> Appendix-M-Drainage-Study — San Marcos City Council, June 24, 2025

Latitude 33 Planning & Engineering
i

DRAINAGE STUDY

ARMORLITE LOFTS

ARMORLITE DRIVE
SAN MARCOS, CALIFORNIA 92069

MAY 26, 2023

PRJ SP23-0001
DRAWING NO. XXXXX-D
APN: 219-162-57
Contact: Gio Posillico
Phone: (858)751-0633
Email: [email protected]
2023
PREPARED BY:

PREPARED FOR: City of San Marcos

JOB NUMBER: 1 900 .00

DRAINAGE STUDY

ARMORLITE LOFTS

ARMORLITE DRIVE

SAN MARCOS, CALIFORNIA

PRJ NO. SP23-0001
DRAWING NO. XXXXX-D

MAY 26, 2023

Prepared For:

LAS POSAS VENTURES, LLC
705 B Street, Suite 3010
San Diego, CA 92101
(619) 981 - 0579

Prepared By:

10731 Treena Street
San Diego, California 92131
Phone (858) 751-0633
Fax (858) 751-0634

Gio Posillico, PE Prepared By: DN R.C.E. 66332 Checked By: RD

Latitude 33 Planning & Engineering
i

DECLARATION OF RESPONSIBLE CHARGE

I, HEREBY DECLARE THAT I AM THE ENGINEER OF WORK FOR THIS PROJECT, THAT I HAVE

EXERCISED RESPONSIBLE CHARGE OVER THE DESIGN OF THE PROJECT AS DEFINED IN SECTION 6703 OF THE BUSINESS AND PROFESSIONS CODE, AND THAT THE DESIGN IS CONSISTENT WITH CURRENT STANDARDS.

I UNDERSTAND THAT THE CHECK OF PROJECT DRAWINGS AND SPECIFICATIONS BY THE CITY OF

SAN DIEGO IS CONFINED TO A REVIEW ONLY AND DOES NOT RELIEVE ME, AS ENGINEER OF WORK, OF MY RESPONSIBILITIES FOR PROJECT DESIGN.

10/22/2024
Gio Posillico R.C.E. 66332 DATE

REGISTERED CIVIL ENGINEER

Latitude 33 Planning & Engineering
1 TABLE OF CONTENTS

1. PROJECT DESCRIPTION ...................................................................................................... 2

1.1. Project Location ..................................................................................................... ......... 2

1.2. Existing Condition ..................................................................................................... ...... 2

1.3. Proposed Condition ..................................................................................................... ... 2

1.4. Hydrologic Context Watershed Contribution .................................................. ............... 3

2. METHODOLOGY & MODEL DEVELOPMENT ....................................................................... 4

2.1 Rational Method Hydrologic Analysis .......................................................................... 4-5

3. CONCLUSIONS AND RECOMMENDATIONS ..................................................................... 6-7

LIST OF FIGURES
Figure 1: Vicinity Map ........................... ................................................... .................................... 2 Figure 2: San Marcos Hydrologic Area ............................................................... .......................... 3

LIST OF TABLES
Table 3-1: Existing Conditions ....................................................................... ................................ 6 Table 3-2: Proposed Conditions (Unmitigated) ......................................................... .................... 6 Table 3-3: Proposed Conditions (Mitigated) ........................................................... ...................... 6 Table 3-4: Site Hydrology Flow Delta ................................................................. ........................... 7

APPENDICES
Appendix A Existing and Proposed Drainage Exhibits
Appendix B Existing Hydrologic Calculations
Appendix C Proposed Hydrologic Calculations
Appendix D PondPack Analysis (Detained Calculations )
Appendix E References

Latitude 33 Planning & Engineering
2 2. PROJECT DESCRIPTION

1.1 Project Location
The proposed project is a 4-story mixed-use residen tial/commercial development above a one- story podium garage with an associated outdoor park ing lot. The parcel is a 2.44 acre undeveloped lot located near the intersection of N Las Posas Road and Armorlite Drive.

Figure 1: Vicinity Map

1.2 Existing Condition
The existing site is an undeveloped lot with waist high vegetation. There is a high point central to the site, with drainage flowing in all directions w hich does not become concentrated on the property.

Regulation Information:

Determined by the size, location, and type of proje ct, the proposed project will not require approval from the Regional Water Quality Board for Federal Clean Water Act (CWA) section 401/ 404.

Because the excavation depth is shallower than the water table, this project does not expect to encounter ground water. Therefore, approval for discharging groundwater was not obtained.

1.3 Proposed Condition
Post construction drainage will sheet flow to 2 designated low points located in the surface parking lot and be treated and detained within proprietary treatment facilities (i.e. Modular Wetland System or approved equal) and an underground storage vault located beneath the parking lot. Runoff is then discharged into the existing storm drain system (POC 1) located along

Latitude 33 Planning & Engineering
3 Armorlite Drive. The proposed building roof surface area will be collected via a roof drain system and piped directly into the Modular Wetland System located in the planting area on the west side of the drive aisle, before ultimately discharging to POC1. In the existing condition, the Q100 to POC1 was calculated to be 1.69 cfs. In the proposed condition after proprietary treatment, the Q100 peak flow will be 1.58 cfs; therefore causing no increase to the existing drainage system.

Exhibits for Proposed and Existing Conditions are located in Appendix A for reference.

1.4 Hydrologic Context Watershed Contribution
The project is located within the Carlsbad Hydrologic Unit (904.52) as defined by the Water Quality Control Plan for the San Diego Basin. San Marcos Creek is the receiving water body, and discharges into the Pacific Ocean, 14.6 miles away, via Batiquitos Lagoon.

Figure 2: San Marcos Hydrologic Area

Latitude 33 Planning & Engineering
4 2. METHODOLOGY
The estimate of the existing and proposed drainage flows has been performed in general conformance with the County of San Diego guidelines. Drainage basins are less than one square mile and therefore the Rational Method was utilized to estimate runoff. The 100-year storm event has been used for runoff estimates. Rational Method parameters were determined as follows.

Runoff Coefficient:

The runoff coefficient is dependent only upon land use and soil type. The County of San Diego has developed a table of Runoff Coefficients for Urban Areas which is located within the County of San Diego Table 3-1. The table categorizes the land use, associated development density (dwelling units per acre) and percentage of impervious area. Each of the categories listed has an associated runoff coefficient, C, for each soil type class. AES utilizes this same table, and land use is user-specified for applicable node to node connections. The land use is chosen based on the individual percentages of imperviousness of associated sub-basins, which can be found in Appendix G of this report.

Time of Concentration:

Time of concentration was calculated per Section 3. 1.4 of the San Diego County Hydrology Manual.

Initial time of concentration values were computed using the Overland Time of Flow Nomograph, as shown on Figure 3-3, included in Appendix F. Overland flow length used for the calculation of initial travel time was restricted to the maximum values per Table 3-2.

Travel time was computed as the sum of the following items:
• For watersheds with flow in natural or pervious areas beyond the initial time of concentration length, the Kirpich Nomograph (Figure 3-4) was utilized. • For flow paths in the street, the Gutter and Roadwa y Discharge - Velocity Chart (Figure 3-6) was utilized. An initial Q was assumed based on the area and C-value of the sub-basin, as well as an intensity calculated from the initial time of concentration. The assumed initial Q and the street grade were used to determine the flow velocity for concentrated flows in curb and gutters. Travel times were then determined by divid ing the flow distance by the velocity of flow.
• For flow paths in ditches, Manning’s Equation (Figu re 3-7) was utilized to determine the velocity. As in the gutter velocity calculation, a n initial Q was assumed based on the initial time of concentration. Travel times were then deter mined by dividing the flow distance by the velocity of flow.

Final times of concentration values for each basin were calculated by adding the initial and final travel times; with a minimum time of 5 minutes. Ti me of concentration calculations are shown in Appendix B.

Latitude 33 Planning & Engineering
5 Rainfall Intensity:

The rainfall intensity was obtained from the “Intensity-Duration Design Chart” as shown in Figure 3-1 of the County of San Diego Guidelines, based on the 100-year P 6 and P 24 isopluvial maps, all included in Appendix F.

Drainage Areas:

The existing condition drainage basins were delineated from the base topographic map as shown on the Existing Hydrology Exhibit provided in Appendix A. The proposed condition drainage basins were delineated using the proposed grading plan as show on the Proposed Hydrology Exhibit also provided in Appendix A. Both the existing and proposed exhibits encompass the whole project area and comparison of flows were done at discharge points.

AES Computer Analysis
AES was utilized to model the 100-year storm with the Modified Rational Method parameters described above for overland flow as well as pipe flow through the proposed storm drain system.

At each structure that combines independent drainage systems, junction analysis will be used by using confluence data. This allows for an accurate peak flow calculation as it models the timing of flows across the sub-basins and through the storm drain system. The analysis input parameters and results are provided in Appendices C and D.

Bentley Pondpack Computer Analysis
Bentley PondPack was used to model the 6 hour time series for our BMP mitigation. In the Proposed-Mitigated PondPack Model, the stormwater d etention vault is modeled as a storage node with a proposed volume. The storage node is co nnected to a weir and a low-flow orifice.

The outflow of water leaving the vault is mitigated through the low-flow orifice resulting in a reduction of flow rate, which decreases the total f low of its corresponding outfall location. The value of the mitigated flow is entered back into AE S as the flow that is leaving the stormwater detention vault. The storage calculations for this concept are displayed in Appendix D.

Calculations are provided for each basin with an increase in peak flow from the existing condition to the proposed unmitigated condition. The followin g method was then utilized to show that enough storage is provided in the basins to mitigate the increase in peak flow.

Bentley PondPack was also utilized to calculate the detention volume required to utilize the stormwater detention vault as a conjunctive use fac ility to mitigate the increase in peak flow from the existing to proposed condition. Section 6 of the San Diego Hydrology Manual was referenced for the creation of the 6 Hour Hydrographs.

Latitude 33 Planning & Engineering
6 3. CONCLUSIONS AND RECOMMENDATIONS
Current Condition: The following flows were obtaine d for the drainage subbasins shown in the attached Drainage Site Plan Exhibits for the existing and proposed conditions (see Appendix A ).

Table 3-1: Existing Conditions

OUTFALL
NUMBER
AREA
(acres) Impervious
Area (acres)
Pervious
Area
(acres)
C I
(in/hr)
Q
(cfs)
Out-01 1.20 0 (0%) 1.20 (100%) 0.30 4.69 1.69
Out-02 0.76 0 (0%) 0.76 (100%) 0.30 5.04 1.15
Out-03 0.48 0 (0%) 0.48 (100%) 0.30 4.23 0.61
Total = 3.45

Table 3-2: Proposed Conditions (Unmitigated)

OUTFALL
NUMBER
AREA
(acres) Impervious
Area (acres)
Pervious
Area
(acres)
C (avg) I
(in/hr)
Q
(cfs)
Out-01 2.44 2.10(86%) 0.34 (14%) 0.78 7.50 14.27
Total = 14.27

Table 3-3: Proposed Conditions (Mitigated)

OUTFALL
NUMBER
AREA
(acres) Impervious
Area (acres)
Pervious
Area
(acres)
C (avg) I
(in/hr)
Q
(cfs)
Out-01 2.44 2.10 (86%) 0.34 (14%) 0.78 0.83 1.58
Total = 1.58

The Q calculated in AES accounts for flow routing, making the outfall lower than the sum of the Qpeak for each subbasins. The I is then determined from equation I = Q/CA.

Table 3-4: Site Hydrology Flow Delta

Latitude 33 Planning & Engineering
7 DISCHARGE
POINT
Q (cfs)

DIFFERENCE EXISTING PROPOSED
(unmitigated)

PROPOSED
(Mitigated)
TOTAL 3.45 14.27 1.58

10.82 cfs Increase
for unmitigated

1.87 cfs Decrease
for mitigated

To account for the increase in CFS a stormwater detention vault will be sized for Q100 mitigation as well as Hydromodification (0.3Q2 to Q10). Per County of San Diego Hydrology Manual Chapter 6, required storage to mitigate for the 100-year storm is based on a 6hr storm Hydrograph.

As shown in Appendix B the proposed underground vault, with a detention volume of 15,075 CF, will be able to mitigate flows to be lower than existing conditions.

3.1 Conclusion/Summary

The hydrologic and hydraulic analysis confirms the proposed development and associated storm drain system effectively conveys the 100-yr storm event. In the existing condition, the project site releases a peak flow of 3.45 CFS of runoff. In the proposed condition, the site releases a peak flow of 1.58 CFS of runoff, resulting in a decrease in peak flow. This decrease is due to the proposed stormwater detention vault detaining and releasing with low flow orifices.

The project will not result in any impacts to potentially jurisdictional waters or wetlands subject to Section 404 or 401 of the Clean Water Act and therefore would not require approvals or permits from the Regional Water Quality Control Board.

In addition, the proposed improvements will not increase the volume and/or velocity of surface flows to the detriment of downstream landowners and/or facilities.

Latitude 33 Planning & Engineering
8 APPENDIX A

EXISTING AND PROPOSED

DRAINAGE EXHIBITS

MHMH
MH
MHMH
MH
MH MH
MH
MH
MH
MH
MH
MH
MH
MH
T
DDD

LEGENDDRAINAGE ANALYSIS NOTES
H:\1900\1900.00 - Cross Real Estate - 225 Las Posas\Engineering\Reports\Drainage\A_Exhibits\1900.0 EX CONDITIONS.dwg, 8/10/2023 3:07:04 PM, DWG To PDF.pc3

T
DDD
I
RD
S
FSW

LEGENDDRAINAGE ANALYSIS NOTES
H:\1900\1900.00 - Cross Real Estate - 225 Las Posas\Engineering\Reports\Drainage\A_Exhibits\1900.0 PROP CONDITIONS.dwg, 8/10/2023 2:26:09 PM, DWG To PDF.pc3

Latitude 33 Planning & Engineering
9 APPENDIX B

EXISTING HYDROLOGIC CALCULATIONS

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

RATIONAL METHOD HYDROLOGY COMPUTER PROGRAM PACKAGE
Reference: SAN DIEGO COUNTY FLOOD CONTROL DISTRICT
2003,1985,1981 HYDROLOGY MANUAL
(c) Copyright 1982-2013 Advanced Engineering Software (aes) Ver. 20.0 Release Date: 06/01/2013 License ID 1523
Analysis prepared by:

************************** DESCRIPTION OF STUDY ************************** * ARMORLITE LOFTS *
* 100-YR EXISTING CONDITION * * POC 1 * ************************************************************************** FILE NAME: 1900EX1.DAT
TIME/DATE OF STUDY: 23:46 08/09/2023
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 100.00
6-HOUR DURATION PRECIPITATION (INCHES) = 3.200
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95 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 0.0313 0.167 0.0150 GLOBAL STREET FLOW-DEPTH CONSTRAINTS:

1. Relative Flow-Depth = 0.00 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
*PIPE MAY BE SIZED TO HAVE A FLOW CAPACITY LESS THAN
UPSTREAM TRIBUTARY PIPE.*
**************************************************************************** FLOW PROCESS FROM NODE 1.10 TO NODE 1.20 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 100.00
UPSTREAM ELEVATION(FEET) = 579.20
DOWNSTREAM ELEVATION(FEET) = 577.75
ELEVATION DIFFERENCE(FEET) = 1.45
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 11.146
WARNING: INITIAL SUBAREA FLOW PATH LENGTH IS GREATER THAN THE MAXIMUM OVERLAND FLOW LENGTH = 76.75
(Reference: Table 3-1B of Hydrology Manual)
THE MAXIMUM OVERLAND FLOW LENGTH IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.027
SUBAREA RUNOFF(CFS) = 0.39
TOTAL AREA(ACRES) = 0.26 TOTAL RUNOFF(CFS) = 0.39 **************************************************************************** FLOW PROCESS FROM NODE 1.20 TO NODE 1.30 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 577.75 DOWNSTREAM(FEET) = 560.40 CHANNEL LENGTH THRU SUBAREA(FEET) = 200.00 CHANNEL SLOPE = 0.0867 CHANNEL BASE(FEET) = 5.00 "Z" FACTOR = 1.250
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 2.00 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.688
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
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.) = 2.61 AVERAGE FLOW DEPTH(FEET) = 0.08 TRAVEL TIME(MIN.) = 1.28 Tc(MIN.) = 12.42
SUBAREA AREA(ACRES) = 0.94 SUBAREA RUNOFF(CFS) = 1.32 AREA-AVERAGE RUNOFF COEFFICIENT = 0.300
TOTAL AREA(ACRES) = 1.2 PEAK FLOW RATE(CFS) = 1.69 END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.10 FLOW VELOCITY(FEET/SEC.) = 3.16 LONGEST FLOWPATH FROM NODE 1.10 TO NODE 1.30 = 300.00 FEET. ============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 1.2 TC(MIN.) = 12.42 PEAK FLOW RATE(CFS) = 1.69
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

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

************************** DESCRIPTION OF STUDY ************************** * ARMORLITE LOFTS * * 100-YR EXISTING CONDITION * * POC 2 * ************************************************************************** FILE NAME: 1900EX2.DAT
TIME/DATE OF STUDY: 23:51 08/09/2023
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 100.00
6-HOUR DURATION PRECIPITATION (INCHES) = 3.200
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95 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 = 0.00 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
*PIPE MAY BE SIZED TO HAVE A FLOW CAPACITY LESS THAN
UPSTREAM TRIBUTARY PIPE.*
**************************************************************************** FLOW PROCESS FROM NODE 2.10 TO NODE 2.20 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 100.00
UPSTREAM ELEVATION(FEET) = 579.20
DOWNSTREAM ELEVATION(FEET) = 576.20
ELEVATION DIFFERENCE(FEET) = 3.00
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 9.985
100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.397
SUBAREA RUNOFF(CFS) = 0.23
TOTAL AREA(ACRES) = 0.14 TOTAL RUNOFF(CFS) = 0.23 **************************************************************************** FLOW PROCESS FROM NODE 2.20 TO NODE 2.30 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 576.20 DOWNSTREAM(FEET) = 568.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 130.00 CHANNEL SLOPE = 0.0631 CHANNEL BASE(FEET) = 5.00 "Z" FACTOR = 1.250
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 2.00 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.063
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 0.70 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 2.08 AVERAGE FLOW DEPTH(FEET) = 0.07 TRAVEL TIME(MIN.) = 1.04 Tc(MIN.) = 11.03
SUBAREA AREA(ACRES) = 0.62 SUBAREA RUNOFF(CFS) = 0.94 AREA-AVERAGE RUNOFF COEFFICIENT = 0.300
TOTAL AREA(ACRES) = 0.8 PEAK FLOW RATE(CFS) = 1.15 END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.09 FLOW VELOCITY(FEET/SEC.) = 2.55 LONGEST FLOWPATH FROM NODE 2.10 TO NODE 2.30 = 230.00 FEET. ============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 0.8 TC(MIN.) = 11.03 PEAK FLOW RATE(CFS) = 1.15
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

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

************************** DESCRIPTION OF STUDY ************************** * ARMORLITE LOFTS * * 100-YR EXISTING CONDITION * * POC 3 * ************************************************************************** FILE NAME: 1900EX3.DAT
TIME/DATE OF STUDY: 23:54 08/09/2023
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 100.00
6-HOUR DURATION PRECIPITATION (INCHES) = 3.200
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95 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 = 0.00 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

2. (Depth)*(Velocity) Constraint = 6.0 (FT*FT/S)
*PIPE MAY BE SIZED TO HAVE A FLOW CAPACITY LESS THAN
UPSTREAM TRIBUTARY PIPE.*
**************************************************************************** FLOW PROCESS FROM NODE 3.10 TO NODE 3.20 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 100.00
UPSTREAM ELEVATION(FEET) = 579.20
DOWNSTREAM ELEVATION(FEET) = 578.60
ELEVATION DIFFERENCE(FEET) = 0.60
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 12.546
WARNING: INITIAL SUBAREA FLOW PATH LENGTH IS GREATER THAN THE MAXIMUM OVERLAND FLOW LENGTH = 54.00
(Reference: Table 3-1B of Hydrology Manual)
THE MAXIMUM OVERLAND FLOW LENGTH IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.658
SUBAREA RUNOFF(CFS) = 0.20
TOTAL AREA(ACRES) = 0.14 TOTAL RUNOFF(CFS) = 0.20 **************************************************************************** FLOW PROCESS FROM NODE 3.20 TO NODE 3.30 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 578.60 DOWNSTREAM(FEET) = 568.25 CHANNEL LENGTH THRU SUBAREA(FEET) = 184.00 CHANNEL SLOPE = 0.0562 CHANNEL BASE(FEET) = 5.00 "Z" FACTOR = 1.250
MANNING'S FACTOR = 0.030 MAXIMUM DEPTH(FEET) = 2.00 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.253
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 0.41 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.62 AVERAGE FLOW DEPTH(FEET) = 0.05 TRAVEL TIME(MIN.) = 1.90 Tc(MIN.) = 14.44
SUBAREA AREA(ACRES) = 0.34 SUBAREA RUNOFF(CFS) = 0.43 AREA-AVERAGE RUNOFF COEFFICIENT = 0.300
TOTAL AREA(ACRES) = 0.5 PEAK FLOW RATE(CFS) = 0.61 END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.06 FLOW VELOCITY(FEET/SEC.) = 1.89 LONGEST FLOWPATH FROM NODE 3.10 TO NODE 3.30 = 284.00 FEET. ============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 0.5 TC(MIN.) = 14.44 PEAK FLOW RATE(CFS) = 0.61
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

Latitude 33 Planning & Engineering
10 APPENDIX C

PROPOSED HYDROLOGIC CALCULATIONS

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

************************** DESCRIPTION OF STUDY ************************** * ARMORLITE LOFTS * * 100-YR PROPOSED CONDITION - UNMITIGATED * * POC 1 * ************************************************************************** FILE NAME: 1900PR1U.DAT
TIME/DATE OF STUDY: 00:00 08/10/2023
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 100.00
6-HOUR DURATION PRECIPITATION (INCHES) = 3.200
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95 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 = 0.00 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

USER-SPECIFIED RUNOFF COEFFICIENT = .5800
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 100.00
UPSTREAM ELEVATION(FEET) = 577.50
DOWNSTREAM ELEVATION(FEET) = 575.10
ELEVATION DIFFERENCE(FEET) = 2.40
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 6.214
WARNING: INITIAL SUBAREA FLOW PATH LENGTH IS GREATER THAN THE MAXIMUM OVERLAND FLOW LENGTH = 79.00
(Reference: Table 3-1B of Hydrology Manual)
THE MAXIMUM OVERLAND FLOW LENGTH IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 7.328
SUBAREA RUNOFF(CFS) = 0.55
TOTAL AREA(ACRES) = 0.13 TOTAL RUNOFF(CFS) = 0.55 **************************************************************************** FLOW PROCESS FROM NODE 1.20 TO NODE 1.30 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 1 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 575.10 DOWNSTREAM ELEVATION(FEET) = 568.95 STREET LENGTH(FEET) = 163.00 CURB HEIGHT(INCHES) = 8.0 STREET HALFWIDTH(FEET) = 30.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 20.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.018
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.018
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0150 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 1.10 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.23
HALFSTREET FLOOD WIDTH(FEET) = 3.59
AVERAGE FLOW VELOCITY(FEET/SEC.) = 3.56
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.81
STREET FLOW TRAVEL TIME(MIN.) = 0.76 Tc(MIN.) = 6.98 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 6.801
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7300
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.674
SUBAREA AREA(ACRES) = 0.22 SUBAREA RUNOFF(CFS) = 1.09 TOTAL AREA(ACRES) = 0.3 PEAK FLOW RATE(CFS) = 1.60 END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.26 HALFSTREET FLOOD WIDTH(FEET) = 5.34 FLOW VELOCITY(FEET/SEC.) = 3.58 DEPTH*VELOCITY(FT*FT/SEC.) = 0.92 LONGEST FLOWPATH FROM NODE 1.10 TO NODE 1.30 = 263.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.30 TO NODE 1.40 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 565.00 DOWNSTREAM(FEET) = 564.40 FLOW LENGTH(FEET) = 53.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 12.0 INCH PIPE IS 5.5 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 4.54
GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 1.60
PIPE TRAVEL TIME(MIN.) = 0.19 Tc(MIN.) = 7.17
LONGEST FLOWPATH FROM NODE 1.10 TO NODE 1.40 = 316.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.40 TO NODE 1.50 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 564.40 DOWNSTREAM(FEET) = 563.20 FLOW LENGTH(FEET) = 200.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 12.0 INCH PIPE IS 6.7 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 3.57
GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 1.60
PIPE TRAVEL TIME(MIN.) = 0.93 Tc(MIN.) = 8.11
LONGEST FLOWPATH FROM NODE 1.10 TO NODE 1.50 = 516.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.50 TO NODE 1.60 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 563.20 DOWNSTREAM(FEET) = 563.00 FLOW LENGTH(FEET) = 33.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 12.0 INCH PIPE IS 6.7 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 3.59
GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 1.60
PIPE TRAVEL TIME(MIN.) = 0.15 Tc(MIN.) = 8.26
LONGEST FLOWPATH FROM NODE 1.10 TO NODE 1.60 = 549.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.60 TO NODE 1.60 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.) = 8.26
RAINFALL INTENSITY(INCH/HR) = 6.10
TOTAL STREAM AREA(ACRES) = 0.35
PEAK FLOW RATE(CFS) AT CONFLUENCE = 1.60
**************************************************************************** FLOW PROCESS FROM NODE 3.10 TO NODE 3.20 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 100.00
UPSTREAM ELEVATION(FEET) = 629.00
DOWNSTREAM ELEVATION(FEET) = 628.00
ELEVATION DIFFERENCE(FEET) = 1.00
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 2.789
WARNING: INITIAL SUBAREA FLOW PATH LENGTH IS GREATER THAN THE MAXIMUM OVERLAND FLOW LENGTH = 60.00
(Reference: Table 3-1B of Hydrology Manual)
THE MAXIMUM OVERLAND FLOW LENGTH IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 8.431
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 1.21
TOTAL AREA(ACRES) = 0.16 TOTAL RUNOFF(CFS) = 1.21 **************************************************************************** FLOW PROCESS FROM NODE 3.20 TO NODE 3.30 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 628.00 DOWNSTREAM(FEET) = 626.00 CHANNEL LENGTH THRU SUBAREA(FEET) = 191.00 CHANNEL SLOPE = 0.0105 CHANNEL BASE(FEET) = 200.00 "Z" FACTOR = 0.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 0.08 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 7.568
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 5.64 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.02 AVERAGE FLOW DEPTH(FEET) = 0.03 TRAVEL TIME(MIN.) = 3.12 Tc(MIN.) = 5.91
SUBAREA AREA(ACRES) = 1.27 SUBAREA RUNOFF(CFS) = 8.65 AREA-AVERAGE RUNOFF COEFFICIENT = 0.900
TOTAL AREA(ACRES) = 1.4 PEAK FLOW RATE(CFS) = 9.74 END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.04 FLOW VELOCITY(FEET/SEC.) = 1.19 LONGEST FLOWPATH FROM NODE 3.10 TO NODE 3.30 = 291.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 3.30 TO NODE 1.60 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 563.60 DOWNSTREAM(FEET) = 563.00 FLOW LENGTH(FEET) = 62.00 MANNING'S N = 0.013

ASSUME FULL-FLOWING PIPELINE
PIPE-FLOW VELOCITY(FEET/SEC.) = 12.40
PIPE FLOW VELOCITY = (TOTAL FLOW)/(PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 9.74
PIPE TRAVEL TIME(MIN.) = 0.08 Tc(MIN.) = 5.99
LONGEST FLOWPATH FROM NODE 3.10 TO NODE 1.60 = 353.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.60 TO NODE 1.60 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.) = 5.99
RAINFALL INTENSITY(INCH/HR) = 7.50
TOTAL STREAM AREA(ACRES) = 1.43
PEAK FLOW RATE(CFS) AT CONFLUENCE = 9.74
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 1.60 8.26 6.100 0.35
2 9.74 5.99 7.500 1.43

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 10.90 5.99 7.500
2 9.53 8.26 6.100
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 10.90 Tc(MIN.) = 5.99
TOTAL AREA(ACRES) = 1.8
LONGEST FLOWPATH FROM NODE 1.10 TO NODE 1.60 = 549.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.60 TO NODE 1.70 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 561.00 DOWNSTREAM(FEET) = 558.50 FLOW LENGTH(FEET) = 21.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 12.0 INCH PIPE IS 9.0 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 17.28
GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 10.90
PIPE TRAVEL TIME(MIN.) = 0.02 Tc(MIN.) = 6.02
LONGEST FLOWPATH FROM NODE 1.10 TO NODE 1.70 = 570.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.70 TO NODE 1.70 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.) = 6.02
RAINFALL INTENSITY(INCH/HR) = 7.48
TOTAL STREAM AREA(ACRES) = 1.78
PEAK FLOW RATE(CFS) AT CONFLUENCE = 10.90
**************************************************************************** FLOW PROCESS FROM NODE 2.10 TO NODE 2.20 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7800
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 100.00
UPSTREAM ELEVATION(FEET) = 573.50
DOWNSTREAM ELEVATION(FEET) = 569.40
ELEVATION DIFFERENCE(FEET) = 4.10
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 3.424
WARNING: INITIAL SUBAREA FLOW PATH LENGTH IS GREATER THAN THE MAXIMUM OVERLAND FLOW LENGTH = 90.50
(Reference: Table 3-1B of Hydrology Manual)
THE MAXIMUM OVERLAND FLOW LENGTH IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 8.431
NOTE: RAINFALL INTENSITY IS BASED ON Tc = 5-MINUTE.

SUBAREA RUNOFF(CFS) = 0.85
TOTAL AREA(ACRES) = 0.13 TOTAL RUNOFF(CFS) = 0.85 **************************************************************************** FLOW PROCESS FROM NODE 2.20 TO NODE 2.30 IS CODE = 62 ---------------------------------------------------------------------------- >>>>>COMPUTE STREET FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>(STREET TABLE SECTION # 1 USED)<<<<<
============================================================================ UPSTREAM ELEVATION(FEET) = 569.40 DOWNSTREAM ELEVATION(FEET) = 561.75 STREET LENGTH(FEET) = 324.00 CURB HEIGHT(INCHES) = 8.0 STREET HALFWIDTH(FEET) = 30.00
DISTANCE FROM CROWN TO CROSSFALL GRADEBREAK(FEET) = 20.00 INSIDE STREET CROSSFALL(DECIMAL) = 0.018
OUTSIDE STREET CROSSFALL(DECIMAL) = 0.018
SPECIFIED NUMBER OF HALFSTREETS CARRYING RUNOFF = 1
STREET PARKWAY CROSSFALL(DECIMAL) = 0.020
Manning's FRICTION FACTOR for Streetflow Section(curb-to-curb) = 0.0150 Manning's FRICTION FACTOR for Back-of-Walk Flow Section = 0.0200 **TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 2.27 STREETFLOW MODEL RESULTS USING ESTIMATED FLOW:

STREET FLOW DEPTH(FEET) = 0.30
HALFSTREET FLOOD WIDTH(FEET) = 7.84
AVERAGE FLOW VELOCITY(FEET/SEC.) = 3.06
PRODUCT OF DEPTH&VELOCITY(FT*FT/SEC.) = 0.92
STREET FLOW TRAVEL TIME(MIN.) = 1.77 Tc(MIN.) = 5.19 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 8.230
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .7800
S.C.S. CURVE NUMBER (AMC II) = 0
AREA-AVERAGE RUNOFF COEFFICIENT = 0.780
SUBAREA AREA(ACRES) = 0.44 SUBAREA RUNOFF(CFS) = 2.82 TOTAL AREA(ACRES) = 0.6 PEAK FLOW RATE(CFS) = 3.66 END OF SUBAREA STREET FLOW HYDRAULICS:

DEPTH(FEET) = 0.34 HALFSTREET FLOOD WIDTH(FEET) = 9.97 FLOW VELOCITY(FEET/SEC.) = 3.38 DEPTH*VELOCITY(FT*FT/SEC.) = 1.15 LONGEST FLOWPATH FROM NODE 2.10 TO NODE 2.30 = 424.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 2.30 TO NODE 2.40 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 561.75 DOWNSTREAM(FEET) = 561.60 CHANNEL LENGTH THRU SUBAREA(FEET) = 15.00 CHANNEL SLOPE = 0.0100 CHANNEL BASE(FEET) = 3.00 "Z" FACTOR = 1.500
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 1.50 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 8.164
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 3.66 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 3.83 AVERAGE FLOW DEPTH(FEET) = 0.28 TRAVEL TIME(MIN.) = 0.07 Tc(MIN.) = 5.26
SUBAREA AREA(ACRES) = 0.00 SUBAREA RUNOFF(CFS) = 0.00 AREA-AVERAGE RUNOFF COEFFICIENT = 0.779
TOTAL AREA(ACRES) = 0.6 PEAK FLOW RATE(CFS) = 3.66 END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.28 FLOW VELOCITY(FEET/SEC.) = 3.83 LONGEST FLOWPATH FROM NODE 2.10 TO NODE 2.40 = 439.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 2.40 TO NODE 2.50 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 560.60 DOWNSTREAM(FEET) = 560.10 FLOW LENGTH(FEET) = 3.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 12.0 INCH PIPE IS 4.2 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 15.13
GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 3.66
PIPE TRAVEL TIME(MIN.) = 0.00 Tc(MIN.) = 5.26
LONGEST FLOWPATH FROM NODE 2.10 TO NODE 2.50 = 442.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 2.50 TO NODE 1.70 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 558.60 DOWNSTREAM(FEET) = 558.50 FLOW LENGTH(FEET) = 6.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 12.0 INCH PIPE IS 8.2 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 6.36
GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 3.66
PIPE TRAVEL TIME(MIN.) = 0.02 Tc(MIN.) = 5.28
LONGEST FLOWPATH FROM NODE 2.10 TO NODE 1.70 = 448.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.70 TO NODE 1.70 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.) = 5.28
RAINFALL INTENSITY(INCH/HR) = 8.14
TOTAL STREAM AREA(ACRES) = 0.57
PEAK FLOW RATE(CFS) AT CONFLUENCE = 3.66
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 10.90 6.02 7.484 1.78
2 3.66 5.28 8.145 0.57

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 13.68 5.28 8.145
2 14.27 6.02 7.484
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 14.27 Tc(MIN.) = 6.02
TOTAL AREA(ACRES) = 2.4
LONGEST FLOWPATH FROM NODE 1.10 TO NODE 1.70 = 570.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.70 TO NODE 1.80 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 554.00 DOWNSTREAM(FEET) = 553.75 FLOW LENGTH(FEET) = 44.00 MANNING'S N = 0.013

ASSUME FULL-FLOWING PIPELINE
PIPE-FLOW VELOCITY(FEET/SEC.) = 18.17
PIPE FLOW VELOCITY = (TOTAL FLOW)/(PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 14.27
PIPE TRAVEL TIME(MIN.) = 0.04 Tc(MIN.) = 6.06
LONGEST FLOWPATH FROM NODE 1.10 TO NODE 1.80 = 614.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.80 TO NODE 1.90 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 553.75 DOWNSTREAM(FEET) = 552.90 FLOW LENGTH(FEET) = 170.00 MANNING'S N = 0.013

ASSUME FULL-FLOWING PIPELINE
PIPE-FLOW VELOCITY(FEET/SEC.) = 18.17
PIPE FLOW VELOCITY = (TOTAL FLOW)/(PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 14.27
PIPE TRAVEL TIME(MIN.) = 0.16 Tc(MIN.) = 6.21
LONGEST FLOWPATH FROM NODE 1.10 TO NODE 1.90 = 784.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.90 TO NODE 4.50 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 552.90 DOWNSTREAM(FEET) = 552.66 FLOW LENGTH(FEET) = 25.00 MANNING'S N = 0.013

ASSUME FULL-FLOWING PIPELINE
PIPE-FLOW VELOCITY(FEET/SEC.) = 18.17
PIPE FLOW VELOCITY = (TOTAL FLOW)/(PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 14.27
PIPE TRAVEL TIME(MIN.) = 0.02 Tc(MIN.) = 6.23
LONGEST FLOWPATH FROM NODE 1.10 TO NODE 4.50 = 809.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 4.50 TO NODE 4.50 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.) = 6.23
RAINFALL INTENSITY(INCH/HR) = 7.31
TOTAL STREAM AREA(ACRES) = 2.35
PEAK FLOW RATE(CFS) AT CONFLUENCE = 14.27
**************************************************************************** FLOW PROCESS FROM NODE 4.10 TO NODE 4.20 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3400
S.C.S. CURVE NUMBER (AMC II) = 0
INITIAL SUBAREA FLOW-LENGTH(FEET) = 100.00
UPSTREAM ELEVATION(FEET) = 572.90
DOWNSTREAM ELEVATION(FEET) = 570.15
ELEVATION DIFFERENCE(FEET) = 2.75
SUBAREA OVERLAND TIME OF FLOW(MIN.) = 8.869
WARNING: INITIAL SUBAREA FLOW PATH LENGTH IS GREATER THAN THE MAXIMUM OVERLAND FLOW LENGTH = 82.50
(Reference: Table 3-1B of Hydrology Manual)
THE MAXIMUM OVERLAND FLOW LENGTH IS USED IN Tc CALCULATION! 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 5.826
SUBAREA RUNOFF(CFS) = 0.12
TOTAL AREA(ACRES) = 0.06 TOTAL RUNOFF(CFS) = 0.12 **************************************************************************** FLOW PROCESS FROM NODE 4.20 TO NODE 4.30 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 570.15 DOWNSTREAM(FEET) = 562.75 CHANNEL LENGTH THRU SUBAREA(FEET) = 286.00 CHANNEL SLOPE = 0.0259 CHANNEL BASE(FEET) = 3.00 "Z" FACTOR = 3.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 2.00 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 4.870
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .3400
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 0.14 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.68 AVERAGE FLOW DEPTH(FEET) = 0.03 TRAVEL TIME(MIN.) = 2.84 Tc(MIN.) = 11.71
SUBAREA AREA(ACRES) = 0.03 SUBAREA RUNOFF(CFS) = 0.05 AREA-AVERAGE RUNOFF COEFFICIENT = 0.340
TOTAL AREA(ACRES) = 0.1 PEAK FLOW RATE(CFS) = 0.15 END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.03 FLOW VELOCITY(FEET/SEC.) = 1.44 LONGEST FLOWPATH FROM NODE 4.10 TO NODE 4.30 = 386.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 4.30 TO NODE 4.40 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 562.75 DOWNSTREAM(FEET) = 562.60 FLOW LENGTH(FEET) = 17.00 MANNING'S N = 0.013

ASSUME FULL-FLOWING PIPELINE
PIPE-FLOW VELOCITY(FEET/SEC.) = 3.04
PIPE FLOW VELOCITY = (TOTAL FLOW)/(PIPE CROSS SECTION AREA) GIVEN PIPE DIAMETER(INCH) = 3.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 0.15
PIPE TRAVEL TIME(MIN.) = 0.09 Tc(MIN.) = 11.80
LONGEST FLOWPATH FROM NODE 4.10 TO NODE 4.40 = 403.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 4.40 TO NODE 4.50 IS CODE = 51 ---------------------------------------------------------------------------- >>>>>COMPUTE TRAPEZOIDAL CHANNEL FLOW<<<<<
>>>>>TRAVELTIME THRU SUBAREA (EXISTING ELEMENT)<<<<<
============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 562.60 DOWNSTREAM(FEET) = 558.33 CHANNEL LENGTH THRU SUBAREA(FEET) = 357.00 CHANNEL SLOPE = 0.0120 CHANNEL BASE(FEET) = 1.50 "Z" FACTOR = 12.000
MANNING'S FACTOR = 0.015 MAXIMUM DEPTH(FEET) = 0.50 100 YEAR RAINFALL INTENSITY(INCH/HOUR) = 3.954
*USER SPECIFIED(SUBAREA):

USER-SPECIFIED RUNOFF COEFFICIENT = .9000
S.C.S. CURVE NUMBER (AMC II) = 0
TRAVEL TIME COMPUTED USING ESTIMATED FLOW(CFS) = 0.17 TRAVEL TIME THRU SUBAREA BASED ON VELOCITY(FEET/SEC.) = 1.36 AVERAGE FLOW DEPTH(FEET) = 0.06 TRAVEL TIME(MIN.) = 4.37 Tc(MIN.) = 16.17
SUBAREA AREA(ACRES) = 0.01 SUBAREA RUNOFF(CFS) = 0.04 AREA-AVERAGE RUNOFF COEFFICIENT = 0.396
TOTAL AREA(ACRES) = 0.1 PEAK FLOW RATE(CFS) = 0.16 END OF SUBAREA CHANNEL FLOW HYDRAULICS:

DEPTH(FEET) = 0.06 FLOW VELOCITY(FEET/SEC.) = 1.28 LONGEST FLOWPATH FROM NODE 4.10 TO NODE 4.50 = 760.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 4.50 TO NODE 4.50 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.) = 16.17
RAINFALL INTENSITY(INCH/HR) = 3.95
TOTAL STREAM AREA(ACRES) = 0.10
PEAK FLOW RATE(CFS) AT CONFLUENCE = 0.16
** CONFLUENCE DATA **
STREAM RUNOFF Tc INTENSITY AREA
NUMBER (CFS) (MIN.) (INCH/HOUR) (ACRE)
1 14.27 6.23 7.313 2.35
2 0.16 16.17 3.954 0.10

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 14.33 6.23 7.313
2 7.87 16.17 3.954
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 14.33 Tc(MIN.) = 6.23
TOTAL AREA(ACRES) = 2.4
LONGEST FLOWPATH FROM NODE 1.10 TO NODE 4.50 = 809.00 FEET. ============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 2.4 TC(MIN.) = 6.23 PEAK FLOW RATE(CFS) = 14.33
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

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

************************** DESCRIPTION OF STUDY ************************** * ARMORLITE LOFTS * * 100-YR PROPOSED CONDITION - MITIGATED * * POC 1 * ************************************************************************** FILE NAME: 1900PR1.DAT
TIME/DATE OF STUDY: 00:17 08/10/2023
---------------------------------------------------------------------------- USER SPECIFIED HYDROLOGY AND HYDRAULIC MODEL INFORMATION:
---------------------------------------------------------------------------- 2003 SAN DIEGO MANUAL CRITERIA
USER SPECIFIED STORM EVENT(YEAR) = 100.00
6-HOUR DURATION PRECIPITATION (INCHES) = 3.200
SPECIFIED MINIMUM PIPE SIZE(INCH) = 18.00
SPECIFIED PERCENT OF GRADIENTS(DECIMAL) TO USE FOR FRICTION SLOPE = 0.95 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 = 0.00 FEET
as (Maximum Allowable Street Flow Depth) - (Top-of-Curb)

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 13.68 5.28 8.145
2 14.27 6.02 7.484
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 14.27 Tc(MIN.) = 6.02
TOTAL AREA(ACRES) = 2.4
LONGEST FLOWPATH FROM NODE 1.10 TO NODE 1.70 = 570.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.70 TO NODE 1.70 IS CODE = 7 ---------------------------------------------------------------------------- >>>>>USER SPECIFIED HYDROLOGY INFORMATION AT NODE<<<<<
============================================================================ USER-SPECIFIED VALUES ARE AS FOLLOWS:

TC(MIN) = 19.02 RAIN INTENSITY(INCH/HOUR) = 3.56
TOTAL AREA(ACRES) = 2.35 TOTAL RUNOFF(CFS) = 1.44 **************************************************************************** FLOW PROCESS FROM NODE 1.70 TO NODE 1.80 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 554.00 DOWNSTREAM(FEET) = 553.75 FLOW LENGTH(FEET) = 44.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 12.0 INCH PIPE IS 6.3 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 3.42
GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 1.44
PIPE TRAVEL TIME(MIN.) = 0.21 Tc(MIN.) = 19.23
LONGEST FLOWPATH FROM NODE 1.10 TO NODE 1.80 = 614.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.80 TO NODE 1.90 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 553.75 DOWNSTREAM(FEET) = 552.90 FLOW LENGTH(FEET) = 170.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 12.0 INCH PIPE IS 6.6 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 3.25
GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 1.44
PIPE TRAVEL TIME(MIN.) = 0.87 Tc(MIN.) = 20.11
LONGEST FLOWPATH FROM NODE 1.10 TO NODE 1.90 = 784.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 1.90 TO NODE 4.50 IS CODE = 41 ---------------------------------------------------------------------------- >>>>>COMPUTE PIPE-FLOW TRAVEL TIME THRU SUBAREA<<<<<
>>>>>USING USER-SPECIFIED PIPESIZE (EXISTING ELEMENT)<<<<< ============================================================================ ELEVATION DATA: UPSTREAM(FEET) = 552.90 DOWNSTREAM(FEET) = 552.66 FLOW LENGTH(FEET) = 25.00 MANNING'S N = 0.013
DEPTH OF FLOW IN 12.0 INCH PIPE IS 5.4 INCHES
PIPE-FLOW VELOCITY(FEET/SEC.) = 4.16
GIVEN PIPE DIAMETER(INCH) = 12.00 NUMBER OF PIPES = 1 PIPE-FLOW(CFS) = 1.44
PIPE TRAVEL TIME(MIN.) = 0.10 Tc(MIN.) = 20.21
LONGEST FLOWPATH FROM NODE 1.10 TO NODE 4.50 = 809.00 FEET. **************************************************************************** FLOW PROCESS FROM NODE 4.50 TO NODE 4.50 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.) = 20.21
RAINFALL INTENSITY(INCH/HR) = 3.43
TOTAL STREAM AREA(ACRES) = 2.35
PEAK FLOW RATE(CFS) AT CONFLUENCE = 1.44
**************************************************************************** FLOW PROCESS FROM NODE 4.10 TO NODE 4.20 IS CODE = 21 ---------------------------------------------------------------------------- >>>>>RATIONAL METHOD INITIAL SUBAREA ANALYSIS<<<<<
============================================================================ *USER SPECIFIED(SUBAREA):

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 1.31 16.17 3.954
2 1.58 20.21 3.425
COMPUTED CONFLUENCE ESTIMATES ARE AS FOLLOWS:

PEAK FLOW RATE(CFS) = 1.58 Tc(MIN.) = 20.21
TOTAL AREA(ACRES) = 2.4
LONGEST FLOWPATH FROM NODE 1.10 TO NODE 4.50 = 809.00 FEET. ============================================================================ END OF STUDY SUMMARY:

TOTAL AREA(ACRES) = 2.4 TC(MIN.) = 20.21 PEAK FLOW RATE(CFS) = 1.58
============================================================================ ============================================================================

END OF RATIONAL METHOD ANALYSIS

Latitude 33 Planning & Engineering
11 APPENDIX D

PONDPACK ANALYSIS (DETAINED CALCULATIONS)

Project Summary
Armorlite Lofts Title
DN Engineer
Latitude 33
Planning &
Engineering
Company
8/10/2023 Date
Notes

Page 1 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Table of Contents
24 Pond Inflow Summary
PO-1 (IN)
22 Pond Routed Hydrograph (total out)
PO-1 (OUT)
21 Level Pool Pond Routing Summary
20 Detention Time
PO-1 (IN)
19 Elevation-Volume-Flow Table (Pond)
PO-1
17 Diverted Hydrograph
Outlet-2
16 Composite Rating Curve
14 Individual Outlet Curves
12 Outlet Input Data
Composite Outlet Structure - 1
11 Volume Equations
10 Elevation-Area Volume Curve
PO-1
8Time vs. Volume PO-1
6Time vs. Elevation PO-1 (OUT)
5 Addition Summary O-1
4 Read Hydrograph CM-1
3 Master Network Summary
2 User Notifications
Subsection: User Notifications
No user
notifications
generated.

User Notifications?

Page 2 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Subsection: Master Network Summary
Catchments Summary
Peak Flow
(ft³/s)
Time to Peak
(min)
Hydrograph
Volume
(ac-ft)
Return
Event
(years)
Scenario Label

14.27 246.000 0.487 0Base CM-1
Node Summary
Peak Flow
(ft³/s)
Time to Peak
(min)
Hydrograph
Volume
(ac-ft)
Return
Event
(years)
Scenario Label

1.44 259.000 0.181 0Base O-1
Pond Summary
Maximum
Pond Storage
(ac-ft)
Maximum
Water
Surface
Elevation
(ft)
Peak Flow
(ft³/s)
Time to Peak
(min)
Hydrograph
Volume
(ac-ft)
Return
Event
(years)
Scenario Label
(N/A) (N/A) 14.27 246.000 0.487 0Base PO-1 (IN)

0.338 558.39 1.44 259.000 0.181 0Base PO-1 (OUT)

Page 3 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: CM-1
Scenario: Base Subsection: Read Hydrograph
ft³/s 14.27 Peak Discharge
min 246.000 Time to Peak
ac-ft 0.487 Hydrograph Volume
HYDROGRAPH ORDINATES (ft³/s)
Output Time Increment = 6.000 min
Time on left represents time for first value in each row.

Flow
(ft³/s)
Flow
(ft³/s)
Flow
(ft³/s)
Flow
(ft³/s)
Flow
(ft³/s)
Time
(min)

0.40 0.40 0.40 0.30 0.00 0.000

0.40 0.40 0.40 0.40 0.40 30.000

0.40 0.40 0.40 0.40 0.40 60.000

0.50 0.50 0.50 0.50 0.50 90.000

0.60 0.60 0.60 0.50 0.50 120.000

0.80 0.70 0.70 0.70 0.60 150.000

1.10 1.00 0.90 0.90 0.80 180.000

2.70 1.90 1.60 1.30 1.20 210.000

1.10 1.50 2.20 14.27 3.30 240.000

0.60 0.70 0.70 0.80 1.00 270.000

0.50 0.50 0.50 0.50 0.60 300.000

0.40 0.40 0.40 0.40 0.40 330.000
(N/A) (N/A) (N/A) 0.00 0.40 360.000

Page 4 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: O-1
Scenario: Base Subsection: Addition Summary
Summary for Hydrograph Addition at 'O-1'
Upstream Node Upstream Link
PO-1 Outlet-2
Node Inflows
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Volume
(ac-ft)
Element Inflow Type

1.44 259.000 0.181 Outlet-2 Flow (From)

1.44 259.000 0.181 O-1 Flow (In)

Page 5 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: PO-1 (OUT)
Scenario: Base Subsection: Time vs. Elevation
Time vs. Elevation (ft)
Output Time increment = 1.000 min
Time on left represents time for first value in each row.

Elevation
(ft)
Elevation
(ft)
Elevation
(ft)
Elevation
(ft)
Elevation
(ft)
Time
(min)
554.01 554.00 554.00 554.00 554.00 0.000
554.03 554.03 554.02 554.02 554.01 5.000
554.07 554.06 554.05 554.05 554.04 10.000
554.10 554.09 554.09 554.08 554.07 15.000
554.13 554.13 554.12 554.11 554.11 20.000
554.17 554.16 554.15 554.15 554.14 25.000
554.20 554.19 554.19 554.18 554.17 30.000
554.23 554.23 554.22 554.21 554.21 35.000
554.26 554.26 554.25 554.24 554.24 40.000
554.29 554.29 554.28 554.28 554.27 45.000
554.32 554.32 554.31 554.31 554.30 50.000
554.35 554.35 554.34 554.34 554.33 55.000
554.38 554.38 554.37 554.37 554.36 60.000
554.41 554.41 554.40 554.39 554.39 65.000
554.44 554.43 554.43 554.42 554.42 70.000
554.47 554.46 554.46 554.45 554.44 75.000
554.49 554.49 554.48 554.48 554.47 80.000
554.52 554.52 554.51 554.50 554.50 85.000
554.56 554.55 554.54 554.54 554.53 90.000
554.59 554.59 554.58 554.57 554.57 95.000
554.63 554.62 554.61 554.61 554.60 100.000
554.66 554.66 554.65 554.64 554.63 105.000
554.70 554.69 554.68 554.68 554.67 110.000
554.73 554.72 554.72 554.71 554.70 115.000
554.76 554.76 554.75 554.74 554.74 120.000
554.80 554.79 554.78 554.78 554.77 125.000
554.84 554.83 554.82 554.81 554.80 130.000
554.88 554.87 554.86 554.85 554.85 135.000
554.92 554.91 554.90 554.89 554.89 140.000
554.96 554.95 554.94 554.94 554.93 145.000
555.00 554.99 554.98 554.98 554.97 150.000
555.05 555.04 555.03 555.02 555.01 155.000
555.10 555.09 555.08 555.07 555.06 160.000
555.15 555.14 555.13 555.12 555.11 165.000
555.20 555.19 555.18 555.17 555.16 170.000
555.26 555.24 555.23 555.22 555.21 175.000
555.31 555.30 555.29 555.28 555.27 180.000
555.38 555.36 555.35 555.34 555.33 185.000
555.44 555.43 555.42 555.40 555.39 190.000
555.51 555.50 555.48 555.47 555.46 195.000
555.59 555.57 555.56 555.54 555.53 200.000
555.67 555.66 555.64 555.62 555.61 205.000
555.76 555.75 555.73 555.71 555.69 210.000

Page 6 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: PO-1 (OUT)
Scenario: Base Subsection: Time vs. Elevation
Time vs. Elevation (ft)
Output Time increment = 1.000 min
Time on left represents time for first value in each row.

Elevation
(ft)
Elevation
(ft)
Elevation
(ft)
Elevation
(ft)
Elevation
(ft)
Time
(min)
555.86 555.84 555.82 555.80 555.78 215.000
555.99 555.96 555.93 555.91 555.89 220.000
556.13 556.10 556.07 556.04 556.01 225.000
556.32 556.28 556.24 556.20 556.16 230.000
556.56 556.51 556.46 556.41 556.37 235.000
557.09 556.93 556.79 556.69 556.62 240.000
558.11 557.96 557.76 557.53 557.30 245.000
558.37 558.35 558.34 558.30 558.23 250.000
558.39 558.39 558.39 558.38 558.37 255.000
558.38 558.38 558.38 558.39 558.39 260.000
558.35 558.35 558.36 558.36 558.37 265.000
558.32 558.33 558.33 558.34 558.34 270.000
558.28 558.29 558.30 558.30 558.31 275.000
558.25 558.26 558.26 558.27 558.28 280.000
558.22 558.23 558.23 558.24 558.24 285.000
558.20 558.20 558.21 558.21 558.22 290.000
558.17 558.18 558.18 558.19 558.19 295.000
558.15 558.16 558.16 558.17 558.17 300.000
558.13 558.14 558.14 558.15 558.15 305.000
558.12 558.12 558.12 558.13 558.13 310.000
558.11 558.11 558.11 558.11 558.12 315.000
558.10 558.10 558.10 558.10 558.10 320.000
558.08 558.09 558.09 558.09 558.09 325.000
558.07 558.07 558.08 558.08 558.08 330.000
558.06 558.06 558.06 558.07 558.07 335.000
558.05 558.05 558.06 558.06 558.06 340.000
558.05 558.05 558.05 558.05 558.05 345.000
558.04 558.04 558.04 558.05 558.05 350.000
558.04 558.04 558.04 558.04 558.04 355.000
558.03 558.03 558.03 558.04 558.04 360.000
558.00 558.00 558.01 558.02 558.02 365.000
557.97 557.97 557.98 557.99 557.99 370.000

Page 7 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: PO-1
Scenario: Base Subsection: Time vs. Volume
Time vs. Volume (ac-ft)
Output Time increment = 1.000 min
Time on left represents time for first value in each row.

Volume
(ac-ft)
Volume
(ac-ft)
Volume
(ac-ft)
Volume
(ac-ft)
Volume
(ac-ft)
Time
(min)

0.001 0.000 0.000 0.000 0.000 0.000

0.003 0.002 0.002 0.001 0.001 5.000

0.005 0.005 0.004 0.004 0.003 10.000

0.008 0.007 0.007 0.006 0.006 15.000

0.010 0.010 0.009 0.009 0.008 20.000

0.013 0.012 0.012 0.011 0.011 25.000

0.015 0.015 0.014 0.014 0.013 30.000

0.018 0.017 0.017 0.016 0.016 35.000

0.020 0.020 0.019 0.019 0.018 40.000

0.023 0.022 0.022 0.021 0.021 45.000

0.025 0.024 0.024 0.024 0.023 50.000

0.027 0.027 0.026 0.026 0.025 55.000

0.029 0.029 0.029 0.028 0.028 60.000

0.032 0.031 0.031 0.030 0.030 65.000

0.034 0.033 0.033 0.032 0.032 70.000

0.036 0.035 0.035 0.035 0.034 75.000

0.038 0.038 0.037 0.037 0.036 80.000

0.040 0.040 0.039 0.039 0.038 85.000

0.043 0.042 0.042 0.041 0.041 90.000

0.046 0.045 0.045 0.044 0.044 95.000

0.048 0.048 0.047 0.047 0.046 100.000

0.051 0.050 0.050 0.049 0.049 105.000

0.054 0.053 0.052 0.052 0.051 110.000

0.056 0.056 0.055 0.055 0.054 115.000

0.059 0.058 0.058 0.057 0.057 120.000

0.061 0.061 0.060 0.060 0.059 125.000

0.064 0.064 0.063 0.062 0.062 130.000

0.068 0.067 0.066 0.066 0.065 135.000

0.071 0.070 0.069 0.069 0.068 140.000

0.074 0.073 0.073 0.072 0.071 145.000

0.077 0.076 0.076 0.075 0.074 150.000

0.081 0.080 0.079 0.079 0.078 155.000

0.084 0.084 0.083 0.082 0.081 160.000

0.088 0.087 0.087 0.086 0.085 165.000

0.092 0.091 0.091 0.090 0.089 170.000

0.097 0.096 0.095 0.094 0.093 175.000

0.101 0.100 0.099 0.098 0.097 180.000

0.106 0.105 0.104 0.103 0.102 185.000

0.111 0.110 0.109 0.108 0.107 190.000

0.116 0.115 0.114 0.113 0.112 195.000

0.122 0.121 0.120 0.119 0.117 200.000

0.129 0.127 0.126 0.125 0.123 205.000

0.136 0.134 0.133 0.131 0.130 210.000

Page 8 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: PO-1
Scenario: Base Subsection: Time vs. Volume
Time vs. Volume (ac-ft)
Output Time increment = 1.000 min
Time on left represents time for first value in each row.

Volume
(ac-ft)
Volume
(ac-ft)
Volume
(ac-ft)
Volume
(ac-ft)
Volume
(ac-ft)
Time
(min)

0.143 0.142 0.140 0.139 0.137 215.000

0.153 0.151 0.149 0.147 0.145 220.000

0.164 0.161 0.159 0.157 0.155 225.000

0.178 0.175 0.172 0.169 0.166 230.000

0.197 0.193 0.189 0.185 0.182 235.000

0.238 0.225 0.215 0.207 0.201 240.000

0.316 0.304 0.289 0.271 0.253 245.000

0.336 0.335 0.334 0.331 0.325 250.000

0.338 0.338 0.337 0.337 0.336 255.000

0.336 0.337 0.337 0.337 0.337 260.000

0.334 0.335 0.335 0.336 0.336 265.000

0.332 0.333 0.333 0.334 0.334 270.000

0.329 0.330 0.331 0.331 0.332 275.000

0.327 0.327 0.328 0.328 0.329 280.000

0.325 0.325 0.326 0.326 0.326 285.000

0.323 0.323 0.324 0.324 0.324 290.000

0.321 0.321 0.322 0.322 0.322 295.000

0.320 0.320 0.320 0.320 0.321 300.000

0.318 0.318 0.319 0.319 0.319 305.000

0.317 0.317 0.317 0.317 0.318 310.000

0.316 0.316 0.316 0.316 0.316 315.000

0.315 0.315 0.315 0.315 0.316 320.000

0.314 0.314 0.314 0.315 0.315 325.000

0.313 0.313 0.313 0.314 0.314 330.000

0.312 0.312 0.313 0.313 0.313 335.000

0.312 0.312 0.312 0.312 0.312 340.000

0.311 0.311 0.311 0.312 0.312 345.000

0.311 0.311 0.311 0.311 0.311 350.000

0.311 0.311 0.311 0.311 0.311 355.000

0.310 0.310 0.310 0.310 0.311 360.000

0.307 0.308 0.308 0.309 0.309 365.000

0.305 0.306 0.306 0.307 0.307 370.000

Page 9 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: PO-1
Scenario: Base Subsection: Elevation-Area Volume Curve Volume (Total)
(ac-ft)
Volume
(ac-ft)
A1+A2+sqr
(A1*A2)
(ft²)
Area
(ft²)
Planimeter
(ft²)
Elevation
(ft)

0.000 0.000 0.000 3,350.000 0.0 554.00

0.077 0.077 10,050.000 3,350.000 0.0 555.00

0.154 0.077 10,050.000 3,350.000 0.0 556.00

0.231 0.077 10,050.000 3,350.000 0.0 557.00

0.308 0.077 10,050.000 3,350.000 0.0 558.00

0.346 0.038 10,050.000 3,350.000 0.0 558.50

Page 10 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: PO-1
Scenario: Base Subsection: Volume Equations
Pond Volume Equations
* Incremental volume computed by the Conic Method for Reservoir Volumes.

Volume = (1/3) * (EL2 - El1) * (Area1 + Area2 + sqr(Area1 * Area2)) Lower and upper elevations of the increment where: EL1, EL2 Areas computed for EL1, EL2, respectively Area1, Area2
Incremental volume between EL1 and EL2 Volume

Page 11 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: Composite Outlet Structure - 1
Scenario: Base Subsection: Outlet Input Data
Requested Pond Water Surface Elevations
ft 554.00 Minimum (Headwater)
ft 0.50 Increment (Headwater)
ft 558.50 Maximum (Headwater)
Outlet Connectivity
E2
(ft)
E1
(ft)
Outfall Direction Outlet ID Structure Type
558.50 554.00 TW Forward Orifice - 2 Orifice-Circular
558.50 558.00 TW Forward Weir - 1 Rectangular Weir
(N/A) (N/A) Tailwater Tailwater Settings

Page 12 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: Composite Outlet Structure - 1
Scenario: Base Subsection: Outlet Input Data
Structure ID: Orifice - 2
Structure Type: Orifice-Circular
1 Number of Openings
ft 554.00 Elevation
in 2.5 Orifice Diameter

0.600 Orifice Coefficient
Structure ID: Weir - 1
Structure Type: Rectangular Weir
1 Number of Openings
ft 558.00 Elevation
ft 1.33 Weir Length
(ft^0.5)/s 3.00 Weir Coefficient
Structure ID: TW
Structure Type: TW Setup, DS Channel
Free Outfall Tailwater Type
Convergence Tolerances
30 Maximum Iterations
ft 0.01 Tailwater Tolerance
(Minimum)
ft 0.50 Tailwater Tolerance
(Maximum)
ft 0.01 Headwater Tolerance
(Minimum)
ft 0.50 Headwater Tolerance
(Maximum)
ft³/s 0.001 Flow Tolerance (Minimum)
ft³/s 10.000 Flow Tolerance (Maximum)

Page 13 of 25 ends

RATING TABLE FOR ONE OUTLET TYPE
Structure ID = Orifice - 2 (Orifice-Circular)
---------------------------------------
Upstream ID = (Pond Water Surface)
Downstream ID = Tailwater (Pond Outfall)
Convergence Error
(ft)
Tailwater Elevation
(ft)
Flow
(ft³/s)
Water Surface
Elevation
(ft)

0.00 (N/A) 0.00 554.00

0.00 (N/A) 0.10 554.50

0.00 (N/A) 0.16 555.00

0.00 (N/A) 0.19 555.50

0.00 (N/A) 0.23 556.00

0.00 (N/A) 0.25 556.50

0.00 (N/A) 0.28 557.00

0.00 (N/A) 0.30 557.50

0.00 (N/A) 0.32 558.00

0.00 (N/A) 0.34 558.50
Computation Messages
Upstream HW &
DNstream TW < Inv.El
H =.40
H =.90
H =1.40
H =1.90
H =2.40
H =2.90
H =3.40
H =3.90
H =4.40

Page 14 of 25 ends

RATING TABLE FOR ONE OUTLET TYPE
Structure ID = Weir - 1 (Rectangular Weir)
---------------------------------------
Upstream ID = (Pond Water Surface)
Downstream ID = Tailwater (Pond Outfall)
Convergence Error
(ft)
Tailwater Elevation
(ft)
Flow
(ft³/s)
Water Surface
Elevation
(ft)

0.00 (N/A) 0.00 554.00

0.00 (N/A) 0.00 554.50

0.00 (N/A) 0.00 555.00

0.00 (N/A) 0.00 555.50

0.00 (N/A) 0.00 556.00

0.00 (N/A) 0.00 556.50

0.00 (N/A) 0.00 557.00

0.00 (N/A) 0.00 557.50

0.00 (N/A) 0.00 558.00

0.00 (N/A) 1.41 558.50
Computation Messages
HW & TW below
Inv.El.=558.000
HW & TW below
Inv.El.=558.000
HW & TW below
Inv.El.=558.000
HW & TW below
Inv.El.=558.000
HW & TW below
Inv.El.=558.000
HW & TW below
Inv.El.=558.000
HW & TW below
Inv.El.=558.000
HW & TW below
Inv.El.=558.000
H=.00; Htw=.00;
Qfree=.00;
H=.50; Htw=.00;
Qfree=1.41;

Page 15 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: Composite Outlet Structure - 1
Scenario: Base Subsection: Composite Rating Curve
Composite Outflow Summary
Convergence Error
(ft)
Tailwater Elevation
(ft)
Flow
(ft³/s)
Water Surface
Elevation
(ft)

0.00 (N/A) 0.00 554.00

0.00 (N/A) 0.10 554.50

0.00 (N/A) 0.16 555.00

0.00 (N/A) 0.19 555.50

0.00 (N/A) 0.23 556.00

0.00 (N/A) 0.25 556.50

0.00 (N/A) 0.28 557.00

0.00 (N/A) 0.30 557.50

0.00 (N/A) 0.32 558.00

0.00 (N/A) 1.75 558.50
Contributing Structures
None Contributing
Orifice - 2
Orifice - 2
Orifice - 2
Orifice - 2
Orifice - 2
Orifice - 2
Orifice - 2
Orifice - 2 + Weir - 1
Orifice - 2 + Weir - 1

Page 16 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: Outlet-2
Scenario: Base Subsection: Diverted Hydrograph
ft³/s 1.44 Peak Discharge
min 259.000 Time to Peak
ac-ft 0.181 Hydrograph Volume
HYDROGRAPH ORDINATES (ft³/s)
Output Time Increment = 1.000 min
Time on left represents time for first value in each row.

Flow
(ft³/s)
Flow
(ft³/s)
Flow
(ft³/s)
Flow
(ft³/s)
Flow
(ft³/s)
Time
(min)

0.00 0.00 0.00 0.00 0.00 3.000

0.01 0.01 0.01 0.01 0.01 8.000

0.02 0.02 0.02 0.01 0.01 13.000

0.03 0.02 0.02 0.02 0.02 18.000

0.03 0.03 0.03 0.03 0.03 23.000

0.04 0.04 0.04 0.03 0.03 28.000

0.05 0.04 0.04 0.04 0.04 33.000

0.05 0.05 0.05 0.05 0.05 38.000

0.06 0.06 0.06 0.05 0.05 43.000

0.06 0.06 0.06 0.06 0.06 48.000

0.07 0.07 0.07 0.07 0.07 53.000

0.08 0.08 0.07 0.07 0.07 58.000

0.08 0.08 0.08 0.08 0.08 63.000

0.09 0.09 0.09 0.08 0.08 68.000

0.09 0.09 0.09 0.09 0.09 73.000

0.10 0.10 0.10 0.10 0.10 78.000

0.10 0.10 0.10 0.10 0.10 83.000

0.11 0.11 0.11 0.11 0.10 88.000

0.11 0.11 0.11 0.11 0.11 93.000

0.12 0.11 0.11 0.11 0.11 98.000

0.12 0.12 0.12 0.12 0.12 103.000

0.12 0.12 0.12 0.12 0.12 108.000

0.13 0.13 0.12 0.12 0.12 113.000

0.13 0.13 0.13 0.13 0.13 118.000

0.13 0.13 0.13 0.13 0.13 123.000

0.14 0.14 0.13 0.13 0.13 128.000

0.14 0.14 0.14 0.14 0.14 133.000

0.15 0.14 0.14 0.14 0.14 138.000

0.15 0.15 0.15 0.15 0.15 143.000

0.15 0.15 0.15 0.15 0.15 148.000

0.16 0.16 0.16 0.16 0.15 153.000

0.16 0.16 0.16 0.16 0.16 158.000

0.17 0.16 0.16 0.16 0.16 163.000

0.17 0.17 0.17 0.17 0.17 168.000

0.17 0.17 0.17 0.17 0.17 173.000

0.18 0.18 0.18 0.17 0.17 178.000

0.18 0.18 0.18 0.18 0.18 183.000

0.19 0.19 0.19 0.18 0.18 188.000

0.19 0.19 0.19 0.19 0.19 193.000

Page 17 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: Outlet-2
Scenario: Base Subsection: Diverted Hydrograph
HYDROGRAPH ORDINATES (ft³/s)
Output Time Increment = 1.000 min
Time on left represents time for first value in each row.

Flow
(ft³/s)
Flow
(ft³/s)
Flow
(ft³/s)
Flow
(ft³/s)
Flow
(ft³/s)
Time
(min)

0.20 0.20 0.20 0.19 0.19 198.000

0.20 0.20 0.20 0.20 0.20 203.000

0.21 0.21 0.21 0.20 0.20 208.000

0.21 0.21 0.21 0.21 0.21 213.000

0.22 0.22 0.22 0.22 0.22 218.000

0.23 0.23 0.23 0.23 0.22 223.000

0.24 0.24 0.24 0.23 0.23 228.000

0.25 0.25 0.25 0.24 0.24 233.000

0.27 0.26 0.26 0.26 0.25 238.000

0.31 0.30 0.29 0.28 0.28 243.000

1.29 1.19 0.98 0.65 0.32 248.000

1.43 1.42 1.40 1.37 1.34 253.000

1.42 1.43 1.44 1.44 1.44 258.000

1.35 1.37 1.38 1.40 1.41 263.000

1.27 1.29 1.30 1.32 1.34 268.000

1.18 1.20 1.22 1.24 1.25 273.000

1.08 1.10 1.12 1.14 1.16 278.000

0.99 1.01 1.02 1.04 1.06 283.000

0.92 0.93 0.95 0.96 0.98 288.000

0.85 0.86 0.88 0.89 0.90 293.000

0.79 0.80 0.81 0.82 0.84 298.000

0.73 0.74 0.76 0.77 0.78 303.000

0.68 0.69 0.70 0.71 0.72 308.000

0.64 0.65 0.65 0.66 0.67 313.000

0.61 0.61 0.62 0.62 0.63 318.000

0.58 0.59 0.59 0.60 0.60 323.000

0.54 0.55 0.56 0.56 0.57 328.000

0.51 0.52 0.52 0.53 0.53 333.000

0.48 0.49 0.49 0.50 0.50 338.000

0.47 0.47 0.47 0.48 0.48 343.000

0.45 0.45 0.46 0.46 0.46 348.000

0.44 0.44 0.44 0.45 0.45 353.000

0.42 0.43 0.43 0.44 0.44 358.000

0.35 0.37 0.39 0.40 0.41 363.000

0.32 0.32 0.32 0.32 0.33 368.000
(N/A) (N/A) (N/A) 0.32 0.32 373.000

Page 18 of 25 ends

0.00 0.00 0.00 3,350.000 0.000 0.00 554.00

55.94 0.10 0.00 3,350.000 0.038 0.10 554.50
111.82 0.16 0.00 3,350.000 0.077 0.16 555.00
167.69 0.19 0.00 3,350.000 0.115 0.19 555.50
223.56 0.23 0.00 3,350.000 0.154 0.23 556.00
279.42 0.25 0.00 3,350.000 0.192 0.25 556.50
335.28 0.28 0.00 3,350.000 0.231 0.28 557.00
391.14 0.30 0.00 3,350.000 0.269 0.30 557.50
446.99 0.32 0.00 3,350.000 0.308 0.32 558.00
504.25 1.75 0.00 3,350.000 0.346 1.75 558.50

Page 19 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: PO-1 (IN)
Scenario: Base Subsection: Detention Time
Infiltration
No Infiltration Infiltration Method
(Computed)
Approximate Detention Times
min 259.000
Time to Peak (Outflow +
Infiltration, Peak to Peak
Detention Time)
min 246.000 Time to Peak (Inflow, Peak
to Peak Detention Time)
min 13.000 Detention Time (Peak to
Peak)
min 263.252 Time to Centroid (Outflow)
min 213.100 Time to Centroid (Inflow)
min 50.152 Detention Time (Centroid to
Centroid)
min 119.413 Weighted Average Plug Time
min 128.000 Maximum Plug Volume Plug
Time
ac-ft 0.018 Maximum Inflow Plug
Volume
min 245.000 Time (Maximum Plug
Volume, Start)
min 246.000 Time (Maximum Plug
Volume, End)

Page 20 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: PO-1 (IN)
Scenario: Base Subsection: Level Pool Pond Routing Summary Infiltration
No Infiltration Infiltration Method
(Computed)
Initial Conditions
ft 554.00 Elevation (Water Surface,
Initial)
ac-ft 0.000 Volume (Initial)
ft³/s 0.00 Flow (Initial Outlet)
ft³/s 0.00 Flow (Initial Infiltration)
ft³/s 0.00 Flow (Initial, Total)
min 1.000 Time Increment
Inflow/Outflow Hydrograph Summary
ft³/s 14.27 Flow (Peak In) min 246.000 Time to Peak (Flow, In) ft³/s 1.44 Flow (Peak Outlet) min 259.000 Time to Peak (Flow, Outlet) ft 558.39 Elevation (Water Surface,
Peak)
ac-ft 0.338 Volume (Peak)
Mass Balance (ac-ft)
ac-ft 0.000 Volume (Initial)
ac-ft 0.487 Volume (Total Inflow)
ac-ft 0.000 Volume (Total Infiltration)
ac-ft 0.181 Volume (Total Outlet
Outflow)
ac-ft 0.305 Volume (Retained)
ac-ft 0.000 Volume (Unrouted)
% 0.1 Error (Mass Balance)

Page 21 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: PO-1 (OUT)
Scenario: Base Subsection: Pond Routed Hydrograph (total out) ft³/s 1.44 Peak Discharge
min 259.000 Time to Peak
ac-ft 0.181 Hydrograph Volume
HYDROGRAPH ORDINATES (ft³/s)
Output Time Increment = 1.000 min
Time on left represents time for first value in each row.

Flow
(ft³/s)
Flow
(ft³/s)
Flow
(ft³/s)
Flow
(ft³/s)
Flow
(ft³/s)
Time
(min)

0.00 0.00 0.00 0.00 0.00 3.000

0.01 0.01 0.01 0.01 0.01 8.000

0.02 0.02 0.02 0.01 0.01 13.000

0.03 0.02 0.02 0.02 0.02 18.000

0.03 0.03 0.03 0.03 0.03 23.000

0.04 0.04 0.04 0.03 0.03 28.000

0.05 0.04 0.04 0.04 0.04 33.000

0.05 0.05 0.05 0.05 0.05 38.000

0.06 0.06 0.06 0.05 0.05 43.000

0.06 0.06 0.06 0.06 0.06 48.000

0.07 0.07 0.07 0.07 0.07 53.000

0.08 0.08 0.07 0.07 0.07 58.000

0.08 0.08 0.08 0.08 0.08 63.000

0.09 0.09 0.09 0.08 0.08 68.000

0.09 0.09 0.09 0.09 0.09 73.000

0.10 0.10 0.10 0.10 0.10 78.000

0.10 0.10 0.10 0.10 0.10 83.000

0.11 0.11 0.11 0.11 0.10 88.000

0.11 0.11 0.11 0.11 0.11 93.000

0.12 0.11 0.11 0.11 0.11 98.000

0.12 0.12 0.12 0.12 0.12 103.000

0.12 0.12 0.12 0.12 0.12 108.000

0.13 0.13 0.12 0.12 0.12 113.000

0.13 0.13 0.13 0.13 0.13 118.000

0.13 0.13 0.13 0.13 0.13 123.000

0.14 0.14 0.13 0.13 0.13 128.000

0.14 0.14 0.14 0.14 0.14 133.000

0.15 0.14 0.14 0.14 0.14 138.000

0.15 0.15 0.15 0.15 0.15 143.000

0.15 0.15 0.15 0.15 0.15 148.000

0.16 0.16 0.16 0.16 0.15 153.000

0.16 0.16 0.16 0.16 0.16 158.000

0.17 0.16 0.16 0.16 0.16 163.000

0.17 0.17 0.17 0.17 0.17 168.000

0.17 0.17 0.17 0.17 0.17 173.000

0.18 0.18 0.18 0.17 0.17 178.000

0.18 0.18 0.18 0.18 0.18 183.000

0.19 0.19 0.19 0.18 0.18 188.000

0.19 0.19 0.19 0.19 0.19 193.000

Page 22 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: PO-1 (OUT)
Scenario: Base Subsection: Pond Routed Hydrograph (total out) HYDROGRAPH ORDINATES (ft³/s)
Output Time Increment = 1.000 min
Time on left represents time for first value in each row.

Flow
(ft³/s)
Flow
(ft³/s)
Flow
(ft³/s)
Flow
(ft³/s)
Flow
(ft³/s)
Time
(min)

0.20 0.20 0.20 0.19 0.19 198.000

0.20 0.20 0.20 0.20 0.20 203.000

0.21 0.21 0.21 0.20 0.20 208.000

0.21 0.21 0.21 0.21 0.21 213.000

0.22 0.22 0.22 0.22 0.22 218.000

0.23 0.23 0.23 0.23 0.22 223.000

0.24 0.24 0.24 0.23 0.23 228.000

0.25 0.25 0.25 0.24 0.24 233.000

0.27 0.26 0.26 0.26 0.25 238.000

0.31 0.30 0.29 0.28 0.28 243.000

1.29 1.19 0.98 0.65 0.32 248.000

1.43 1.42 1.40 1.37 1.34 253.000

1.42 1.43 1.44 1.44 1.44 258.000

1.35 1.37 1.38 1.40 1.41 263.000

1.27 1.29 1.30 1.32 1.34 268.000

1.18 1.20 1.22 1.24 1.25 273.000

1.08 1.10 1.12 1.14 1.16 278.000

0.99 1.01 1.02 1.04 1.06 283.000

0.92 0.93 0.95 0.96 0.98 288.000

0.85 0.86 0.88 0.89 0.90 293.000

0.79 0.80 0.81 0.82 0.84 298.000

0.73 0.74 0.76 0.77 0.78 303.000

0.68 0.69 0.70 0.71 0.72 308.000

0.64 0.65 0.65 0.66 0.67 313.000

0.61 0.61 0.62 0.62 0.63 318.000

0.58 0.59 0.59 0.60 0.60 323.000

0.54 0.55 0.56 0.56 0.57 328.000

0.51 0.52 0.52 0.53 0.53 333.000

0.48 0.49 0.49 0.50 0.50 338.000

0.47 0.47 0.47 0.48 0.48 343.000

0.45 0.45 0.46 0.46 0.46 348.000

0.44 0.44 0.44 0.45 0.45 353.000

0.42 0.43 0.43 0.44 0.44 358.000

0.35 0.37 0.39 0.40 0.41 363.000

0.32 0.32 0.32 0.32 0.33 368.000
(N/A) (N/A) (N/A) 0.32 0.32 373.000

Page 23 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Label: PO-1 (IN)
Scenario: Base Subsection: Pond Inflow Summary
Summary for Hydrograph Addition at 'PO-1'
Upstream Node Upstream Link
CM-1 <Catchment to Outflow Node>
Node Inflows
Flow (Peak)
(ft³/s)
Time to Peak
(min)
Volume
(ac-ft)
Element Inflow Type

14.27 246.000 0.487 CM-1 Flow (From)

14.27 246.000 0.487 PO-1 Flow (In)

Page 24 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc
Index
User Notifications...2
U
Pond Routed Hydrograph (total out)...22, 23
Pond Inflow Summary...24
PO-1 (Volume Equations)...

PO-1 (Time vs. Volume)...

PO-1 (OUT) (Time vs. Elevation)...

PO-1 (OUT) (Pond Routed Hydrograph (total out))...

PO-1 (IN) (Pond Inflow Summary)...

PO-1 (IN) (Level Pool Pond Routing Summary)...

PO-1 (IN) (Detention Time)...

PO-1 (Elevation-Volume-Flow Table (Pond))...

PO-1 (Elevation-Area Volume Curve)...

P
Outlet-2 (Diverted Hydrograph)...

Outlet Input Data...12, 13
O-1 (Addition Summary)...

O
Master Network Summary...3
M
Composite Rating Curve...16
Composite Outlet Structure - 1 (Outlet Input Data)...

Composite Outlet Structure - 1 (Individual Outlet Curves)...

Composite Outlet Structure - 1 (Composite Rating Curve)...

CM-1 (Read Hydrograph)...

Page 25 of 25 ends

Watertown, CT 06795 USA +1-203-755-1666
8/10/2023
PondPack CONNECT Edition
[10.02.00.01]
Bentley Systems, Inc. Haestad Methods Solution
Center Vault 1 - 100 year.ppc

Latitude 33 Planning & Engineering
12 APPENDIX E

REFERENCE DRAWINGS

/51/51/176/48/48/39
/51/50/176/52/53/39
/51/50/176/51/48/39
/51/51/176/49/53/39
/49/49/55/176/49/53/39 /49/49/55/176/48/48/39 /49/49/54/176/52/53/39 /49/49/54/176/51/48/39 /49/49/54/176/49/53/39 /49/49/54/176/51/48/39/49/49/54/176/52/53/39/49/49/55/176/48/48/39/49/49/55/176/49/53/39/49/49/55/176/51/48/39 /49/49/54/176/49/53/39 /51/51/176/49/53/39
/51/50/176/52/53/39
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/79/67/69/65/78/83/73/68/69
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/83/79/76/65/78/65/32/66/69/65/67/72
/68/69/76/32/77/65/82
/83/68
/82/105/118/101/114/115/105/100/101/32/67/111/117/110/116/121 /79/114/97/110/103/101/32
/67/111/117/110/116/121
/77/32/32/101/32/32/120/32/32/105/32/32/99/32/32/111
/73/109/112/101/114/105/97/108/32/67/111/117/110/116/121 /80/32/97/32/99/32/105/32/102/32/105/32/99/32/32/32/32/79/32/99/32/101/32/97/32/110 /33/34/94/36
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/78
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/83
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/51/51/176/48/48/39
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/83/79/76/65/78/65/32/66/69/65/67/72
/68/69/76/32/77/65/82
/83/68
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/67/111/117/110/116/121
/77/32/32/101/32/32/120/32/32/105/32/32/99/32/32/111
/73/109/112/101/114/105/97/108/32/67/111/117/110/116/121 /80/32/97/32/99/32/105/32/102/32/105/32/99/32/32/32/32/79/32/99/32/101/32/97/32/110 /56/46/48
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/78
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100

3.2 5.6
57 3.2

SEE AES

San Diego County Hydrology Manual Sect ion: 3
Date: June 2003 Page: 6 of 26

Table 3-1

RUNOFF COEFFICIENTS FOR URBAN AREAS

Land Use Runoff Coefficient “C”
Soil Type
NRCS Elements County Elements % IMPER. A B C D
Undisturbed Natural Terrain (Natural) Permanent Open Space 0* 0.20 0.25 0.30 0.35 Low Density Residential (LDR) Residential, 1.0 DU/A or less 10 0.27 0.32 0.36 0.41 Low Density Residential (LDR) Residential, 2.0 DU/A or less 20 0.34 0.38 0.42 0.46 Low Density Residential (LDR) Residential, 2.9 DU/A or less 25 0.38 0.41 0.45 0.49 Medium Density Residential (MDR) Residential, 4.3 DU/A or less 30 0.41 0.45 0.48 0.52 Medium Density Residential (MDR) Residential, 7.3 DU/A or less 40 0.48 0.51 0.54 0.57 Medium Density Residential (MDR) Residential, 10.9 DU/A or less 45 0.52 0.54 0.57 0.60 Medium Density Residential (MDR) Residential, 14.5 DU/A or less 50 0.55 0.58 0.60 0.63 High Density Residential (HDR) Residential, 24.0 DU/A or less 65 0.66 0.67 0.69 0.71 High Density Residential (HDR) Residential, 43.0 DU/A or less 80 0.76 0.77 0.78 0.79 Commercial/Industrial (N. Com) Neighborhood Commercial 80 0.76 0.77 0.78 0.79 Commercial/Industrial (G. Com) General Commercial 85 0.80 0.80 0.81 0.82 Commercial/Industrial (O.P. Com) Office Professional/Commercial 90 0.83 0.84 0.84 0.85 Commercial/Industrial (Limited I.) Limited Industrial 90 0.83 0.84 0.84 0.85 Commercial/Industrial (General I.) General Industrial 95 0.87 0.87 0.87 0.87

*The values associated with 0% impervious may be use d for direct calculation of the runoff coefficient as described in Section 3.1.2 (representing the pervious runoff coefficient, Cp, for the soil type), or for areas that will remain undisturbed in perpetuity. Justification must be given that the area will remain natural forever (e.g., the area is located in Cleveland National Forest).

DU/A = dwelling units per acre
NRCS = National Resources Conservation Service

3-6

San Diego County Hydrology Manual Section: 3
Date: June 2003 Page: 12 of 26

Note that the Initial Time of Concentration should be reflective of the general land-use at the upstream end of a drainage basin. A single lot with an area of two or less acres does not have a significant effect where the drainage basin area is 20 to 600 acres.

Table 3-2 provides lim its of the length (Maximum Length ( LM)) of sheet flow to be used in hydrology studies. Initial Ti values based on average C values for the Land Use Elem ent are also included. These values can b e used in planning and design applic ations a s described below. Exceptions m ay be approved by the “Regulating Agency” when subm itted with a detailed study.

Table 3-2

MAXIMUM OVERLAND FLOW LENGTH (LM)
& INITIAL TIME OF CONCENTRATION (Ti)
.5% 1% 2% 3% 5% 10% Element*

DU/
Acre LM Ti LM Ti LM Ti LM Ti LM Ti LM Ti
Natural 50 13.2 70 12.5 85 10.9 100 10.3 100 8.7 100 6.9 LDR 1 50 12.2 70 11.5 85 10.0 100 9.5 100 8.0 100 6.4
LDR 2 50 11.3 70 10.5 85 9.2 100 8.8 100 7.4 100 5.8
LDR 2.9 50 10.7 70 10.0 85 8.8 95 8.1 100 7.0 100 5.6
MDR 4.3 50 10.2 70 9.6 80 8.1 95 7.8 100 6.7 100 5.3
MDR 7.3 50 9.2 65 8.4 80 7.4 95 7.0 100 6.0 100 4.8
MDR 10.9 50 8.7 65 7.9 80 6.9 90 6.4 100 5.7 100 4.5
MDR 14.5 50 8.2 65 7.4 80 6.5 90 6.0 100 5.4 100 4.3
HDR 24 50 6.7 65 6.1 75 5.1 90 4.9 95 4.3 100 3.5
HDR 43 50 5.3 65 4.7 75 4.0 85 3.8 95 3.4 100 2.7
N. Com 50 5.3 60 4.5 75 4.0 85 3.8 95 3.4 100 2.7
G. Com 50 4.7 60 4.1 75 3.6 85 3.4 90 2.9 100 2.4
O.P./Com 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2
Limited I. 50 4.2 60 3.7 70 3.1 80 2.9 90 2.6 100 2.2
General I. 50 3.7 60 3.2 70 2.7 80 2.6 90 2.3 100 1.9
*See Table 3-1 for more detailed description

3-12
Nomograph for Determination of
Time of Concentration (Tc) or Travel Time (Tt) for Natural Watersheds

F I G U R E
SOURCE: USDOT, FHWA, HDS-3 (1961)
3-7
Manning’s Equation Nomograph
s = 0.003
n = 0.02
SLOPE in feet per foot -s
HYDRAULIC RADIUS in feet - R
VELOCITY in feet per second - V

EXAMPLE
R=0.6
V=2.9
EQUATION: V = ____ R2/3 s1/21.49
n

0.3 0.2

0.15 0.10

0.09 0.08

0.07 0.06

0.05 0.04

0.03 0.02

0.01 0.009

0.008

0.007

0.006

0.005

0.004

0.003

0.002

0.0003

0.0004

0.0005

0.0006

0.0007

0.0008

0.0009

0.001
20 10
9 8
7 6
5 4
3 2

1.0 0.9

0.8 0.7

0.6 0.5

0.2 0.3

0.4 0.5

0.6 0.7

0.8 0.9

1.0 2
3 4
10 9
8 7
6 5
50 40
30 20

0.01 0.02

0.03 0.04

0.05 0.06

0.07 0.08

0.09 0.10

0.2 0.3

0.4 GENERAL SOLUTION
ROUGHNESS Coefficient - n

San Diego County Hydraulic Design Manual Page 2-17
September 2014

Figure 2-4 6-inch Gutter and Roadway Discharge-Velocity Chart Figure 2-4

San Marcos City CouncilJune 24, 2025

San Marcos City Council
June 24, 2025