACRES) = 1.8 TOTAL RUNOFF(CFS) = 5.07
TC(MIN.) = 7.95
**************************************************************************** FLOW PROCESS FROM NODE 178.00 TO NODE 199.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.57 FLOW LENGTH(FEET) = 43.00 MANNING'S N = 0.013
ESTIMATED PIPE DIAMETER(INCH) INCREASED TO 18.000
DEPTH OF FLOW IN 18.0 INCH PIPE IS 9.1 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 5.67
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 5.07
PIPE TRAVEL TIME(MIN.) = 0.13 Tc(MIN.) = 8.08
LONGEST FLOWPATH FROM NODE 162.00 TO NODE 199.00 = 492.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 199.00 TO NODE 199.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 3 ARE:

TIME OF CONCENTRATION(MIN.) = 8.08
RAINFALL INTENSITY(INCH/HR) = 3.48
TOTAL STREAM AREA(ACRES) = 1.78
PEAK FLOW RATE(CFS) AT CONFLUENCE = 5.07
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 11.56 7.78 3.567 3.75
2 8.32 6.79 3.894 2.48
3 5.07 8.08 3.481 1.78

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 3 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 23.17 6.79 3.894
2 24.07 7.78 3.567
3 23.79 8.08 3.481
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 24.07 Tc(MIN.) = 7.78
TOTAL AREA(ACRES) = 8.0
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 199.00 = 888.57 FEET. ============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 8.0 TC(MIN.) = 7.78
PEAK FLOW RATE(CFS) = 24.07
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

____________________________________________________________________________ ****************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * SANTEE TOWN CENTER *
* POST-PROJECT CONDITIONS 50-YEAR EVENT, POC 1 *
* JN-20075 *
************************************************************************** FILE NAME: TC100P50.RAT
TIME/DATE OF STUDY: 15:31 09/10/2025
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 50.00
6-HOUR DURATION PRECIPITATION (INCHES) = 2.400
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.90 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

1. Relative Flow-Depth = 0.50 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 336.00
DOWNSTREAM ELEVATION(FEET) = 335.75
ELEVATION DIFFERENCE(FEET) = 0.25
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 4.650
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.323
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.51
TOTAL AREA(ACRES) = 0.10 TOTAL RUNOFF(CFS) = 0.51
**************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 104.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 3 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 335.75 DOWNSTREAM ELEVATION(FEET) = 334.50 STREET LENGTH(FEET) = 145.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 26.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 21.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0180 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.16 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.27
HALFSTREET FLOOD WIDTH(FEET) = 8.16
AVERAGE FLOW VELOCITY(FEET/SEC.) = 1.54
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.41
STREET FLOW TRAVEL TIME(MIN.) = 1.57 Tc(MIN.) = 6.22
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.493
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.810
SUBAREA AREA(ACRES) = 0.29 SUBAREA RUNOFF(CFS) = 1.29
TOTAL AREA(ACRES) = 0.4 PEAK FLOW RATE(CFS) = 1.74
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.30 HALFSTREET FLOOD WIDTH(FEET) = 9.72
FLOW VELOCITY(FEET/SEC.) = 1.68 DEPTH*VELOCITY(FT*FT/SEC.) = 0.50 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 104.00 = 195.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 104.00 TO NODE 104.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.493
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8100
SUBAREA AREA(ACRES) = 0.29 SUBAREA RUNOFF(CFS) = 1.29
TOTAL AREA(ACRES) = 0.7 TOTAL RUNOFF(CFS) = 3.03
TC(MIN.) = 6.22
**************************************************************************** FLOW PROCESS FROM NODE 104.00 TO NODE 110.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 97.65 FLOW LENGTH(FEET) = 235.00 MANNING'S N = 0.013
ESTIMATED PIPE DIAMETER(INCH) INCREASED TO 18.000
DEPTH OF FLOW IN 18.0 INCH PIPE IS 6.8 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 4.94
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 3.03
PIPE TRAVEL TIME(MIN.) = 0.79 Tc(MIN.) = 7.01
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 110.00 = 430.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 110.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.085
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8100
SUBAREA AREA(ACRES) = 0.23 SUBAREA RUNOFF(CFS) = 0.95
TOTAL AREA(ACRES) = 0.9 TOTAL RUNOFF(CFS) = 3.75
TC(MIN.) = 7.01
**************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 110.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.085
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8200
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8135
SUBAREA AREA(ACRES) = 0.50 SUBAREA RUNOFF(CFS) = 2.08
TOTAL AREA(ACRES) = 1.4 TOTAL RUNOFF(CFS) = 5.83
TC(MIN.) = 7.01
**************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 110.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 7.01
RAINFALL INTENSITY(INCH/HR) = 5.08
TOTAL STREAM AREA(ACRES) = 1.41
PEAK FLOW RATE(CFS) AT CONFLUENCE = 5.83
**************************************************************************** FLOW PROCESS FROM NODE 170.00 TO NODE 172.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

SUBAREA RUNOFF(CFS) = 0.40
TOTAL AREA(ACRES) = 0.07 TOTAL RUNOFF(CFS) = 0.40
**************************************************************************** FLOW PROCESS FROM NODE 172.00 TO NODE 174.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 338.20 DOWNSTREAM(FEET) = 334.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 416.47 CHANNEL SLOPE = 0.0101 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 10.00
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.323
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .8700
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 3.37
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.31 AVERAGE FLOW DEPTH(FEET) = 0.13 TRAVEL TIME(MIN.) = 3.01 Tc(MIN.) = 4.67
SUBAREA AREA(ACRES) = 1.08 SUBAREA RUNOFF(CFS) = 5.94
AREA-AVERAGE RUNOFF COEFFICIENT = 0.872
TOTAL AREA(ACRES) = 1.2 PEAK FLOW RATE(CFS) = 6.34
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.18 FLOW VELOCITY(FEET/SEC.) = 2.89
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 174.00 = 466.47 FEET. **************************************************************************** FLOW PROCESS FROM NODE 174.00 TO NODE 110.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 2 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 334.00 DOWNSTREAM ELEVATION(FEET) = 332.20 STREET LENGTH(FEET) = 184.10 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 14.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 9.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0180 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 6.62 ***STREET FLOW SPLITS OVER STREET-CROWN***
FULL DEPTH(FEET) = 0.39 FLOOD WIDTH(FEET) = 14.00
FULL HALF-STREET VELOCITY(FEET/SEC.) = 2.22
SPLIT DEPTH(FEET) = 0.31 SPLIT FLOOD WIDTH(FEET) = 10.17 SPLIT FLOW(CFS) = 2.07 SPLIT VELOCITY(FEET/SEC.) = 1.85 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.39
HALFSTREET FLOOD WIDTH(FEET) = 14.00
AVERAGE FLOW VELOCITY(FEET/SEC.) = 2.22
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.86
STREET FLOW TRAVEL TIME(MIN.) = 1.38 Tc(MIN.) = 6.05
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.590
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.874
SUBAREA AREA(ACRES) = 0.11 SUBAREA RUNOFF(CFS) = 0.55
TOTAL AREA(ACRES) = 1.3 PEAK FLOW RATE(CFS) = 6.34
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.39 HALFSTREET FLOOD WIDTH(FEET) = 14.00 FLOW VELOCITY(FEET/SEC.) = 2.22 DEPTH*VELOCITY(FT*FT/SEC.) = 0.86 LONGEST FLOWPATH FROM NODE 170.00 TO NODE 110.00 = 650.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 110.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.590
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8747
SUBAREA AREA(ACRES) = 0.02 SUBAREA RUNOFF(CFS) = 0.10
TOTAL AREA(ACRES) = 1.3 TOTAL RUNOFF(CFS) = 6.34
TC(MIN.) = 6.05
NOTE: PEAK FLOW RATE DEFAULTED TO UPSTREAM VALUE
**************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 110.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 6.05
RAINFALL INTENSITY(INCH/HR) = 5.59
TOTAL STREAM AREA(ACRES) = 1.28
PEAK FLOW RATE(CFS) AT CONFLUENCE = 6.34
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 5.83 7.01 5.085 1.41
2 6.34 6.05 5.590 1.28

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 11.38 6.05 5.590
2 11.60 7.01 5.085
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 11.60 Tc(MIN.) = 7.01
TOTAL AREA(ACRES) = 2.7
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 110.00 = 650.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 180.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.64 FLOW LENGTH(FEET) = 36.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 13.8 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.90
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 11.60
PIPE TRAVEL TIME(MIN.) = 0.09 Tc(MIN.) = 7.10
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 180.00 = 686.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 180.00 TO NODE 180.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.044
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8451
SUBAREA AREA(ACRES) = 0.12 SUBAREA RUNOFF(CFS) = 0.54
TOTAL AREA(ACRES) = 2.8 TOTAL RUNOFF(CFS) = 11.98
TC(MIN.) = 7.10
**************************************************************************** FLOW PROCESS FROM NODE 180.00 TO NODE 182.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.88 FLOW LENGTH(FEET) = 12.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 14.2 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.95
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 11.98
PIPE TRAVEL TIME(MIN.) = 0.03 Tc(MIN.) = 7.13
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 182.00 = 698.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 182.00 TO NODE 182.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.031
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .7900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8313
SUBAREA AREA(ACRES) = 0.94 SUBAREA RUNOFF(CFS) = 3.74
TOTAL AREA(ACRES) = 3.8 TOTAL RUNOFF(CFS) = 15.68
TC(MIN.) = 7.13
**************************************************************************** FLOW PROCESS FROM NODE 182.00 TO NODE 199.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 98.10 FLOW LENGTH(FEET) = 190.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 15.2 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 7.46
ESTIMATED PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 15.68
PIPE TRAVEL TIME(MIN.) = 0.42 Tc(MIN.) = 7.55
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 199.00 = 888.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 199.00 TO NODE 199.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 7.55
RAINFALL INTENSITY(INCH/HR) = 4.85
TOTAL STREAM AREA(ACRES) = 3.75
PEAK FLOW RATE(CFS) AT CONFLUENCE = 15.68
**************************************************************************** FLOW PROCESS FROM NODE 152.00 TO NODE 154.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 338.00
DOWNSTREAM ELEVATION(FEET) = 337.80
ELEVATION DIFFERENCE(FEET) = 0.20
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.207
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.323
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.40
TOTAL AREA(ACRES) = 0.07 TOTAL RUNOFF(CFS) = 0.40
**************************************************************************** FLOW PROCESS FROM NODE 154.00 TO NODE 160.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 337.80 DOWNSTREAM(FEET) = 331.30 CHANNEL LENGTH THRU SUBAREA(FEET) = 485.57 CHANNEL SLOPE = 0.0134 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 10.00
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.461
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .8700
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 3.79
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.64 AVERAGE FLOW DEPTH(FEET) = 0.12 TRAVEL TIME(MIN.) = 3.07 Tc(MIN.) = 6.28
SUBAREA AREA(ACRES) = 1.40 SUBAREA RUNOFF(CFS) = 6.65
AREA-AVERAGE RUNOFF COEFFICIENT = 0.871
TOTAL AREA(ACRES) = 1.5 PEAK FLOW RATE(CFS) = 7.00
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.18 FLOW VELOCITY(FEET/SEC.) = 3.23
LONGEST FLOWPATH FROM NODE 152.00 TO NODE 160.00 = 535.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 160.00 TO NODE 160.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.461
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8724
SUBAREA AREA(ACRES) = 0.05 SUBAREA RUNOFF(CFS) = 0.25
TOTAL AREA(ACRES) = 1.5 TOTAL RUNOFF(CFS) = 7.24
TC(MIN.) = 6.28
**************************************************************************** FLOW PROCESS FROM NODE 160.00 TO NODE 160.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.461
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8737
SUBAREA AREA(ACRES) = 0.08 SUBAREA RUNOFF(CFS) = 0.39
TOTAL AREA(ACRES) = 1.6 TOTAL RUNOFF(CFS) = 7.63
TC(MIN.) = 6.28
**************************************************************************** FLOW PROCESS FROM NODE 160.00 TO NODE 160.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.461
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8511
SUBAREA AREA(ACRES) = 0.88 SUBAREA RUNOFF(CFS) = 3.89
TOTAL AREA(ACRES) = 2.5 TOTAL RUNOFF(CFS) = 11.53
TC(MIN.) = 6.28
**************************************************************************** FLOW PROCESS FROM NODE 160.00 TO NODE 199.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.53 FLOW LENGTH(FEET) = 47.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 13.8 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.89
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 11.53
PIPE TRAVEL TIME(MIN.) = 0.11 Tc(MIN.) = 6.39
LONGEST FLOWPATH FROM NODE 152.00 TO NODE 199.00 = 582.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 199.00 TO NODE 199.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 6.39
RAINFALL INTENSITY(INCH/HR) = 5.40
TOTAL STREAM AREA(ACRES) = 2.48
PEAK FLOW RATE(CFS) AT CONFLUENCE = 11.53
**************************************************************************** FLOW PROCESS FROM NODE 162.00 TO NODE 164.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 337.00
DOWNSTREAM ELEVATION(FEET) = 336.75
ELEVATION DIFFERENCE(FEET) = 0.25
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 4.650
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.323
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.46
TOTAL AREA(ACRES) = 0.09 TOTAL RUNOFF(CFS) = 0.46
**************************************************************************** FLOW PROCESS FROM NODE 164.00 TO NODE 168.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 3 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 336.75 DOWNSTREAM ELEVATION(FEET) = 333.00 STREET LENGTH(FEET) = 306.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 26.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 21.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0180 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.46 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.27
HALFSTREET FLOOD WIDTH(FEET) = 8.40
AVERAGE FLOW VELOCITY(FEET/SEC.) = 1.85
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.50
STREET FLOW TRAVEL TIME(MIN.) = 2.76 Tc(MIN.) = 7.41
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.905
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.810
SUBAREA AREA(ACRES) = 0.50 SUBAREA RUNOFF(CFS) = 1.99
TOTAL AREA(ACRES) = 0.6 PEAK FLOW RATE(CFS) = 2.34
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.31 HALFSTREET FLOOD WIDTH(FEET) = 10.21 FLOW VELOCITY(FEET/SEC.) = 2.08 DEPTH*VELOCITY(FT*FT/SEC.) = 0.64 LONGEST FLOWPATH FROM NODE 162.00 TO NODE 168.00 = 356.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 168.00 TO NODE 178.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.07 FLOW LENGTH(FEET) = 93.00 MANNING'S N = 0.013
ESTIMATED PIPE DIAMETER(INCH) INCREASED TO 18.000
DEPTH OF FLOW IN 18.0 INCH PIPE IS 5.9 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 4.62
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 2.34
PIPE TRAVEL TIME(MIN.) = 0.34 Tc(MIN.) = 7.75
LONGEST FLOWPATH FROM NODE 162.00 TO NODE 178.00 = 449.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 178.00 TO NODE 178.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.767
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8100
SUBAREA AREA(ACRES) = 0.24 SUBAREA RUNOFF(CFS) = 0.93
TOTAL AREA(ACRES) = 0.8 TOTAL RUNOFF(CFS) = 3.20
TC(MIN.) = 7.75
**************************************************************************** FLOW PROCESS FROM NODE 178.00 TO NODE 178.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.767
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8100
SUBAREA AREA(ACRES) = 0.36 SUBAREA RUNOFF(CFS) = 1.39
TOTAL AREA(ACRES) = 1.2 TOTAL RUNOFF(CFS) = 4.60
TC(MIN.) = 7.75
**************************************************************************** FLOW PROCESS FROM NODE 178.00 TO NODE 178.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.767
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8100
SUBAREA AREA(ACRES) = 0.59 SUBAREA RUNOFF(CFS) = 2.28
TOTAL AREA(ACRES) = 1.8 TOTAL RUNOFF(CFS) = 6.87
TC(MIN.) = 7.75
**************************************************************************** FLOW PROCESS FROM NODE 178.00 TO NODE 199.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.57 FLOW LENGTH(FEET) = 43.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 11.0 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.09
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 6.87
PIPE TRAVEL TIME(MIN.) = 0.12 Tc(MIN.) = 7.87
LONGEST FLOWPATH FROM NODE 162.00 TO NODE 199.00 = 492.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 199.00 TO NODE 199.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 3 ARE:

TIME OF CONCENTRATION(MIN.) = 7.87
RAINFALL INTENSITY(INCH/HR) = 4.72
TOTAL STREAM AREA(ACRES) = 1.78
PEAK FLOW RATE(CFS) AT CONFLUENCE = 6.87
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 15.68 7.55 4.847 3.75
2 11.53 6.39 5.398 2.48
3 6.87 7.87 4.721 1.78

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 3 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 31.19 6.39 5.398
2 32.63 7.55 4.847
3 32.23 7.87 4.721
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 32.63 Tc(MIN.) = 7.55
TOTAL AREA(ACRES) = 8.0
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 199.00 = 888.57 FEET. ============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 8.0 TC(MIN.) = 7.55
PEAK FLOW RATE(CFS) = 32.63
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

____________________________________________________________________________ ****************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * SANTEE TOWN CENTER *
* POST-PROJECT CONDITIONS 100-YEAR EVENT, POC 1 *
* JN-20075 *
************************************************************************** FILE NAME: TC100P00.RAT
TIME/DATE OF STUDY: 15:00 09/10/2025
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 100.00
6-HOUR DURATION PRECIPITATION (INCHES) = 2.500
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.90 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

1. Relative Flow-Depth = 0.50 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 336.00
DOWNSTREAM ELEVATION(FEET) = 335.75
ELEVATION DIFFERENCE(FEET) = 0.25
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 4.650
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.587
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.53
TOTAL AREA(ACRES) = 0.10 TOTAL RUNOFF(CFS) = 0.53
**************************************************************************** FLOW PROCESS FROM NODE 102.00 TO NODE 104.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 3 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 335.75 DOWNSTREAM ELEVATION(FEET) = 334.50 STREET LENGTH(FEET) = 145.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 26.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 21.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0180 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.21 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.27
HALFSTREET FLOOD WIDTH(FEET) = 8.32
AVERAGE FLOW VELOCITY(FEET/SEC.) = 1.55
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.42
STREET FLOW TRAVEL TIME(MIN.) = 1.56 Tc(MIN.) = 6.21
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.728
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.810
SUBAREA AREA(ACRES) = 0.29 SUBAREA RUNOFF(CFS) = 1.35
TOTAL AREA(ACRES) = 0.4 PEAK FLOW RATE(CFS) = 1.81
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.30 HALFSTREET FLOOD WIDTH(FEET) = 9.88
FLOW VELOCITY(FEET/SEC.) = 1.70 DEPTH*VELOCITY(FT*FT/SEC.) = 0.52 LONGEST FLOWPATH FROM NODE 100.00 TO NODE 104.00 = 195.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 104.00 TO NODE 104.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.728
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8100
SUBAREA AREA(ACRES) = 0.29 SUBAREA RUNOFF(CFS) = 1.35
TOTAL AREA(ACRES) = 0.7 TOTAL RUNOFF(CFS) = 3.15
TC(MIN.) = 6.21
**************************************************************************** FLOW PROCESS FROM NODE 104.00 TO NODE 110.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 97.65 FLOW LENGTH(FEET) = 235.00 MANNING'S N = 0.013
ESTIMATED PIPE DIAMETER(INCH) INCREASED TO 18.000
DEPTH OF FLOW IN 18.0 INCH PIPE IS 7.0 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 5.00
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 3.15
PIPE TRAVEL TIME(MIN.) = 0.78 Tc(MIN.) = 6.99
LONGEST FLOWPATH FROM NODE 100.00 TO NODE 110.00 = 430.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 110.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.305
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8100
SUBAREA AREA(ACRES) = 0.23 SUBAREA RUNOFF(CFS) = 0.99
TOTAL AREA(ACRES) = 0.9 TOTAL RUNOFF(CFS) = 3.91
TC(MIN.) = 6.99
**************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 110.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.305
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8200
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8135
SUBAREA AREA(ACRES) = 0.50 SUBAREA RUNOFF(CFS) = 2.18
TOTAL AREA(ACRES) = 1.4 TOTAL RUNOFF(CFS) = 6.09
TC(MIN.) = 6.99
**************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 110.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 6.99
RAINFALL INTENSITY(INCH/HR) = 5.31
TOTAL STREAM AREA(ACRES) = 1.41
PEAK FLOW RATE(CFS) AT CONFLUENCE = 6.09
**************************************************************************** FLOW PROCESS FROM NODE 170.00 TO NODE 172.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 340.00
DOWNSTREAM ELEVATION(FEET) = 338.20
ELEVATION DIFFERENCE(FEET) = 1.80
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 1.661
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.587
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.41
TOTAL AREA(ACRES) = 0.07 TOTAL RUNOFF(CFS) = 0.41
**************************************************************************** FLOW PROCESS FROM NODE 172.00 TO NODE 174.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 338.20 DOWNSTREAM(FEET) = 334.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 416.47 CHANNEL SLOPE = 0.0101 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 10.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.587
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .8700
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 3.51
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.40 AVERAGE FLOW DEPTH(FEET) = 0.13 TRAVEL TIME(MIN.) = 2.89 Tc(MIN.) = 4.55
SUBAREA AREA(ACRES) = 1.08 SUBAREA RUNOFF(CFS) = 6.19
AREA-AVERAGE RUNOFF COEFFICIENT = 0.872
TOTAL AREA(ACRES) = 1.2 PEAK FLOW RATE(CFS) = 6.60
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.19 FLOW VELOCITY(FEET/SEC.) = 2.90
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 174.00 = 466.47 FEET. **************************************************************************** FLOW PROCESS FROM NODE 174.00 TO NODE 110.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 2 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 334.00 DOWNSTREAM ELEVATION(FEET) = 332.20 STREET LENGTH(FEET) = 184.10 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 14.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 9.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0180 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 6.90 ***STREET FLOW SPLITS OVER STREET-CROWN***
FULL DEPTH(FEET) = 0.39 FLOOD WIDTH(FEET) = 14.00
FULL HALF-STREET VELOCITY(FEET/SEC.) = 2.22
SPLIT DEPTH(FEET) = 0.32 SPLIT FLOOD WIDTH(FEET) = 10.73 SPLIT FLOW(CFS) = 2.35 SPLIT VELOCITY(FEET/SEC.) = 1.90 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.39
HALFSTREET FLOOD WIDTH(FEET) = 14.00
AVERAGE FLOW VELOCITY(FEET/SEC.) = 2.22
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.86
STREET FLOW TRAVEL TIME(MIN.) = 1.38 Tc(MIN.) = 5.93
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.899
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.874
SUBAREA AREA(ACRES) = 0.11 SUBAREA RUNOFF(CFS) = 0.58
TOTAL AREA(ACRES) = 1.3 PEAK FLOW RATE(CFS) = 6.60
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.39 HALFSTREET FLOOD WIDTH(FEET) = 14.00 FLOW VELOCITY(FEET/SEC.) = 2.22 DEPTH*VELOCITY(FT*FT/SEC.) = 0.86 LONGEST FLOWPATH FROM NODE 170.00 TO NODE 110.00 = 650.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 110.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.899
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8747
SUBAREA AREA(ACRES) = 0.02 SUBAREA RUNOFF(CFS) = 0.11
TOTAL AREA(ACRES) = 1.3 TOTAL RUNOFF(CFS) = 6.60
TC(MIN.) = 5.93
**************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 110.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 2
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 5.93
RAINFALL INTENSITY(INCH/HR) = 5.90
TOTAL STREAM AREA(ACRES) = 1.28
PEAK FLOW RATE(CFS) AT CONFLUENCE = 6.60
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 6.09 6.99 5.305 1.41
2 6.60 5.93 5.899 1.28

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 2 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 11.77 5.93 5.899
2 12.03 6.99 5.305
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 12.03 Tc(MIN.) = 6.99
TOTAL AREA(ACRES) = 2.7
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 110.00 = 650.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 110.00 TO NODE 180.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.64 FLOW LENGTH(FEET) = 36.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 14.2 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.95
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 12.03
PIPE TRAVEL TIME(MIN.) = 0.09 Tc(MIN.) = 7.08
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 180.00 = 686.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 180.00 TO NODE 180.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.264
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8451
SUBAREA AREA(ACRES) = 0.12 SUBAREA RUNOFF(CFS) = 0.57
TOTAL AREA(ACRES) = 2.8 TOTAL RUNOFF(CFS) = 12.50
TC(MIN.) = 7.08
**************************************************************************** FLOW PROCESS FROM NODE 180.00 TO NODE 182.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.88 FLOW LENGTH(FEET) = 12.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 14.6 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 7.00
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 12.50
PIPE TRAVEL TIME(MIN.) = 0.03 Tc(MIN.) = 7.11
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 182.00 = 698.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 182.00 TO NODE 182.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.250
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .7900
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8313
SUBAREA AREA(ACRES) = 0.94 SUBAREA RUNOFF(CFS) = 3.90
TOTAL AREA(ACRES) = 3.8 TOTAL RUNOFF(CFS) = 16.37
TC(MIN.) = 7.11
**************************************************************************** FLOW PROCESS FROM NODE 182.00 TO NODE 199.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 98.10 FLOW LENGTH(FEET) = 190.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 24.0 INCH PIPE IS 15.7 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 7.53
ESTIMATED PIPE DIAMETER(INCH) = 24.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 16.37
PIPE TRAVEL TIME(MIN.) = 0.42 Tc(MIN.) = 7.53
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 199.00 = 888.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 199.00 TO NODE 199.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 1 ARE:

TIME OF CONCENTRATION(MIN.) = 7.53
RAINFALL INTENSITY(INCH/HR) = 5.06
TOTAL STREAM AREA(ACRES) = 3.75
PEAK FLOW RATE(CFS) AT CONFLUENCE = 16.37
**************************************************************************** FLOW PROCESS FROM NODE 152.00 TO NODE 154.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 338.00
DOWNSTREAM ELEVATION(FEET) = 337.80
ELEVATION DIFFERENCE(FEET) = 0.20
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.207
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.587
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.41
TOTAL AREA(ACRES) = 0.07 TOTAL RUNOFF(CFS) = 0.41
**************************************************************************** FLOW PROCESS FROM NODE 154.00 TO NODE 160.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 337.80 DOWNSTREAM(FEET) = 331.30 CHANNEL LENGTH THRU SUBAREA(FEET) = 485.57 CHANNEL SLOPE = 0.0134 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 10.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.728
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .8700
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 3.94
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.70 AVERAGE FLOW DEPTH(FEET) = 0.13 TRAVEL TIME(MIN.) = 3.00 Tc(MIN.) = 6.21
SUBAREA AREA(ACRES) = 1.40 SUBAREA RUNOFF(CFS) = 6.98
AREA-AVERAGE RUNOFF COEFFICIENT = 0.871
TOTAL AREA(ACRES) = 1.5 PEAK FLOW RATE(CFS) = 7.34
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.18 FLOW VELOCITY(FEET/SEC.) = 3.35
LONGEST FLOWPATH FROM NODE 152.00 TO NODE 160.00 = 535.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 160.00 TO NODE 160.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.728
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8724
SUBAREA AREA(ACRES) = 0.05 SUBAREA RUNOFF(CFS) = 0.26
TOTAL AREA(ACRES) = 1.5 TOTAL RUNOFF(CFS) = 7.60
TC(MIN.) = 6.21
**************************************************************************** FLOW PROCESS FROM NODE 160.00 TO NODE 160.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.728
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8737
SUBAREA AREA(ACRES) = 0.08 SUBAREA RUNOFF(CFS) = 0.41
TOTAL AREA(ACRES) = 1.6 TOTAL RUNOFF(CFS) = 8.01
TC(MIN.) = 6.21
**************************************************************************** FLOW PROCESS FROM NODE 160.00 TO NODE 160.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.728
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8511
SUBAREA AREA(ACRES) = 0.88 SUBAREA RUNOFF(CFS) = 4.08
TOTAL AREA(ACRES) = 2.5 TOTAL RUNOFF(CFS) = 12.09
TC(MIN.) = 6.21
**************************************************************************** FLOW PROCESS FROM NODE 160.00 TO NODE 199.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.53 FLOW LENGTH(FEET) = 47.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 21.0 INCH PIPE IS 14.3 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.95
ESTIMATED PIPE DIAMETER(INCH) = 21.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 12.09
PIPE TRAVEL TIME(MIN.) = 0.11 Tc(MIN.) = 6.32
LONGEST FLOWPATH FROM NODE 152.00 TO NODE 199.00 = 582.57 FEET. **************************************************************************** FLOW PROCESS FROM NODE 199.00 TO NODE 199.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
============================================================================ TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 2 ARE:

TIME OF CONCENTRATION(MIN.) = 6.32
RAINFALL INTENSITY(INCH/HR) = 5.66
TOTAL STREAM AREA(ACRES) = 2.48
PEAK FLOW RATE(CFS) AT CONFLUENCE = 12.09
**************************************************************************** FLOW PROCESS FROM NODE 162.00 TO NODE 164.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 337.00
DOWNSTREAM ELEVATION(FEET) = 336.75
ELEVATION DIFFERENCE(FEET) = 0.25
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 4.650
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.587
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.48
TOTAL AREA(ACRES) = 0.09 TOTAL RUNOFF(CFS) = 0.48
**************************************************************************** FLOW PROCESS FROM NODE 164.00 TO NODE 168.00 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 3 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 336.75 DOWNSTREAM ELEVATION(FEET) = 333.00 STREET LENGTH(FEET) = 306.00 CURB HEIGHT(INCHES) = 6.0
STREET HALFWIDTH(FEET) = 26.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 21.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.020
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.020
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0180 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.53 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.28
HALFSTREET FLOOD WIDTH(FEET) = 8.57
AVERAGE FLOW VELOCITY(FEET/SEC.) = 1.86
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.51
STREET FLOW TRAVEL TIME(MIN.) = 2.74 Tc(MIN.) = 7.39
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.119
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.810
SUBAREA AREA(ACRES) = 0.50 SUBAREA RUNOFF(CFS) = 2.07
TOTAL AREA(ACRES) = 0.6 PEAK FLOW RATE(CFS) = 2.45
END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.31 HALFSTREET FLOOD WIDTH(FEET) = 10.46 FLOW VELOCITY(FEET/SEC.) = 2.07 DEPTH*VELOCITY(FT*FT/SEC.) = 0.65 LONGEST FLOWPATH FROM NODE 162.00 TO NODE 168.00 = 356.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 168.00 TO NODE 178.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.07 FLOW LENGTH(FEET) = 93.00 MANNING'S N = 0.013
ESTIMATED PIPE DIAMETER(INCH) INCREASED TO 18.000
DEPTH OF FLOW IN 18.0 INCH PIPE IS 6.1 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 4.67
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 2.45
PIPE TRAVEL TIME(MIN.) = 0.33 Tc(MIN.) = 7.72
LONGEST FLOWPATH FROM NODE 162.00 TO NODE 178.00 = 449.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 178.00 TO NODE 178.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.976
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8100
SUBAREA AREA(ACRES) = 0.24 SUBAREA RUNOFF(CFS) = 0.97
TOTAL AREA(ACRES) = 0.8 TOTAL RUNOFF(CFS) = 3.35
TC(MIN.) = 7.72
**************************************************************************** FLOW PROCESS FROM NODE 178.00 TO NODE 178.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.976
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8100
SUBAREA AREA(ACRES) = 0.36 SUBAREA RUNOFF(CFS) = 1.45
TOTAL AREA(ACRES) = 1.2 TOTAL RUNOFF(CFS) = 4.80
TC(MIN.) = 7.72
**************************************************************************** FLOW PROCESS FROM NODE 178.00 TO NODE 178.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.976
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8100
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8100
SUBAREA AREA(ACRES) = 0.59 SUBAREA RUNOFF(CFS) = 2.38
TOTAL AREA(ACRES) = 1.8 TOTAL RUNOFF(CFS) = 7.17
TC(MIN.) = 7.72
**************************************************************************** FLOW PROCESS FROM NODE 178.00 TO NODE 199.00 IS CODE = 31 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING COMPUTER-ESTIMATED PIPESIZE (NON-PRESSURE FLOW)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 100.00 DOWNSTREAM(FEET) = 99.57 FLOW LENGTH(FEET) = 43.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 18.0 INCH PIPE IS 11.3 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.15
ESTIMATED PIPE DIAMETER(INCH) = 18.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 7.17
PIPE TRAVEL TIME(MIN.) = 0.12 Tc(MIN.) = 7.84
LONGEST FLOWPATH FROM NODE 162.00 TO NODE 199.00 = 492.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 199.00 TO NODE 199.00 IS CODE = 1 ---------------------------------------------------------------------------- >>>>>DESIGNATE INDEPENDENT STREAM FOR CONFLUENCE<<<<<
>>>>>AND COMPUTE VARIOUS CONFLUENCED STREAM VALUES<<<<< ============================================================================ TOTAL NUMBER OF STREAMS = 3
CONFLUENCE VALUES USED FOR INDEPENDENT STREAM 3 ARE:

TIME OF CONCENTRATION(MIN.) = 7.84
RAINFALL INTENSITY(INCH/HR) = 4.93
TOTAL STREAM AREA(ACRES) = 1.78
PEAK FLOW RATE(CFS) AT CONFLUENCE = 7.17
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 16.37 7.53 5.059 3.75
2 12.09 6.32 5.662 2.48
3 7.17 7.84 4.928 1.78

RAINFALL INTENSITY AND TIME OF CONCENTRATION RATIO
CONFLUENCE FORMULA USED FOR 3 STREAMS.
** PEAK FLOW RATE TABLE **
STREAM RUNOFF Tc INTENSITY
NUMBER (CFS) (MIN.) (INCH/HOUR)
1 32.50 6.32 5.662
2 34.06 7.53 5.059
3 33.64 7.84 4.928
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 34.06 Tc(MIN.) = 7.53
TOTAL AREA(ACRES) = 8.0
LONGEST FLOWPATH FROM NODE 170.00 TO NODE 199.00 = 888.57 FEET. ============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 8.0 TC(MIN.) = 7.53
PEAK FLOW RATE(CFS) = 34.06
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

____________________________________________________________________________ ****************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * SANTEE TOWN CENTER *
* POST-PROJECT CONDITIONS 10-YEAR EVENT, POC 2 *
* JN-20075 *
************************************************************************** FILE NAME: TC200P10.RAT
TIME/DATE OF STUDY: 19:37 09/09/2025
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 10.00
6-HOUR DURATION PRECIPITATION (INCHES) = 1.800
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.90 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

1. Relative Flow-Depth = 0.50 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
*SIZE PIPE WITH A FLOW CAPACITY GREATER THAN
OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.*
**************************************************************************** FLOW PROCESS FROM NODE 200.00 TO NODE 202.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8700
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.13
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.81 AVERAGE FLOW DEPTH(FEET) = 0.06 TRAVEL TIME(MIN.) = 1.57 Tc(MIN.) = 4.77
SUBAREA AREA(ACRES) = 0.38 SUBAREA RUNOFF(CFS) = 1.57
AREA-AVERAGE RUNOFF COEFFICIENT = 0.875
TOTAL AREA(ACRES) = 0.5 PEAK FLOW RATE(CFS) = 1.91
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.08 FLOW VELOCITY(FEET/SEC.) = 2.20
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 299.00 = 220.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 299.00 TO NODE 299.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 10 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.743
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .8500
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8645
SUBAREA AREA(ACRES) = 0.34 SUBAREA RUNOFF(CFS) = 1.37
TOTAL AREA(ACRES) = 0.8 TOTAL RUNOFF(CFS) = 3.28
TC(MIN.) = 4.77
============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 0.8 TC(MIN.) = 4.77
PEAK FLOW RATE(CFS) = 3.28
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

____________________________________________________________________________ ****************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * SANTEE TOWN CENTER *
* POST-PROJECT CONDITIONS 50-YEAR EVENT, POC 2 *
* JN-20075 *
************************************************************************** FILE NAME: TC200P50.RAT
TIME/DATE OF STUDY: 19:40 09/09/2025
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 50.00
6-HOUR DURATION PRECIPITATION (INCHES) = 2.400
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.90 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

1. Relative Flow-Depth = 0.50 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
*SIZE PIPE WITH A FLOW CAPACITY GREATER THAN
OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.*
**************************************************************************** FLOW PROCESS FROM NODE 200.00 TO NODE 202.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 335.10
DOWNSTREAM ELEVATION(FEET) = 335.00
ELEVATION DIFFERENCE(FEET) = 0.10
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.207
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.323
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.46
TOTAL AREA(ACRES) = 0.08 TOTAL RUNOFF(CFS) = 0.46
**************************************************************************** FLOW PROCESS FROM NODE 202.00 TO NODE 299.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 335.00 DOWNSTREAM(FEET) = 333.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 170.00 CHANNEL SLOPE = 0.0118 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.013 MAXIMUM DEPTH(FEET) = 5.00
50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.323
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8700
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.50
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.93 AVERAGE FLOW DEPTH(FEET) = 0.07 TRAVEL TIME(MIN.) = 1.47 Tc(MIN.) = 4.67
SUBAREA AREA(ACRES) = 0.38 SUBAREA RUNOFF(CFS) = 2.09
AREA-AVERAGE RUNOFF COEFFICIENT = 0.875
TOTAL AREA(ACRES) = 0.5 PEAK FLOW RATE(CFS) = 2.55
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.09 FLOW VELOCITY(FEET/SEC.) = 2.42
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 299.00 = 220.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 299.00 TO NODE 299.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 50 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.323
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .8500
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8645
SUBAREA AREA(ACRES) = 0.34 SUBAREA RUNOFF(CFS) = 1.83
TOTAL AREA(ACRES) = 0.8 TOTAL RUNOFF(CFS) = 4.37
TC(MIN.) = 4.67
============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 0.8 TC(MIN.) = 4.67
PEAK FLOW RATE(CFS) = 4.37
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

____________________________________________________________________________ ****************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * SANTEE TOWN CENTER *
* POST-PROJECT CONDITIONS 100-YEAR EVENT, POC 2 *
* JN-20075 *
************************************************************************** FILE NAME: TC200P00.RAT
TIME/DATE OF STUDY: 16:26 08/14/2025
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 100.00
6-HOUR DURATION PRECIPITATION (INCHES) = 2.500
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.90 SAN DIEGO HYDROLOGY MANUAL "C"-VALUES USED FOR RATIONAL METHOD NOTE: USE MODIFIED RATIONAL METHOD PROCEDURES FOR CONFLUENCE ANALYSIS *USER-DEFINED STREET-SECTIONS FOR COUPLED PIPEFLOW AND STREETFLOW MODEL* HALF- CROWN TO STREET-CROSSFALL: CURB GUTTER-GEOMETRIES: MANNING

1. Relative Flow-Depth = 0.50 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
*SIZE PIPE WITH A FLOW CAPACITY GREATER THAN
OR EQUAL TO THE UPSTREAM TRIBUTARY PIPE.*
**************************************************************************** FLOW PROCESS FROM NODE 200.00 TO NODE 202.00 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 50.00
UPSTREAM ELEVATION(FEET) = 335.10
DOWNSTREAM ELEVATION(FEET) = 335.00
ELEVATION DIFFERENCE(FEET) = 0.10
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.207
WARNING: THE MINIMUM OVERLAND FLOW SLOPE, 0.5%, IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.587
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.47
TOTAL AREA(ACRES) = 0.08 TOTAL RUNOFF(CFS) = 0.47
**************************************************************************** FLOW PROCESS FROM NODE 202.00 TO NODE 299.00 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 335.00 DOWNSTREAM(FEET) = 333.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 170.00 CHANNEL SLOPE = 0.0118 CHANNEL BASE(FEET) = 10.00 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.013 MAXIMUM DEPTH(FEET) = 5.00
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.587
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.
*USER SPECIFIED(SUBAREA):

NEIGHBORHOOD COMMERCIAL RUNOFF COEFFICIENT = .8700
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.56
TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.01 AVERAGE FLOW DEPTH(FEET) = 0.07 TRAVEL TIME(MIN.) = 1.41 Tc(MIN.) = 4.61
SUBAREA AREA(ACRES) = 0.38 SUBAREA RUNOFF(CFS) = 2.18
AREA-AVERAGE RUNOFF COEFFICIENT = 0.875
TOTAL AREA(ACRES) = 0.5 PEAK FLOW RATE(CFS) = 2.65
END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.10 FLOW VELOCITY(FEET/SEC.) = 2.47
LONGEST FLOWPATH FROM NODE 200.00 TO NODE 299.00 = 220.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 299.00 TO NODE 299.00 IS CODE = 81 ---------------------------------------------------------------------------- >>>>>ADDITION OF SUBAREA TO MAINLINE PEAK FLOW<<<<<
============================================================================ 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.587
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.
*USER SPECIFIED(SUBAREA):

GENERAL INDUSTRIAL RUNOFF COEFFICIENT = .8500
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.8645
SUBAREA AREA(ACRES) = 0.34 SUBAREA RUNOFF(CFS) = 1.90
TOTAL AREA(ACRES) = 0.8 TOTAL RUNOFF(CFS) = 4.56
TC(MIN.) = 4.61
============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 0.8 TC(MIN.) = 4.61
PEAK FLOW RATE(CFS) = 4.56
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

APPENDIX C
Backup for Weighted Runoff Coefficients
Santee Town Center Project
J-20075
9/10/2025
Runoff Coefficient Back-up Pre-Project
100 102 3652 3652 100% 0% 0.35
102 105 84147 84147 100% 0% 0.35
105 105 2661 0 0% 100% 0.90
110 112 3258 0 0% 100% 0.90
112 120 60734 6073 10% 90% 0.85
120 120 3512 0 0% 100% 0.90
130 132 3145 0 0% 100% 0.90
132 140 46012 2301 5% 95% 0.87
135 137 3273 3273 100% 0% 0.35
137 140 83628 81955 98% 2% 0.36
140 144 3274.6 0 0% 100% 0.90
144 144 1266.1 0 0% 100% 0.90
146 146 5349.4 0 0% 100% 0.90
150 150 40885.6 8177 20% 80% 0.79
200 202 3349.2 0 0% 100% 0.90
202 299 20410.8 4082 20% 80% 0.79
299 299 15674 1567 10% 90% 0.85
Notes:
%
Pervious
% Impervious
Weighted
Runoff
Coefficient

1. The runoff coefficients for each land use are based on guidance provided in Table 3-1 of the San Diego County Hydrology Manual (June 2003) and are modeled based on type 'D' soils.

U/S Node D/S Node Area (SF) Pervious Area
(SF)
Land Use
Runoff Coefficient for 'D' Soils1

0.35 Pervious Impervious

0.9 Santee Town Center Project
J-20075
9/10/2025
Runoff Coefficient Back-up Post-Project
100 102 4435 754 17% 83% 0.81
102 104 12556 2135 17% 83% 0.81
104 104 12838 2182 17% 83% 0.81
110 110 10170 1729 17% 83% 0.81
110 110 21653 3681 17% 83% 0.81
170 172 3145 0 0% 100% 0.90
172 174 47154 2358 5% 95% 0.87
174 110 4818 0 0% 100% 0.90
110 110 941 0 0% 100% 0.90
180 180 5349 0 0% 100% 0.90
182 182 40886 8177 20% 80% 0.79
152 154 3258.0 0 0% 100% 0.90
154 160 60798 3040 5% 95% 0.87
160 160 3512.0 0 0% 100% 0.90
160 160 1997.0 0 0% 100% 0.90
160 160 38464.0 6539 17% 83% 0.81
162 164 3763 640 17% 83% 0.81
164 168 21904.0 3724 17% 83% 0.81
180 180 10425.0 1772 17% 83% 0.81
180 180 15871.0 2698 17% 83% 0.81
180 180 25604.0 4353 17% 83% 0.81
200 202 2631.9 0 0% 100% 0.90
202 299 16632 832 5% 95% 0.87
299 299 14882 1488 10% 90% 0.85
Notes:
%
Pervious % Impervious
Weighted
Runoff
Coefficient

1. The runoff coefficients for each land use are based on guidance provided in Table 3-1 of the San Diego County Hydrology Manual (June 2003) and are modeled based on type 'D' soils.

U/S Node D/S Node Area (SF) Pervious Area
(SF)
Land Use
Pervious Impervious
Runoff Coefficient for 'D' Soils1

0.35 0.9
Hydrologic Soil Group—San Diego County Area, California Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
3/6/2025

Page 1 of 4 ends

3633450 3633500 3633550 3633600 3633650 3633700 3633750 3633450 3633500 3633550 3633600 3633650 3633700 3633750 500670 500720 500770 500820 500870 500920 500970 501020 501070 501120 500670 500720 500770 500820 500870 500920 500970 501020 501070 501120 32° 50' 30'' N
116° 59' 34'' W
32° 50' 30'' N
116° 59' 16'' W
32° 50' 20'' N
116° 59' 34'' W
32° 50' 20'' N
116° 59' 16'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 11N WGS84 0 100 200 400 600
Feet
0 30 60 120 180
Meters
Map Scale: 1:2,190 if printed on A landscape (11" x 8.5") sheet.

Soil Map may not be valid at this scale.

MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.

Warning: Soil Map may not be valid at this scale.

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Please rely on the bar scale on each map sheet for map
measurements.

Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: San Diego County Area, California
Survey Area Data: Version 20, Aug 30, 2024
Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Mar 24, 2022—Apr 29, 2022
The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Hydrologic Soil Group—San Diego County Area, California Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
3/6/2025

Page 2 of 4 ends

Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI GoA Grangeville fine sandy
loam, 0 to 2 percent
slopes
B 15.4 91.6%
PfC Placentia sandy loam,
thick surface, 2 to 9
percent slo pes
D 1.4 8.4%
Totals for Area of Interest 16.8 100.0%
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms.

The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows:

Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission.

Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture.

These soils have a moderate rate of water transmission.

Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission.

Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission.

If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes.

Hydrologic Soil Group—San Diego County Area, California Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
3/6/2025

Page 3 of 4 ends

Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Hydrologic Soil Group—San Diego County Area, California Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
3/6/2025

Page 4 of 4 ends

10 year, 50 year, 100 year – 6 hour Isopluvials

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$."(*-3 *4(%1-+"(*
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:%"++$*2$%1"&&"(*(4

9"&2%(')0+1-,0(*+-"*"*4(%1-+"(*:9"099-&;$$*%$2%(')0$':"+9 2$%1"&&"(*.%-*+$';,9(1-&%(+9$%&!-2&

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APPENDIX D
Inlet Sizing Calculations
These calculations will be provided with a future submittal.

APPENDIX E
Storm Drain Sizing Calculations
Santee Town Center
J-2007509/18/2025
Manning's n: 0.013
Sizing Factor (%): 30
Slope at:

Node ID
(Post-Project)
Q100
(cfs1)
Q100 with Sizing
Factor
(cfs1)
Minimum Pipe
Size2
(feet)
Recommended
Pipe Size
(inches)
Minimum Pipe
Size2
(feet)
Recommended
Pipe Size
(inches)
Node 104 - 110 3.2 4.2 1.21 18" 1.06 18"Node 110 - 110 2.0 2.6 1.01 12" 0.88 12"Node 178 - 178 1.0 1.3 0.78 10" 0.68 10"Node 178 - 178 1.5 1.9 0.90 12" 0.79 10"Node 178 - 178 2.4 3.1 1.08 18" 0.95 12"Node 178 - 199 7.2 9.3 1.63 24" 1.43 18"

0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3"0.0 0.00 3" 0.00 3" Note:1. "cfs" = cubic feet per second.2. Minimum pipe sizes are calculated using the Manning's equation and are based on the flow rates with 30% factor.

Preliminary Storm Drain Size
The purpose of this table is to provide an estimated pipe size to convey the 100-year flow rates with a sizing factor.

0.5% 1.0%
C:\RICK\Projects\C20000\20075_TownCenterMF\WaterRes\Hydraulics\20075_Hydraulics_Storm_Drain_Sizing.xls

APPENDIX F
Hydraulic Capacity Calculations
______________________________________________________________________________ ******************************************************************************

PIPE-FLOW HYDRAULICS COMPUTER PROGRAM PACKAGE
(Reference: LACFCD,LACRD, AND OCEMA HYDRAULICS CRITERION) (c) Copyright 1982-2014 Advanced Engineering Software (aes) Ver. 21.0 Release Date: 06/01/2014 License ID 1261
Analysis prepared by:

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * J-20075, THE EXCHANGE AT SANTEE TOWN CENTER *
* MAIN SD CAPACITY RUN, 100-YEAR STORM EVENT *
* EXISTING FLOW RATE *
************************************************************************** FILE NAME: 130E.PIP
TIME/DATE OF STUDY: 08:37 09/11/2025
______________________________________________________________________________ ******************************************************************************

GRADUALLY VARIED FLOW ANALYSIS FOR PIPE SYSTEM

NODAL POINT STATUS TABLE
(Note: "*" indicates nodal point data used.)

UPSTREAM RUN DOWNSTREAM RUN
NODE MODEL PRESSURE PRESSURE+ FLOW PRESSURE+

NUMBER PROCESS HEAD(FT) MOMENTUM(POUNDS) DEPTH(FT) MOMENTUM(POUNDS) 130.00- 3.76* 1316.57 1.90 Dc 722.33
} FRICTION
120.00- 4.44* 1616.31 1.90 Dc 722.33
} CATCH BASIN
120.00- 4.04* 1122.32 1.90 Dc 242.91
------------------------------------------------------------------------------ MAXIMUM NUMBER OF ENERGY BALANCES USED IN EACH PROFILE = 25 ------------------------------------------------------------------------------ NOTE: STEADY FLOW HYDRAULIC HEAD-LOSS COMPUTATIONS BASED ON THE MOST

CONSERVATIVE FORMULAE FROM THE CURRENT LACRD,LACFCD, AND OCEMA DESIGN MANUALS.
****************************************************************************** DOWNSTREAM PIPE FLOW CONTROL DATA:

NODE NUMBER = 130.00 FLOWLINE ELEVATION = 325.61
PIPE FLOW = 34.15 CFS PIPE DIAMETER = 36.00 INCHES
ASSUMED DOWNSTREAM CONTROL HGL = 329.370 FEET
------------------------------------------------------------------------------ NODE 130.00 : HGL = < 329.370>;EGL= < 329.732>;FLOWLINE= < 325.610> ****************************************************************************** FLOW PROCESS FROM NODE 130.00 TO NODE 120.00 IS CODE = 1 UPSTREAM NODE 120.00 ELEVATION = 325.61 (FLOW IS UNDER PRESSURE) ------------------------------------------------------------------------------ CALCULATE FRICTION LOSSES(LACFCD):

PIPE FLOW = 34.15 CFS PIPE DIAMETER = 36.00 INCHES
PIPE LENGTH = 269.51 FEET MANNING'S N = 0.01300
*WARNING -- PIPE INVERT SLOPE IS LESS THAN .0001, AND DEFAULTED TO .0001 SF=(Q/K)**2 = (( 34.15)/( 680.084))**2 = 0.00252
HF=L*SF = ( 269.51)*(0.00252) = 0.680
------------------------------------------------------------------------------ NODE 120.00 : HGL = < 330.050>;EGL= < 330.412>;FLOWLINE= < 325.610> ****************************************************************************** FLOW PROCESS FROM NODE 120.00 TO NODE 120.00 IS CODE = 8 UPSTREAM NODE 120.00 ELEVATION = 326.44 (FLOW IS UNDER PRESSURE) ------------------------------------------------------------------------------ CALCULATE CATCH BASIN ENTRANCE LOSSES(LACFCD):

PIPE FLOW = 34.15 CFS PIPE DIAMETER = 36.00 INCHES
FLOW VELOCITY = 4.83 FEET/SEC. VELOCITY HEAD = 0.363 FEET CATCH BASIN ENERGY LOSS = .2*(VELOCITY HEAD) = .2*( 0.363) = 0.073 ------------------------------------------------------------------------------ NODE 120.00 : HGL = < 330.484>;EGL= < 330.484>;FLOWLINE= < 326.440> ****************************************************************************** UPSTREAM PIPE FLOW CONTROL DATA:

NODE NUMBER = 120.00 FLOWLINE ELEVATION = 326.44
ASSUMED UPSTREAM CONTROL HGL = 328.34 FOR DOWNSTREAM RUN ANALYSIS ==============================================================================

END OF GRADUALLY VARIED FLOW ANALYSIS

______________________________________________________________________________ ******************************************************************************

RICK ENGINEERING COMPANY
5620 Friars Road
San Diego, California 92110
619-291-0707 Fax 619-291-4165
************************** DESCRIPTION OF STUDY ************************** * J-20075, THE EXCHANGE AT SANTEE TOWN CENTER *
* MAIN SD CAPACITY RUN, 100-YEAR STORM EVENT *
* PROPOSED FLOW RATE *
************************************************************************** FILE NAME: 130P.PIP
TIME/DATE OF STUDY: 08:31 09/11/2025
______________________________________________________________________________ ******************************************************************************

GRADUALLY VARIED FLOW ANALYSIS FOR PIPE SYSTEM

NODAL POINT STATUS TABLE
(Note: "*" indicates nodal point data used.)

UPSTREAM RUN DOWNSTREAM RUN
NODE MODEL PRESSURE PRESSURE+ FLOW PRESSURE+

NUMBER PROCESS HEAD(FT) MOMENTUM(POUNDS) DEPTH(FT) MOMENTUM(POUNDS) 130.00- 3.76* 1314.89 1.90 Dc 719.80
} FRICTION
120.00- 4.44* 1612.99 1.90 Dc 719.80
} CATCH BASIN
120.00- 4.04* 1119.67 1.90 Dc 242.15
------------------------------------------------------------------------------ MAXIMUM NUMBER OF ENERGY BALANCES USED IN EACH PROFILE = 25 ------------------------------------------------------------------------------ NOTE: STEADY FLOW HYDRAULIC HEAD-LOSS COMPUTATIONS BASED ON THE MOST

CONSERVATIVE FORMULAE FROM THE CURRENT LACRD,LACFCD, AND OCEMA DESIGN MANUALS.
****************************************************************************** DOWNSTREAM PIPE FLOW CONTROL DATA:

NODE NUMBER = 130.00 FLOWLINE ELEVATION = 325.61
PIPE FLOW = 34.06 CFS PIPE DIAMETER = 36.00 INCHES
ASSUMED DOWNSTREAM CONTROL HGL = 329.370 FEET
------------------------------------------------------------------------------ NODE 130.00 : HGL = < 329.370>;EGL= < 329.731>;FLOWLINE= < 325.610> ****************************************************************************** FLOW PROCESS FROM NODE 130.00 TO NODE 120.00 IS CODE = 1 UPSTREAM NODE 120.00 ELEVATION = 325.61 (FLOW IS UNDER PRESSURE) ------------------------------------------------------------------------------ CALCULATE FRICTION LOSSES(LACFCD):

PIPE FLOW = 34.06 CFS PIPE DIAMETER = 36.00 INCHES
PIPE LENGTH = 269.51 FEET MANNING'S N = 0.01300
*WARNING -- PIPE INVERT SLOPE IS LESS THAN .0001, AND DEFAULTED TO .0001 SF=(Q/K)**2 = (( 34.06)/( 680.157))**2 = 0.00251
HF=L*SF = ( 269.51)*(0.00251) = 0.676
------------------------------------------------------------------------------ NODE 120.00 : HGL = < 330.046>;EGL= < 330.406>;FLOWLINE= < 325.610> ****************************************************************************** FLOW PROCESS FROM NODE 120.00 TO NODE 120.00 IS CODE = 8 UPSTREAM NODE 120.00 ELEVATION = 326.44 (FLOW IS UNDER PRESSURE) ------------------------------------------------------------------------------ CALCULATE CATCH BASIN ENTRANCE LOSSES(LACFCD):

PIPE FLOW = 34.06 CFS PIPE DIAMETER = 36.00 INCHES
FLOW VELOCITY = 4.82 FEET/SEC. VELOCITY HEAD = 0.361 FEET CATCH BASIN ENERGY LOSS = .2*(VELOCITY HEAD) = .2*( 0.361) = 0.072 ------------------------------------------------------------------------------ NODE 120.00 : HGL = < 330.478>;EGL= < 330.478>;FLOWLINE= < 326.440> ****************************************************************************** UPSTREAM PIPE FLOW CONTROL DATA:

NODE NUMBER = 120.00 FLOWLINE ELEVATION = 326.44
ASSUMED UPSTREAM CONTROL HGL = 328.34 FOR DOWNSTREAM RUN ANALYSIS ==============================================================================

END OF GRADUALLY VARIED FLOW ANALYSIS

MAP POCKET 1
Drainage Study Map
for
The Exchange at Santee Town Center
[Pre-Project]
335.7
336.3
336.1
336.3
334.4
329.7
334.5 335.5
336.4
5 6
9 333.111
333.877
335.19
333.6
333.6
335.1
334.9
334.5 334.0
334.3
336.8
X329.0
X329.5
X
X329.9
330
330
330
X330.5
X330.7
X330.7
X330.8
X331.1
X331.3
X331.3
X331.3
X331.4
X
X331.5
X331.5
X331.5
X331.7
IRR
X331.8
X331.8
X
X
IRR
X
X
X332.1
X
X332.2
X
X
X
X
X332.3
X332.3
X
IRR
IRR
X
X
X
X
X
X332.8
X
X
X332.9
X332.9
CB
X
X332.9
X
X333.1
X
E
X
X333.2
X
X
X
X333.2
X
X333.3
IRR
X333.3
X
X
X333.3
X333.4
IRR
X
X
IRR
X333.5
X333.5
X333.6
X
X
E
X
IRR
X
IRR
X
X
X333.6
ERX
X
PBX
X333.7
X
SC
X
PBX
X
X
X
X
X
X333.9
E
X
X
X
IRR
X
X
X333.9
X
E
X
E
X
X
X334.0
IRR
X
X
TLRX
EVX
X334.1
E
X
X X
X
X334.2
X X X
X
X
X334.4
X
X
X
X334.4
X
X
X
X
X
X
X334.5
X
X
X
EV
X
X
X
X334.6
X334.6
X334.6
X
X
X334.7
X
X
X
X334.7
X334.8
X
X
X334.9
X
X X
XX
X
X
335
335
335
3 3
5 335
335
3 3
5 335
3 3
5 3
3 5
3 3
5 X
X335.1
X
X
X335.1
X
X
X335.1
X
X335.2
X
X
X
X335.2
X
X
X335.3
X
X
X
X335.4
X
X335.4
X335.4
X335.4
X
X
X
X
X335.5
X335.5
X335.6
X
X335.6
X335.6
X
X335.7
X
X335.7
X335.7
X335.8
X335.8
X
X
X
X
X
X336.2
X336.3
X
X336.3
X
X
XX
X
X
X336.3
X
X
X336.4
X336.4
X336.4
X336.5
X
X336.5
X
X336.6
X336.6
X336.7
X336.7
X336.8
X
X336.9
X
X
X337.1
X337.2
X337.2
X337.2
X337.2
X337.2
X337.2
X337.3
X337.3
X337.4
X337.4
X337.4
X337.4
X337.7
X337.7
X337.7
X
X337.9
X337.9
X338.1
X
X338.6
X
11-SEP-2025 14:08
C:\RICK\Projects\C20000\20075_TownCenterMF\WaterRes\SD CorpStds 2005.dscript C:\RICK\Projects\C20000\20075_TownCenterMF\WaterRes\20075_drn_pre01.dgn c 2021 Rick
Engineering Com
pany

NOT FOR CONSTRUCTION - EXHIBIT FOR DRAINAGE STUDY ONLY
LEGEND:

XXX
X.X AC

SUB BASIN BOUNDARY

BASIN BOUNDARY

BASIN ID

SUB BASIN AREA

NODE NUMBER

FLOW DIRECTION
POC

BASIN X
(PRE-PROJECT)

SANTEE TOWN CENTER

THE EXCHANGE AT
FOR

DRAINAGE STUDY MAP
110
112
120
100
105
102
150
144
146
140
200
202
130
132
BASIN 100
BASIN 200

GRASS SWALE

EXISTING

GRASS SWALE

EXISTING

0.08 AC

1.39 AC

0.08 AC

1.93 AC

0.06 AC

0.07 AC

1.06 AC

0.08 AC

1.92 AC

0.08 AC

0.03 AC

0.12 AC

0.94 AC

0.08 AC

0.47 AC

0.36 AC

7.92 AC
135
137
BASIN 200 - NODE 299
Q100 = 4.94 cfs
Tc = 5.0 min
A= 0.90 ac

PRE-PROJECT
POC 1 - BASIN 100 - NODE 199
Q100 = 27.58 cfs
Tc = 6.35 min
A= 7.92 ac

PRE-PROJECT
0 GRAPHIC SCALE 1" = 40'
40 20 40 80 120
CBX
X
X
X
X X
X
X
5620 FRIARS ROAD
SAN DIEGO, CA 92110
619-291-0707
rickengineering.com

SANTA CLARITA PHOENIX TUCSON LAS VEGAS DENVER
SAN DIEGO ORANGE RIVERSIDE SACRAMENTO SAN LUIS OBISPO J-20075 September 18, 2025 MAP POCKET 2
Drainage Study Map
for
The Exchange at Santee Town Center
[Post-Project]
336.4
5 6
333.111
333.877
333.6
333.6
335.1
334.9
334.5 334.0
334.3
336.8
X329.5
X329.9
330
X330.5
X330.7
X330.7
X330.8
X331.1
X331.3
X331.3
X331.3
X331.4
X331.5
X331.5
X331.5
X331.7
X331.8
X331.8
X332.1
X332.2
X332.3
X332.3
X
X332.8
X
X332.9
X332.9
CB
X
X332.9
X
X333.2
X333.3
X333.3
X333.4
X333.5
X333.5
X333.6
X
X333.6
X
X333.7
X
X333.9
X333.9
X
X334.0
X334.1
X334.2
X
X334.4
X
X334.4
X334.5
X
X334.6
X334.6
X334.6
X334.7
X
X
335
335
3 3
5 3
3 5
3 3
5 X335.1
X335.1
X
X335.4
X335.4
X335.8
X336.3
X
X336.8
X
X
X337.2 X337.4 X337.2
11-SEP-2025 14:55
C:\RICK\Projects\C20000\20075_TownCenterMF\WaterRes\SD CorpStds 2005.dscript C:\RICK\Projects\C20000\20075_TownCenterMF\WaterRes\20075_drn_post01.dgn c 2021 Rick
Engineering Com
pany

NOT FOR CONSTRUCTION - EXHIBIT FOR DRAINAGE STUDY ONLY
LEGEND:

XXX
X.X AC

SUB BASIN BOUNDARY

BASIN BOUNDARY

BASIN ID

SUB BASIN AREA

NODE NUMBER

FLOW DIRECTION
POC

BASIN X
(POST-PROJECT)

SANTEE TOWN CENTER

THE EXCHANGE AT
FOR

DRAINAGE STUDY MAP
0 GRAPHIC SCALE 1" = 40'
40 20 40 80 120
100
102
104
152
154
160
170
172
174
180
182
BASIN 200
202
200
BASIN 200 - NODE 299
POC 2
BASIN 100 - NODE 199
POC 1

0.07 AC

0.08 AC

0.07 AC

0.34 AC

0.38 AC
Q100 = 4.94 cfs
Tc = 5.0 min
A= 0.90 ac

PRE-PROJECT
Q100 = 4.56 cfs
Tc = 5.0 min
A= 0.80 ac

POST-PROJECT

0.10 AC

0.29 AC

0.50 AC

0.13 AC

0.50 AC

0.88 AC
110

0.11 AC 1.08 AC

0.12 AC

0.94 AC 0.02 AC

0.05 AC

0.08 AC

1.40 AC
162
164
168
178

0.24 AC

0.36 AC

0.59 AC
Q100 = 34.06 cfs
Tc = 7.53 min
A= 8.0 ac

POST-PROJECT
Q100 = 27.58 cfs
Tc = 6.35 min
A= 7.9 ac

PRE-PROJECT

0.09 AC
4:
4 1
:1
4:1
4:1
D9-A4
D9-A4
8-8
8-8
4-13
4-13
D9-A4
D9-A4
4-6
4-6
4-8
4-8
4-8
CBX
X
X
X
X X
X
X
533
533
335
335
335
335
335 335
335
335
335
335
335
335
335
335
335 335
335
335
335
5620 FRIARS ROAD
SAN DIEGO, CA 92110
619-291-0707
rickengineering.com

SANTA CLARITA PHOENIX TUCSON LAS VEGAS DENVER
SAN DIEGO ORANGE RIVERSIDE SACRAMENTO SAN LUIS OBISPO J-20075 September 18, 2025 NOTES
DISCHARGE. THEREFORE, DETENTION IS NOT NECESSARY.

LOWER THAN THE MASTER DRAINAGE STUDY PEAK
POST-PROJECT PEAK DISCHARGE IS 34.06 CFS WHICH IS
FROM THE SITE (34.15 CFS). THE CALCULATED

ASSUMED UTELITY BUILD OUT CONDITION FLOW RATES
JULY 2023. THE SANTEE MASTER DRAINAGE STUDY USED

CAPACITY PER THE SANTEE MASTER DRAINAGE STUDY,

THE DOWNSTREAM SYSTEM DEMONSTRATES SUFFICIENT
DISCHARGE TO POC-1 IN POST-PROJECT CONDITIONS,

1. ALTHOUGH THERE IS AN INCREASE IN PEAK
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003

CITY OF SANTEE

PRIORITY DEVELOPMENT PROJECT (PDP)

STORM WATER QUALITY MANAGEMENT PLAN (SWQMP)
FOR

THE EXCHANGE AT SANTEE TOWN CENTER
TM-2025-0003
Town Center Parkway
Santee, CA 92071
ASSESSOR'S PARCEL NUMBER(S):
381-040-36-00
ENGINEER OF WORK:

Shavger Rekani PE
___________________________________________________________________________________ Shavger Rekani PE 90893, 3/26
PREPARED FOR:

Borstein Enterprises
11766 Wilshire Boulevard, Suite 820
Los Angeles, California 90025
PDP SWQMP PREPARED BY:

RICK
5620 Friars Rd, San Diego, CA 92110
(619) 291-0707
PLANS PREPARED BY:

RICK
5620 Friars Rd, San Diego, CA 92110
(619) 291-0707
DATE OF SWQMP:

March 7, 2025
Revised May 30, 2025
Revised September 18, 2025
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Page intentionally blank
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003

TABLE OF CONTENTS
Acronym Sheet
PDP SWQMP Preparer's Certification Page
PDP SWQMP Project Owner's Certification Page
Submittal Record
Project Vicinity Map
FORM I-1 Applicability of Permanent, Post-Construction Storm Water BMP Requirements FORM I-2 Project Type Determination Checklist (Standard Project or PDP) FORM I-3B Site Information Checklist for PDPs
FORM I-4 Source Control BMP Checklist for All Development Projects FORM I-5 Site Design BMP Checklist for All Development Projects FORM I-6 Summary of PDP Structural BMPs
Attachment 1: Backup for PDP Pollutant Control BMPs
Attachment 1a: DMA Exhibit
Attachment 1b: Tabular Summary of DMAs and Design Capture Volume Calculations Attachment 1c: Harvest and Use Feasibility Screening (when applicable) Attachment 1d: Categorization of Infiltration Feasibility Condition (when applicable) Attachment 1e: Pollutant Control BMP Design Worksheets / Calculations Attachment 2: Backup for PDP Hydromodification Control Measures Attachment 2a: Hydromodification Management Exhibit
Attachment 2b: Management of Critical Coarse Sediment Yield Areas Attachment 2c: Geomorphic Assessment of Receiving Channels Attachment 2d: Flow Control Facility Design
Attachment 3: Structural BMP Maintenance Plan
Attachment 3a: B Structural BMP Maintenance Thresholds and Actions Attachment 3b: Draft Maintenance Agreement (when applicable) Attachment 4: Copy of Plan Sheets Showing Permanent Storm Water BMPs PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003

ACRONYMS
APN Assessor's Parcel Number
BMP Best Management Practice
HMP Hydromodification Management Plan
HSG Hydrologic Soil Group
MS4 Municipal Separate Storm Sewer System
N/A Not Applicable
NRCS Natural Resources Conservation Service
PDP Priority Development Project
PE Professional Engineer
SC Source Control
SD Site Design
SDRWQCB San Diego Regional Water Quality Control Board
SIC Standard Industrial Classification
SWQMP Storm Water Quality Management Plan
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003

SWQMP PREPARER'S

CERTIFICATION PAGE
Project Name: THE EXCHANGE AT SANTEE TOWN CENTER
Permit Application Number: TM-2025-0002

PREPARER'S CERTIFICATION
I hereby declare that I am the Engineer in Responsible Charge of design of storm water best management practices (BMPs) for this project, and that I have exercised responsible charge over the design of the BMPs as defined in Section 6703 of the Business and Professions Code, and that the design is consistent with the PDP requirements of the City of Santee BMP Design Manual, which is a design manual for compliance with local City of Santee and regional MS4 Permit (California Regional Water Quality Control Board San Diego Region Order No. R9-2015-0100) requirements for storm water management.

I have read and understand that the [City Engineer] has adopted minimum requirements for managing urban runoff, including storm water, from land development activities, as described in the BMP Design Manual. I certify that this PDP SWQMP has been completed to the best of my ability and accurately reflects the project being proposed and the applicable BMPs proposed to minimize the potentially negative impacts of this project's land development activities on water quality. I understand and acknowledge that the plan check review of this PDP SWQMP by the [City Engineer] is confined to a review and does not relieve me, as the Engineer in Responsible Charge of design of storm water BMPs for this project, of my responsibilities for project design.
________________________________________________________ Engineer of Work's Signature, PE Number & Expiration Date Shavger Rekani, PE# 90893, Exp. 3/26
________________________________________________________ Print Name
RICK______________________________
Company
9/18/2025
Date
Engineer's Seal:

PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Page intentionally blank
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003

SWQMP PROJECT OWNER'S

CERTIFICATION PAGE
Project Name: THE EXCHANGE AT SANTEE TOWN CENTER
Permit Application Number: TM-2025-0003

PROJECT OWNER'S CERTIFICATION
This PDP SWQMP has been prepared for Borstein Enterprises by RICK. The PDP SWQMP is intended to comply with the PDP requirements of the City of Santee BMP Design Manual, which is a design manual for compliance with local City of Santee and regional MS4 Permit (California Regional Water Quality Control Board San Diego Region Order No. R9-2015-0100) requirements for storm water management.

The undersigned, while it owns the subject property, is responsible for the implementation of the provisions of this plan. Once the undersigned transfers its interests in the property, its successor-ininterest shall bear the aforementioned responsibility to implement the best management practices (BMPs) described within this plan, including ensuring on-going operation and maintenance of structural BMPs. A signed copy of this document shall be available on the subject property into perpetuity. _______________________________________________________ Project Owner's Signature
________________________________________________________ Print Name
Borstein Enterprises
________________________________________________________ Company
9/18/2025
____________________________
Date
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Page intentionally blank
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003

SUBMITTAL RECORD
Use this Table to keep a record of submittals of this PDP SWQMP. Each time the PDP SWQMP is resubmitted, provide the date and status of the project. In column 4 summarize the changes that have been made or indicate if response to plancheck comments is included. When applicable, insert response to plancheck comments behind this page.

Submittal
Number
Date Project Status Summary of Changes
1 3/7/2025  Preliminary Design /
Planning/ CEQA
 Final Design
Initial Submittal
2 5/30/2025  Preliminary Design /
Planning/ CEQA
 Final Design
Refer to Response to City Comments
3 9/18/2025  Preliminary Design /
Planning/ CEQA
 Final Design
2 nd report revisions addressing City
comments. Removal of detention
vault.
 Preliminary Design /
Planning/ CEQA
 Final Design
 Preliminary Design /
Planning/ CEQA
 Final Design
X
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Page intentionally blank
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003

PROJECT VICINITY MAP
Project Name: THE EXCHANGE AT SANTEE TOWN CENTER
Permit Application Number: TM-2025-0003
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Applicability of Permanent, Post-Construction
Storm Water BMP Requirements
(Storm Water Intake Form for all Development Permit Applications) Form I-1
Model BMP Design
Manual
[August 31, 2015]
Project Identification
Project Name: THE EXCHANGE AT SANTEE TOWN CENTER
Permit Application Number: TM-2025-0003 Date: 9/18/2025 Project Address:

Town Center Parkway, Santee, CA 92071
Determination of Requirements
The purpose of this form is to identify permanent, post-construction requirements that apply to the project. This form serves as a short summary of applicable requirements, in some cases referencing separate forms that will serve as the backup for the determination of requirements.

Answer each step below, starting with Step 1 and progressing through each step until reaching "Stop".

Upon reaching a Stop, do not complete further Steps beyond the Stop.

Refer to BMP Design Manual sections and/or separate forms referenced in each step below.

Step Answer Progression
Step 1: Is the project a "development
project"?
See Section 1.3 of the BMP Design
Manual for guidance.
 Yes Go to Step 2.
 No Stop.

Permanent BMP requirements do not apply.

No SWQMP will be required. Provide
discussion below.

Discussion / justification if the project is not a "development project" (e.g., the project includes only interior remodels within an existing building):

Step 2: Is the project a Standard
Project, Priority Development Project
(PDP), or exception to PDP definitions?
To answer this item, see Section 1.4 of
the BMP Design Manual in its entirety
for guidance, AND complete Form I-2,
Project Type Determination.
 Standard
Project
Stop.

Only Standard Project requirements apply,
including Standard Project SWQMP.
 PDP Standard and PDP requirements apply,
including PDP SWQMP.

Go to Step 3.
 Exception
to PDP
definitions
Stop.

Standard Project requirements apply, and any
additional requirements specific to the type of
project. Provide discussion and list any
additional requirements below. Prepare
Standard Project SWQMP.

X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Form I-1 Page 2, Form Template Date: August 31, 2015
[Step 2 Continued from Page 1] Discussion / justification, and additional requirements for exceptions to PDP definitions, if applicable:

Step 3 (PDPs only). Is the project
subject to earlier PDP requirements
due to a prior lawful approval?
See Section 1.10 of the BMP Design
Manual for guidance.
 Yes Consult the [City Engineer] to determine
requirements. Provide discussion and identify
requirements below.

Go to Step 4.
 No BMP Design Manual PDP requirements apply.

Go to Step 4.

Discussion / justification of prior lawful approval, and identify requirements (not required if prior lawful approval does not apply):

Step 4 (PDPs only). Do
hydromodification control
requirements apply?
See Section 1.6 of the BMP Design
Manual for guidance.
 Yes PDP structural BMPs required for pollutant
control (Chapter 5) and hydromodification
control (Chapter 6).

Go to Step 5.
 No Stop.

PDP structural BMPs required for pollutant
control (Chapter 5) only.

Provide brief discussion of exemption to
hydromodification control below.

Discussion / justification if hydromodification control requirements do not apply:

Step 5 (PDPs subject to
hydromodification control
requirements only). Does protection
of critical coarse sediment yield areas
 Yes Management measures required for
protection of critical coarse sediment yield
areas (Chapter 6.2).

Stop.
x
x
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
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apply based on review of WMAA
Potential Critical Coarse Sediment
Yield Area Map?
See Section 6.2 of the BMP Design
Manual for guidance.
 No Management measures not required for
protection of critical coarse sediment yield
areas.

Provide brief discussion below.

There are no critical coarse sediment yield
areas on the project site. Critical coarse
sediment protection measures are not
required if the project does not impact any
yield areas. Attachment 2B provides a map
showing the absence of critical coarse
sediment yield areas on the project site.

X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
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Priority Determination Form
Form I-2
Model BMP Design Manual
[August 31, 2015]
Project Information
Project Name: THE EXCHANGE AT SANTEE TOWN CENTER
Permit Application Number: TM-2025-0003 Date: 9/18/2025 Project Address:

Town Center Parkway, Santee, CA 92071
Project Type Determination: Standard Project or Priority Development Project (PDP) The project is (select one):  New Development  Redevelopment The total proposed newly created or replaced impervious area is: _148,016_ ft2(__3.4__) acres Is the project in any of the following categories, (a) through (f)? Yes

No

(a) New development projects that create 10,000 square feet or more of impervious surfaces (collectively over the entire project site). This includes commercial, industrial, residential, mixed-use, and public development projects on public or private land.

Yes

No

(b) Redevelopment projects that create and/or replace 5,000 square feet or more of impervious surface (collectively over the entire project site on an existing site of 10,000 square feet or more of impervious surfaces). This includes commercial, industrial, residential, mixed-use, and public development projects on public or private land.

Yes

No

(c) New and redevelopment projects that create and/or replace 5,000 square feet or more of impervious surface (collectively over the entire project site), and support one or more of the following uses:
(i) Restaurants. This category is defined as a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and refreshment stands selling prepared foods and drinks for immediate consumption (Standard Industrial Classification (SIC) code 5812). (ii) Hillside development projects. This category includes development on any natural slope that is twenty-five percent or greater.
(iii) Parking lots. This category is defined as a land area or facility for the temporary parking or storage of motor vehicles used personally, for business, or for commerce.
(iv) Streets, roads, highways, freeways, and driveways. This category is defined as any paved impervious surface used for the transportation of automobiles, trucks, motorcycles, and other vehicles.

X
X
X
X
PDP SWQMP Template Date: February 2016
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Form I-2 Page 2, Form Template Date: August 31, 2015
Yes

No

(d) New or redevelopment projects that create and/or replace 2,500 square feet or more of impervious surface (collectively over the entire project site), and discharging directly to an Environmentally Sensitive Area (ESA). “Discharging directly to” includes flow that is conveyed overland a distance of 200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an isolated flow from the project to the ESA (i.e. not commingled with flows from adjacent lands).

Note: ESAs are areas that include but are not limited to all Clean Water Act Section 303(d) impaired water bodies; areas designated as Areas of Special Biological Significance by the State Water Board and San Diego Water Board; State Water Quality Protected Areas; water bodies designated with the RARE beneficial use by the State Water Board and San Diego Water Board; and any other equivalent environmentally sensitive areas which have been identified by the Copermittees. See BMP Design Manual Section 1.4.2 for additional guidance.

Yes

No

(e) New development projects, or redevelopment projects that create and/or replace 5,000 square feet or more of impervious surface, that support one or more of the following uses:
(i) Automotive repair shops. This category is defined as a facility that is categorized in any one of the following SIC codes: 5013, 5014, 5541, 7532- 7534, or 7536-7539.
(ii) Retail gasoline outlets (RGOs). This category includes RGOs that meet the following criteria: (a) 5,000 square feet or more or (b) a projected Average Daily Traffic (ADT) of 100 or more vehicles per day.

Yes

No

(f) New or redevelopment projects that result in the disturbance of one or more acres of land and are expected to generate pollutants post construction.

Note: See BMP Design Manual Section 1.4.2 for additional guidance.

Does the project meet the definition of one or more of the Priority Development Project categories (a) through (f) listed above?
 No – the project is not a Priority Development Project (Standard Project).  Yes – the project is a Priority Development Project (PDP).

The following is for redevelopment PDPs only:

The area of existing (pre-project) impervious area at the project site is: ___0___ ft2(A) The total proposed newly created or replaced impervious area is _148,016_ ft2(B) Percent impervious surface created or replaced (B/A)*100: __100__% The percent impervious surface created or replaced is (select one based on the above calculation):
 less than or equal to fifty percent (50%) – only new impervious areas are considered PDP OR
 greater than fifty percent (50%) – the entire project site is a PDP X
X
X
X
X
PDP SWQMP Template Date: February 2016
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Site Design Checklist
For PDPs
Form I-3B (PDPs)
Model BMP Design Manual
[August 31, 2015]
Project Summary Information
Project Name THE EXCHANGE AT SANTEE TOWN CENTER
Project Address Town Center Parkway, Santee, CA 92071
Assessor's Parcel Number(s) (APN(s)) 381-040-36-00
Permit Application Number TM-2025-0003
Project Hydrologic Unit Select One:
 Santa Margarita 902
 San Luis Rey 903
 Carlsbad 904
 San Dieguito 905
 Penasquitos 906
 San Diego 907
 Pueblo San Diego 908
 Sweetwater 909
 Otay 910
 Tijuana 911
Project Watershed
(Complete Hydrologic Unit, Area, and Subarea
Name with Numeric Identifier)
San Diego Hydrologic Unit
Lower San Diego Hydrologic Area
Santee Hydrologic Subarea (907.12)
Parcel Area
(total area of Assessor's Parcel(s) associated
with the project)
__5.3_ Acres (____230,868__ Square Feet)
Area to be Disturbed by the Project
(Project Area) _4.1_ Acres (___178,332___ Square Feet)
Project Proposed Impervious Area
(subset of Project Area) __3.4_ Acres (__148,016___ Square Feet) Project Proposed Pervious Area
(subset of Project Area) __0.7_ Acres (___30,316____ Square Feet) Note: Proposed Impervious Area + Proposed Pervious Area = Area to be Disturbed by the Project.

This may be less than the Parcel Area.

X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
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Form I-3B Page 2 of 10, Form Template Date: August 31, 2015 Description of Existing Site Condition
Current Status of the Site (select all that apply):
 Existing development
 Previously graded but not built out
 Demolition completed without new construction
 Agricultural or other non-impervious use
 Vacant, undeveloped/natural
Description / Additional Information:

The existing site is an undeveloped vacant lot.

Existing Land Cover Includes (select all that apply):
 Vegetative Cover
 Non-Vegetated Pervious Areas
 Impervious Areas
Description / Additional Information:

The existing land cover is a grassed area.

Underlying Soil belongs to Hydrologic Soil Group (select all that apply):
 NRCS Type A
 NRCS Type B
 NRCS Type C
 NRCS Type D
Approximate Depth to Groundwater (GW):
 GW Depth < 5 feet
 5 feet < GW Depth < 10 feet
 10 feet < GW Depth < 20 feet
 GW Depth > 20 feet
X
X
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
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Existing Natural Hydrologic Features (select all that apply):
 Watercourses
 Seeps
 Springs
 Wetlands
 None
Description / Additional Information:

X
PDP SWQMP Template Date: February 2016
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Form I-3B Page 3 of 10, Form Template Date: August 31, 2015 Description of Existing Site Drainage Patterns
How is storm water runoff conveyed from the site? At a minimum, this description should answer:
(1) whether existing drainage conveyance is natural or urban; The existing drainage conveyance onsite is natural, with no existing inlets or storm drains to convey flows. Existing onsite drainage splits in the west direction and east direction, sheet flowing offsite to an existing curb inlet and grate inlet which discharges to the San Diego River located North of the site. (2) Is runoff from offsite conveyed through the site? if yes, quantify all offsite drainage areas, design flows, and locations where offsite flows enter the project site, and summarize how such flows are conveyed through the site,
No offsite drainage is conveyed through the site.
(3) Provide details regarding existing project site drainage conveyance network, including any existing storm drains, concrete channels, swales, detention facilities, storm water treatment facilities, natural or constructed channels;
No existing drainage conveyance exists on site. The existing is natural grassed area. (4) Identify all discharge locations from the existing project site along with a summary of conveyance system size and capacity for each of the discharge locations. Provide summary of the pre-project drainage areas and design flows to each of the existing runoff discharge locations; The pre-project drainage area is split between two areas, POC-1 and POC-2. POC-1 is located at a curb inlet that’s connected to an existing 36” RCP. POC-1 drains 7.9 acres with a 100-year peak flow of approximately 27.6 CFS. POC-2 is located at existing grate inlet that’s connected to the adjacent conveyance network. POC-2 drains 0.9 acres with a 100-year peak flow of approximately 4.9 CFS. (5) Describe existing site drainage patterns;
Existing onsite drainage splits in the west direction and east direction, sheet flowing offsite to an existing curb inlet in the west on an adjacent road, and an existing grate inlet in the east at the adjacent property. Drainage is conveyed north and discharges to the San Diego River, which ultimately flows west and discharges to the Pacific Ocean.

PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Form I-3B Page 4 of 10, Form Template Date: August 31, 2015 Description of Proposed Site Development
Project Description / Proposed Land Use and/or Activities:

The proposed project is a new 4.1-acre development that includes the construction of multifamily housing, residential streets with parking, landscaping, open spaces, a green court, and stormwater treatment features for water quality treatment.

List/describe proposed impervious features of the project (e.g., buildings, roadways, parking lots, courtyards, athletic courts, other impervious features):

The project’s impervious features include multifamily dwellings and residential streets with parking.

List/describe proposed pervious features of the project (e.g., landscape areas):

The project’s pervious features include landscaped areas, water quality elements like modular wetlands, open space, and a green court.

Does the project include grading and changes to site topography?  Yes
 No
Description / Additional Information:

The site will be mass graded for the proposed development.

X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
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Form I-3B Page 5 of 10, Form Template Date: August 31, 2015 Description of Proposed Site Drainage Patterns
Does the project include changes to site drainage (e.g., installation of new storm water conveyance systems)?
 Yes
 No
If yes, provide details regarding the proposed project site drainage conveyance network, including storm drains, concrete channels, swales, detention facilities, storm water treatment facilities, natural or constructed channels, and the method for conveying offsite flows through or around the proposed project site. Identify all discharge locations from the proposed project site along with a summary of the conveyance system size and capacity for each of the discharge locations. Provide a summary of pre- and post-project drainage areas and design flows to each of the runoff discharge locations. Reference the drainage study for detailed calculations.

The proposed drainage system will collect surface flows via a series of curb opening modular wetland systems and conveyed through underground storm drains. The proposed drainage system includes planter box modular wetland systems conveying into 3 distinct storm drain routes that will confluence at POC-1. Stormwater is conveyed west through the project site and enters the proposed conveyance network which then discharges to POC-1 located at an existing 36” storm drain junction. The preproject drainage area for POC-1 is 7.9 acres, which drains 27.6 CFS. The post-project drainage area for POC-1 is 8.0 acres, which drains 34.0 CFS. Although there’s an increase of area and flow to POC-1, there is enough capacity in the storm drain downstream of POC-1. Please refer to Section 3.2 of the Drainage Study for additional details.

Describe proposed site drainage patterns:

Drainage patterns for the proposed condition will remain similar to drainage patterns in the preproject condition. Drainage is divided between two drainage areas, with one area draining west to POC 1, and another draining east to POC 2. In comparison to the existing condition, drainage is also divided between POC-1 and POC-2, but the drainage area to each POC vary. In the post project, drainage area tributary to POC-1 has increased by 0.1 acres as the entirety of the proposed development drains to it. Although there’s a slight increase of 0.1 acres in the tributary area to POC-1, this change is considered minimal, and the downstream system will have enough capacity for this increase in acreage. As a result of increased tributary area to POC-1, POC-2 tributary area has decreased in the proposed condition. After leaving the site, drainage from both POC-1 and POC-2 are conveyed through the existing storm drain system, outfalls at the San Diego River, which ultimately discharges to the Pacific Ocean.

X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
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Form I-3B Page 6 of 10, Form Template Date: August 31, 2015 Identify whether any of the following features, activities, and/or pollutant source areas will be present (select all that apply):
 On-site storm drain inlets
 Interior floor drains and elevator shaft sump pumps
 Interior parking garages
 Need for future indoor & structural pest control
 Landscape/Outdoor Pesticide Use
 Pools, spas, ponds, decorative fountains, and other water features  Food service
 Refuse areas
 Industrial processes
 Outdoor storage of equipment or materials
 Vehicle and Equipment Cleaning
 Vehicle/Equipment Repair and Maintenance
 Fuel Dispensing Areas
 Loading Docks
 Fire Sprinkler Test Water
 Miscellaneous Drain or Wash Water
 Plazas, sidewalks, and parking lots
Description / Additional Information:

X
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
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Form I-3B Page 7 of 10, Form Template Date: August 31, 2015 Identification and Narrative of Receiving Water and Pollutants of Concern Runoff from the project site is directed to a hard-piped connection to the adjacent existing storm drain system, which flows directly into the San Diego River. After entering the San Diego River, runoff is discharged to the Pacific Ocean.

List any 303(d) impaired water bodies within the path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable), identify the pollutant(s)/stressor(s) causing impairment, and identify any TMDLs and/or Highest Priority Pollutants from the WQIP for the impaired water bodies:
303(d) Impaired Water Body Pollutant(s)/Stressor(s)
TMDLs / WQIP Highest Priority
Pollutant
San Diego River Indicator bacteria, Phosphorus,
Total Dissolved Solids, Nitrogen,
Cadmium, Benthic Community
Effects, Dissolved Oxygen, and
Toxicity
Indicator bacteria.

Identification of Project Site Pollutants*
*Identification of project site pollutants is only required if flow-thru treatment BMPs are implemented onsite in lieu of retention or biofiltration BMPs (note the project must also participate in an alternative compliance program unless prior lawful approval to meet earlier PDP requirements is demonstrated)
Identify pollutants expected from the project site based on all proposed use(s) of the site (see BMP Design Manual Appendix B.6):

Pollutant
Not Applicable to the
Project Site
Expected from the
Project Site
Also a Receiving Water
Pollutant of Concern
Sediment
Nutrients
Heavy Metals
Organic Compounds
Trash & Debris
Oxygen Demanding
Substances
Oil & Grease
Bacteria & Viruses
Pesticides
Form I-3B Page 8 of 10, Form Template Date: August 31, 2015 PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Hydromodification Management Requirements
Do hydromodification management requirements apply (see Section 1.6 of the BMP Design Manual)?  Yes, hydromodification management flow control structural BMPs required.  No, the project will discharge runoff directly to existing underground storm drains discharging directly to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean.  No, the project will discharge runoff directly to conveyance channels whose bed and bank are concrete-lined all the way from the point of discharge to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean.
 No, the project will discharge runoff directly to an area identified as appropriate for an exemption by the WMAA for the watershed in which the project resides.

Description / Additional Information (to be provided if a 'No' answer has been selected above):

Runoff from the project site is conveyed directly to the existing adjacent storm drain system which discharges directly to the San Diego River. After entering the San Diego River, runoff is discharged to the Pacific Ocean.

X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
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Critical Coarse Sediment Yield Areas*
*This Section only required if hydromodification management requirements apply Based on the maps provided within the WMAA, do potential critical coarse sediment yield areas exist within the project drainage boundaries?
 Yes
 No, No critical coarse sediment yield areas to be protected based on WMAA maps If yes, have any of the optional analyses presented in Section 6.2 of the BMP Design Manual been performed?
 6.2.1 Verification of Geomorphic Landscape Units (GLUs) Onsite  6.2.2 Downstream Systems Sensitivity to Coarse Sediment  6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite  No optional analyses performed, the project will avoid critical coarse sediment yield areas identified based on WMAA maps
If optional analyses were performed, what is the final result?  No critical coarse sediment yield areas to be protected based on verification of GLUs onsite  Critical coarse sediment yield areas exist but additional analysis has determined that protection is not required. Documentation attached in Attachment 2.b of the SWQMP.  Critical coarse sediment yield areas exist and require protection. The project will implement management measures described in Sections 6.2.4 and 6.2.5 as applicable, and the areas are identified on the SWQMP Exhibit.

Discussion / Additional Information:

X
PDP SWQMP Template Date: February 2016
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Form I-3B Page 9 of 10, Form Template Date: August 31, 2015 Flow Control for Post-Project Runoff*
*This Section only required if hydromodification management requirements apply List and describe point(s) of compliance (POCs) for flow control for hydromodification management (see Section 6.3.1). For each POC, provide a POC identification name or number correlating to the project's HMP Exhibit and a receiving channel identification name or number correlating to the project's HMP Exhibit.
(No hydromodification is required for this project)
 No, the low flow threshold is 0.1Q2 (default low flow threshold)  Yes, the result is the low flow threshold is 0.1Q2
 Yes, the result is the low flow threshold is 0.3Q2
 Yes, the result is the low flow threshold is 0.5Q2
If a geomorphic assessment has been performed, provide title, date, and preparer:

Discussion / Additional Information: (optional)
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
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Form I-3B Page 10 of 10, Form Template Date: August 31, 2015 Other Site Requirements and Constraints
When applicable, list other site requirements or constraints that will influence storm water management design, such as zoning requirements including setbacks and open space, or local codes governing minimum street width, sidewalk construction, allowable pavement types, and drainage requirements.

The northern boundary of the project site contains an existing 20.0-foot water pipeline and associated incidental rights easement, along with a 10.0-foot water pipeline easement for Padre Dam Municipal Water District, and a 15.0-foot sewer pipeline easement for Lakeside Sanitation District.

Optional Additional Information or Continuation of Previous Sections As Needed This space provided for additional information or continuation of information from previous sections as needed.

PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Source Control BMP Checklist
for All Development Projects
(Standard Projects and Priority Development Projects)
Form I-4
Model BMP Design
Manual
[August 31, 2015]
Project Identification
Project Name: THE EXCHANGE AT SANTEE TOWN CENTER
Permit Application Number: TM-2025-0003
Source Control BMPs
All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible. See Chapter 4 and Appendix E of the Model BMP Design Manual for information to implement source control BMPs shown in this checklist.

Answer each category below pursuant to the following.
• "Yes" means the project will implement the source control BMP as described in Chapter 4 and/or Appendix E of the Model BMP Design Manual. Discussion / justification is not required. • "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion / justification must be provided.
• "N/A" means the BMP is not applicable at the project site because the project does not include the feature that is addressed by the BMP (e.g., the project has no outdoor materials storage areas).

Discussion / justification may be provided.

Source Control Requirement Applied?
SC-1 Prevention of Illicit Discharges into the MS4  Yes  No  N/A Discussion / justification if SC-1 not implemented:

SC-2 Storm Drain Stenciling or Signage  Yes  No  N/A Discussion / justification if SC-2 not implemented:

SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal
 Yes  No  N/A
Discussion / justification if SC-3 not implemented:

Not anticipated for site.

SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and Wind Dispersal
 Yes  No  N/A
Discussion / justification if SC-4 not implemented:

Not anticipated for site.

X
X
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
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Form I-4 Page 2 of 2, Form Template Date: August 31, 2015 Source Control Requirement Applied?
SC-5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal
 Yes  No  N/A
Discussion / justification if SC-5 not implemented:

SC-6 Additional BMPs Based on Potential Sources of Runoff Pollutants (must answer for each source listed below)
 On-site storm drain inlets
 Interior floor drains and elevator shaft sump pumps
 Interior parking garages
 Need for future indoor & structural pest control
 Landscape/Outdoor Pesticide Use
 Pools, spas, ponds, decorative fountains, and other water features  Food service
 Refuse areas
 Industrial processes
 Outdoor storage of equipment or materials
 Vehicle and Equipment Cleaning
 Vehicle/Equipment Repair and Maintenance
 Fuel Dispensing Areas
 Loading Docks
 Fire Sprinkler Test Water
 Miscellaneous Drain or Wash Water
 Plazas, sidewalks, and parking lots
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 No
 No
 No
 No
 No
 No
 No
 No
 No
 No
 No
 No
 No
 No
 No
 No
 No
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
X
X
X
X X
X
X
X
X
X
X
x
x
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
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Discussion / justification if SC-6 not implemented. Clearly identify which sources of runoff pollutants are discussed. Justification must be provided for all "No" answers shown above.

PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Site Design BMP Checklist
for All Development Projects
(Standard Projects and Priority Development Projects)
Form I-5
Model BMP Design
Manual
[August 31, 2015]
Project Identification
Project Name: THE EXCHANGE AT SANTEE TOWN CENTER
Permit Application Number: TM-2025-0003
Site Design BMPs
All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible. See Chapter 4 and Appendix E of the Model BMP Design Manual for information to implement site design BMPs shown in this checklist.

Answer each category below pursuant to the following.
• "Yes" means the project will implement the site design BMP as described in Chapter 4 and/or Appendix E of the Model BMP Design Manual. Discussion / justification is not required. • "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion / justification must be provided.
• "N/A" means the BMP is not applicable at the project site because the project does not include the feature that is addressed by the BMP (e.g., the project site has no existing natural areas to conserve).

Discussion / justification may be provided.

Site Design Requirement Applied?
SD-1 Maintain Natural Drainage Pathways and Hydrologic Features  Yes  No  N/A Discussion / justification if SD-1 not implemented:

No existing natural drainage pathways or hydrologic features exist on site.

SD-2 Conserve Natural Areas, Soils, and Vegetation  Yes  No  N/A Discussion / justification if SD-2 not implemented:

SD-3 Minimize Impervious Area  Yes  No  N/A
Discussion / justification if SD-3 not implemented:

SD-4 Minimize Soil Compaction  Yes  No  N/A
Discussion / justification if SD-4 not implemented:

SD-5 Impervious Area Dispersion  Yes  No  N/A
Discussion / justification if SD-5 not implemented:

X
X
X
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Form I-5 Page 2 of 2, Form Template Date: August 31, 2015 Site Design Requirement Applied?
SD-6 Runoff Collection  Yes  No  N/A
Discussion / justification if SD-6 not implemented:

Rain barrels or permeable pavements not proposed; therefore runoff collection is not applicable to project.

SD-7 Landscaping with Native or Drought Tolerant Species  Yes  No  N/A Discussion / justification if SD-7 not implemented:

SD-8 Harvesting and Using Precipitation  Yes  No  N/A Discussion / justification if SD-8 not implemented:

Harvest and use is not feasible for project. Reference Worksheet B.3-1 (Form I-7) in Attachment 1c of this report for the Harvest and Use Feasibility Screening Checklist.

X
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Summary of PDP Structural BMPs
Form I-6 (PDPs)
Model BMP Design Manual
[August 31, 2015]
Project Identification
Project Name: THE EXCHANGE AT SANTEE TOWN CENTER
Permit Application Number: TM-2025-0003
PDP Structural BMPs
All PDPs must implement structural BMPs for storm water pollutant control (see Chapter 5 of the BMP Design Manual). Selection of PDP structural BMPs for storm water pollutant control must be based on the selection process described in Chapter 5. PDPs subject to hydromodification management requirements must also implement structural BMPs for flow control for hydromodification management (see Chapter 6 of the BMP Design Manual). Both storm water pollutant control and flow control for hydromodification management can be achieved within the same structural BMP(s).

PDP structural BMPs must be verified by the local jurisdiction at the completion of construction. This may include requiring the project owner or project owner's representative and engineer of record to certify construction of the structural BMPs (see Section 1.12 of the BMP Design Manual). PDP structural BMPs must be maintained into perpetuity, and the local jurisdiction must confirm the maintenance (see Section 7 of the BMP Design Manual).

Use this form to provide narrative description of the general strategy for structural BMP implementation at the project site in the box below. Then complete the PDP structural BMP summary information sheet (page 3 of this form) for each structural BMP within the project (copy the BMP summary information page as many times as needed to provide summary information for each individual structural BMP).

Describe the general strategy for structural BMP implementation at the site. This information must describe how the steps for selecting and designing storm water pollutant control BMPs presented in Section 5.1 of the BMP Design Manual were followed, and the results (type of BMPs selected). For projects requiring hydromodification flow control BMPs, indicate whether pollutant control and flow control BMPs are integrated or separate.

The site consists of nine drainage management areas. DMA-1 through DMA-9 consist of areas that each drain to an appropriately sized modular wetland system. The proposed BMP implementation allows for sheet flows to enter the storm drain system from curb openings in the modular wetland system and roof drains along the residential buildings. Modular wetland systems picking up area flow from the residential roof drains do not require curb openings due to their proximity to storm drain inlets. The modular wetland systems are set up in a series that conveys to a confluence point at POC1. All DMA’s require only pollutant control BMPs. DMA areas range from 0.2 acres to 0.9 acres. The total drainage area is 4.1 acres. BMP-1, BMP -3, BMP-5, BMP-6, and BMP-9 will require bypass storm drains to convey the Q100.
(Continue on page 2 as necessary.)
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Form I-6 Page 1 of 9 (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No. BMP – 1
Construction Plan Sheet No.

Type of structural BMP:
 Retention by harvest and use (HU-1)
 Retention by infiltration basin (INF-1)
 Retention by bioretention (INF-2)
 Retention by permeable pavement (INF-3)
 Partial retention by biofiltration with partial retention (PR-1)  Biofiltration (BF-1)
 Biofiltration with Nutrient Sensitive Media Design (BF-2)  Proprietary Biofiltration (BF-3) meeting all requirements of Appendix F  Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/description in discussion section below)
 Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration BMP it serves in discussion section below)
 Flow-thru treatment control with alternative compliance (provide BMP type/description in discussion section below)
 Detention pond or vault for hydromodification management  Other (describe in discussion section below)
Underground stormwater vault for detention only.

Purpose:
 Pollutant control only
 Hydromodification control only
 Combined pollutant control and hydromodification control  Pre-treatment/forebay for another structural BMP
 Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
RICK Engineering Company
Shavger Rekani PE
(619) 291-0707
Who will be the final owner of this BMP? HOA
Who will maintain this BMP into perpetuity? HOA
What is the funding mechanism for maintenance? HOA
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Form I-6 Page 2 of 9 (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No. BMP – 2
Construction Plan Sheet No.

Purpose:
 Pollutant control only
 Hydromodification control only
 Combined pollutant control and hydromodification control  Pre-treatment/forebay for another structural BMP
 Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the party
responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
RICK Engineering Company
Shavger Rekani PE
(619) 291-0707
Who will be the final owner of this BMP? HOA
Who will maintain this BMP into perpetuity? HOA
What is the funding mechanism for maintenance? HOA
X
X
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Form I-6 Page 3 of 9 (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No. BMP – 3
Construction Plan Sheet No.

Purpose:
 Pollutant control only
 Hydromodification control only
 Combined pollutant control and hydromodification control  Pre-treatment/forebay for another structural BMP
 Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
RICK Engineering Company
Shavger Rekani PE
(619) 291-0707
Who will be the final owner of this BMP? HOA
Who will maintain this BMP into perpetuity? HOA
What is the funding mechanism for maintenance? HOA
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Form I-6 Page 4 of 9 (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No. BMP – 4
Construction Plan Sheet No.

Purpose:
 Pollutant control only
 Hydromodification control only
 Combined pollutant control and hydromodification control  Pre-treatment/forebay for another structural BMP
 Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
RICK Engineering Company
Shavger Rekani PE
(619) 291-0707
Who will be the final owner of this BMP? HOA
Who will maintain this BMP into perpetuity? HOA
What is the funding mechanism for maintenance? HOA
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Form I-6 Page 5 of 9 (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No. BMP – 5
Construction Plan Sheet No.

Purpose:
 Pollutant control only
 Hydromodification control only
 Combined pollutant control and hydromodification control  Pre-treatment/forebay for another structural BMP
 Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
RICK Engineering Company
Shavger Rekani PE
(619) 291-0707
Who will be the final owner of this BMP? HOA
Who will maintain this BMP into perpetuity? HOA
What is the funding mechanism for maintenance? HOA
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Form I-6 Page 6 of 9 (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No. BMP – 6
Construction Plan Sheet No.

Purpose:
 Pollutant control only
 Hydromodification control only
 Combined pollutant control and hydromodification control  Pre-treatment/forebay for another structural BMP
 Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
RICK Engineering Company
Shavger Rekani PE
(619) 291-0707
Who will be the final owner of this BMP? HOA
Who will maintain this BMP into perpetuity? HOA
What is the funding mechanism for maintenance? HOA
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Form I-6 Page 7 of 9 (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No. BMP – 7
Construction Plan Sheet No.

Purpose:
 Pollutant control only
 Hydromodification control only
 Combined pollutant control and hydromodification control  Pre-treatment/forebay for another structural BMP
 Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
RICK Engineering Company
Shavger Rekani PE
(619) 291-0707
Who will be the final owner of this BMP? HOA
Who will maintain this BMP into perpetuity? HOA
What is the funding mechanism for maintenance? HOA
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Form I-6 Page 8 of 9 (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No. BMP – 8
Construction Plan Sheet No.

Purpose:
 Pollutant control only
 Hydromodification control only
 Combined pollutant control and hydromodification control  Pre-treatment/forebay for another structural BMP
 Other (describe in discussion section below)
Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
RICK Engineering Company
Shavger Rekani PE
(619) 291-0707
Who will be the final owner of this BMP? HOA
Who will maintain this BMP into perpetuity? HOA
What is the funding mechanism for maintenance? HOA
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Form I-6 Page 9 of 9 (Copy as many as needed) , Form Template Date: August 31, 2015 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No. BMP – 9
Construction Plan Sheet No.

BACKUP FOR PDP POLLUTANT CONTROL BMPS
This is the cover sheet for Attachment 1.

Indicate which Items are Included behind this cover sheet:

Attachment
Sequence
Contents Checklist
Attachment 1a DMA Exhibit (Required)
See DMA Exhibit Checklist on the back of
this Attachment cover sheet.
 Included
Attachment 1b Tabular Summary of DMAs Showing
DMA ID matching DMA Exhibit, DMA
Area, and DMA Type (Required)*
*Provide table in this Attachment OR on
DMA Exhibit in Attachment 1a
 Included on DMA Exhibit in
Attachment 1a
 Included as Attachment 1b, separate
from DMA Exhibit
Attachment 1c Form I-7, Harvest and Use Feasibility
Screening Checklist (Required unless the
entire project will use infiltration BMPs)
Refer to Appendix B.3-1 of the BMP
Design Manual to complete Form I-7.
 Included
 Not included because the entire
project will use infiltration BMPs
Attachment 1d Form I-8, Categorization of Infiltration
Feasibility Condition (Required unless
the project will use harvest and use
BMPs)
Refer to Appendices C and D of the BMP
Design Manual to complete Form I-8.
 Included
 Not included because the entire
project will use harvest and use
BMPs
Attachment 1e Pollutant Control BMP Design
Worksheets / Calculations (Required)
Refer to Appendices B and E of the BMP
Design Manual for structural pollutant
control BMP design guidelines
 Included
X
X
X
X
1 3
4 -
1 3
6 Q
1 0
0 =
6 .
6 2
c
f
s
X
1 3
4 -
1 3
6 Q
1 0
0 =
6 PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Use this checklist to ensure the required information has been included on the DMA Exhibit:

The DMA Exhibit must identify:
 Underlying hydrologic soil group
 Approximate depth to groundwater
 Existing natural hydrologic features ( watercourses, seeps, springs, wetlands)  Critical coarse sediment yield areas to be protected
 Existing topography and impervious areas
 Existing and proposed site drainage network and connections to drainage offsite  Proposed demolition
 Proposed grading
 Proposed impervious features
 Proposed design features and surface treatments used to minimize imperviousness  Drainage management area (DMA) boundaries, DMA ID numbers, and DMA areas (square footage or acreage), and DMA type (i.e., drains to BMP, self-retaining, or self-mitigating)  Potential pollutant source areas and corresponding required source controls (see Chapter 4, Appendix E.1, and Form I-3B)
 Structural BMPs (identify location, type of BMP, and size/detail) X
X
X
X
X
X
X
X
X
X
X
X
Attachment 1A
330
X
IRR
X
X
IRR
X
X
X
X
X
X
X
IRR
IRR
X
X
X
X
CB
X
X
X
X
X
X
X
IRR
X
IRR
X
PBX
X
PBX
X
X
X
X
X
X
IRR
X
X
IRR
X
X
EVX
E
X
X X
X
X X X
X
X
X
X
X
X
EV
X
X
X
X
X
335
335
3 3
5 3
3 5
X
X
X
X
X
X
X
X
X
X
X
X
X
X
AREA

PERVIOUS DISPERSION

TO PERVIOUS AREA

IMPERVIOUS AREA DIRECTED
11-SEP-2025 14:25
C:\RICK\Projects\C20000\20075_TownCenterMF\WaterRes\SD CorpStds 2005.dscript C:\RICK\Projects\C20000\20075_TownCenterMF\WaterRes\20075_swqmp_01.dgn c 2021 Rick
Engineering Com
pany

NOT FOR CONSTRUCTION - EXHIBIT FOR PDP SWQMP ONLY
POC-1
DMA-1
BMP-5

0.36 AC

0.59 AC

0.43 AC

0.24 AC

0.59 AC

0.23 AC

0.50 AC
DMA-3 0.68 AC
DMA-2
DMA-4
DMA-5
DMA-6
DMA-9
BMP-3
BMP-2
BMP-1
BMP-4
BMP-8
BMP-9
BMP-6
BMP-7
DMA-8
DMA-7

0.46 AC
SD-5
SD-5
SD-7
SC-2
SC-1
SC-2
SC-1
SC-2
SC-1
SC-2
SC-1
SC-1
SC-2
SC-1
SC-2
SC-1
SD-2
SD-2
SD-2
SD-2
D9-A4
D9-A4
8-8
8-8
4 -13
4 -13
D9-A4
D9-A4
4-6
4-6
4-8
4-8
4-8
ACC

VAN ACC
ACC

EV EV EV EV
STOP
STOP
STOP
STOP
OTSP
STOP
STOP
STOP
STOP
4:
4 1
:1
4:1
4:1
0 GRAPHIC SCALE 1" = 30'
30 15 30 60 90

AND VEGETATION

CONSERVE NATURAL AREAS, SOILS,
CBX
X
X
X
X X
SD-7
SC-1
533
335
335
335
533
533
335
335
335
533
335 335
335
335
335
335
335
335
335
335
335 335
335
335
335
SD-4
SC-6
SD-3
SC-6
SD-4
SD-3
SD-4
SD-4
SD-4
SD-3
SD-3
SD-3
SC-2
SC-1
SD-4 MINIMIZE SOIL COMPACTION
SC-1
SC-2 STORM DRAIN STENCILING / SIGNAGE
SD-5
SD-7

TOLERANT SPECIES

LANDSCAPING WITH NATIVE / DROUGHT
SC-6

IMPERVIOUS AREA DISPERSION

ADDITIONAL BMP'S
SD-3
TO THE MS4

PREVENTION OF ILLICIT DISCHARGES
SD-2

MINIMIZE IMPERVIOUS AREA
NOTES

5. 85TH PERCENTILE STORM EVENT = 0.50 IN.

DEPTH BELOW 13-FEET, PER GEOTECHNICAL REPORT.

4. DEPTH TO GROUNDWATER WAS ENCOUNTERED AT A
IS PREVIOUSLY DEVELOPED AND GRADED.

THE LAYER IS A HIGH LEVEL ESTIMATE AND THE SITE

POTENTIAL CRITICAL COARSE SEDIMENT YIELD AREAS,

ALTHOUGH THE COUNTY WIDE GIS LAYER SHOWS

3. NO PCCSYA ARE WITHIN THE PROJECT AREA.

IDENTIFIED ON SITE.

2. HYDROLOGIC SOIL GROUP TYPE "B" HAVE BEEN
DESIGN MANUAL DATED FEBRUARY 2016.

QUALITY REQUIREMENTS OF THE CITY OF SANTEE BMP

THIS EXHIBIT ADDRESS THE PERMANENT STORM WATER

1. SIZES OF THE POLLUTANT CONTROL BMP's SHOWN ON
XXX
DISPERSION (2,754 SF)
PERV. AREA
(5,899 SF)
IMP. AREA
DISPERSION (2,551 SF)
PERV. AREA
(6,121 SF)
IMP. AREA
XX.X AC.
5620 FRIARS ROAD
SAN DIEGO, CA 92110
619-291-0707
rickengineering.com

SANTA CLARITA PHOENIX TUCSON LAS VEGAS DENVER

SAN DIEGO ORANGE RIVERSIDE SACRAMENTO SAN LUIS OBISPO
(DMA) BOUNDARY

DRAINAGE MANAGEMENT AREA

DMA AREA

SOURCE CONTROL/SITE DESIGN LEGEND STORM WATER MANAGEMENT BMP LEGEND (BMP) ELEMENT

BEST MANAGEMENT PRACTICE

POINT OF INTEREST
J-20075

DMA/BMP ID
March 7, 2025
Revised: May 30, 2025
Revised: September 18, 2025

SANTEE TOWN CENTER

THE EXCHANGE AT
FOR

AREA EXHIBIT

DRAINAGE MANAGEMENT
Attachment 1B
DMA ID

TRIBUTARY AREA
(SQ FT)
AREA
(ACRES)

IMPERVIOUS
AREA (ACRES) %IMPERVIOUS HSG

IMPERVIOUS
RUNOFF
FACTOR

PERVIOUS
RUNOFF
FACTOR

AREA WEIGHTED

RUNOFF FACTOR
DCV (Cubic
Feet) TREATED BY

POLLUTANT

CONTROL TYPE

DRAINS TO
(POC ID)
DMA-1 29830 0.7 0.6 83% B 0.90 0.1 0.76 950 BMP-1 PROP. BIOFILTRATION POC-1 DMA-2 21988 0.5 0.4 83% B 0.90 0.1 0.76 700 BMP-2 PROP. BIOFILTRATION POC-1DMA-3 10171 0.2 0.2 83% B 0.90 0.1 0.76 324 BMP-3 PROP. BIOFILTRATION POC-1 DMA -4 25667 0.6 0.5 83% B 0.90 0.1 0.76 817 BMP-4 PROP. BIOFILTRATION POC-1DMA -5 10425 0.2 0.2 83% B 0.90 0.1 0.76 332 BMP-5 PROP. BIOFILTRATION POC-1 DMA - 6 15872 0.4 0.3 83% B 0.90 0.1 0.76 505 BMP-6 PROP. BIOFILTRATION POC-1DMA - 7 19924 0.5 0.4 83% B 0.90 0.1 0.76 634 BMP-7 PROP. BIOFILTRATION POC-1DMA - 8 18852 0.4 0.4 83% B 0.90 0.1 0.76 600 BMP-8 PROP. BIOFILTRATION POC-1DMA - 9 25603 0.6 0.5 83% B 0.90 0.1 0.76 815 BMP-9 PROP. BIOFILTRATION POC-1 SUM 178332 4.1 3.4 5677
NO OF DMA TOTAL DMA AREA (ACRES) TOTAL IMPERVIOUS AREA (ACRES) % IMP AREA WEIGHTED RUNOFF COEFFICIENT TOTAL DCV (CUBIC FEET) TOTAL AREA TREATED (ACRES) NO. OF POCS 9 4.1 3.4 83% 0.76 5677 4.1 1
TABULAR SUMMARY OF DMAs, (THE EXCHANGE AT SANTEE TOWN CENTER)SUMMARY OF DMA INFORMATION (MUST MATCH PROJECT DESCRIPTION AND SWQMP NARRATIVE) C:\RICK\Projects\C20000\20075_TownCenterMF\WaterRes\WaterQuality\20075_Drainage_WQ.xlsx Attachment 1C
13 February 2016
Worksheet 0-2. Harvest and Use Feasibility Screening
Harvest and Use Feasibility Screening Worsksheet B.3-1

1. Is there a demand for harvested water (check all that apply) at the project site that is reliably present during the wet season?
Toilet and urinal flushing
Landscape irrigation
Other:______________

2. If there is a demand; estimate the anticipated average wet season demand over a period of 36 hours. Guidance for planning level demand calculations for toilet/urinal flushing and landscape irrigation is provided in Section B.3.2.
[Provide a summary of calculations here]

3. Calculate the DCV using worksheet B-2.1.
[Provide a results here]
3a. Is the 36-hour demand
greater than or equal to the
DCV?
Yes / No
3b. Is the 36-hour demand greater
than 0.25DCV but less than the full
DCV?
Yes / No
3c. Is the 36-hour
demand less than

0.25DCV?
Yes
Harvest and use appears to be
feasible. Conduct more detailed
evaluation and sizing
calculations to confirm that
DCV can be used at an adequate
rate to meet drawdown criteria.

Harvest and use may be feasible.

Conduct more detailed evaluation and
sizing calculations to determine
feasibility. Harvest and use may only
be able to be used for a portion of the
site, or (optionally) the storage may
need to be upsized to meet long term
capture targets while draining in
longer than 36 hours.

Harvest and use is
considered to be
infeasible.
11 February 2016
Worksheet 0-1. DCV
Design Capture Volume Worksheet B-2.1
1 85th percentile 24-hr storm depth from Figure B.1-1 d= inches 2 Area tributary to BMP (s) A= acres
3 Area weighted runoff factor (estimate using Appendix B.1.1 and B.2.1) C= unitless
4 Street trees volume reduction TCV= cubic-feet
5 Rain barrels volume reduction RCV= cubic-feet
6 Calculate DCV =
(3630 x C x d x A) – TCV - RCV DCV= cubic-feet
Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods for Structural BMPs
www.sandiegocounty.gov/stormwater B-7 Effective September 15, 2020 Figure B.1-1: 85th Percentile 24-hour Isopluvial Map
Attachment 1D
Attachment 1E

THE EXCHANGE AT SANTEE TOWN CENTER
J-200759/10/2025
Water Quality - Mod Wetland - BMP Sizing Calculations
DMA/BMP Name BMP Type
Drainage
Management
Area
(acres)
Drainage
Management
Area
(ft2)
% Impervious
Impervious
Area
(ft2)
Pervious Area
(ft2)
Runoff Factor
for Impervious
Area
Runoff Factor
for Pervious
Area
Effective
Impervious
Area
(ft2)
Runoff Factor
85th Percentile
Storm Event
(in)
Design
Capture
Volume (c.f.)
DCV Multiplier
Volume
Required
(ft3)
Water Quality
Intensity (in/hr)
Water Quality
Flow Rate, Q
(cfs)
Required Water
Quality Flow
Rate (cfs) 1.5*Q
Provided
Volume-Based
Treatment
Capacity (ft3)
Provided BMP
Flow Rate (cfs) MWS Model Name
DMA-1 Compact Biofiltration - Mod Wetlands 0.68 29830 83% 24759 5071 0.9 0.1 22,790 0.76 0.50 950 1.50 1,424 0.2 0.105 0.157 0.175 MWS-L-8-8DMA-2 Compact Biofiltration - Mod Wetlands 0.50 21988 83% 18250 3738 0.9 0.1 16,799 0.76 0.50 700 1.50 1,050 0.2 0.077 0.116 0.144 MWS-L-4-13DMA-3 Compact Biofiltration - Mod Wetlands 0.23 10171 83% 8442 1729 0.9 0.1 7,771 0.76 0.50 324 1.50 486 0.2 0.036 0.054 0.073 MWS-L-4-6DMA-4 Compact Biofiltration - Mod Wetlands 0.59 25667 83% 21304 4363 0.9 0.1 19,610 0.76 0.50 817 1.50 1,226 0.2 0.090 0.135 0.144 MWS-L-4-13DMA-5 Compact Biofiltration - Mod Wetlands 0.24 10425 83% 8653 1772 0.9 0.1 7,965 0.76 0.50 332 1.50 498 0.2 0.037 0.055 0.073 MWS-L-4-6DMA-6 Compact Biofiltration - Mod Wetlands 0.36 15872 83% 13174 2698 0.9 0.1 12,126 0.76 0.50 505 1.50 758 0.2 0.056 0.084 0.115 MWS-L-4-8DMA-7 Compact Biofiltration - Mod Wetlands 0.46 19924 83% 16537 3387 0.9 0.1 15,222 0.76 0.50 634 1.50 951 0.2 0.070 0.105 0.115 MWS-L-4-8DMA-8 Compact Biofiltration - Mod Wetlands 0.43 18852 83% 15647 3205 0.9 0.1 14,403 0.76 0.50 600 1.50 900 0.2 0.066 0.099 0.115 MWS-L-4-8DMA-9 Compact Biofiltration - Mod Wetlands 0.59 25603 83% 21250 4353 0.9 0.1 19,561 0.76 0.50 815 1.50 1,223 0.2 0.090 0.135 0.144 MWS-L-8-8 178332 5,677

1. The required and provided Water Quality volumes are based on the 2013 MS4 permit and the City of Santee BMP Design Manual 2. Runoff Factors for pervious and impervious areas were determined from Table 0-1: " Runoff Factors for Surfaces Draining to BMPs - Pollutant Control BMPs" from the City of Santee BMP Design Manual3.The DCV multiplier was found using Section B.4.2 Percent Capture Method and Figure 0-1 Percent Capture Nomgraph from the City of Santee BMP Design Manual Project Name
BMP ID
1 178332 sq. ft.
2 0.76
3 0.5 inches
4 5647 cu. ft.
5 0 in/hr.
6 2
7 0 in/hr.
10 130 cu. ft.

When Line 8 > 8% =

0.0000013 x Line 83 - 0.000057 x Line 82 + 0.0086 x Line 8 - 0.014 When Line 8 ≤ 8% = 0.023
Target volume retention [Line 9 x Line 4]Reliable infiltration rate, for biofiltration BMP sizing [Line 5 / Line 6] 8 Average annual volume reduction target (Figure B.5-2)

3.5 9
Fraction of DCV to be retained (Figure B.5-3)

0.023
% When Line 7 > 0.01 in/hr. = Minimum (40, 166.9 x Line 7 +6.62) When Line 7 ≤ 0.01 in/hr. = 3.5%
Factor of safety
Area draining to the BMP
The Exchange at Santee Town Center
Sizing Method for Volume Retention Criteria Worksheet B.5-2 Adjusted runoff factor for drainage area (Refer to Appendix B.1 and B.2) 85th percentile 24-hour rainfall depth
Design capture volume [Line 1 x Line 2 x (Line 3/12)]
Volume Retention Requirement
Measured infiltration rate in the DMA Note:

When mapped hydrologic soil groups are used enter 0.10 for NRCS Type D soils and for NRCS Type C soils enter 0.30
When in no infiltration condition and the actual measured infiltration rate is unknown enter 0.0 if there are geotechnical and/or groundwater hazards identified in Appendix C 9/10/2025 Version 1.0 - June 2017
Project Name
BMP ID
1 sq. ft.
2 3 sq. ft.
4 sq. ft.
5 sq. ft.

Identification 1 4 5
6 2551
7 6121
10 sq. ft.
11 sq. ft.
12 13
14 cu. ft.
15 cu. ft.

Identification
1 cu. ft.
2 cu. ft.
3 cu. ft.
4 cu. ft.
5 cu. ft.
cu. ft.
17 Volume Retention Performance Standard is Met
Site Design BMP
Is Line 11 ≥ Line 4? Volume Retention Performance Standard is Met CreditSite Design Type
Sum of volume retention benefits from other site design BMPs (e.g. trees; rain barrels etc.). [sum of Line 16 Credits for Id’s 1 to 5]Provide documentation of how the site design credit is calculated in the PDP SWQMP. 0 16
Is Line 16 ≥ Line 15?
Volume retention required from other site design BMPs
[(1-Line 13) x Line 14] -52
Volume Retention for No Infiltration Condition Worksheet B.5-6 178332

0.76 Area draining to the biofiltration BMPAdjusted runoff factor for drainage area (Refer to Appendix B.1 and B.2) Required area for Evapotranspiration [Line 3 x 0.03]Biofiltration BMP Footprint 3 2754
0 0
Impervious to Pervious Area ratio [Line 7/Line 6]Effective Credit AreaIf (Line 8 >1.5, Line 6, Line 7/1.5]Target Volume Retention [Line 10 from Worksheet B.5.2] 130 The Exchange at Santee Town Center
Landscape area that meet the requirements in SD-B and SD-F Fact Sheet (sq. ft.)Impervious area draining to the landscape area (sq. ft.) 5899 135532
4066
376
Landscape Area (must be identified on DS-3247)
2 5305
5681
Effective impervious area draining to the BMP [Line 1 x Line 2] Fraction of the performance standard met through the BMP footprint and/or landscaping [Line 11/Line 4] 1.4 Volume Retention Performance Standard
Sum of Landscape area [sum of Line 9 Id’s 1 to 5]Provided footprint for evapotranspiration [Line 5 + Line 10] 0 8 2.40 2.14 0.00 0.00 0.00
9 2551 2754
9/10/2025 Version 1.0 - June 2017

PLAN VIEW

ELEVATION VIEW RIGHT END VIEW

STANDARD DETAIL

STORMWATER BIOFILTRATION SYSTEM
MWS-L-8-8-V

LEFT END VIEW

INSTALLATION NOTES

SITE SPECIFIC DATA

PLAN VIEW

ELEVATION VIEW RIGHT END VIEW

STANDARD DETAIL

STORMWATER BIOFILTRATION SYSTEM
MWS-L-4-13-V

FOR PATENT INFORMATION, GO TO
www.ContechES.com/IP

LEFT END VIEW

INSTALLATION NOTES

SITE SPECIFIC DATA

PLAN VIEW

ELEVATION VIEW RIGHT END VIEW

STANDARD DETAIL

STORMWATER BIOFILTRATION SYSTEM
MWS-L-4-6-V

FOR PATENT INFORMATION, GO TO
www.ContechES.com/IP

LEFT END VIEW

INSTALLATION NOTES

SITE SPECIFIC DATA

PLAN VIEW

ELEVATION VIEW RIGHT END VIEW

STANDARD DETAIL

STORMWATER BIOFILTRATION SYSTEM
MWS-L-4-8-V

FOR PATENT INFORMATION, GO TO
www.ContechES.com/IP

LEFT END VIEW

INSTALLATION NOTES

SITE SPECIFIC DATA
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
ATTACHMENT 2

BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES
This is the cover sheet for Attachment 2.
 Mark this box if this attachment is empty because the project is exempt from PDP hydromodification management requirements.

Indicate which Items are Included behind this cover sheet:

Attachment
Sequence
Contents Checklist
Attachment 2a Hydromodification Management Exhibit
(Required)
 Included
See Hydromodification Management
Exhibit Checklist on the back of this
Attachment cover sheet.

Attachment 2b Management of Critical Coarse Sediment
Yield Areas (WMAA Exhibit is required,
additional analyses are optional)
See Section 6.2 of the BMP Design
Manual.
 Exhibit showing project drainage
boundaries marked on WMAA
Critical Coarse Sediment Yield Area
Map (Required)
Optional analyses for Critical Coarse
Sediment Yield Area Determination
 6.2.1 Verification of Geomorphic
Landscape Units Onsite
 6.2.2 Downstream Systems
Sensitivity to Coarse Sediment
 6.2.3 Optional Additional Analysis of
Potential Critical Coarse Sediment
Yield Areas Onsite
Attachment 2c Geomorphic Assessment of Receiving
Channels (Optional)
See Section 6.3.4 of the BMP Design
Manual.
 Not performed
 Included
 Submitted as separate stand-alone
document
Attachment 2d Flow Control Facility Design, including
Structural BMP Drawdown Calculations
and Overflow Design Summary
(Required)
See Chapter 6 and Appendix G of the
BMP Design Manual
 Included
 Submitted as separate stand-alone
document
Attachment 2e Vector Control Plan (Required when
structural BMPs will not drain in 96
hours)
 Included
 Not required because BMPs will
drain in less than 96 hours
X
X
X
X
X
X
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Use this checklist to ensure the required information has been included on the Hydromodification Management Exhibit:

The Hydromodification Management Exhibit must identify:
 Underlying hydrologic soil group
 Approximate depth to groundwater
 Existing natural hydrologic features ( watercourses, seeps, springs, wetlands)  Critical coarse sediment yield areas to be protected
 Existing topography
 Existing and proposed site drainage network and connections to drainage offsite  Proposed grading
 Proposed impervious features
 Proposed design features and surface treatments used to minimize imperviousness  Point(s) of Compliance (POC) for Hydromodification Management  Existing and proposed drainage boundary and drainage area to each POC (when necessary, create separate exhibits for pre-development and post-project conditions)  Structural BMPs for hydromodification management (identify location, type of BMP, and size/detail) Note: Please Reference Attachment 1A to find specified information.

Attachment 2A
Reference Attachment 1A for HMP Specifications
J
U
S
TA
L
N
WILLOW
G
RO
V
E
C
T
WIL
L
O
W
G
R
O
V
E
C
R
WIL
L
O
W
G
R
O
V
E
P
L

WILLOWGROVE AV

RIVERVIEW PY

GORGE AV

CARLTON
HILLS
BL

MISSION GORGE RD

TOWN CENTER PY
342' 330' 342'
338'
338'
328'
340'
340'
326'
332'
326'
338'
322'
332'
320'
318'
336'
334'
336'
336'
322'
328'
330'
322'
338'
318'
324'
322'
338'
336'
322'
322'
330'
340'
340'
338'
324'
320'
322'
320'
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320'
324'
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330'
330'
328'
334'
320'
320'
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340'
320'
326'
318'
330'
320'
334'
340'
318'
330'
338'
338'
334'
336'
320'
340'
338'
340'
338'
328'
328'
332'
336'
324'
330'
324'
340'
334'
338'
320' 338'
338'
328'
326'
338'
330'
338'
322'
322'
318'
340'
320'
322'
338'
330'
318'
3 320'
24'
324'
330'
320'
324'
324'
338'
334'
320'
322'
322'
320'
340'
340'
338'
338'
332'
322'
330'
340'
320'
318'
322'
340'
324'
338'
322'
336'
322'
334' 338'
322'
318'
320'
342'
316'
322'
320'
336'
322'
320'
324'
338'
338'
334'
318'
334'
336'
326'
338'
320'
324'
32 0'
324'
324'
320'
334'
324'
324'
322'
332'
324'
336'
320'
320'
324'
324'
316'
330'
326'
342'
322'
338'
322'
338'
322'
338'
322'
338'
316'
336'
332'
320'
324'
340'
320' 322'
334'
326'
328'
322'
330'
336'
340'
322'
340'
320'
324'
332'
322'
324'
338'
320'
332'
330'
338'
340'
336'
320'
338'
330'
338'
322'
340'
324'
324'
322'
320'
320'
338'
338'
338'
340'
324'
338'
340' 320'
332'
324'
338'
334'
332'
338'
324'
320'
324'
340'
322'
338'
338'
340'
338'
336'
324'
332'
322'
336'
316'
338'
336'
336'
326'
340'
340'
332'
340'
320'
330'
320'
338'
324'
322'
324'
334'
338'
332'
330'
330'
324'
336'
324'
340'
330'
320'
338'
324'
336'
322'
322'
338'
322'
320'
336'
338'
340'
340'
338'
338'
326'
336'
338'
328'
328'
332'
328'
340'
320'
330'
320'
322'
330'
328'
336'
332'
338'
336'
336'
332'
324'
324'
334'
336'
340'
324'
330'
322'
328'
338'
328'
336'
326'
324'
324'
318'
336'
328'
322'
320'
324'
338'
320'
340'
336'
334'
336'
320'
334'
322'
326'
320' 318'
324'
322'
340'
324' 340'
338'
320'
330'
328'
338'
340'
320'
338'
338'
324'
338'
318'
322'
322'
320'
Source: Esri, Maxar, Earthstar Geographics, and the GIS User Community Legend
Utilities
<all other values>
PType
Box Culvert
Concrete Channel
Concrete Ditch
Earthen Channel
SD_Pipe
Subcatchments
ROADS
Parcels
Exempt_Systems
Date of Exhibit: 9/10/2025
DigitalGlobe Aerial Image: 04.2013
The Exchange at Santee Town Center
-
\\cp .rickeng.com \p rojects\C20000\20075_TownCenterM F\GIS\20075_H M P_Exem pt_Exhibit.m xd [
North
200 100 0 200 Feet
Attachment 2B
SANDAG & SanGIS
Legend
Critical Coarse Sediment Yield Areas
Project Area
Date of Exhibit: 9/10/2025
DigitalGlobe Aerial Image: See Lower Right of Image
Critical Coarse Sediment Yield Areas Exhibit
0 1,000 2,000
Scale in Feet
[
North
The Exchange at Santee Town Center
\\cp.rickeng.com\projects\C20000\20075_TownCenterMF\GIS\20075_CCSYA_Exhibit_portrait.mxd Jn - 20075

PROJECT AREA
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
ATTACHMENT 3
Structural BMP Maintenance Information
This is the cover sheet for Attachment 3.

Indicate which Items are Included behind this cover sheet:

Attachment
Sequence
Contents Checklist
Attachment 3a Structural BMP Maintenance Thresholds
and Actions (Required)
 Included
See Structural BMP Maintenance
Information Checklist on the back of
this Attachment cover sheet.

Attachment 3b Draft Maintenance Agreement (when
applicable)
 Included
 Not Applicable
X
ATTACHMENT 3B TO BE INCLUDED DURING FINAL ENGINEERING
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
Use this checklist to ensure the required information has been included in the Structural BMP Maintenance Information Attachment:
 Preliminary Design / Planning / CEQA level submittal:

Attachment 3a must identify:
 Typical maintenance indicators and actions for proposed structural BMP(s) based on Section 7.7 of the BMP Design Manual
Attachment 3b is not required for preliminary design / planning / CEQA level submittal.  Final Design level submittal:

Attachment 3a must identify:
 Specific maintenance indicators and actions for proposed structural BMP(s). This shall be based on Section 7.7 of the BMP Design Manual and enhanced to reflect actual proposed components of the structural BMP(s)
 How to access the structural BMP(s) to inspect and perform maintenance  Features that are provided to facilitate inspection (e.g., observation ports, cleanouts, silt posts, or other features that allow the inspector to view necessary components of the structural BMP and compare to maintenance thresholds)
 Manufacturer and part number for proprietary parts of structural BMP(s) when applicable
 Maintenance thresholds specific to the structural BMP(s), with a location-specific frame of reference (e.g., level of accumulated materials that triggers removal of the materials, to be identified based on viewing marks on silt posts or measured with a survey rod with respect to a fixed benchmark within the BMP)
 Recommended equipment to perform maintenance
 When applicable, necessary special training or certification requirements for inspection and maintenance personnel such as confined space entry or hazardous waste management
Attachment 3b: For private entity operation and maintenance, Attachment 3b shall include a draft maintenance agreement in the local jurisdiction's standard format (PDP applicant to contact the [City Engineer] to obtain the current maintenance agreement forms).

X
X
Attachment 3A

INSPECTION

FREQUENCY

MAINTENANCE

FREQUENCY MAINTENANCE METHOD INCLUDED IN O&M MANUAL
SHEET

NUMBER(S)

LANDSCAPED AREAS
MONTHLY (NOTE: INSPECTOR SHALL

CHECK FOR THE FOLLOWING
MAINTENANCE INDICATORS: EROSION

IN THE FORM OF RILLS OR GULLIES,

PONDING WATER, BARE AREAS,
BURROWS, MOUNDS, AND TRASH.)

1. AS DETERMINED BY INSPECTION; AND

2. ON OR BEFORE SEPTEMBER 30TH.

1. FILL AND COMPACT AREAS OF RUTS, RILLS, OR
GULLIES;

2. RE-SEED AND/OR PLANT SLOPES AND AREAS OF
EXPOSED SOILS; AND

3. ROUTINE MOWING AND TRIMMING AND TRASH
REMOVAL.

YES

OUTLET PROTECTION

1. MONTHLY;

2. WITHIN 24 HOURS AFTER EACH
"SIGNIFICANT RAIN EVENT" AND

3. WITHIN 24 HOURS FOLLOWING

CONSTRUCTION IN IMMEDIATE AREA

OF OUTLET PROTECTION

1. AS DETERMINED BY INSPECTION;

2. WHEN DISTURBED OR MISSING ROCKS
(RIP RAP), OR SOIL EROSION BELOW

AND/OR ADJACENT TO OUTLET
PROTECTION ARE OBSERVED.

1. REMOVE TRASH, DEBRIS AND LEAVES. REPAIR ANY
DAMAGE TO ROOF DRAINS; 2. IMMEDIATELY REPOSITION
ALL DISPLACED ENERGY DISSIPATER; AND 3. IF SOIL
EROSION IS FOUND, EXTEND ENERGY DISSIPATER (I.E.

LANDSCAPE ROCKS AND/OR SPLASH PADS);

REPOSITION OR INCREASE LIMITS OF ENERGY
DISSIPATER TO COVER ERODED AREA.

YES

EFFECTIVE

IRRIGATION SYSTEM

MONTHLY WHEN BROKEN SPRINKLER HEADS, RAIN

SHUTOFF DEVICES, AND FLOW
REDUCERS ARE OBSERVED; OR

RUNNING SPRINKLERS IN RAIN ARE
OBSERVED.

REPAIR OR REPLACE THE BROKEN AND/OR
MALFUNCTIONING PARTS OF IRRIGATION SYSTEM.

YES

TRASH STORAGE
AREAS
WEEKLY 1. AS DETERMINED BY INSPECTION;

2. STANDING WATER IN TRASH
STORAGE AREA.

3. LOOSE TRASH OR DEBRIS.

4. LEAKED OR SPILLED MATERIALS.

5. COMPROMISED FENCE, SCREEN,
GATE, WALL, BIN. LID OR ROOF AWNING
(WHERE APPLICABLE).

6. CRACKED OR OTHERWISE

COMPROMISED PAVING OR OTHER

FLAWED FLOOR SURFACE (AS
APPLICABLE).

1. IF STANDING WATER IS OBSERVED IN THE AREA,

DETERMINE THE WATER SOURCE AND REMOVE THE
SOURCE. ALLOW STANDING WATER TO EVAPORATE. IF
WATER DOES NOT EVAPORATE IN 48 HOURS,
REDISTRIBUTE THE WATER TO LANDSCAPED AREA(S).

DO NOT DRAIN WATER TO STORM DRAIN SYSTEM;

2. REMOVE AND PROPERLY DISPOSE LOOSE TRASH,
DEBRIS, AND LEAKED OR SPILLED MATERIALS. USE

APPROPRIATE SPILL CLEANUP MATERIAL AS

NECESSARY TO REMOVE ALL LEAKED AND SPILLED

MATERIALS INCLUDING MATERIALS ADHERED TO
PAVEMENT. IDENTIFY AND REMOVE OR REPAIR THE
SOURCE OF ANY LEAKED OR SPILLED MATERIALS; AND

3. REPAIR THE FOLLOWING AS APPLICABLE:

COMPROMISED FENCE, SCREEN, GATE, WALL, BIN, LID

OR ROOF AWNING, CRACKED OR COMPROMISED
PAVING OR OTHER FLOOR SURFACE.

YES

PREVENTIVE

STENCILING AND

SIGNAGE

ANNUALLY WHEN FULLY OR PARTIALLY ERASED
SIGNS ARE OBSERVED; WHEN DUMPING

OF TRASH ARE OBSERVED AT PUBLIC

ACCESS POINTS, BUILDING ENTRANCES,
PUBLIC PARKS, ETC.

1. REPLACE OR REPAINT THE STENCILS AND SIGNAGE
SO THAT THEY ARE LEGIBLE; AND

2. MAKE SURE THAT THEY ARE PLACED AT ALL
REQUIRED LOCATIONS (I.E.- ALL INLETS).

YES

MODULAR WETLAND
SYSTEM (BMP-1 to
BMP-9)

1. MINIMUM TWICE A YEAR (ON OR
BEFORE SEPTEMBER 15TH AND

FOLLOWING THE RAINY SEASON
AFTER MAY 1ST); AND

2. AFTER EACH "SIGNIFICANT RAIN
EVENT"

AS NEEDED BASED ON INSPECTION

FINDINGS

1. ROUTINE MAINTENANCE TO REMOVE THE

ACCUMULATED MATERIALS IN THE SCREENING FILTER,

SEPARATION CHAMBER, AND PERIMETER FILTER
(BIOMEDIA GREEN) AND REPLACE FILTER MEDIA

PERFORMED BY A QUALIFIED SERVICE PROVIDER PER

MANUFACTUER'S GUIDELINES AND CONDITIONS
DEFINED IN THE WASHINGTON ECOLOGY T.A.P.E.

CERTIFICATION.

2. IF INSPECTION INDICATES INTERNAL COMPONENTS
ARE DAMAGED, ADDITIONAL NON‐ROUTINE

MAINTENANCE WILL BE REQUIRED TO REPAIR OR
REPLACE DAMAGED PARTS AS APPLICABLE.

YES
NOTES:

SITE DESIGN
SOURCE

CONTROL

1. REFER TO THE "PRIORITY DEVELOPMENT PROJECT (PDP) STORM WATER QUALITY MANAGEMENT PLAN (SWQMP) MISSION GROVE VILLAS", DATED SEPTEMBER 18, 2025, OR ANY REVISIONS THEREOF FOR MORE SPECIFIC INFORMATION.

2. A SIGNIFICANT RAIN EVENT CONSIDERED WHENEVER THE NATIONAL WEATHER SERVICE REPORTS 0.50" OF RAIN IN 48 HOURS FOR THE LOCAL COMMUNITY.

3. DURING THE FIRST YEAR OF NORMAL OPERATION, ALL BMPS SHOULD BE INSPECTED ONCE BEFORE AUGUST 31 AND THEN MONTHLY FROM SEPTEMBER THROUGH MAY. THE MINIMUM INSPECTION AND MAINTENANCE FREQUENCY SHOULD BE DETERMINED BASED ON THE RESULTS OF THE FIRST YEAR INSPECTIONS.

SITE DESIGN, SOURCE CONTROL AND POLLUTANT CONTROL BMP OPERATION & MAINTENANCE PROCEDURE DETAILS STORM WATER MANAGEMENT AND DISCHARGE CONTROL MAINTENANCE AGREEMENT APPROVAL NO.:

O&M RESPONSIBLE PARTY DESIGNEE:

STRUCTURAL
BMP

BMP DESCRIPTION

OPERATION AND MAINTENANCE

PROCEDURES THE EXCHANGE AT SANTEE TOWN CENTER
JN-20075
PDP SWQMP Template Date: February 2016
PDP SWQMP Preparation Date: [9-18-2025]
SFR:JS:ar:C20000/WR/Reports/PDPSWQMP/3rdSub/20075.003
ATTACHMENT 4
Copy of Plan Sheets Showing Permanent Storm Water BMPs
This is the cover sheet for Attachment 4.

Use this checklist to ensure the required information has been included on the plans:

The plans must identify:
 Structural BMP(s) with ID numbers matching Form I-6 Summary of PDP Structural BMPs  The grading and drainage design shown on the plans must be consistent with the delineation of DMAs shown on the DMA exhibit
 Details and specifications for construction of structural BMP(s)  Signage indicating the location and boundary of structural BMP(s) as required by the [City Engineer]  How to access the structural BMP(s) to inspect and perform maintenance  Features that are provided to facilitate inspection (e.g., observation ports, cleanouts, silt posts, or other features that allow the inspector to view necessary components of the structural BMP and compare to maintenance thresholds)
 Manufacturer and part number for proprietary parts of structural BMP(s) when applicable  Maintenance thresholds specific to the structural BMP(s), with a location-specific frame of reference (e.g., level of accumulated materials that triggers removal of the materials, to be identified based on viewing marks on silt posts or measured with a survey rod with respect to a fixed benchmark within the BMP)
 Recommended equipment to perform maintenance
 When applicable, necessary special training or certification requirements for inspection and maintenance personnel such as confined space entry or hazardous waste management  Include landscaping plan sheets showing vegetation requirements for vegetated structural BMP(s)  All BMPs must be fully dimensioned on the plans
 When proprietary BMPs are used, site-specific cross section with outflow, inflow, and model number shall be provided. Photocopies of general brochures are not acceptable.

X
X
X
X
X
X
X
X
X
X
Attachment 4
June 2025

NOISE AND VIBRATION IMPACT ANALYSIS

THE EXCHANGE AT SANTEE TOWN CENTER

SANTEE, CALIFORNIA
June 2025

NOISE AND VIBRATION IMPACT ANALYSIS

THE EXCHANGE AT SANTEE TOWN CENTER

SANTEE, CALIFORNIA
Submitted to:

EPD Solutions, Inc.
3333 Michelson Drive, Suite 500
Irvine, California 92612
Prepared by:

LSA
3210 El Camino Real, Suite 100
Irvine, California 92602
(949) 553-0666
Project No. ESL2201.107

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TABLE OF CONTENTS
FIGURES AND TABLES ............................................................................................................................ iv LIST OF ABBREVIATIONS AND ACRONYMS............................................................................................. v INTRODUCTION .......................................................................................................... 1 Project Location and Description .................................................................................................. 1 Existing Land Uses in the Project Area.......................................................................................... 4 NOISE AND VIBRATION FUNDAMENTALS .................................................................... 5 Characteristics of Sound................................................................................................................ 5 Measurement of Sound................................................................................................................. 5 Physiological Effects of Noise........................................................................................................ 6 Fundamentals of Vibration............................................................................................................ 8 REGULATORY SETTING.............................................................................................. 10 Applicable Noise Standards......................................................................................................... 10 California Code of Regulations .........................................................................................................10 City of Santee ...................................................................................................................................10 Applicable Vibration Standards................................................................................................... 13 California Department of Transportation.........................................................................................13 OVERVIEW OF THE EXISTING NOISE ENVIRONMENT.................................................. 15 Ambient Noise Measurements ................................................................................................... 15 Long-Term Noise Measurements.....................................................................................................15 Existing Aircraft Noise ................................................................................................................. 15 PROJECT IMPACTS .................................................................................................... 17 Short-Term Construction Noise Impacts..................................................................................... 17 Short-Term Construction Vibration Impacts............................................................................... 20 Long-Term Off-Site Traffic Noise Impacts................................................................................... 22 Long-Term Traffic-Related Vibration Impacts............................................................................. 23 ON-SITE LAND USE COMPATIBILITY ANALYSIS ........................................................... 24 On-Site Exterior Noise Impacts ................................................................................................... 24 On-Site Interior Noise Impacts.................................................................................................... 24 REFERENCES ............................................................................................................. 25

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FIGURES AND TABLES

FIGURES
Figure 1: Project Location....................................................................................................................... 2 Figure 2: Site Plan................................................................................................................................... 3 Figure 3: Noise Monitoring Locations .................................................................................................. 16 TABLES
Table A: Definitions of Acoustical Terms................................................................................................ 7 Table B: Common Sound Levels and Their Noise Sources...................................................................... 8 Table C: Santee General Plan Land Use Compatibility Guidelines (Ldn)................................................ 12 Table D: Interpretation of Vibration Criteria for Detailed Analysis...................................................... 13 Table E: Construction Vibration Damage Criteria ................................................................................ 14 Table F: Existing Noise Level Measurements....................................................................................... 15 Table G: Typical Construction Equipment Noise Levels....................................................................... 18 Table H: Potential Construction Noise Impacts at Nearest Receptor.................................................. 19 Table I: Vibration Source Amplitudes for Construction Equipment..................................................... 21 Table J: Potential Construction Vibration Annoyance Impacts at Nearest Receptor........................... 21 Table K: Potential Construction Vibration Damage Impacts at Nearest Receptor............................... 22

APPENDICES
A: NOISE MONITORING DATA
B: CONSTRUCTION NOISE LEVEL CALCULATIONS

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LIST OF ABBREVIATIONS AND ACRONYMS
ADT average daily traffic
APN Assessor’s Parcel Number
Caltrans California Department of Transportation
Caltrans’ Manual California Department of Transportation’s Transportation and Construction Vibration Guidance Manual
CCR California Code of Regulations
CEQA California Environmental Quality Act
City City of Santee
CNEL Community Noise Equivalent Level
D distance from the receiver to a piece of equipment
dB decibel(s)
dBA A-weighted decibel(s)
FHWA Federal Highway Administration
FTA Federal Transit Administration
FTA Manual Federal Transit Administration’s 2018 Transit Noise and Vibration Impact Assessment Manual
HVAC heating, ventilation, and air conditioning
in/sec inches per second
L50 median noise level
Ldn day-night average noise level
Leq equivalent continuous sound level
Lmax maximum instantaneous sound level
LV vibration velocity
PPV peak particle velocity
project The Exchange at Santee Town Center

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) iv RMS root-mean-square
SDCRAA San Diego County Regional Airport Authority
SPL sound pressure level
SR- State Route
STC Sound Transmission Class
U.F. usage factor
USEPA United States Environmental Protection Agency
V root-mean-square velocity amplitude
Vref reference velocity amplitude

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INTRODUCTION
This Noise and Vibration Impact Analysis has been prepared to evaluate the potential noise and vibration impacts and reduction measures associated with The Exchange at Santee Town Center (project) in Santee, California. This report is intended to satisfy the City of Santee (City) requirement for a project-specific noise impact analysis by examining the impacts of the project site and evaluating noise reduction measures that the project may require.

PROJECT LOCATION AND DESCRIPTION
The project site is located southern portion of the City of Santee in San Diego County in the unsectioned portion (Section 00) of Township 15 South, Range 1 West in the El Cajon, California (7.5-minute) quadrangle. The 5.26-gross-acre (4.18-net-acre) project site consists of one parcel identified as Assessor’s Parcel Number (APN) 381-040-30. Regional access to the site is provided via State Route (SR-) 52, SR-125, and SR-67. Local access to the site is provided via Mission Gorge Road.

The project proposes to subdivide the approximately 4.18-acre parcel and develop the site with 100 attached town-home residential units. Additionally, the proposed project includes landscaping, parking, private roadways, open space, and utility and stormwater improvements.

The proposed residences would be three stories with a maximum height of 36 feet, measured from finish grade to top of highest roof ridges. The residences would have a variety of architectural elements, including articulated massing and finish material palates, and have design characteristics consistent with modern styles. The project would provide 7,320 square feet of private open space, which would average 73 square feet of private open space per unit. The project would also provide 52,227 square feet of common open space. Open space amenities include an open turf lawn for active and passive play, a tot lot on rubberized play surface, an overhead shade structure with barbeque island, picnic tables, bench seating, trash receptacles for small social events and gatherings, and a fenced-in dog run with artificial turf.

The project would include a 6-foot-tall split-face block wall along the southern and eastern property lines and a 6-foot-tall concrete modular wall along the northern property line. Additionally, a 5-foot, 6-inch, tube steel fence would be installed around the perimeter of the dog run in the northern portion of the site. Figures 1 and 2 below show the project location and site plan, respectively.

Construction activities for the project would occur over one phase lasting approximately 16 months, beginning in February 2026 and ending in June 2027. Construction would occur in the following stages: (1) site preparation and grading; (2) building construction; (3) paving; and (4) architectural coatings. Construction activities would be limited to the hours of 7:00 a.m. to 7:00 p.m., Monday through Saturday, and no work on Sundays or City-recognized holidays, consistent with Municipal Code Section 5.04.090.

SOURCE: USGS The National Map (2025)
I:\E\ESL2201.107\GIS\Pro\Mission Gorge Project\Mission Gorge Project.aprx (10/28/2025) FIGURE 1
The Exchange at Santee Town Center

S A N D I E G O

C O U N T Y
163
54 56
67 78
52 125
209
282
94 8
5 15
805
San Diego
Project Vicinity
0 1000 2000
FEET
Project Location
Project Location
P
P

26.0 10.0

26.0 26.0

26.0 26.0 20.0

20.0 20.0 28.1

28.1 28.2

10.0 10.0

14.7 26.0

21.9 21.9

10.0 17.1

17.1 42.0

49.9 46.9
9,903 SF
3 6
4 4
1 1
3 5
5 3
8 12
22 9
5 5
5 5 5 2
5 5
3 7
7 7 5 1
3 BLDG D
BLDG D
BLDG D
BLDG D

BLDG C BLDG D
BLDG C
BLDG C

BLDG C BLDG B BLDG B
BLDG A
BLDG A
BLDG A
BLDG A
BLDG A
BLDG D
BLDG D

EXISTING POST OFFICE
(NOT A PART)
15,820 SF EXISTING LOWE'S
(NOT A PART)

EXISTING WALMART PARKING
(NOT A PART)

EXISTING MEDICAL
(NOT A PART)
11 11
11 11
13 5
14 14 14
14 14
5 EVCSEVCSEVCSEVCS
S00°13'45"W 441.41'
S89°43'47"E 479.99'
N00°13'54"E 801.16'
N89°43'47"E 431.99'
S00°13'54"W 359.75'
16 15
15 15
15 20 19 18 17
21 45.1

PVT DRIVE 'F'

PVT DRIVE 'A'

PVT DRIVE 'B'

PVT DRIVE 'C'

PVT DRIVE 'D'

PVT DRIVE 'E'
1 2 3 4 5 6 7 8 9 10 11
12 13 14 15
16 17 18
19 20
21 22
23 24
25 26
27 28
29 4.7

4.6 5.0

14.7 10

10.0 10.0
7 10.0

6.0 7.9

11.9 MISSION GORGE ROAD
N89°43'47"W 48.00'

TYPICAL PARKING DIMENSIONS (NTS)

PARALLEL

20.0 12.0 5.0 9.0 9.0

25.0 8.0
VAN

ACCESSIBLE

ACCESSIBLESTANDARD

PERPENDICULAR
WHEEL STOP, TYP.

SCALE:

SEPTEMBER 19, 2025

ANTEE, CA

ORSTEIN ENTERPRISES
766 WILSHIRE BLVD., STE 820
OS ANGELES, CA 90025

0.582.1991

THE EXCHANGE AT SANTEE TOWN CENTER

KEYNOTES
1 PROPERTY LIN
2 PERPENDICUL
3 PARALLEL PAR
4 ACCESSIBLE PA
5 4FT MINIMUM
6 COMMON REC
7 SETBACK LINE
8 EXISTING ACC

EASEMENT
9 PERIMETER WA
10 BIKE RACK
11 PEDESTRIAN G
12 EXISTING ACC

TO THE CITY

LANDSCAPED
13 TRAIL CONNE
14 UTILITY EASEM
15 CURB RAMPS
16 USPS DESIGNA
17 TOT LOT WIT

EQUIPMENT
18 BBQ & SEATIN
19 OPEN TURF PL
20 DOG RUN
21 MAILBOX LOC
22 COMPOSITE F
0 30 60 90
N
LEGEND

PROPERTY LINE

PATH OF TRAVEL

EV CHARGER EVCS

ADAPTABLE UNITS ADA
PARKING SPACE # 7
NOTES

1. TRASH RECEPTAPLES (TRASH, RECYCLE AND

ORGANIC) ARE LOCATED IN THE GARAGE OF EACH
UNIT

2. ALL MECHANICAL EQUIPMENT SHALL BE

ADEQUATELY SCREENED
SOURCE: SUMA Architecture
FIGURE 2
Site Plan
The Exchange at Santee Town Center
I:\E\ESL2201.107\G\Site_Plan.ai (10/28/2025)
0 45 90
FEET

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 4 Existing Land Uses in the Project Area
The project site is primarily surrounded by commercial and residential uses. The areas adjacent to the project site include the following uses:
• North: Existing Walmart department store.
• West: Existing home improvement store and single-family residences. • South: Existing United States Postal Service office.
• East: Existing medical offices and commercial uses (fast food chains).

The nearest sensitive receptors are the existing single-family residences located approximately 15 feet west of the project site boundary.

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NOISE AND VIBRATION FUNDAMENTALS

CHARACTERISTICS OF SOUND
Noise is usually defined as unwanted sound. Noise consists of any sound that may produce physiological or psychological damage and/or interfere with communication, work, rest, recreation, and sleep.

To the human ear, sound has two significant characteristics: pitch and loudness. Pitch is generally an annoyance, while loudness can affect the ability to hear. Pitch is the number of complete vibrations, or cycles per second, of a sound wave, which results in the tone’s range from high to low. Loudness is the strength of a sound, and it describes a noisy or quiet environment; it is measured by the amplitude of the sound wave. Loudness is determined by the intensity of the sound waves combined with the reception characteristics of the human ear. Sound intensity is the average rate of sound energy transmitted through a unit area perpendicular to the direction in which the sound waves are traveling. This characteristic of sound can be precisely measured with instruments. The analysis of the project defines the noise environment of the project area in terms of sound intensity and its effect on adjacent sensitive land uses.

MEASUREMENT OF SOUND
Sound intensity is measured with the A-weighted decibel (dBA) scale to correct for the relative frequency response of the human ear. That is, an A-weighted noise level de-emphasizes low and very high frequencies of sound, similar to the human ear’s de-emphasis of these frequencies.

Decibels (dB), unlike the linear scale (e.g., inches or pounds), are measured on a logarithmic scale representing points on a sharply rising curve.

For example, 10 dB is 10 times more intense than 0 dB, 20 dB is 100 times more intense than 0 dB, and 30 dB is 1,000 times more intense than 0 dB. Thirty decibels (30 dB) represent 1,000 times as much acoustic energy as 0 dB. The decibel scale increases as the square of the change, representing the sound pressure energy. A sound as soft as human breathing is about 10 times greater than 0 dB.

The decibel system of measuring sound gives a rough connection between the physical intensity of sound and its perceived loudness to the human ear. A 10 dB increase in sound level is perceived by the human ear as only a doubling of the sound’s loudness. Ambient sounds generally range from 30 dB (very quiet) to 100 dB (very loud).

Sound levels are generated from a source, and their decibel level decreases as the distance from that source increases. Sound levels dissipate exponentially with distance from their noise sources. For a single point source, sound levels decrease approximately 6 dB for each doubling of distance from the source. This drop-off rate is appropriate for noise generated by stationary equipment. If noise is produced by a line source (e.g., highway traffic or railroad operations), the sound decreases 3 dB for each doubling of distance in a hard site environment. Line source sound levels decrease 4.5 dB for each doubling of distance in a relatively flat environment with absorptive vegetation.

There are many ways to rate noise for various time periods, but an appropriate rating of ambient noise affecting humans also accounts for the annoying effects of sound. The equivalent continuous

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 6 sound level (Leq) is the total sound energy of time-varying noise over a sample period. However, the predominant rating scales for human communities in the State of California are the Leq and Community Noise Equivalent Level (CNEL) or the day-night average noise level (Ldn) based on A-weighted decibels. CNEL is the time-weighted average noise over a 24-hour period, with a 5 dBA weighting factor applied to the hourly Leq for noises occurring from 7:00 p.m. to 10:00 p.m. (defined as relaxation hours) and a 10 dBA weighting factor applied to noises occurring from 10:00 p.m. to 7:00 a.m. (defined as sleeping hours). Ldn is similar to the CNEL scale but without the adjustment for events occurring during the relaxation. CNEL and Ldn are within 1 dBA of each other and are normally interchangeable. The City of Santee uses the Ldn noise scale for long-term traffic noise impact assessment.

Other noise rating scales of importance when assessing the annoyance factor include the maximum instantaneous noise level (Lmax), which is the highest sound level that occurs during a stated time period. The noise environments discussed in this analysis for short-term noise impacts are specified in terms of maximum levels denoted by Lmax, which reflects peak operating conditions and addresses the annoying aspects of intermittent noise. It is often used together with another noise scale, or noise standards in terms of percentile noise levels, in noise ordinances for enforcement purposes. For example, the L10 noise level represents the noise level exceeded 10 percent of the time during a stated period. The L50 noise level represents the median noise level. Half the time the noise level exceeds this level, and half the time it is less than this level. The L90 noise level represents the noise level exceeded 90 percent of the time and is considered the background noise level during a monitoring period. For a relatively constant noise source, the Leq and L50 are approximately the same.

Noise impacts can be described in three categories. The first category includes audible impacts, which are increases in noise levels noticeable to humans. Audible increases in noise levels generally refer to a change of 3 dB or greater because this level has been found to be barely perceptible in exterior environments. The second category, potentially audible, refers to a change in the noise level between 1 dB and 3 dB. This range of noise levels has been found to be noticeable only in laboratory environments. The last category includes changes in noise levels of less than 1 dB, which are inaudible to the human ear. Only audible changes in existing ambient or background noise levels are considered potentially significant.

PHYSIOLOGICAL EFFECTS OF NOISE
Physical damage to human hearing begins at prolonged exposure to sound levels higher than 85 dBA. Exposure to high sound levels affects the entire system, with prolonged sound exposure in excess of 75 dBA increasing body tensions, thereby affecting blood pressure and functions of the heart and the nervous system. In comparison, extended periods of sound exposure above 90 dBA would result in permanent cell damage. When the sound level reaches 120 dBA, a tickling sensation occurs in the human ear, even with short-term exposure. This level of sound is called the threshold of feeling. As the sound reaches 140 dBA, the tickling sensation is replaced by a feeling of pain in the ear (i.e., the threshold of pain). A sound level of 160–165 dBA will result in dizziness or a loss of equilibrium. The ambient or background noise problem is widespread and generally more concentrated in urban areas than in outlying, less developed areas.

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 7 Table A lists definitions of acoustical terms, and Table B shows common sound levels and their sources.

Table A: Definitions of Acoustical Terms
Term Definitions
Decibel, dB A unit of sound measurement that denotes the ratio between two quantities that are proportional to power; the number of decibels is 10 times the logarithm (to the base 10) of this ratio.

Frequency, hertz Of a function periodic in time, the number of times that the quantity repeats itself in 1 second (i.e., the number of cycles per second).

A-Weighted Sound
Level, dBA
The sound level obtained by use of A-weighting. The A-weighting filter de-emphasizes the very low and very high frequency components of the sound in a manner similar to the frequency response of the human ear and correlates well with subjective reactions to noise. (All sound levels in this report are A-weighted unless reported otherwise.) L01, L10, L50, L90 The fast A-weighted noise levels that are equaled or exceeded by a fluctuating sound level 1%, 10%, 50%, and 90% of a stated time period, respectively.

Equivalent Continuous
Noise Level, Leq
The level of a steady sound that, in a stated time period and at a stated location, has the same A-weighted sound energy as the time-varying sound.

Community Noise
Equivalent Level, CNEL
The 24-hour A-weighted average sound level from midnight to midnight, obtained after the addition of 5 dBA to sound levels occurring in the evening from 7:00 p.m. to 10:00 p.m. and after the addition of 10 dBA to sound levels occurring in the night between 10:00 p.m. and 7:00 a.m.

Day/Night Noise Level, Ldn The 24-hour A-weighted average sound level from midnight to midnight, obtained after the addition of 10 dBA to sound levels occurring in the night between 10:00 p.m. and 7:00 a.m.

Lmax, Lmin The maximum and minimum A-weighted sound levels measured on a sound level meter, during a designated time interval, using fast time averaging.

Ambient Noise Level The all-encompassing noise associated with a given environment at a specified time.

Usually a composite of sound from many sources from many directions, near and far; no particular sound is dominant.

Intrusive The noise that intrudes over and above the existing ambient noise at a given location. The relative intrusiveness of a sound depends upon its amplitude, duration, frequency, time of occurrence, and tonal or informational content, as well as the prevailing ambient noise level.

Sources: (1) Technical Noise Supplement (Caltrans 2013); (2) Transit Noise and Vibration Impact Assessment Manual (FTA 2018).

Caltrans = California Department of Transportation
FTA = Federal Transit Administration

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 8 Table B: Common Sound Levels and Their Noise Sources
Noise Source A-Weighted Sound
Level in Decibels Noise Environments Subjective Evaluations Near Jet Engine 140 Deafening 128 times as loud
Civil Defense Siren 130 Threshold of Pain 64 times as loud Hard Rock Band 120 Threshold of Feeling 32 times as loud Accelerating Motorcycle at a Few Feet Away 110 Very Loud 16 times as loud Pile Driver; Noisy Urban Street/Heavy City
Traffic
100 Very Loud 8 times as loud
Ambulance Siren; Food Blender 95 Very Loud —
Garbage Disposal 90 Very Loud 4 times as loud
Freight Cars; Living Room Music 85 Loud —
Pneumatic Drill; Vacuum Cleaner 80 Loud 2 times as loud Busy Restaurant 75 Moderately Loud —
Near Freeway Auto Traffic 70 Moderately Loud Reference level Average Office 60 Quiet One-half as loud
Suburban Street 55 Quiet —
Light Traffic; Soft Radio Music in Apartment 50 Quiet One-quarter as loud Large Transformer 45 Quiet —
Average Residence without Stereo Playing 40 Faint One-eighth as loud Soft Whisper 30 Faint —
Rustling Leaves 20 Very Faint —
Human Breathing 10 Very Faint Threshold of Hearing
— 0 Very Faint —
Source: Compiled by LSA (2022).

FUNDAMENTALS OF VIBRATION
Vibration refers to ground-borne noise and perceptible motion. Ground-borne vibration is almost exclusively a concern inside buildings and is rarely perceived as a problem outdoors, where the motion may not be discernible, but without the effects associated with the shaking of a building there is less adverse reaction. Vibration energy propagates from a source through intervening soil and rock layers to the foundations of nearby buildings. The vibration then propagates from the foundation throughout the remainder of the structure. Building vibration may be perceived by occupants as the motion of building surfaces, the rattling of items sitting on shelves or hanging on walls, or a low-frequency rumbling noise. The rumbling noise is caused by the vibration of walls, floors, and ceilings that radiate sound waves.

Typical sources of ground-borne vibration are construction activities (e.g., blasting, pile-driving, and operating heavy-duty earthmoving equipment), steel-wheeled trains, and occasional traffic on rough roads. Problems with both ground-borne vibration and noise from these sources are usually localized to areas within approximately 100 feet of the vibration source, although there are examples of ground-borne vibration causing interference out to distances greater than 200 feet as detailed in the Federal Transit Administration’s (FTA) 2018 Transit Noise and Vibration Impact Assessment Manual (FTA Manual). When roadways are smooth, vibration from traffic, even heavy trucks, is rarely perceptible. It is assumed for most projects that the roadway surface will be smooth enough that ground-borne vibration from street traffic will not exceed the impact criteria; however,

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 9 construction of the project could result in ground-borne vibration that may be perceptible and annoying.

Ground-borne noise is not likely to be a problem because noise arriving via the normal airborne path will usually be greater than ground-borne noise.

Ground-borne vibration has the potential to disturb people and damage buildings. Although it is very rare for train-induced ground-borne vibration to cause even cosmetic building damage, it is not uncommon for construction processes such as blasting and pile-driving to cause vibration of sufficient amplitudes to damage nearby buildings (FTA 2018). Ground-borne vibration is usually measured in terms of vibration velocity, either the root-mean-square (RMS) velocity or peak particle velocity (PPV). The RMS is best for characterizing human response to building vibration, and PPV is used to characterize the potential for damage. Decibel notation acts to compress the range of numbers required to describe vibration. Vibration velocity level in decibels is defined as Lv = 20 log10 [V/Vref]
where “Lv” is the vibration velocity in decibels (VdB), “V” is the vibration amplitude, and “Vref” is the reference velocity amplitude, or 1 x 10-6 inches per second (in/sec) used in the United States.

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REGULATORY SETTING

APPLICABLE NOISE STANDARDS
The applicable noise standards governing the project site include the criteria in the California Code of Regulations, the City’s Noise Element of the General Plan (Noise Element) and the Santee Municipal Code.

California Code of Regulations
Interior noise levels for residential habitable rooms are regulated by Title 24 of the California Code of Regulations (CCR) California Noise Insulation Standards. Title 24, Chapter 12, Section 1206.4, of the 2019 California Building Code requires that interior noise levels attributable to exterior sources not exceed 45 CNEL/Ldn in any habitable room. A habitable room is a room used for living, sleeping, eating, or cooking. Bathrooms, closets, hallways, utility spaces, and similar areas are not considered habitable rooms for this regulation (CCR Title 24, Chapter 12, Section 1206.4).

City of Santee
Noise Element of the General Plan
The goals, objectives, and policies in the City’s General Plan Noise Element are designed to provide noise compatible land use relationships by establishing noise standards utilized for design and siting purposes and minimize noise impacts from significant noise generators. The following goals and policies are applicable to the proposed project:

Objective 1.0. Control noise from sources adjacent to residential, institutional, and other noisesensitive receptors. • Policy 1.1: The City shall support a coordinated program to protect and improve the acoustical environment of the City including development review for new public and private development and code compliance for existing development.
• Policy 1.2: The City shall utilize noise studies and noise contour maps when evaluating development proposals during the discretionary review process. • Policy 1.4: The City shall promote alternative sound attenuation measures rather than traditional wall barrier wherever feasible; these may include glass or polycarbonate walls, berms, landscaping, and the siting of noise-sensitive uses on a parcel away from the roadway or other noise source.
• Policy 1.5: The City shall review future projects with particular scrutiny regarding the reduction of unnecessary noise near noise-sensitive areas such as hospitals, schools, parks, etc.

Objective 2.0. Ensure that future developments will be constructed to minimize interior and exterior noise levels.

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 11 • Policy 2.1: The City shall adhere to planning guidelines and building codes which include noise control for the exterior and interior living space of all new residential developments within noise impacted areas.
• Policy 2.2: The City should require new development to mitigate noise impacts to existing uses resulting from new development when: 1) such development adds traffic to existing City streets that necessitates the widening of the street; and 2) the additional traffic generated by new development causes the noise standard or significance thresholds to be exceeded. • Policy 2.3: The City should not require new development to mitigate noise impacts to existing uses when new development only adds traffic already anticipated by the City’s General Plan to an existing street, but does not necessitate widening of that street.

Section 8.1 of the City’s Noise Element discusses thresholds for California Environmental Quality Act (CEQA) impact determination. CEQA encourages jurisdictions to establish local thresholds for determining whether a particular impact is significant if, as a direct result of the proposed development, noise levels which already exceed the levels considered compatible for that use are increased by 3 or more decibels.

Development standards should be applied to future projects during the discretionary review process and should include the following:

1. Whenever it appears that new development will result in any existing or future noise sensitive uses being subjected to noise levels of 65 dB(A) Ldn, or greater, as depicted in Table C, an acoustical study will be required.

For residential uses, noise sensitive areas shall include rear yard areas on single family residences and ground floor common areas and private patio areas for multiple family residences. For other noise sensitive uses such as libraries, schools or hospitals, noise sensitive areas shall be those areas that serve a significant function for the use that could be adversely affected by noise. Examples include resting or patient recovery areas at hospitals, outdoor service areas for churches (excluding areas used for short-term social gatherings) or outdoor teaching or discussion areas at schools (does not include playgrounds or other active outdoor areas).

2. If the acoustical study shows that the noise levels at any noise sensitive area will exceed 65 dB(A) Ldn, the development should not be approved unless the following findings are made:
a. Modifications to the development have been, or will be made, which will reduce the exterior noise level in noise sensitive areas to 65 dBA Ldn or less, or b. If, with current noise abatement technology, it is not feasible to reduce the exterior noise level to 65 dBA Ldn or less, then modifications to the development will have been, or will be made which reduce the exterior noise level to the maximum extent feasible and the interior noise level to 45 dBA Ldn or less. Particular attention shall be given to noise sensitive spaces such as bedrooms.

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 12 Table C: Santee General Plan Land Use Compatibility Guidelines (Ldn) Land Use Category Normally
Acceptable
Conditionally
Acceptable
Normally
Unacceptable
Clearly
Unacceptable
Residential – Low Density,
Single-Family, Duplex, Mobile
Homes
50 – 65 65 – 70 70 – 75 75 – 85
Residential – Multiple family 50 – 65 65 – 70 70 – 75 75 – 85 Transient Lodging – Motel,
Hotels 50 – 65 65 – 70 70 – 80 80 – 85
Schools, Libraries, Churches,
Hospitals, Nursing Homes1 50 – 65 65 – 70 70 – 80 80 – 85 Auditoriums, Concert Halls,
Amphitheaters 50 – 60 60 – 70 NA 70 – 85
Sports Arenas, Outdoor
Spectator Sports 50 – 65 65 – 75 NA 75 – 85
Playgrounds, Neighborhood
Parks 50 – 70 NA 70 – 75 75 – 85
Golf Courses, Riding Stables,
Water Recreation, Cemeteries 50 – 75 NA 75 – 80 80 – 85 Office Buildings, Business
Commercial, and Professional 50 – 70 70 – 75 75 – 85 NA Industrial, Manufacturing,
Utilities, Agriculture 50 – 75 75 – 80 80 – 85 NA
Source: City of Santee (2003).

Notes: Ldn = day-night Noise Level; NA = not applicable 1 Applies to noise-sensitive areas which serve a significant function for the use which could be adversely affected by noise such as outside areas used primarily for instruction, meditation areas, rest and relaxation areas, and other areas where general peace and quiet are important.

Normally Acceptable: Specified land use is satisfactory, based upon the assumption that any buildings involved are of normal conventional construction, without any special noise insulation requirements.

Conditionally Acceptable: New construction or development should be undertaken only after a detailed analysis of the noise reduction requirements is made and needed noise insulation features have been included in the design. Conventional construction, but with closed windows and fresh air supply systems or air conditioning, will normally suffice.

Normally Unacceptable: New construction or development should be discouraged. If new construction or development does proceed, a detailed analysis of the noise reduction requirements must be made and needed noise insulation features must be included in the design.

Clearly Unacceptable: New construction or development should generally not be undertaken.

Table C presents the Noise Element guidelines for determining acceptable and unacceptable community noise exposure limits for various land use categories.

City of Santee Municipal Code
The City of Santee addresses noise impacts in Chapter 5.04 of the City’s Municipal Code. Section

5.04.040, which establishes the City’s noise regulation, generally prohibits nuisance noise and states that it is unlawful for any person to make, continue, or cause to be made or continued within the City limits any disturbing, excessive, or offensive noise that causes discomfort or annoyance to reasonable persons of normal sensitivity residing in the area. This section details several specific sources of nuisance noise and outlines how it may be determined that the noise is in violation of the code. Specific sources of nuisance noise include, but are not limited to, devices for producing or reproducing sound, drums and other musical instruments, yelling, and animals.

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 13 Section 5.04.040 also provides the following requirements for HVAC units:

4. Heating and Air Conditioning Equipment and Generators. a. It is unlawful for any person to operate or allow the operation of any generator, air conditioning, refrigeration or heating equipment in such manner as to create a noise disturbance on the premises of any other occupied property, or if a condominium, apartment house, duplex, or attached business, within any adjoining unit.
b. All generators, heating, air conditioning, or refrigeration equipment are subject to the setback and screening requirements in this code.

Section 5.04.090, which specifically pertains to construction equipment, makes operation of any construction equipment outside the hours of 7:00 a.m. through 7:00 p.m., Monday through Saturday, except holidays, unlawful unless the operation is expressly approved by the Director of Development Services. Construction equipment with a manufacturer’s noise rating of 85 dBA Lmax or greater may only operate at a specific location for 10 consecutive workdays. If work involving such equipment would involve more than 10 consecutive workdays, a notice must be provided to all property owners and residents within 300 feet of the site no later than 10 days before the start of construction. The notice must be approved by the City and describe the proposed project and the expected duration of work and provide a point of contact to resolve noise complaints.

APPLICABLE VIBRATION STANDARDS
California Department of Transportation
Vibration standards included in the California Department of Transportation’s (Caltrans) Transportation and Construction Vibration Guidance Manual (Caltrans Manual) (2020) are used in this analysis for ground-borne vibration impacts on human annoyance and building damage. The criteria for environmental impact from ground-borne vibration are based on the maximum levels for a single event and the RMS vibration level. Table D provides the criteria for assessing the potential for interference or annoyance from vibration levels in a building.

Table D: Interpretation of Vibration Criteria for
Detailed Analysis
Human Response Vibration Level (RMS in/sec)
Barely perceptible 0.01
Distinctly perceptible 0.04
Strongly perceptible 0.10
Severe 0.40
Source: Transportation and Construction Vibration Guidance Manual (Caltrans 2020).

Caltrans = California Department of Transportation
in/sec = inch/inches per second
RMS = root-mean-square

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 14 Table E lists the potential vibration building damage criteria associated with construction activities, as suggested in the Caltrans Manual. Caltrans guidelines show that a vibration level of up to

0.5 in/sec in PPV is considered safe for newer residential structures and modern industrial or commercial buildings and would not result in any construction vibration damage.

Table E: Construction Vibration Damage Criteria
Structure / Condition PPV (in/sec)
Extremely fragile historic buildings, ruins, ancient monuments 0.08 Fragile buildings 0.10
Historic and some old buildings 0.25
Older residential structures 0.30
New residential structures 0.50
Modern industrial / commercial buildings 0.50
Source: Transportation and Construction Vibration Guidance Manual, Table 19 (Caltrans 2020).

Caltrans = California Department of Transportation
in/sec = inch/inches per second
PPV = peak particle velocity

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 15

OVERVIEW OF THE EXISTING NOISE ENVIRONMENT
The primary existing noise sources in the project area include vehicle traffic on SR-52, Mission Gorge Road, and local roads in the vicinity of the project.

AMBIENT NOISE MEASUREMENTS
Long-Term Noise Measurements
To assess existing noise levels, LSA conducted three long-term noise measurements in the vicinity of the project site. The long-term (24-hour) noise level measurements were conducted on May 5 and 6, 2025, using three Larson Davis Spark 706RC Dosimeters. Table F provides a summary of the measured hourly noise levels from the long-term noise level measurements. Noise measurement sheets are provided in Appendix A. Figure 3 shows the long-term monitoring locations.

Table F: Existing Noise Level Measurements
Location
Number Location Description
Daytime Noise
Levels1
(dBA Leq)
Nighttime
Noise Levels3
(dBA Leq)
Average
Daily Noise
Levels
(dBA Ldn)
Primary
Noise Sources
LT-1
Near the northwest corner of the
project site, on a tree. Approximately
1,750 feet from the SR-52 centerline. 45.4-60.2 40.8–55.0 58.3 Vehicle traffic
on SR-52 and
Mission
Gorge Road
LT-2
Near San Ysidro Health Center, 120
Town Center Parkway, on a tree
southwest of the building. Just east
of the project site. Approximately
1,750 feet from the SR-52 centerline.

49.1-62.1 43.7-55.4 59.6
Vehicle traffic
on SR-52 and
Mission
Gorge Road
LT-3
On the east side of Lowe’s, 9416
Mission Gorge Road, on a tree. West
of the project site. Approximately
1,350 feet from the SR-52 centerline.

52.4-61.9 45.7-57.1 60.8
Vehicle traffic
on SR-52 and
Mission
Gorge Road
Source: Compiled by LSA (2025). 1 Daytime Noise Levels = noise levels during the hours of 7:00 a.m. to 10:00 p.m. 2 Nighttime Noise Levels = noise levels during the hours of 10:00 p.m. to 7:00 a.m.

Ldn = Day-night average noise level
dBA = A-weighted decibels
Leq = equivalent continuous sound level
SR- = State Route

EXISTING AIRCRAFT NOISE
The project site is approximately 0.9 mile northwest of Gillespie Field Airport. Based on the Gillespie Field Airport Land Use Compatibility Plan (SDCRAA 2010), the project is located outside of the 65 dBA CNEL noise contour for Gillespie Field. Because the project site is not located within the 65 dBA CNEL noise contour, no further analysis associated with aircraft noise impacts is necessary.

Additionally, there are no helipads or private airstrips within 2 miles of the project area.

Town Center Pkwy
Mission Gorge Rd
0 100 200
FEET
FIGURE 3
The Exchange at Santee Town Center
SOURCE: Google Earth 2025 Noise Monitoring Locations
I:\E\ESL2201.107\G\Noise_Locs.ai (10/28/2025)
LEGEND
Project Site Boundary
LT-1 Long-term Noise Monitoring Location
LT-1
LT-2
LT-3
LT-2
LT-3

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 17

PROJECT IMPACTS

SHORT-TERM CONSTRUCTION NOISE IMPACTS
Two types of short-term noise impacts could occur during the construction of the proposed project.

First, construction crew commutes and the transport of construction equipment and materials to the site for the proposed project would incrementally increase noise levels on access roads leading to the site. Although there would be a relatively high single-event noise-exposure potential causing intermittent noise nuisance (passing trucks at 50 feet would generate up to 84 dBA Lmax), the effect on longer-term ambient noise levels would be small when compared to the existing average daily traffic (ADT) volume on Mission Gorge Road. Based on the ADT provided by the City of Santee Mobility Element, the ADT on Mission Gorge Road is approximately 32,200 based on projections for the year 2013. While the existing ADT is likely higher, using 32,200 ADT as the existing count would be a conservative approach. During the grading phase, approximately 1,209 acoustically equivalent trips would occur during an average day from worker and delivery activities resulting in a traffic noise increase of approximately 0.2 dBA, as shown in Appendix B. A noise level increase of less than 3 dBA would not be perceptible to the human ear. Therefore, short-term construction-related impacts associated with worker commutes and equipment transport to the project site would be less than significant.

The second type of short-term noise impact is related to noise generated during construction, which includes site preparation, grading, building construction, paving, and architectural coating on the project site. Construction is completed in discrete steps, each of which has its own mix of equipment and, consequently, its own noise characteristics. These various sequential phases would change the character of the noise generated on the site and, therefore, the noise levels surrounding the site as construction progresses. Despite the variety in the type and size of construction equipment, similarities in the dominant noise sources and patterns of operation allow construction-related noise ranges to be categorized by work phase. Table G lists typical construction equipment noise levels recommended for noise impact assessments, based on a distance of 50 feet between the equipment and a noise receptor, taken from the Federal Highway Administration’s (FHWA) FHWA Roadway Construction Noise Model (FHWA 2006).

In addition to the reference maximum noise level, the usage factor provided in Table G is used to calculate the hourly noise level impact for each piece of equipment based on the following equation:


 

 += − 50 log20.).log(10..)( D
eq FULEequipL
“Leq (equip)” is the Leq at a receiver resulting from the operation of a single piece of equipment over a specified time period,
“E.L.” is the noise emission level of the particular piece of equipment at a reference distance of 50 feet,

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 18 Table G: Typical Construction Equipment Noise Levels
Equipment Description Acoustical Usage
Factor (%)1
Maximum Noise Level
(Lmax) at 50 ft2
Auger Drill Rig 20 84
Backhoes 40 80
Compactor (ground) 20 80
Compressor 40 80
Cranes 16 85
Dozers 40 85
Dump Trucks 40 84
Excavators 40 85
Flat Bed Trucks 40 84
Forklift 20 85
Front-end Loaders 40 80
Graders 40 85
Impact Pile Drivers 20 95
Jackhammers 20 85
Paver 50 77
Pickup Truck 40 55
Pneumatic Tools 50 85
Pumps 50 77
Rock Drills 20 85
Rollers 20 85
Scrapers 40 85
Tractors 40 84
Trencher 50 80
Welder 40 73
Source: FHWA Roadway Construction Noise Model User’s Guide, Table 1 (FHWA 2006).

Note: Noise levels reported in this table are rounded to the nearest whole number. 1 Usage factor is the percentage of time during a construction noise operation that a piece of construction equipment is operating at full power. 2 Maximum noise levels were developed based on Specification 721.560 from the Central Artery/Tunnel program to be consistent with the City of Boston’s Noise Code for the “Big Dig” project.

FHWA = Federal Highway Administration
ft = foot/feet
Lmax = maximum instantaneous sound level
“U.F.” is the usage factor that accounts for the fraction of time that the equipment is in use over the specified period of time, and
“D” is the distance from the receiver to the piece of equipment.

Each piece of construction equipment operates as an individual point source. Using the following equation, a composite noise level can be calculated when multiple sources of noise operate simultaneously:

𝐿𝐿𝐿𝐿𝐿𝐿 (𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 ) = 10 ∗ log10 ��10
𝐿𝐿𝐿𝐿
10 1
�

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 19 Using the equations from the methodology above, the reference information in Table H, and the construction equipment list provided, the composite noise levels of each construction phase were calculated. The project construction composite noise levels at a distance of 50 feet would range from 74 dBA Leq to 88 dBA Leq, with the highest noise levels occurring during the site preparation phase.

Table H: Potential Construction Noise Impacts at Nearest Receptor Receptor (Location) Composite Noise Level
(dBA Leq) at 50 ft1
Distance
(ft)
Composite Noise
Level (dBA Leq)
Commercial Uses (East)
88 250 74
Residential Uses (West) 280 73
Postal Office (South) 280 73
Commercial Uses (West) 320 72
Commercial Uses (North) 415 69
Source: Compiled by LSA (2025). 1 The composite construction noise level represents the site preparation and paving phases, which are expected to result in the greatest noise level as compared to other phases.
dBA = A-weighted decibels
ft = foot/feet
Leq = equivalent continuous sound level
Once composite noise levels are calculated, reference noise levels can then be adjusted for distance using the following equation:

𝐿𝐿𝐿𝐿𝐿𝐿 (𝑎𝑎 𝑑𝑑 𝑑𝑑 𝑋𝑋) = 𝐿𝐿𝐿𝐿𝐿𝐿 (𝑎𝑎 50 𝑓𝑓 ) − 20 ∗ log10 � 𝑋𝑋
50�
In general, this equation shows that doubling the distance would decrease noise levels by 6 dBA, and halving the distance would increase noise levels by 6 dBA.

Table H shows the nearest sensitive uses to the project site, their distance from the center of construction activities, and composite noise levels expected during construction. These noise level projections do not consider intervening topography or barriers. Construction equipment calculations are provided in Appendix B.

Although construction noise will vary, it is expected that composite noise levels during construction at the nearest off-site commercial uses to the east would approach 74 dBA Leq, and construction noise levels would approach 73 dBA Leq at the nearest residential use to the west during daytime hours. These predicted noise levels would only occur when all construction equipment is operating simultaneously and, therefore, are assumed to be rather conservative in nature.

Although the project construction-related short-term noise levels have the potential to be up to 20 dBA higher than the average daytime ambient noise at the closest sensitive receptor to the west, construction noise would occur for 20 days or less during the grading phase and would then cease to occur once the project construction is completed and the exposure would be temporary. In accordance with Santee Municipal Code Section 5.04.090, construction activities would not occur

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 20 before 7:00 a.m. or after 7:00 p.m. on Mondays through Saturdays and would not occur any time on Sundays and holidays. Additionally, as required by the Santee Municipal Code, a notice would be provided to all owners and occupants within 300 feet of the project site if the construction equipment has a manufacturer’s noise rating of 85 dB and operates at a specific location for ten consecutive workdays. Although construction noise levels would exceed the existing ambient noise environment, construction noise impacts would be less than significant because construction activities would occur during the hours specified in the Santee Municipal Code and notice would be provided to nearby occupants. With incorporation of standard best business practices for noise reduction, the overall noise levels generated will be minimized, and construction noise impacts would be less than significant, and no mitigation is required.

Construction Best Business Practices:the project contractor implement the following measures during construction of the project:
• Equip all construction equipment, fixed or mobile, with properly operating and maintained mufflers consistent with manufacturers’ standards.
• Place all stationary construction equipment so that emitted noise is directed away from sensitive receptors nearest the active project site.
• Locate equipment staging in areas that would create the greatest possible distance between construction-related noise sources and noise-sensitive receptors nearest the active project site during all project construction.
• Ensure that all construction related activities are restricted to the hours 7:00 a.m. through 7:00 p.m., Monday through Saturday, with no construction on holidays. • Designate a "disturbance coordinator" at the City of Santee who would be responsible for responding to any local complaints about construction noise. The disturbance coordinator would determine the cause of the noise complaint (e.g., starting too early, bad muffler) and would determine and implement reasonable measures warranted to correct the problem.

SHORT-TERM CONSTRUCTION VIBRATION IMPACTS
This construction vibration impact analysis discusses the level of human annoyance using vibration levels in RMS and assesses the potential for building damages using vibration levels in PPV (in/sec).

This is because vibration levels calculated in RMS are best for characterizing human response to building vibration, and vibration level in PPV is best for characterizing the potential for damage.

Table I shows the PPV and RMS values at 25 feet from the construction vibration source. As shown in Table I, bulldozers, and other heavy-tracked construction equipment (expected to be used for this project) generate approximately 0.089 PPV in/sec or 0.062 RMS in/sec of ground-borne vibration when measured at 25 feet, based on the Caltrans Manual. The distance to the nearest buildings for vibration impact analysis is measured between the nearest off-site buildings, and the project construction boundary (assuming the construction equipment would be used at or near the project setback line).

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 21 Table I: Vibration Source Amplitudes for Construction Equipment Equipment Reference PPV/LV at 25 ft
PPV (in/sec) RMS (in/sec)1
Pile Driver (Impact), Typical 0.644 0.451
Pile Driver (Sonic), Typical 0.170 0.119
Vibratory Roller 0.210 0.147
Hoe Ram 0.089 0.062
Large Bulldozer2 0.089 0.062
Caisson Drilling 0.089 0.062
Loaded Trucks2 0.076 0.053
Jackhammer 0.035 0.025
Small Bulldozer 0.003 0.002
Source: Transportation and Construction Vibration Guidance Manual (Caltrans 2020). 1 RMS vibration velocity is 70 percent of maximum PPV. 2 Equipment shown in bold is expected to be representative of the equipment used on site.

Caltrans = California Department of Transportation
ft = foot/feet
in/sec = inch/inches per second
LV = vibration velocity in decibels
PPV = peak particle velocity
RMS = root-mean-square
The formula for vibration transmission is provided below, and Tables J and K, below, provide a summary of off-site construction vibration levels. The material dampening coefficient, ‘n’, ranges between 1.1 and 1.5 depending on soil type and distance from equipment.

PPVequip = PPVref x (25/D)n
Table J: Potential Construction Vibration Annoyance Impacts at Nearest Receptor
Receptor (Location) Reference Vibration Level
(RMS in/sec) at 25 ft1 Distance (ft) 2 Vibration Level(RMS in/sec) Commercial Uses (East)

0.062
250 0.002
Residential Uses (West) 280 0.002
Postal Office (South) 280 0.002
Commercial Uses (West) 320 0.001
Commercial Uses (North) 415 0.001
Source: Compiled by LSA (2025). 1 The reference vibration level is associated with a large bulldozer, which is expected to be representative of the heavy equipment used during construction. 2 The assessment distance is associated with the average condition, identified by the distance from the center of construction activities to surrounding uses.
ft = foot/feet
in/sec = inches per second
RMS = root-mean-square

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 22 Table K: Potential Construction Vibration Damage Impacts at Nearest Receptor
Receptor (Location) Reference Vibration
Level (PPV) at 25 ft1 Distance (ft) Vibration Level (PPV) Commercial Uses (East)

0.089
15 0.191
Residential Uses (West) 15 0.191
Postal Office (South) 50 0.031
Commercial Uses (West) 85 0.014
Commercial Uses (North) 180 0.005
Source: Compiled by LSA (2025). 1 The reference vibration level is associated with a large bulldozer, which is expected to be representative of the heavy equipment used during construction. 2 The assessment distance is associated with the peak condition, identified by the distance from the perimeter of construction activities to surrounding structures.
ft = foot/feet
PPV = peak particle velocity
As previously shown in Table D, the threshold at which vibration levels would result in annoyance would be 0.04 in/sec RMS. Based on the information provided in Table J, vibration levels are expected to approach 0.002 in/sec RMS at the closest receptors and would not exceed the annoyance thresholds.

As discussed above, the standards indicate that the construction vibration damage criterion is

0.5 in/sec in PPV. Based on the information provided in Table K, the closest structures to external construction activities are the commercial uses to the east and the residential uses to west. Using the reference data from Table I and the equation above, it is expected that vibration levels generated by dump trucks and other large equipment would generate ground-borne vibration levels of up to 0.191 PPV (in/sec) at the closest structures to the project site. This vibration level would not exceed the 0.5 in/sec PPV threshold considered safe for newer residential structures and modern industrial or commercial buildings, which would result in a less than significant impact. Vibration levels at all other buildings would be lower. Therefore, construction would not result in any vibration damage, and impacts would be less than significant.

LONG-TERM OFF-SITE TRAFFIC NOISE IMPACTS
In order to assess the potential traffic impacts related to the proposed project, it is estimated that the proposed project would result in an increase of 600 daily trips based on the Trip Generation and Vehicle Miles Traveled Technical Memorandum (EPD Solutions, inc., 2024). Based on the ADTs provided by the City of Santee Mobility Element, the ADT along Mission Gorge Road in the project vicinity is approximately 32,200 based on projections for the year 2013. While the existing ADT is likely higher, using 32,200 ADT as the existing count would be a conservative approach. The following equation was used to determine the potential impacts of the project:

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 23 Change in Ldn = 10 log10 [Ve+p/Vexisting]
Where: Vexisting = the existing daily volume
Ve+p = existing daily volumes plus project
Change in Ldn = the increase in noise level due to the project The results of the calculations show that an increase of 0.1 dBA Ldn is expected along Mission Gorge Road. A noise level increase of less than 3 dBA would not be perceptible to the human ear; therefore, the traffic noise increase along Mission Gorge Road resulting from the proposed project would be less than significant. No mitigation is required.

LONG-TERM TRAFFIC-RELATED VIBRATION IMPACTS
The proposed project would not generate vibration levels related to on-site operations. In addition, vibration levels generated from project-related traffic on the adjacent roadways are unusual for onroad vehicles because the rubber tires and suspension systems of on-road vehicles provide vibration isolation. Based on a reference vibration level of 0.076 in/sec PPV, structures greater than 20 feet from the roadways that contain project trips would experience vibration levels below the most conservative standard of 0.12 in/sec PPV; therefore, vibration levels generated from project-related traffic on the adjacent roadways would be less than significant, and no mitigation measures are required.

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P:\A-E\ESL2201.107\Product\NoiseAndVibrationReport_20251023.docx (10/28/25) 24

ON-SITE LAND USE COMPATIBILITY ANALYSIS
The proposed project is in an area where parcels surrounding the project site are currently in use.

For this reason, this analysis relies on the existing measured noise levels as well as future predicted noise levels to provide the most accurate description of the noise environment related to traffic noise impacts.

As described in the City’s Noise Element of the General Plan, an exterior noise level of up to 65 dBA Ldn is considered “normally acceptable” for multi-family residential uses, while interior spaces shall meet a noise level of 45 dBA Ldn.

ON-SITE EXTERIOR NOISE IMPACTS
Based on the monitoring results shown in Table F, existing traffic noise levels at the project site range from 58.3 dBA Ldn near the northwestern project boundary to 60.8 dBA Ldn near the southwestern project boundary.

The main amenity area where humans will spend time includes the open space amenities proposed near the northern boundary of the project site. After distance attenuation and shielding from the proposed buildings and fencing, the noise levels at the amenity would remain below the acceptable level of 65 dBA Ldn, and no mitigation measures would be required.

ON-SITE INTERIOR NOISE IMPACTS
In addition to the exterior noise level standards, the project must demonstrate compliance with the interior noise standard of 45 dBA Ldn. The traffic noise levels at Buildings B and C would approach 61 dBA Ldn at the southern façade of the proposed building closest to Mission Gorge Road.

Based on the United States Environmental Protection Agency’s (USEPA) Protective Noise Levels (1974), with windows and doors open, interior noise levels at the units along the northern and eastern boundaries would be 62.4 dBA (i.e., 61 dBA - 12 dBA = 49 dBA), which would exceed the 45 dBA Ldn interior noise standard. The proposed project includes an HVAC system that would allow windows to remain closed. Based on reference information from transmission loss test reports for Greenworld Windows (2018), the necessary reduction can be achieved with standard building construction along with standard windows in the range of Sound Transmission Class (STC) 25 would yield an interior noise level below 45 dBA Ldn.

Once final plans are available to detail the exterior wall construction and a window manufacturer has been chosen, a Final Acoustical Report would be required to confirm the reduction capability of the exterior façades and to identify any specific upgrades necessary to achieve an interior noise level of 45 dBA Ldn or below.

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REFERENCES
California Department of Transportation (Caltrans). 2020. Transportation and Construction Vibration Guidance Manual. April.

City of Santee. 2003. General Plan Noise Element. August 27. _______. 2017. Mobility Element. October 25.
_______. 2024. Santee Municipal Code. December 11.

EPD Solutions, Inc. 2024. Trip Generation and Vehicle Miles Traveled Technical Memorandum.

August 22.

Federal Highway Administration (FHWA). 2006. FHWA Roadway Construction Noise Model User’s Guide. January. Washington, D.C. Website: www.fhwa.dot.gov/environment/ noise/ construction_noise/rcnm/rcnm.pdf (accessed June 2025).

Federal Transit Administration (FTA). 2018. Transit Noise and Vibration Impact Assessment Manual.

Office of Planning and Environment. Report No. 0123. September.

Greenworld Windows. 2018. Various Transmission Loss Reports.

San Diego County Regional Airport Authority (SDCRAA). 2010. Gillespie Field Airport Land Use Compatibility Plan.

United States Environmental Protection Agency (USEPA). 1974. Protective Noise Levels.

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APPENDIX A

NOISE MONITORING DATA
Noise Measurement Survey – 24 HR
Project Number: ESL2201.107 Test Personnel: Corey Knips Project Name: Mission Gorge Residential Equipment: LD Spark 706RC (SN: 17814) Site Number: LT-1 Start Date: 5/5/2025 Time: From 1:00 p.m. To 1:00 p.m.

Site Location: Near the northwest corner of the project site, on a tree. Approximately 1,750 feet from the State Route 52 (SR-52) centerline.

Primary Noise Sources: Traffic on SR-52 and Mission Gorge Road.

Comments:

Photo:

Long-Term (24-Hour) Noise Level Measurement Results at LT-1 Start Time Date Noise Level (dBA)
Leq Lmax Lmin
1:00 PM 5/5/2025 58.5 74.4 49.5
2:00 PM 5/5/2025 58.6 74.4 49.0
3:00 PM 5/5/2025 56.8 73.4 49.6
4:00 PM 5/5/2025 56.9 76.6 50.3
5:00 PM 5/5/2025 57.0 76.1 49.9
6:00 PM 5/5/2025 58.0 75.3 49.6
7:00 PM 5/5/2025 52.6 74.8 45.3
8:00 PM 5/5/2025 50.2 68.1 40.9
9:00 PM 5/5/2025 45.4 61.1 39.6
10:00 PM 5/5/2025 42.7 56.3 37.5
11:00 PM 5/5/2025 44.4 58.6 36.6
12:00 AM 5/6/2025 41.3 60.4 36.6
1:00 AM 5/6/2025 46.0 62.1 37.1
2:00 AM 5/6/2025 40.8 56.8 37.1
3:00 AM 5/6/2025 43.4 66.8 36.7
4:00 AM 5/6/2025 43.8 58.7 37.8
5:00 AM 5/6/2025 55.0 77.1 41.9
6:00 AM 5/6/2025 55.0 78.4 42.6
7:00 AM 5/6/2025 59.0 79.6 42.2
8:00 AM 5/6/2025 57.9 85.9 42.4
9:00 AM 5/6/2025 56.9 73.3 45.5
10:00 AM 5/6/2025 60.2 82.0 44.8
11:00 AM 5/6/2025 59.3 75.8 44.5
12:00 PM 5/6/2025 58.1 83.3 42.9
Source: Compiled by LSA Associates, Inc. (2025).
dBA = A-weighted decibel
Leq = equivalent continuous sound level
Lmax = maximum instantaneous noise level
Lmin = minimum measured sound level
Noise Measurement Survey – 24 HR
Project Number: ESL2201.107 Test Personnel: Corey Knips Project Name: Mission Gorge Residential Equipment: LD Spark 706RC (SN: 18571) Site Number: LT-2 Start Date: 5/5/2025 Time: From 1:00 p.m. To 1:00 p.m.

Site Location: Near San Ysidro Health Center, 120 Town Center Parkway, on a tree southwest of the building. Just east of the project site. Approximately 1,750 feet from the SR-52 centerline.

Primary Noise Sources: Traffic on SR-52 and Mission Gorge Road.

Comments:

Photo:

Long-Term (24-Hour) Noise Level Measurement Results at LT-2 Start Time Date Noise Level (dBA)
Leq Lmax Lmin
1:00 PM 5/5/2025 60.4 74.1 51.5
2:00 PM 5/5/2025 60.5 82.2 51.3
3:00 PM 5/5/2025 58.3 72.0 51.7
4:00 PM 5/5/2025 60.2 82.4 52.1
5:00 PM 5/5/2025 59.3 73.7 50.9
6:00 PM 5/5/2025 57.6 75.1 49.0
7:00 PM 5/5/2025 54.0 71.2 46.9
8:00 PM 5/5/2025 51.7 69.6 44.4
9:00 PM 5/5/2025 49.1 68.8 41.7
10:00 PM 5/5/2025 47.3 61.4 40.1
11:00 PM 5/5/2025 46.6 69.0 38.8
12:00 AM 5/6/2025 45.4 65.8 39.2
1:00 AM 5/6/2025 44.7 59.4 39.0
2:00 AM 5/6/2025 43.7 52.7 39.0
3:00 AM 5/6/2025 44.5 63.3 38.9
4:00 AM 5/6/2025 50.2 72.0 40.3
5:00 AM 5/6/2025 55.0 78.9 42.9
6:00 AM 5/6/2025 55.4 71.8 42.6
7:00 AM 5/6/2025 57.1 76.4 45.3
8:00 AM 5/6/2025 62.1 78.2 44.7
9:00 AM 5/6/2025 55.0 75.3 46.0
10:00 AM 5/6/2025 60.2 78.2 45.6
11:00 AM 5/6/2025 58.0 73.6 45.4
12:00 PM 5/6/2025 61.0 85.2 46.2
Source: Compiled by LSA Associates, Inc. (2025).
dBA = A-weighted decibel
Leq = equivalent continuous sound level
Lmax = maximum instantaneous noise level
Lmin = minimum measured sound level
Noise Measurement Survey – 24 HR
Project Number: ESL2201.107 Test Personnel: Corey Knips Project Name: Mission Gorge Residential Equipment: LD Spark 706RC (SN: 17637) Site Number: LT-3 Start Date: 5/5/2025 Time: From 1:00 p.m. To 1:00 p.m.

Site Location: On the east side of Lowe’s, 9416 Mission Gorge Road, on a tree. West of the project site. Approximately 1,350 feet from the SR-52 centerline.

Primary Noise Sources: Traffic on SR-52 and Mission Gorge Road.

Comments:

Photo:

Long-Term (24-Hour) Noise Level Measurement Results at LT-3 Start Time Date Noise Level (dBA)
Leq Lmax Lmin
1:00 PM 5/5/2025 60.8 85.4 53.5
2:00 PM 5/5/2025 61.9 81.0 52.9
3:00 PM 5/5/2025 59.5 75.1 54.2
4:00 PM 5/5/2025 60.9 77.8 53.4
5:00 PM 5/5/2025 60.0 75.9 52.7
6:00 PM 5/5/2025 58.8 76.5 51.2
7:00 PM 5/5/2025 56.3 74.4 48.3
8:00 PM 5/5/2025 53.4 72.3 44.2
9:00 PM 5/5/2025 52.4 68.6 41.7
10:00 PM 5/5/2025 47.4 63.4 40.6
11:00 PM 5/5/2025 47.3 62.9 39.0
12:00 AM 5/6/2025 45.7 64.8 38.5
1:00 AM 5/6/2025 47.9 62.8 38.3
2:00 AM 5/6/2025 47.4 70.6 39.2
3:00 AM 5/6/2025 49.8 70.6 38.4
4:00 AM 5/6/2025 53.6 74.5 40.8
5:00 AM 5/6/2025 54.9 80.1 44.9
6:00 AM 5/6/2025 57.1 77.7 46.7
7:00 AM 5/6/2025 59.9 79.3 45.8
8:00 AM 5/6/2025 56.7 80.0 44.9
9:00 AM 5/6/2025 57.7 75.9 45.6
10:00 AM 5/6/2025 61.4 80.0 45.5
11:00 AM 5/6/2025 58.8 76.2 47.2
12:00 PM 5/6/2025 61.2 83.6 47.2
Source: Compiled by LSA Associates, Inc. (2025).
dBA = A-weighted decibel
Leq = equivalent continuous sound level
Lmax = maximum instantaneous noise level
Lmin = minimum measured sound level

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APPENDIX B

CONSTRUCTION NOISE LEVEL CALCULATIONS
Phase: Site Preparation
Lmax Leq
Tractor 4 84 40 50 0.5 84 86
Dozer 3 82 40 50 0.5 82 83
Combined at 50 feet 86 88
Combined at Receptor 250 feet 72 74
Combined at Receptor 280 feet 71 73
Combined at Receptor 320 feet 70 72
Combined at Receptor 415 feet 68 69
Phase: Grading
Lmax Leq
Grader 1 85 40 50 0.5 85 81
Dozer 1 82 40 50 0.5 82 78
Tractor 3 84 40 50 0.5 84 85
Excavator 1 81 40 50 0.5 81 77
Combined at 50 feet 89 87
Combined at Receptor 250 feet 75 73
Combined at Receptor 280 feet 74 72
Combined at Receptor 415 feet 71 69
Phase:Building Construction
Lmax Leq
Man Lift 3 75 20 50 0.5 75 73
Crane 1 81 16 50 0.5 81 73
Generator 1 81 50 50 0.5 81 78
Tractor 3 84 40 50 0.5 84 85
Welder / Torch 1 74 40 50 0.5 74 70
Combined at 50 feet 87 86
Combined at Receptor 250 feet 74 72
Phase: Paving
Lmax Leq
Paver 2 77 50 50 0.5 77 77
Roller 2 80 20 50 0.5 80 76
All Other Equipment > 5 HP 2 85 50 50 0.5 85 85
Combined at 50 feet 87 86
Combined at Receptor 250 feet 73 72
Phase:Architectural Coating
Lmax Leq
Compressor (air) 1 78 40 50 0.5 78 74
Combined at 50 feet 78 74
Combined at Receptor 250 feet 64 60
Phase:Architectural Coating
Lmax Leq
Slurry Trenching Machine 1 80 50 50 0.5 80 77
excavator 1 81 40 50 0.5 81 77
Compactor (ground) 2 83 20 50 0.5 83 79
Front End Loader 1 79 40 50 0.5 79 75
Tractor 2 84 40 50 0.5 84 83
Combined at 50 feet 89 86
Combined at Receptor 250 feet 75 72
Sources: RCNM
1 - Percentage of time that a piece of equipment is operating at full power. dBA – A-weighted Decibels
Lmax- Maximum Level
Leq- Equivalent Level
Ground Effects
Noise Level (dBA) Equipment Quantity Reference (dBA) 50 ft Lmax
Usage
Factor1
Distance to
Receptor (ft)
Equipment Ground Effects
Distance to
Receptor (ft)
Usage
Factor1
Reference (dBA) 50 ft
Lmax Quantity
Equipment Quantity
Noise Level (dBA)
Ground Effects
Distance to
Receptor (ft)
Usage
Factor1
Reference (dBA) 50 ft
Lmax
Equipment Quantity
Noise Level (dBA)
Ground Effects
Distance to
Receptor (ft)
Usage
Factor1
Reference (dBA) 50 ft
Lmax
Equipment Quantity
Noise Level (dBA)
Construction Calculations
Equipment Quantity Reference (dBA) 50 ft
Lmax
Usage
Factor1
Distance to
Receptor (ft) Ground Effects
Noise Level (dBA)
Noise Level (dBA)
Ground Effects
Distance to
Receptor (ft)
Usage
Factor1
Reference (dBA) 50 ft
Lmax
Construction Traffic Noise Calculator
Construction Phase
One-Way
Worker
Trip/Day
One Way
Vendor
Trip/Day
One Way
Hauling
Trip
Number
Total
Phase
Number Phase Name Number of Days
Site Preparation 17.5 0 0 17.5 1 Site Preparation 10
Grading 15 0 62.5 77.5 2 Grading 20
Building Construction 72 10.7 0 82.7 3
Building
Construction 230
Paving 15 0 0 15 4 Paving 20
Architectural Coating 14.4 0 0 14.4 5
Architectural
Coating 20
Utilities & Storm 14.4 0 0 14.4 6 Utilities & Storm 60
Maximum 83
Speed MT Factor HT Factor
25 12.6 39.8
Roadway Speed Existing Volume MT Factor HT Factor 30 8.9 26.3 Mission Gorge 35 32,200 7.1 19.1 35 7.1 19.1
40 5.8 15.1
45 5 12.9
Worker
Trip/Day
Vendor
Trip/Day
Hauling
Trip
Number Total
Overlap? 50 4.5 11.5
Site Preparation 18 0 0 18 55 4.1 10.4
Grading 15 0 1,194 1209 60 3.7 9.6
Building Construction 72 141 0 213 65 3.5 8.9
Paving 15 0 0 15
Architectural Coating 14 0 0 15
Utilities & Storm 14 0 0 15
Overlap? N
Total Equivalent Vehicles 1,209
Noise Increase (dBA) 0.2
Urban Planning ■ Due Diligence ■ Entitlements ■ CEQA/NEPA ■ Development Services ■ Management ■ Public Outreach 3333 Michelson Drive, Suite 500 ■ Irvine, Calif. 92612
949.794.1180 ■ [email protected]
Date: October 24, 2025
Prepared by: Simon Lin, EIT; Chad Karns; Meghan Macias, TE EPD Solutions, Inc.

To: City of Santee Engineering Department
Site: The Exchange at Santee Town Center
Northwest Corner of Mission Gorge Rd and Town Center Pkwy, Santee EPD Project Number: 24-080
Subject: Trip Generation and Vehicle Miles Traveled Technical Memorandum This Vehicle Miles Traveled (VMT) Technical Memorandum provides an evaluation of the proposed Exchange at Santee Town Center residential project (proposed Project) located on Mission Gorge Rd, 330 feet west of Town Center Pkwy, adjacent to US Post Office (north side) and Walmart (south side), in the City of Santee.

The purpose of this memo is to determine whether a VMT analysis would be required for the Project. The Project proposes an infill subdivision consisting of 100 residential units on a 4.18-net acre parcel (5.26-gross acres with the dedicated roadway), with a density of 24 DU/acre. The conceptual site plan is shown in Figure

1. This memo uses the City of Santee VMT Analysis Guidelines (April 2022), and City of Santee Traffic Analysis Intake Form attached in Appendix A.

Project Trip Generation
The proposed Project trip generation was calculated using trip rates from the San Diego Association of Governments’ (SANDAG’s) (Not So) Brief Guide of Vehicular Traffic Generation Rates for the San Diego Region (2002). The proposed 100 residential units were analyzed as Apartment (or any multi-family units more than 20 DU/acre).

Table 1 presents the trip generation estimate for the proposed Project. As shown in Table 1, the proposed Project would generate a total of 600 daily trips, 48 AM, and 54 PM net new peak hour trips.

According to the City of Santee Traffic Analysis Intake Form, • Projects projected to have less than 1,000 daily trips are not required to prepare a traffic study level of service (LOS) analysis
o Projects projected to have less than 900 daily trips are not required to prepare a LOS technical memorandum
• Projects projected to have less than 500 daily trips for projects are not required to prepare a VMT analysis
o Projects projected to have less than 450 daily trips are not required to prepare a VMT technical memorandum
Therefore, a LOS technical memorandum is not required for the Project. However, a VMT technical memorandum is required for the Project.

The Exchange at Santee Town Center
Trip Generation and VMT Technical Memorandum
2 VMT Screening Analysis
Senate Bill (SB) 743 was signed by Governor Brown in 2013 and required the Governor’s Office of Planning and Research (OPR) to amend the CEQA Guidelines to provide an alternative to LOS for evaluating Transportation impacts. SB 743 specified that the new criteria should promote the reduction of greenhouse gas emissions, the development of multimodal transportation networks and a diversity of land uses. The bill also specified that delay-based level of service could no longer be considered an indicator of a significant impact on the environment. In response, Section 15064.3 was added to the CEQA Guidelines beginning January 1, 2019. Section 15064.3 - Determining the Significance of Transportation Impacts states that VMT is the most appropriate measure of transportation impacts and provides lead agencies with the discretion to choose the most appropriate methodology and thresholds for evaluating VMT. The provisions of Section 15064.3(c) were implemented statewide beginning on July 1, 2020.

The City adopted City of Santee VMT Analysis Guidelines on April 13, 2022. Based on the City’s Guidelines, if a project meets any of the following criteria, then the VMT impact of the project would be considered less than significant, and no further VMT analysis would be required:

1. Projects Located in a Transit-Accessible Area

2. Small Projects

3. Projects in a VMT-Efficient Area

4. Locally-Serving Retail Projects

5. Locally-Serving Public Facilities

6. Redevelopment Projects with Lower Total VMT

7. Infill affordable housing
The applicability of each criterion to the project is discussed below:

Screening Criteria 1 – Projects Located in a Transit-Accessible Area: As per the City’s guidelines, projects located within a half-mile radius of an existing major transit stop or an existing stop along a high-quality transit corridor 1 may be presumed to have a less than significant impact. The Project is located approximately 2,600 feet (or .49 mile) from the Santee Town Center Trolley Station, which is a stop for the Metropolitan Transit System Copper Line Trolley with a service interval of 15 minutes from 5 AM to 11 PM.

The presumption of a less than significant impact near these transit stops may not be appropriate if the project:
• Has a Floor Area Ratio of less than 0.75
• Includes more parking for use by residents, customers, or employees of the project than required by the City’s Municipal Code.
• Is inconsistent with SANDAG’s most recent Sustainable Communities Strategy or the land use growth assumption accommodated by the Land Use Element portion of the General Plan • Replaces affordable residential units with a smaller number of moderate- or high-income residential units
• Does not have basic walking and biking access to transit (e.g., sidewalks connecting to transit stops)
1 Major transit stop: a site containing an existing rail transit station, a ferry terminal served by either a bus or rail transit service, or the intersection of two or more major bus routes with a frequency of service interval of 15 minutes or less during the morning and afternoon peak commute periods. High quality transit corridor: a corridor with fixed route bus service with service intervals no longer than 15 minutes during peak commute periods.

The Exchange at Santee Town Center
Trip Generation and VMT Technical Memorandum
3 As shown in Figure 1, the Project does not meet any of the above criteria because it:
• Has a Floor Area Ratio of more than 0.75 (as shown, 168,540 SF for 100 total units on 4.18 acres equates to a 0.93 FAR)
• Includes 200 parking spaces for use by residents2, which is less than the 225 spaces required by the City’s Municipal Code.
• Is consistent with the City of Santee’s Town Center Land Use Plan adopted October 12, 2022 (City Council Resolution No. 127-2022)
• Does not replace affordable residential units
• Has a trail connection at the Northeast corner of the Project site that provides access to transit Therefore, the Project would satisfy the requirements of Screening Criteria 1 because it is within a half mile of an existing stop along a high-quality transit corridor and does not meet any of the exceptions to the presumption that VMT impacts are less than significant.

Screening Criteria 2 – Small Projects: As per the City’s guidelines, projects generating 500 or fewer net new daily vehicle trips may be presumed to have a less than significant impact.

As shown in Table 1, the proposed Project would generate a total of 600 daily trips. Therefore, the Project would not satisfy the requirements of Screening Criteria 2.

Screening Criteria 3 – Projects in a VMT Efficient Area: As per the City’s guidelines, projects located in a VMT-Efficient Area may be presumed to have a less than significant impact. A VMT-Efficient area for residential projects is any area with an average VMT/capita 15% below the baseline City average for the traffic analysis zone (TAZ) that the project is located within. VMT-Efficient areas are determined using the SANDAG’s SB 743 VMT Web maps3.

The output from SANDAG’s SB743 VMT Web maps for the Project TAZ can be found in Figure 2. As shown in Figure 2, the proposed Project is not located in a VMT-Efficient Area. Therefore, the Project would not satisfy the requirements of Screening Criteria 3.

Screening Criteria 4 – Locally-Serving Retail Projects: As per the City’s guidelines, local serving retail projects less than 50,000 square feet that are expected to draw approximately 75% of customers from the local area (roughly 3-miles), are presumed to have a less than significant impact.

Because the Project is a residential project and does not propose retail use, the Project would not satisfy the requirements of Screening Criteria 4.

Screening Criteria 5 – Locally-Serving Public Facilities: As per the City’s guidelines, public facilities that serve the surrounding community or public facilities that are passive use may be presumed to have a less than significant impact.

Because the Project is a residential project and does not propose a public facilities use, the Project would not satisfy the requirements of Screening Criteria 5.

Screening Criteria 6 – Redevelopment Projects with Lower Total VMT: As per the City’s guidelines, a redevelopment project may be presumed to have a less than significant impact, absent substantial evidence 2 Parking supply references only spaces intended for use by residents, excluding visitor parking. This is consistent with the VMT screening threshold which specifies that the screening criteria may not apply if the project “includes more parking for use by residents, customers, or employees of the project than required by the City’s Municipal Code.” 3 San Diego Region SB743 VMT Maps sandag.maps.arcgis.com The Exchange at Santee Town Center
Trip Generation and VMT Technical Memorandum
4 to the contrary, if the proposed project’s total VMT is less than the VMT generated by the existing land use and if the CEQA action includes closing the existing land use.

Because the Project is not a redevelopment project, the Project would not satisfy the requirements of Screening Criteria 6.

Screening Criteria 7 – Infill affordable housing: As per the City’s guidelines, deed-restricted affordable housing projects that meet the following conditions meet the City’s screening criteria and would not require a VMT analysis.
• Is an infill project (note that most of the City of Santee is presumed to be an infill location); • Consists of a minimum of 52% affordable housing;
• Is within half- mile radius of a transit stop or station; and • Project-provided parking does not exceed parking required by the City’s Municipal Code.

The Project does not satisfy the requirements of Screening Criteria 7.

VMT Screening Conclusion
Because the Project would meet the City’s screening criteria 1 – Projects Located in a Transit-Accessible Area, the Project’s impact on VMT would be considered less than significant and an analysis of VMT would not be required.

If you have any questions, please feel free to contact us at [email protected] or at (949) 794- 1180.

The Exchange at Santee Town Center
Trip Generation and VMT Technical Memorandum
5 Table 1: Project Trip Generation
The Exchange at Santee Town Center
Trip Generation and VMT Technical Memorandum
6 Figure 1: Conceptual Site Plan
Source: Summa Architecture
The Exchange at Santee Town Center
Trip Generation and VMT Technical Memorandum
7 Figure 2: Output from SANDAG’s SB743 VMT Web Maps
Source: SANDAG
The Exchange at Santee Town Center
Trip Generation and VMT Technical Memorandum
8 APPENDIX A – City of Santee Traffic Analysis Intake Form

TRAFFIC ANALYSIS INTAKE FORM
The traffic analysis intake form shall be submitted with all new development projects to help determine what traffic analysis will be required. These guidelines apply to most development projects. However, the City reserves the right to request both Vehicle Miles Traveled (VMT) and Level of Service (LOS) analysis depending on the specifics of the project. All questions regarding this intake form should be directed to the City of Santee Traffic Engineering division.

1. Project Information
Applicant Name
Project Address or
Street/Cross Streets
APN
Project No.

2. Project Description

3. Trip Generation Information
# Land Use Description
Size
(Number of
dwelling units
or square feet)
Trip Generation Rate Data Source
(Subject to City Staff approval)
Trip
Generation
Rate
Total
Daily Trips
1  SANDAG 2002 Trip Generation Rate
 Other:________________________________
2  SANDAG 2002 Trip Generation Rate
 Other:________________________________
3  SANDAG 2002 Trip Generation Rate
 Other:________________________________
4  SANDAG 2002 Trip Generation Rate
 Other:________________________________
Projected Total Average Daily Trips (ADT) for the site:______________________________

4. Vehicle Miles Traveled (VMT) Analysis
Projects that are projected to generate more than 500 Average Daily Trips (ADT) may be required to submit a full VMT analysis. If a VMT analysis is required, applicant shall refer to the City of Santee VMT Analysis guidelines.

Is the proposed project projected to have more than 500 ADT?  NO VMT analysis is not required for this project
 YES VMT analysis prepared may be required

5. Traffic Study Level of Service (LOS) Analysis
Projects that are projected to generate more than 1,000 Average Daily Trips (ADT) may be required to submit a traffic study that evaluates traffic impact and performs a LOS analysis. If a traffic study with LOS analysis is required, applicant shall refer to the San Diego ITE’s Guidelines for Transportation Impact Studies in the San Diego Region, May 2019.

Is the proposed project projected to have more than 1,000 ADT?  NO A traffic study is not required for this project
 YES A traffic study LOS analysis may be required
Is the proposed project projected to have more than 2,500 ADT?  NO A SANDAG model run is not required.
 YES A SANDAG model run may be required.

6. Technical Memorandum
If the total ADT is within 10% of any of the limits listed above, at the City’s discretion, a technical memorandum prepared by a registered traffic engineer may be required to verify calculations.

Is the proposed project projected Average Daily Trips over 450 VMT or 900 LOS?  NO A traffic memorandum is not required.
 YES A traffic memorandum prepared by a registered traffic engineer detailing if a VMT or Traffic Study LOS analysis may be required.

7. Certification
Application Certification: I certify that this intake form has been completed to the best of my ability and accurately reflects the project being proposed. I understand that this intake form is for guidance only and that the City may require additional information or studies.

Date:

Signature of Applicant:

Printed Name:

S:\TRAFFIC\Development Review\Traffic Analyss Intake Form.docx

Santee City CouncilDecember 10, 2025

Santee City Council
December 10, 2025