ATTACHMENT D.8
PRELIMINARY HYDROLOGY STUDY
PRELIMINARY
HYDROLOGY STUDY
FOR
S
OUTH SANTA FE TOWNHOMES
2972 &2982 S SANTA FE AVENUE
APN:
217
-
161
-
17,
217
-
161
-
18 , 217
-
161
-
19 CITY OF
SAN MARCOS
, CA
PREPARED FOR:
SANTA FE FLORES LP
P.O. BOX 903
RANCHO SANTA FE, CA 92067
PREPARED BY:
PLSA
34270 PACIFIC COAST HIGHWAY, SUITE B
DANA POINT
, CA 926
29 949
-
661
-
6695
Prepared
:
June
202
5 __________________________________________________
William J. Suiter, RCE 68964
DATE
TABLE OF CONTENTS
SECTION
Executive Summary
1.0 Introduction
1.1 Existing Conditions
1.2 Proposed Project
1.3 Conclusions
1. 4
References
1.5 Methodology
2.0 Rational Method
2.1 County of San Diego Criteria
2.2 AES Rational Method Computer Model
2.3 Hydrologic Analysis
3.0 Existing Condition
Hydrologic Model Output
(
100
-
Year Event)
3.1 Proposed Condition
Hydrologic Model Output
3.2 (100
-
Year Event Undetained)
Detention
Analysis
3.3 Proposed Condition Hydrologic Model Output
3.4 (100
-
Year Event De
tained)
Hydromodification
Management
3.5 Storm Water Pollutant Contr
ol
3.6 Appendices
Appendix A: Hydrology Support Material
Appendix B:
Detention Support Material
Appendix C:
Existing and Proposed
Condition
Hydrology
Exhibits
1.0 EXECUTIVE
SUMMARY
1.1 Introduction
This Hydrology Study for
the proposed
development
has been prepared to analyze the
hydrologic characteristics of the existing and proposed project site. This report present s
both
the methodology and the calculations used for determining the storm
water
runoff from the
project site in the pre
-
developed (existing) conditions and the post
-
developed (proposed)
conditions produced by the 100
-
year
, 6
-
hour storm
event
.
1.2 Existing Conditions
The subject pro
perty is locate
d
at
2972 & 2982 S. Santa Fe Avenue
in the City of
San Marcos
.
The site is
west of Las Flores Drive
,
north of South Santa Fe Avenue, and
approximately
1/4
mile
north
of the 78 freeway.
Vicinity Map
The site is surrounded by residential homes to the
north
,
east
and
south
, and
industrial offices
to the
west
.
The site
is primarily undeveloped with a shared access driveway at the property’s southerly boundary
.
The driveway also provides access to the adjacent commercial property’s parking lot and
commercial building
.
The southern portion of the site is relatively flat while the central portion slopes up to an elevated pad at the north end of the site. Las Flores Drive along the property’s eastern boundary has approximately a 15
-
20% grade upward to the north to
allow vehicle access over the railroad tracks north of the property.
Elevations across the site
range from a high of approximately
546
feet
in the north
east
corner
of the property to a low of
approximately
494.50
feet a
t
the
southwest
corner
of the property.
The
project site
is approximately
2. 60
acre
s.
In the existing condition
,
the project site is divided
into
four
drainage basins
(see
Existing Condition
Hydrology
Exhibit
in Appendix C)
.
Drainage basin E1 consists of t
he north
erly half graded
pad
where
runoff
flows overland and
into an existing storm drain inlet structure in the center of the pad. Captured runoff exits the site through an existing 18” RCP at the easterly boundary and into the public storm drain system within Las Flores Drive.
Drainage Basin E2 is a
similar, but much smaller, sump
condition into
an existing
storm drain inlet structure just southerly of the north half sump condition mentioned above. Capture
d
runoff also exits the site through a separate 18” RCP at the easterly boundary and into the public storm drain system within Las Flores Drive where it confluences with the north half
pad
runoff.
Pipe flows continue to travel southerly down Las
Flores Drive before
combining with flows from a 54” RCP and 24” RCP. Combined pipe flows are then diverted
westerly
along South Santa Fe Avenue through a 60” RCP.
Drainage Basin E3 consists of t
he southern half of the site
where
runoff generate
d
from the
adjacent liquor store property and the project site
combines
to surface flow southerly. Surface
runoff exits the drainage basin through the existing shared access driveway on South Santa Fe Avenue then into the public street’s curb and gutter and flows northerly approximately 100’ before being captured by an existing curb inlet structure. Captured runoff is diverted across South Santa Fe Avenue through an 18” RCP storm drain pipe and
confluences with basins E1
and E2 into the
60” RCP
mentioned above. Captured runoff then continues flowing westerly down South Santa Fe Avenue.
Drainage Basin E4 is located along the west edge of Drainage Basin E1 north half pad, a small area of existing graded slopes that surface flows to the west and onto the adjacent property.
Per the United States Department of Agriculture Web Soil Survey, the project site is underlain
with Hydrologic Soil Group
C
and D
.
Refer to
Appendix A for soil information.
Area weighted runoff coefficients were calculated using the methodology
(see Appendix A)
described in section 3.2.1 of the San Diego County Hydrology Manual and Table 3 -
1 Runoff
Coefficients for Urban Areas
.
Using the Rational Method Procedure outlined in the San Diego County Hydrology Manual, a peak flow rate was calculated for the existing condition
100
-
year,
6 -
hour storm event.
The
following
table summarizes the existing condition hydrologic data.
Summary of
Existing Condition
100
-
yr Peak Discharge Rates
Drainage Basin
ID
Area (ac)
Q100 (cfs)
E1
1.24 2.35
E2
0.04 0.10
E3
1. 65
5.16 E4
0 .1
4 0.3
7 Refer to the existing condition hydrologic calculations included in S
ection 3.1 for detailed
analysis.
1.3 Proposed Project
The project proposes to develop the existing site into a
46 -
unit
multifamily
residential
development consisting of
multifamily
townhome
buildings
, access drive,
parking stalls,
landscape, associated utilities and improvements,
proprietary biofiltration systems
to meet the
requirements for pollutant control and underground storm water storage facilities to meet the requirements for hydromodification management flow control and to mitigate for the 100 -
year
6 -
hour storm event.
In the proposed condition, onsite storm water runoff will be collected in
a
proposed storm
drain
system
and conveyed to proposed
proprietary biofiltration system
s
(BMPs)
and
subsequently the proposed underground storage facilities (BMPs).
Two storm drain systems,
each with their own BMPs, are proposed to maintain the site’s historical points of discharge.
In the proposed condition, the
project
site consists of
six
drainage basins
(see
Proposed
Condition
Hydrology
Exhibit
in Appendix C).
Drainage Basin P1 consists of the proposed site’s upper level building s, buildings 3 and 4,
and a
portion of
existing
hillside area
from an adjacent lot
that drains into the project site at the
northeast corner of the property.
Runoff from areas P1.0 and P1.1 will be captured by a series of area drains around the buildings and a ribbon gutter within the building drive aisles then
drain to a
proprietary biofiltration system. Treated flows and peak flows then
enter the private
storm drain pipe system
again
and flow
to a
n
underground storm water storage facility
for
detention.
Area P1.2 is a self
-
mitigating area along the north property line of the project where a ditch captures perimeter surface runoff then pipe flows to the underground detention facility to confluence with P1.0 and P1.1.
A weir bypass structure
downstream of the detention system
will control flow rates to meet hydromodification and peak 100 -
year storm
flow rates before
confluencing with
Area
P1.3
. Area P1.3 generates surface runoff that drains into the project site from the adjacent hillside lot at the north east corner of the site . A new concrete ditch is
proposed along the project’s
north
easterly boundary to capture off
-
site run
-
on
from the hillside
that will bypass treatment and detention.
Detained
and bypass flows will then confluence
before exiting the project site through an existing 18” RCP storm drain pipe that flows out into the public storm drain system in Las Flores Drive.
Drainage Basin P2 consists of the proposed site
’s
2 lower level
building
s (building 1 and 2)
,
south
amenity
area
s
, and
portion of
the on
-
site access road
.
Areas P2.0 and P2.1 generate
s
urface runoff
that
sheet flow
s
southerly down the access road
via curb and gutter into
a curb
inlet
then flows via underground pipe to a
proprietary biofiltration system
within the southeast
amenity area for the project
. Treated flows and peak flows
from the biofiltration system will
then exit and pipe
flow to an underground storm water storage facility
for detention
.
A
rea
P2.3
is a self
-
mitigating area that
bypasses treatment but pipe flows to the detention system to confluence with areas P2.0 and P2.1
.
Subareas P2.4 and P2.5
generate runoff from a portion of
the lower access road that sheet flows southerly via curb and gutter into a biofiltration system with a curb inlet, but will bypass detention
.
Treated and peak flows from the biofiltration
system will then exit and pipe flow
to
confluence with the
detention tank’s outlet pipe flows.
All
flow from P2
will confluence with detained flows from P3 and P4
before exiting the project site
through a new
18”
RCP storm drain pip
e and connect to the existing 60” RCP storm drain pipe
in South Santa Fe Avenue.
Drainage Basin P3 consists of the
proposed site’s upper parking areas and building 5
.
Surface
runoff will be captured in a ribbon gutter and routed to a curb inlet which leads to a proprietary biofiltration system. Treated flows and peak flows will enter the private storm drain pipe system then divert pipe flows to an underground storm water storage facility . Flows exiting the
detention system will pipe flow down the access road to confluence with detained flows from P4 and P2
before exiting the project site through a new 18” RCP storm drain pipe and connect to the existing 60” RCP storm drain pipe in South Santa Fe Avenue.
Drainage Basin P4 consists of
proposed buildings 6 and 7, and the 2:1 slopes
between the two
buildings
.
Runoff will be captured in
area drains around both buildings
that
will then pipe flow
a
proprietary biofiltration system. Treated flows and peak flows will enter the private storm drain pipe system then divert pipe flows to an underground storm water storage facility
within the
amenity area north of Building 2. Flows exiting the detention system will pipe flow into the access road to confluence with P3 then pipe flow down the access road to confluence with P2
before exiting the project site through a new 18” RCP storm drain pipe
and
connect to the
existing 60” RCP storm drain pipe in South Santa Fe Avenue.
Drainage Basin P5
consists of the adjacent property’s existing commercial building, existing parking area and existing undeveloped hillside to the west of the project site. A new concrete ditch is proposed along the project site’s westerly boundary along the new access road and a new ribbon gutter along the existing parking area to capture the P5 runoff
without comingling
with on
-
site
project
runoff
. Surface flows from P5 then flow southerly via ribbon gutter and onto South Santa Fe Avenue
curb and gutter via new curb outlet.
Drainage Basin P6 consists of downslopes on the
north
western side of the project site.
Storm
water runoff will surface flow onto the adjacent property.
This area is infeasible to capture
and
is
considered self
-
mitigating
.
The BMPs will provide hydromodification management flow control and storm water pollutant control to meet the requirements the California Regional Water Quality Control Board San Diego Region municipal storm water permit (Order No. R9 -
2013
-
0001, referred to as MS4
Permit).
For detailed pollutant control and HMP calculations refer to the report titled “Priority
Development Project
(PDP)
Storm Water Quality Management Plan
(SWQMP)
for
S
outh
Santa
Fe Townhomes
” dated
December 2024
,
prepared by Pasco Laret Suiter & Associates.
Area weighted
runoff coefficient
s were
calculated
(see Appendix A)
using the methodology
described in section 3.2.1 of the San Diego County Hydrology Manual and Table 3 -
1 Runoff
Coefficients for Urban Areas.
Using the Rational Method Procedure outlined in the San Diego County Hydrology Manual, a peak flow rate was calculat
ed for the
proposed condition
100
-
year, 6
-
hour storm event.
The
underground storm water storage facilities provide mitigation for the 100
-
year 6
-
hour storm event. A detention analysis was performed to evaluate the effects of the storage facilities on the 100
-
year, 6
-
hour storm event peak discharge rates.
The
following
table summarizes the proposed condition hydrologic data.
Summary of
Proposed
Condition 100
-
yr Peak Discharge Rates
Drainage Basin ID
Area (ac)
Q100 (cfs)
Undetained
Q100 (cfs)
Detained
P1
0.74 3.82
0.44 P2
1.12 10.77
2.74 P3
0.4 0
P4
0. 50
P5
0.29 2.04
N/A
P6
0.01 0.03
N/A
Refer to the proposed undetained and detained hydrologic calculations and detention analysis
included in Section
s
3.2 ,
3.3,
3.4 and Appendix B
for detailed analysis.
1.4 Conclusions
Based upon the analyses included in this report, the proposed proprietary biofiltration devices
and underground storage
facilities
are
sized to accommodate the increase in peak runoff in the proposed
condition and
are
designed to meet the requirements of the MS4 Permit for pollutant control
and
hydromodification
management.
1. 5
References
“San Diego County Hydrology Manual”,
revised June 2003, County of San Diego, Department of
Public Works, Flood Control Section.
Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Web Soil Survey. Available online at
03 .
2.0 METHODOLOGY
Pursuant to the San Diego County Hydrology Manual
(SDCHM)
dated June 2003, the Rational
Method is recommended for analyzing the runoff response from drainage areas up to approximately 1 square mile in size. The
proposed
project and associated watershed basins are
less than 1 square mile, therefore the Rational Method was used to analyze the project’s hydrologic characteristics in the existing and proposed conditions.
2.1 Rational Method
The Rational Method (RM) formula estimates the peak rate of runoff based on the variables of area, runoff coefficient, and rainfall intensity. The rainfall intensity (I) is equal to:
I = 7.44 x P
6 x D
-
0.645
Where:
I = Intensity (in/hr)
P
6 = 6
-
hour precipitation (in)
D = duration (min
–
use Tc)
Using the Time of Concentration (Tc)
which
is the time required for a given element of water
that originates at the most remote point of the basin being analyzed to reach the point at which the runoff from the basin is being analyzed, the RM equation determines the storm water runoff rate (Q) for a given basin in terms of flow
,
typically in cubic feet per second (cfs). The RM
equation is as follows:
Q = CIA
Where:
Q= flow (cfs)
C = runoff coefficient, ratio of rainfall that produces storm water
runoff (runoff vs. infiltration/evaporation/absorption/etc)
I = average rainfall intensity for a duration equal to the Tc for the
a
rea (in/hr)
A = drainage area contributing to the basin (ac)
The RM equation assumes that the storm event being analyzed delivers precipitation to the entire basin uniformly, and therefore the peak discharge rate will occur when a raindrop that falls at the most remote portion of the basin arrives at the point of analysis. The RM also assumes that the fraction of rainfall that becomes runoff or the runoff coefficient ,
C
,
is not
affected by the storm intensity, I, or the precipitation zone number.
2.2 County of San Diego Criteria
The County of San Diego has developed its own tables, nomographs, and methodologies for analyzing storm water runoff for areas within the County. The County has also developed precipitation isopluvial contour maps that show even lines of rainfall anticipated from a given storm event (i.e. 100
-
year, 6
-
hour storm). The 100
-
year 6
-
hour storm event rainfall isopluvi
al
map is included in Appendix A
.
One of the variables of the RM equation is the runoff coefficient ,
C
,
which is dependent upon
land use and soil type. Table 3
-
1 Runoff Coefficients for Urban Areas in the SDCHM categorizes the land use, the associated development density (dwelling units per acre) and the percentage of impervious area. Each of the categories listed has an associated runoff coefficient for each soil type class. A composite runoff coefficient can also be calculated for an area based on soil type and impervious percentage using the following equation from Section 3.1.2 of the SDCHM:
C = 0.90 × (% Impervious) + Cp × (1
-
% Impervious)
Where: Cp = Pervious Coefficient Runoff Value for the soil type
(shown in Table 3
-
1 as Undisturbed Natural Terrain/Permanent Open
Space, 0% Impervious)
The onsite hydrologic calculations contained herein figure a composite runoff coefficient for the onsite project areas based on the percentage of impervious area and the percentage of pervious or landscape area.
Refer to Appendix A for runoff coefficient calculations.
The County has also illustrated in detail the methodology for determining the time of concentration, in particular the initial time of concentration. The County has adopted the Federal Aviation Agency’s (FAA) overland time of flow equation. This equation essentially limits the flow path length for the initial time of concentration to lengths of 100 feet or less, and is dependent on land use and slope.
2.3 AES Rational Method Computer Model
The Rational Method computer program developed by Advanced Engineering Software (AES) satisfies the County of San Diego design criteria, therefore it is the computer model used for this study. The AES hydrologic model is capable of creating independent node -
link models of
each interior drainage basin and linking these sub
-
models together at confluence points to
determine peak flow rates. The program utilizes base information input by the user to perform calculations for up to 15 hydrologic processes. The required base information includes drainage basin area, storm water facility locations and sizes, land uses, flow patterns, and topographic elevations. The hydrologic conditions were analyzed in accordance with the 2003 County of San Diego Hydrology Manual criteria as follows:
Design Storm
100
-
year, 6
-
hour
1 00
-
year, 6
-
hour Precipitation
3. 3
inches
Rainfall Intensity
Based on the 2003 County of San Diego Hydrology
Manual criteria
Runoff Coeffi
cient*
Pervious
C
soil
C
= 0.3
0 Pervious D soil
C =0.
35 Impervious
C
soil
C = 0.90
Impervious
D soil
C = 0.90
Soil Type
C & D
*Weighted runoff coefficients were calculated where appropriate . Refer to Appendix A.
3.0 HYDROLOGIC ANALYSIS
Table 1 below
compares and
summarizes the hydrologic
calculations
provided in Sections 3.1,
3.2 and 3.4.
Table 1: Summary of 100
-
yr Peak Discharge Rates
Existing
Proposed
(Undetained)
Proposed
(
Detained
)
Drainage
Basin ID
Area
(ac)
Q100
(cfs)
Drainage
Basin ID
Area
(ac)
Q100
(cfs)
Drainage
Basin ID
Area
(ac)
Q100
(cfs)
E1
1.24 2.35
P1
0.74 3.82
P1
0.74 0.44
E2
0.04 0.10
P2
1.12 10.77
P2
1.12 2.74
E3
1. 65
5.16 P3
0.4 0
P3
0.4 0
E4
0.14 0.37
P4
0. 50
P4
0. 50
P5
0.29 2.04
P6
0.01 0.03
Existing
(Cumulative)
Proposed (Detained, Cumulative)
Drainage
Basin ID
Area
(ac)
Q100
(cfs)
Drainage Basin ID
Area (ac)
Q100 (cfs)
E1, E2 & E3
2.93 7.61
P1, P2, P3
, P4
& P
5 3.0
5 5.
7 2
E4
0.12 0.31
P
6 0.0
1 0.
03 3.1
Existing Condition
Hydrologic Model Output (
100
-
Year Event)
3.2 Proposed
Undetained
Condition
Hydrologic Model Output
(
100
-
Year Event)
3.3 Detention
Analysis
(100
-
Year Event)
The
underground storm water storage facilities (BMPs) provide
hydromodification
management
flow control
and mitigation of the 100
-
year storm event peak flow rate. The
100
-
year storm event detention analysis was performed using HydroCAD Stormwater Modeling
software
.
The inflow runoff hydrographs to the BMPs were modeled using RatHydro which is a Rational Method Design Storm Hydrograph software that creates a hydrograph using the results of the Rational Method calculations.
HydroCAD
has the ability to
route the 100
-
year 6
-
hour storm event inflow hydrograph through the
BMPs
.
B
ased on the
BMP
cross sectional
geometry
,
stage storage and outlet structure data
, HydroCAD
calculate
s
the detained peak flow
rate and detained time to peak.
Each
underground storm water storage
facility has a low
-
flow orifice to comply with HMP
requirements and an overflow weir for larger storm events .
Refer to
the plans
for
facility
details
.
The proposed BMP at the
high
side
of the project site
in Drainage Basin 1
will discharge via
proposed storm drain
to
the
east and into the existing public storm drain system within Las Flores Drive
.
The proposed BMP
s throughout the rest
of the project site
will discharge
via
proposed storm drain pipe to the south and into the existing public storm drain system within South Santa Fe Drive.
For the proposed detained
hydrologic analysis
, the effects of the detention provided by the
four
(
4 )
underground storage facilities
were incorporated into the AES analysis. This
was done
by inserting
the results from
the
HydroCAD
analysis, detained peak flow rate and detained time
to peak, into the proposed undetained condition AES model to create the proposed detained condition model.
Refer
to Section 3.4 for the
detained AES output.
B
ased on the results of the
HydroCAD
analysis
,
mitigation for the
100
-
year storm event peak
flow rate
is
provided
.
Refer to Appendix
B
for the
HydroCAD
detention detailed output
.
3.4 Propos
ed Detained
Condition Hydrologic Model Output (100
-
Year Event)
3.5 Hydromodification
Management
To satisfy the requirements of the MS4 Permit, a hydromodification management strategy has been developed for the project based on the Final Hydromodification Management Plan dated March 2011, (Final HMP).
A continuous simulation model,
the Environmental Protection Agency
(EPA) Storm Water Management Model (SWMM) version 5.1, was selected to size mitigation measures. The SWMM model is capable of modeling hydromodification management facilities to mitigate the effects of increased runoff from the post -
development conditions
and use
changes that may cause negative impacts (i.e. erosion) to downstream channels.
For
HMP
calculations refer to the report titled
“Priority Development Project (PDP) Storm Water Quality Management Plan (SWQMP) for S
outh Santa Fe Townhomes
” dated
December 2024
, prepared
by Pasco Laret Suiter & Associates.
3.6 Storm Water
Pollutant Control
To meet the requirements of the
MS4
Permit
, the
Modular Wetland
s
Systems are
designed to
treat onsite
storm water
pollutants f
or the
24 -
hour, 85
th
percentile storm event.
For
detailed
pollutant control calculations refer to the report titled “Priority Development Project (PDP)
Storm Water Quality Management Plan (SWQMP) for S
outh Santa Fe Townhomes
” dated
December 2024
,
prepared by Pasco Laret Suiter & Associates.
APPENDIX
A
Hydrology Support Material
United States
Department of
Agriculture
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
San Diego County
Area, California
Natural
Resources
Conservation
Service
July 27, 2021
Preface
Soil surveys contain information that affects land use planning in survey areas.
They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers.
Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment.
Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions.
The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/ portal/nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (https://offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations.
The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey.
Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require 2 alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer.
3 Contents
Preface.................................................................................................................... 2 How Soil Surveys Are Made..................................................................................5 Soil Information for All Uses.................................................................................8 Soil Properties and Qualities................................................................................ 8 Soil Qualities and Features...............................................................................8 Hydrologic Soil Group (2972/2982 South Santa Fe Avenue)........................8 References............................................................................................................13 4 How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity.
Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape.
Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil 5 scientists classified and named the soils in the survey area, they compared the individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research.
The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas.
Soil scientists make many field observations in the process of producing a soil map.
The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil-landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded.
These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape.
Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties.
While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management.
Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil.
Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date.
After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and Custom Soil Resource Report
6 identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately.
Custom Soil Resource Report
7 Soil Information for All Uses
Soil Properties and Qualities
The Soil Properties and Qualities section includes various soil properties and qualities displayed as thematic maps with a summary table for the soil map units in the selected area of interest. A single value or rating for each map unit is generated by aggregating the interpretive ratings of individual map unit components. This aggregation process is defined for each property or quality.
Soil Qualities and Features
Soil qualities are behavior and performance attributes that are not directly measured, but are inferred from observations of dynamic conditions and from soil properties. Example soil qualities include natural drainage, and frost action. Soil features are attributes that are not directly part of the soil. Example soil features include slope and depth to restrictive layer. These features can greatly impact the use and management of the soil.
Hydrologic Soil Group (2972/2982 South Santa Fe
Avenue)
Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission.
8 Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material.
These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes.
Custom Soil Resource Report
9 10
Custom Soil Resource Report
Map—Hydrologic Soil Group (2972/2982 South Santa Fe Avenue) 3668700 3668720 3668740 3668760 3668780 3668800 3668820 3668840 3668860 3668880 3668900 3668700 3668720 3668740 3668760 3668780 3668800 3668820 3668840 3668860 3668880 3668900 481290 481310 481330 481350 481370 481390 481410 481430 481290 481310 481330 481350 481370 481390 481410 481430 33° 9' 31'' N
117° 12' 2'' W
33° 9' 31'' N
117° 11' 56'' W
33° 9' 24'' N
117° 12' 2'' W
33° 9' 24'' N
117° 11' 56'' W
N
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 11N WGS84 0 50 100 200 300
Feet
0 15 30 60 90
Meters
Map Scale: 1:1,060 if printed on A portrait (8.5" x 11") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.
Soil Survey Area: San Diego County Area, California
Survey Area Data: Version 15, May 27, 2020
Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.
Date(s) aerial images were photographed: Jan 24, 2020—Feb 12, 2020
The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.
Custom Soil Resource Report
11 Table—Hydrologic Soil Group (2972/2982 South Santa Fe Avenue)
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI DaD Diablo clay, 9 to 15
percent slopes, warm
MAAT
C 1.7 72.6%
HrC Huerhuero loam, 2 to 9
percent slopes
D 0.6 27.4%
Totals for Area of Interest 2.3 100.0%
Rating Options—Hydrologic Soil Group (2972/2982 South Santa Fe Avenue)
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Custom Soil Resource Report
12 References
American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition.
American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00.
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31.
Federal Register. July 13, 1994. Changes in hydric soils of the United States.
Federal Register. September 18, 2002. Hydric soils of the United States.
Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States.
National Research Council. 1995. Wetlands: Characteristics and boundaries.
Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service.
U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_054262
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section.
United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1.
United States Department of Agriculture, Natural Resources Conservation Service.
National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374
United States Department of Agriculture, Natural Resources Conservation Service.
National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 13 United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report
14 South Santa Fe Townhomes
PLSA Project No. 3527
12/6/2024
C = 0.9(%Impervious)+Cp(1 - %Impervious)
Soil Type C D
Impervious 0.9 0.9
Pervious, Cp 0.3 0.35
E1 53762 C 0 53762 0 0.30
E2 1834 C 0 1834 0 0.30
E3 71987 D 12919 59068 17.9% 0.45
E4 5960 C 0 5960 0 0.30
P1.0 1783 C 1199 584 67.2% 0.70
P1.1 20578 C 14667 5911 71.3% 0.73
P1.2 2103 C 703 1400 33.4% 0.50
P1.3 7799 C 396 7403 5.1% 0.33
P2.0 3477 C 3195 282 91.9% 0.85
P2.1 15761 C 13663 2098 86.7% 0.82
P2.2 19061 D 10476 8585 55.0% 0.65
P2.3 3163 D 0 3163 0.0% 0.35
P2.4 3221 D 3086 135 95.8% 0.88
P2.5 4215 D 2857 1358 67.8% 0.72
P3.0 4239 C 3477 762 82.0% 0.79
P3.1 2184 C 1577 607 72.2% 0.73
P3.2 11168 C 7807 3361 69.9% 0.72
P4.0 1524 C 1364 160 89.5% 0.84
P4.1 6639 C 4489 2150 67.6% 0.71
P4.2 13806 D 5971 7835 43.2% 0.59
P5.0 5461 D 4391 1070 80.4% 0.79
P5.1 7098 D 7098 0 100.0% 0.90
P6.0 204 C 0 204 0.0% 0.30
Runoff Coefficient Table
Weighted Runoff
Coefficient, C
EXISTING CONDITION
PROPOSED CONDITION
% Impervious Weighted Runoff
Coefficient, C
Impervious
Area (sf)
Drainage Basin
ID
Total Area
(sf)
Pervious
Area (sf)
Soil
Type
Drainage Basin
ID
Total Area
(sf)
Soil
Type
Impervious
Area (sf)
Pervious
Area (sf)
% Impervious
APPENDIX B
Detention Support Material
1L
Inflow to Rtank 1-B
2L
Inflow to StormTrap 2-B
2P
Rtank 1-B Alt1
3L
Inflow to Rtank 3-B
3P
Stormgate 1
4L
Inflow to StormTrap 4-B
4P
StormTrap 2-B Alt 1
5P
Rtank 3-B Alt1
6P
Stormgate 2
7P
StormTrap 4-B Alt1
Routing Diagram for 3527
Prepared by Pasco Laret Suiter & Assoc, Printed 12/4/2024 HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Subcat
Reach
Pond
Link
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Summary for Link 1L: Inflow to Rtank 1-B
Inflow
=
3.410 cfs
@
4.10 hrs
, Volume=
0.109 af
Primary
=
3.410 cfs
@
4.10 hrs
, Volume=
0.109 af
, Atten= 0%
, Lag= 0.0 min
Routed to Pond 2P : Rtank 1-B Alt1
Primary outflow = Inflow, Time Span= 0.00-96.00 hrs, dt= 0.01 hrs DISCHARGE Imported from Tank-1 B RatHydro.csv
Link 1L: Inflow to Rtank 1-B
Inflow
Primary
Hydrograph
Time (hours)
95 90
85 80
75 70
65 60
55 50
45 40
35 30
25 20
15 10
5 0
Flow (cfs)
3 2
1 0
DISCHARGE
Imported from
Tank-1 B RatHydro.csv
3.410 cfs
3.410 cfs
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Summary for Pond 2P: Rtank 1-B Alt1
Inflow
=
3.410 cfs
@
4.10 hrs
, Volume=
0.109 af
Outflow
=
0.045 cfs
@
6.06 hrs
, Volume=
0.109 af
, Atten= 99%
, Lag= 117.3 min
Primary
=
0.045 cfs
@
6.06 hrs
, Volume=
0.109 af
Routed to Pond 3P : Stormgate 1
Routing by Dyn-Stor-Ind method, Time Span= 0.00-96.00 hrs, dt= 0.01 hrs Peak Elev= 528.62'
@ 6.06 hrs
Surf.Area= 2,200 sf
Storage= 4,212 cf
Plug-Flow detention time=
1,087.8 min calculated for 0.109 af (100% of inflow)
Center-of-Mass det. time=
1,087.6 min ( 1,300.2 - 212.6 )
Volume
Invert
Avail.Storage
Storage Description
#1
526.60'
10,701 cf
Tank 1-B (Conic)
Listed below
Elevation
Surf.Area
Voids
Inc.Store
Cum.Store
Wet.Area
(feet)
(sq-ft)
(%)
(cubic-feet)
(cubic-feet)
(sq-ft)
526.60
2,200
0.0 0
0 2,200
527.00
2,200
95.0 836
836
2,267
528.00
2,200
95.0 2,090
2,926
2,433
529.00
2,200
95.0 2,090
5,016
2,599
530.00
2,200
95.0 2,090
7,106
2,765
531.72
2,200
95.0 3,595
10,701
3,051
Device
Routing
Invert
Outlet Devices
#1
Primary
526.60'
12.00" Round Culvert
L=
6.0'
RCP,
square
edge
headwall,
Ke=
0.500
Inlet
/
Outlet
Invert=
526.60'
/
526.53'
S=
0.0117
'/'
Cc=
0.900
n=
0.013,
Flow
Area=
0.79 sf
#2
Device 1
526.60'
1.10" Vert. Orifice
C= 0.600
Limited to weir flow at low heads
Primary OutFlow
Max=0.045 cfs
@ 6.06 hrs
HW=528.62'
TW=526.63'
(Dynamic Tailwater)
1=Culvert
(Passes 0.045 cfs of 4.655 cfs potential flow)
2=Orifice
(Orifice Controls 0.045 cfs @ 6.76 fps)
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Pond 2P: Rtank 1-B Alt1
Inflow
Primary
Hydrograph
Time (hours)
95 90
85 80
75 70
65 60
55 50
45 40
35 30
25 20
15 10
5 0
Flow (cfs)
3 2
1 0
Peak Elev=528.62'
Storage=4,212 cf
3.410 cfs
0.045 cfs
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Summary for Pond 3P: Stormgate 1
Inflow
=
0.045 cfs
@
6.06 hrs
, Volume=
0.109 af
Outflow
=
0.045 cfs
@
6.06 hrs
, Volume=
0.109 af
, Atten= 0%
, Lag= 0.3 min
Primary
=
0.045 cfs
@
6.06 hrs
, Volume=
0.109 af
Routing by Dyn-Stor-Ind method, Time Span= 0.00-96.00 hrs, dt= 0.01 hrs Peak Elev= 526.63'
@ 6.06 hrs
Surf.Area= 16 sf
Storage= 2 cf
Plug-Flow detention time=
0.9 min calculated for 0.109 af (100% of inflow)
Center-of-Mass det. time=
0.8 min ( 1,301.0 - 1,300.2 )
Volume
Invert
Avail.Storage
Storage Description
#1
526.53'
91 cf
Stormgate (Conic)
Listed below
Elevation
Surf.Area
Voids
Inc.Store
Cum.Store
Wet.Area
(feet)
(sq-ft)
(%)
(cubic-feet)
(cubic-feet)
(sq-ft)
526.53
16 0.0
0 0
16 527.00
16 100.0
8 8
23 528.00
16 100.0
16 24
37 529.00
16 100.0
16 40
51 530.00
16 100.0
16 56
65 531.72
16 100.0
28 83
90 532.22
16 100.0
8 91
97 Device
Routing
Invert
Outlet Devices
#1
Primary
526.53'
12.00" Round Culvert
L=
13.0'
RCP,
square
edge
headwall,
Ke=
0.500
Inlet
/
Outlet
Invert=
526.53'
/
526.08'
S=
0.0346
'/'
Cc=
0.900
n=
0.013,
Flow
Area=
0.79 sf
#2
Primary
531.72'
Custom Weir, Cv= 2.62 (C= 3.28)
Head
(feet)
0.00 0.50
0.50 Width
(feet)
4.00 4.00
0.00 Primary OutFlow
Max=0.045 cfs
@ 6.06 hrs
HW=526.63'
(Free Discharge)
1=Culvert
(Inlet Controls 0.045 cfs @ 1.08 fps)
2=Custom Weir
( Controls 0.000 cfs)
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Pond 3P: Stormgate 1
Inflow
Primary
Hydrograph
Time (hours)
95 90
85 80
75 70
65 60
55 50
45 40
35 30
25 20
15 10
5 0
Flow (cfs)
0.048
0.046
0.044
0.042
0.04 0.038
0.036
0.034
0.032
0.03 0.028
0.026
0.024
0.022
0.02 0.018
0.016
0.014
0.012
0.01 0.008
0.006
0.004
0.002
0 Peak Elev=526.63'
Storage=2 cf
0.045 cfs
0.045 cfs
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Summary for Link 2L: Inflow to StormTrap 2-B
Inflow
=
5.023 cfs
@
4.08 hrs
, Volume=
0.182 af
Primary
=
5.023 cfs
@
4.08 hrs
, Volume=
0.182 af
, Atten= 0%
, Lag= 0.0 min
Routed to Pond 4P : StormTrap 2-B Alt 1
Primary outflow = Inflow, Time Span= 0.00-96.00 hrs, dt= 0.01 hrs DISCHARGE Imported from Tank-2 B RatHydro adj.csv
Link 2L: Inflow to StormTrap 2-B
Inflow
Primary
Hydrograph
Time (hours)
95 90
85 80
75 70
65 60
55 50
45 40
35 30
25 20
15 10
5 0
Flow (cfs)
5 4
3 2
1 0
DISCHARGE
Imported from
Tank-2 B RatHydro adj.csv
5.023 cfs
5.023 cfs
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Summary for Pond 4P: StormTrap 2-B Alt 1
Inflow
=
5.023 cfs
@
4.08 hrs
, Volume=
0.182 af
Outflow
=
1.089 cfs
@
4.19 hrs
, Volume=
0.148 af
, Atten= 78%
, Lag= 6.4 min
Primary
=
1.089 cfs
@
4.19 hrs
, Volume=
0.148 af
Routing by Dyn-Stor-Ind method, Time Span= 0.00-96.00 hrs, dt= 0.01 hrs Peak Elev= 491.85'
@ 4.19 hrs
Surf.Area= 1,400 sf
Storage= 5,858 cf
Plug-Flow detention time=
1,380.3 min calculated for 0.148 af (81% of inflow)
Center-of-Mass det. time=
1,361.2 min ( 1,573.6 - 212.4 )
Volume
Invert
Avail.Storage
Storage Description
#1
486.93'
6,747 cf
Tank 2-B (Conic)
Listed below
Elevation
Surf.Area
Voids
Inc.Store
Cum.Store
Wet.Area
(feet)
(sq-ft)
(%)
(cubic-feet)
(cubic-feet)
(sq-ft)
486.93
1,400
0.0 0
0 1,400
488.00
1,400
85.0 1,273
1,273
1,542
489.00
1,400
85.0 1,190
2,463
1,675
490.00
1,400
85.0 1,190
3,653
1,807
490.93
1,400
85.0 1,107
4,760
1,931
491.00
1,400
85.0 83
4,843
1,940
492.00
1,400
85.0 1,190
6,033
2,072
492.60
1,400
85.0 714
6,747
2,152
Device
Routing
Invert
Outlet Devices
#1
Primary
486.93'
12.00" Round Culvert
L=
34.0'
RCP,
square
edge
headwall,
Ke=
0.500
Inlet
/
Outlet
Invert=
486.93'
/
486.59'
S=
0.0100
'/'
Cc=
0.900
n=
0.013,
Flow
Area=
0.79 sf
#2
Device 1
486.93'
0.50" Vert. Orifice
C= 0.600
Limited to weir flow at low heads
#3
Device 1
490.93'
12.00" W x 3.00" H Vert. Orifice
C= 0.600
Limited
to
weir
flow
at
low
heads
#4
Device 1
492.10'
Custom Weir, Cv= 2.62 (C= 3.28)
Head
(feet)
0.00 0.50
0.50 Width
(feet)
5.00 5.00
0.00 Primary OutFlow
Max=1.089 cfs
@ 4.19 hrs
HW=491.85'
(Free Discharge)
1=Culvert
(Passes 1.089 cfs of 7.953 cfs potential flow)
2=Orifice
(Orifice Controls 0.015 cfs @ 10.66 fps)
3=Orifice
(Orifice Controls 1.074 cfs @ 4.30 fps)
4=Custom Weir
( Controls 0.000 cfs)
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Pond 4P: StormTrap 2-B Alt 1
Inflow
Primary
Hydrograph
Time (hours)
95 90
85 80
75 70
65 60
55 50
45 40
35 30
25 20
15 10
5 0
Flow (cfs)
5 4
3 2
1 0
Peak Elev=491.85'
Storage=5,858 cf
5.023 cfs
1.089 cfs
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Summary for Link 3L: Inflow to Rtank 3-B
Inflow
=
2.480 cfs
@
4.10 hrs
, Volume=
0.088 af
Primary
=
2.480 cfs
@
4.10 hrs
, Volume=
0.088 af
, Atten= 0%
, Lag= 0.0 min
Routed to Pond 5P : Rtank 3-B Alt1
Primary outflow = Inflow, Time Span= 0.00-96.00 hrs, dt= 0.01 hrs DISCHARGE Imported from Tank-3 B RatHydro.csv
Link 3L: Inflow to Rtank 3-B
Inflow
Primary
Hydrograph
Time (hours)
95 90
85 80
75 70
65 60
55 50
45 40
35 30
25 20
15 10
5 0
Flow (cfs)
2 1
0 DISCHARGE
Imported from
Tank-3 B RatHydro.csv
2.480 cfs
2.480 cfs
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Summary for Pond 5P: Rtank 3-B Alt1
Inflow
=
2.480 cfs
@
4.10 hrs
, Volume=
0.088 af
Outflow
=
0.032 cfs
@
6.07 hrs
, Volume=
0.088 af
, Atten= 99%
, Lag= 118.1 min
Primary
=
0.032 cfs
@
6.07 hrs
, Volume=
0.088 af
Routed to Pond 6P : Stormgate 2
Routing by Dyn-Stor-Ind method, Time Span= 0.00-96.00 hrs, dt= 0.01 hrs Peak Elev= 522.92'
@ 6.07 hrs
Surf.Area= 1,264 sf
Storage= 3,435 cf
Plug-Flow detention time=
1,224.1 min calculated for 0.088 af (100% of inflow)
Center-of-Mass det. time=
1,223.7 min ( 1,431.6 - 207.9 )
Volume
Invert
Avail.Storage
Storage Description
#1
520.06'
8,406 cf
Tank 3-B (Conic)
Listed below
Elevation
Surf.Area
Voids
Inc.Store
Cum.Store
Wet.Area
(feet)
(sq-ft)
(%)
(cubic-feet)
(cubic-feet)
(sq-ft)
520.06
1,264
0.0 0
0 1,264
521.00
1,264
95.0 1,129
1,129
1,382
522.00
1,264
95.0 1,201
2,330
1,509
523.00
1,264
95.0 1,201
3,530
1,635
524.00
1,264
95.0 1,201
4,731
1,761
525.00
1,264
95.0 1,201
5,932
1,887
526.00
1,264
95.0 1,201
7,133
2,013
527.06
1,264
95.0 1,273
8,406
2,146
Device
Routing
Invert
Outlet Devices
#1
Primary
520.06'
12.00" Round Culvert
L=
14.0'
RCP,
square
edge
headwall,
Ke=
0.500
Inlet
/
Outlet
Invert=
520.06'
/
519.94'
S=
0.0086
'/'
Cc=
0.900
n=
0.013,
Flow
Area=
0.79 sf
#2
Device 1
520.06'
0.85" Vert. Orifice
C= 0.600
Limited to weir flow at low heads
Primary OutFlow
Max=0.032 cfs
@ 6.07 hrs
HW=522.92'
TW=520.02'
(Dynamic Tailwater)
1=Culvert
(Passes 0.032 cfs of 5.810 cfs potential flow)
2=Orifice
(Orifice Controls 0.032 cfs @ 8.09 fps)
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Pond 5P: Rtank 3-B Alt1
Inflow
Primary
Hydrograph
Time (hours)
95 90
85 80
75 70
65 60
55 50
45 40
35 30
25 20
15 10
5 0
Flow (cfs)
2 1
0 Peak Elev=522.92'
Storage=3,435 cf
2.480 cfs
0.032 cfs
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Summary for Pond 6P: Stormgate 2
Inflow
=
0.032 cfs
@
6.07 hrs
, Volume=
0.088 af
Outflow
=
0.032 cfs
@
6.07 hrs
, Volume=
0.088 af
, Atten= 0%
, Lag= 0.4 min
Primary
=
0.032 cfs
@
6.07 hrs
, Volume=
0.088 af
Routing by Dyn-Stor-Ind method, Time Span= 0.00-96.00 hrs, dt= 0.01 hrs Peak Elev= 520.02'
@ 6.07 hrs
Surf.Area= 16 sf
Storage= 1 cf
Plug-Flow detention time=
1.0 min calculated for 0.088 af (100% of inflow)
Center-of-Mass det. time=
0.9 min ( 1,432.5 - 1,431.6 )
Volume
Invert
Avail.Storage
Storage Description
#1
519.94'
120 cf
Stormgate 2 (Conic)
Listed below
Elevation
Surf.Area
Voids
Inc.Store
Cum.Store
Wet.Area
(feet)
(sq-ft)
(%)
(cubic-feet)
(cubic-feet)
(sq-ft)
519.94
16 0.0
0 0
16 521.00
16 100.0
17 17
31 522.00
16 100.0
16 33
45 523.00
16 100.0
16 49
59 524.00
16 100.0
16 65
74 525.00
16 100.0
16 81
88 526.00
16 100.0
16 97
102
527.06
16 100.0
17 114
117
527.46
16 100.0
6 120
123
Device
Routing
Invert
Outlet Devices
#1
Primary
519.94'
12.00" Round Culvert
L=
290.0'
RCP,
square
edge
headwall,
Ke=
0.500
Inlet
/
Outlet
Invert=
519.94'
/
490.01'
S=
0.1032
'/'
Cc=
0.900
n=
0.013,
Flow
Area=
0.79 sf
#2
Primary
527.06'
Custom Weir, Cv= 2.62 (C= 3.28)
Head
(feet)
0.00 0.40
0.40 Width
(feet)
4.00 4.00
0.00 Primary OutFlow
Max=0.032 cfs
@ 6.07 hrs
HW=520.02'
(Free Discharge)
1=Culvert
(Inlet Controls 0.032 cfs @ 0.99 fps)
2=Custom Weir
( Controls 0.000 cfs)
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Pond 6P: Stormgate 2
Inflow
Primary
Hydrograph
Time (hours)
95 90
85 80
75 70
65 60
55 50
45 40
35 30
25 20
15 10
5 0
Flow (cfs)
0.034
0.032
0.03 0.028
0.026
0.024
0.022
0.02 0.018
0.016
0.014
0.012
0.01 0.008
0.006
0.004
0.002
0 Peak Elev=520.02'
Storage=1 cf
0.032 cfs
0.032 cfs
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Summary for Link 4L: Inflow to StormTrap 4-B
Inflow
=
2.560 cfs
@
4.10 hrs
, Volume=
0.092 af
Primary
=
2.560 cfs
@
4.10 hrs
, Volume=
0.092 af
, Atten= 0%
, Lag= 0.0 min
Routed to Pond 7P : StormTrap 4-B Alt1
Primary outflow = Inflow, Time Span= 0.00-96.00 hrs, dt= 0.01 hrs DISCHARGE Imported from Tank-4 B RatHydro.csv
Link 4L: Inflow to StormTrap 4-B
Inflow
Primary
Hydrograph
Time (hours)
95 90
85 80
75 70
65 60
55 50
45 40
35 30
25 20
15 10
5 0
Flow (cfs)
2 1
0 DISCHARGE
Imported from
Tank-4 B RatHydro.csv
2.560 cfs
2.560 cfs
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Summary for Pond 7P: StormTrap 4-B Alt1
Inflow
=
2.560 cfs
@
4.10 hrs
, Volume=
0.092 af
Outflow
=
1.225 cfs
@
4.16 hrs
, Volume=
0.088 af
, Atten= 52%
, Lag= 3.7 min
Primary
=
1.225 cfs
@
4.16 hrs
, Volume=
0.088 af
Routing by Dyn-Stor-Ind method, Time Span= 0.00-96.00 hrs, dt= 0.01 hrs Peak Elev= 495.15'
@ 4.16 hrs
Surf.Area= 600 sf
Storage= 2,456 cf
Plug-Flow detention time=
1,094.2 min calculated for 0.088 af (95% of inflow)
Center-of-Mass det. time=
1,087.6 min ( 1,296.9 - 209.3 )
Volume
Invert
Avail.Storage
Storage Description
#1
490.33'
2,892 cf
Tank 4-B (Conic)
Listed below
Elevation
Surf.Area
Voids
Inc.Store
Cum.Store
Wet.Area
(feet)
(sq-ft)
(%)
(cubic-feet)
(cubic-feet)
(sq-ft)
490.33
600
0.0 0
0 600
491.00
600
85.0 342
342
658
492.00
600
85.0 510
852
745
493.00
600
85.0 510
1,362
832
494.00
600
85.0 510
1,872
919
495.00
600
85.0 510
2,382
1,006
496.00
600
85.0 510
2,892
1,092
Device
Routing
Invert
Outlet Devices
#1
Primary
490.33'
12.00" Round Culvert
L=
32.0'
RCP,
square
edge
headwall,
Ke=
0.500
Inlet
/
Outlet
Invert=
490.33'
/
490.01'
S=
0.0100
'/'
Cc=
0.900
n=
0.013,
Flow
Area=
0.79 sf
#2
Device 1
490.33'
0.40" Vert. Orifice
C= 0.600
Limited to weir flow at low heads
#3
Device 1
494.00'
12.00" W x 3.00" H Vert. Orifice
C= 0.600
Limited
to
weir
flow
at
low
heads
#4
Primary
495.50'
Custom Weir, Cv= 2.62 (C= 3.28)
Head
(feet)
0.00 0.50
0.50 Width
(feet)
2.50 2.50
0.00 Primary OutFlow
Max=1.224 cfs
@ 4.16 hrs
HW=495.15'
(Free Discharge)
1=Culvert
(Passes 1.224 cfs of 7.856 cfs potential flow)
2=Orifice
(Orifice Controls 0.009 cfs @ 10.55 fps)
3=Orifice
(Orifice Controls 1.215 cfs @ 4.86 fps)
4=Custom Weir
( Controls 0.000 cfs)
San_Diego 6-hr Rainfall=3.30"
3527
Printed 12/4/2024
Prepared by Pasco Laret Suiter & Assoc
HydroCAD® 10.20-5c s/n 10097 © 2023 HydroCAD Software Solutions LLC Pond 7P: StormTrap 4-B Alt1
Inflow
Primary
Hydrograph
Time (hours)
95 90
85 80
75 70
65 60
55 50
45 40
35 30
25 20
15 10
5 0
Flow (cfs)
2 1
0 Peak Elev=495.15'
Storage=2,456 cf
2.560 cfs
1.225 cfs
APPENDIX
C
Existing and Proposed Hydrology Maps
575
570
570
565
565
560
560
560
555
555
555
555
550
550
550
550
545
545
545
545
545
540
540
540
540
540
540
540
540
540
540
540
540
540
540
540
535
535
535
535
535
535
535
535
535
535
535
535
535
535
530
530
530
530
530
530
530
530
530
530
525
525
525
525
525
525
525
525
525
520
520
520
520
520
520
520
520
515
515
515
515
515
515
515
515
510
510
510
510
510
510
510
510
505
505
505
505
505
505
505
500
500
500
500
500
500
500
500
495
495
495
495
495
495
495
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
LAS FLORES DRIVE
S. SANTA FE AVENUE
L=149'
L=270'
L=57'
L=34'
L=100'
L=100'
L=92'
L=29'
E1.1
A=1.11 AC
E1.0
A=0.13 AC
E4.0
A=0.14 AC
E2.0
A=0.04 AC
E3.0
A=0.22 AC
E3.1
A=1.43 AC
EX. P/L
N23°37'25"E
302.74'
PROPERTY BOUNDARY
N71°25'12"W
102.01'
PROPERTY BOUNDARY
N23°19'42"E
222.07'
PROPERTY BOUNDARY
N66°38'44"W
250.78'
167.99'
EX. ROW
EX. ROW
APN: 217-16-17
APN: 217-16-25
PROPERTY BOUNDARY
N71°08'14"E
28.75'
PROPERTY BOUNDARY
N61°17'56"E
40.16'
NODE #145
ELEV=494.68
Q100=5.16 CFS
V100=3.24 FPS
EX. 60-INCH RCP
EX. 18-INCH RCP
EX. CURB INLET
EX. 60-INCH RCP
EX. 60-INCH RCP
EX. 36-INCH RCP
EX. CURB INLET
EX. 18-INCH RCP
EX. 24-INCH RCP
EX. TYPE B-1 INLET
EX. 42-INCH RCP
EX. 18-INCH RCP
EX. TYPE A-4 CLEANOUT
EX. 18-INCH RCP
EX. TYPE A-4 CLEANOUT
NODE #120
ELEV=543.68
NODE #115
526.08 IE
Q100=2.35 CFS
V100=6.21 FPS
NODE #105
ELEV=538.97
NODE #110
ELEV=532.40
528.18 IE
EX. CMP RISER
EX. 18-INCH RCP
EX. TYPE B-1 INLET
NODE #135
ELEV=538.13
NODE #150
ELEV=538.66
NODE #155, ELEV=527.29
Q100=0.37 CFS
V100=4.38 FPS
NODE #125
ELEV=523.57
517.12 IE
EX. TYPE F
CATCH BASIN
EX. 18-INCH RCP
NODE #130
516.53 IE
Q100=0.10 CFS
V100=2.39 FPS
PROP. P/L PER
SEPARATE LLA
EX. P/L TO BE
REMOVED
EX. P/L TO BE
REMOVED
EX. P/L TO BE ADJUSTED
PER SEPARATE LLA
N23°34'48"
PROJECT BOUNDARY
PROPERTY BOUNDARY
N23°32'36"E
0.60'
PROPERTY BOUNDARY
N71°30'04"E
8.15'
PROPERTY BOUNDARY
N66°25'12"E
3.98'
PROPERTY BOUNDARY
N23°50'13"E
32.84'
EX. P/L
NODE #100
ELEV=575.97
NODE #140
ELEV=517.74
GRAPHIC SCALE: 1" =
20'
0 20'
40'
60'
J:\ACTIVE JOBS\3527 MAYER-SOUTH SANTA FE AVE\CIVIL\REPORTS\HYDROLOGY\TOWNHOME SITE PLAN\Appendix C - Existing and Proposed Condition Hydro Exhibits
EXISTING CONDITION HYDROLOGY EXHIBIT
SOUTH SANTA FE TOWNHOMES
CITY OF SAN MARCOS
EXISTING CONDITION HYDROLOGY EXHIBIT
SOUTH SANTA FE TOWNHOMES
LEGEND
RIGHT OF WAY
PROPERTY BOUNDARY
BASIN BOUNDARY
SUBAREA BOUNDARY
EXISTING CONTOURS
LIMITS OF EXISTING BUILDING
LIMITS OF EXISTING AC PAVEMENT
STREET CENTERLINE
SURFACE DRAINAGE DEPTH
UNDERGROUND PIPE DRAINAGE PATH
STORM DRAINAGE PIPE
570
570
565
565
560
560
560
555
555
555
555
550
550
550
550
545
545
545
545
545 540
540
540
540
540
540
540
540
540540
540
540
540
540
540
535535
535535
535
535
535
535
535535535535535
535
530
530
530 530 530 530 530
530
530
530
525
525
525525525525525
525
525
520
520520
520520520
520
520
515515
515 515 515
515
515
515
510510
510510510
510
510510
505
505
505505505
505
505 500
500
500500
500
500
500500
495
495
495
495
495 495 495
XXXXXXXXXXXXXXXXXXXXXXX
SDSDSDSDSDSDSD
SD
SDSDSD
SDSDSD
SDSDSD
SDSDSDSDSDSDSD
SDSDSDSDSDSD
SDSD
SDSDSDSDSDSDSDSDSDSDSDSDSDSDSDSD
SD
SDSDSDSDSDSDSDSDSD
SDSDSDSDSDSDSDSDSD
SDSDSDSD
SD
SDSDSDSDSDSDSD
SDSDSDSDSDSDSDSDSDSDSDSDSD
SDSDSD
SDSDSD
SDSDSDSDSDSDSDSDSD
SDSDSD
SDSD
SD
SDSDSD SDSDSDSD
SDSDSD
SDSD
SDSDSD
SD
SD
SD
SD
SD
SDSDSDSDSDSDSDSDSDSDSD
L=147'
L=169'
L=13'
L=5'L=198'
LAS FLORES DRIVE
S. SANTA FE AVENUE
APN: 217-161-25APN: 217-161-25
APN: 217-560-51
APN: 219-114-28 APN: 219-114-28APN: 219-114-28
PROP. UNDERGROUNDDETENTION SYSTEM "1-B"
PROP.UNDERGROUNDDETENTIONSYSTEM "2-B"
PROP. WEIR BYPASSSTRUCTURE
PROP. PROPRIETARYBIOFILTRATION SYSTEM "2-A"
PROP. PROPRIETARYBIOFILTRATION SYSTEM"5-A"
PROP. PROPRIETARYBIOFILTRATION SYSTEM "4-A"
PROP. PROPRIETARYBIOFILTRATION SYSTEM "1-A"PROP. WEIR BYPASSSTRUCTURE 1 L=6'
EX. TYPE A-4 CLEANOUTEX. TYPE A-4 CLEANOUTEX. 18-INCH RCP EX. 18-INCH RCPEX. 18-INCH RCPEX. 18-INCH RCPEX. 42-INCH RCPEX. 42-INCH RCPEX. 18-INCH RCP EX. 18-INCH RCPEX. CURB INLET
EX. CURB INLETEX. 54-INCH RCP
EX. 60-INCH RCP
EX. 60-INCH RCPEX. 18-INCH RCPEX. CURB INLET
PROP. CURB OUTLET
PROP. SDCO
PROP. RIBBON GUTTER
PROP. PROPRIETARYBIOFILTRATION SYSTEM "3-A"
L=8'
L=109' L=2'
L=3'L=68'
L=32'
PROP.UNDERGROUNDDETENTIONSYSTEM "3-B"
PROP.UNDERGROUNDDETENTIONSYSTEM "4-B"
L=17'
NODE #300ELEV=538.73 FS
NODE #305ELEV=534.51 FL
NODE #255ELEV=494.90 FSELEV=490.82 IE
NODE #445ELEV=487.96 IEQ100=10.77 CFS (UNDETAINED)V100= 5.29 FPS (UNDETAINED)Q100=2.74 CFS (DETAINED)V100=3.88 FPS (DETAINED) NODE #160ELEV=526.08 IEQ100=3.82 CFS (UNDETAINED)V100=8.88 FPS (UNDETAINED)Q100=0.44 CFS (DETAINED)V100=5.20 FPS (DETAINED) NODE #220ELEV=494.93 IE
NODE #210ELEV=498.60 FL497.10 IE OUT
NODE #215ELEV=496.19 IE (OUT)ELEV=495.99 IE (IN)
NODE #245ELEV=498.60 FLNODE #250ELEV=498.09 FL
NODE #500ELEV=509.20 FG
NODE #510ELEV=493.99 FLQ100=2.04 CFSV100=3.10 FPS
L=148'
NODE #120ELEV=546.4 FG
NODE #125ELEV=538.60 FLELEV=535.60 IE
NODE #115ELEV=530.54 IENODE #135ELEV=526.53 IE
NODE #140ELEV=575.97 FG
NODE #145ELEV=538.40 FLELEV=536.40 IE
NODE #110ELEV=532.20 IE INELEV=530.87 IE OUT
NODE #100ELEV=535.65 FLNODE #105ELEV=535.35 FLELEV=533.71 IE NODE #200ELEV=532.55 FS
NODE #130ELEV=526.60 IENODE #150ELEV=526.53 IENODE #155ELEV=526.33 IE NODE #225ELEV=522.0 FGNODE #230ELEV=502.0 FGELEV=500.00 IE L=6'
NODE #605ELEV=523.4 FGQ100=0.03 CFS
NODE #600ELEV=526.0 FG
NODE #115ELEV=530.42 IE
NODE #205ELEV=530.26 FSL=83'
NODE #220ELEV=494.25 IE
L=96'
NODE #235ELEV=490.26 IENODE #240ELEV=488.79 IE
NODE #260ELEV=488.05 IE
NODE #310ELEV=531.08 FLELEV=528.08 IE
NODE #315ELEV=527.88 FS
NODE #320ELEV=527.47 IEELEV=526.14 IE
NODE #325ELEV=526.06 IE
NODE #330ELEV=520.06 IE
NODE #340ELEV=492.34 IE
NODE #400ELEV=525.20 FL
NODE #405ELEV=525.00 FLELEV=523.30 IEL=17' NODE #410ELEV=521.38 IENODE #415ELEV=499.51 IE NODE #420ELEV=499.50 IEELEV=498.17
NODE #425ELEV=497.33 IENODE #430ELEV=492.66 IE
NODE #505ELEV=496.66 FS
L=60'
L=177'
L=34'L=302'
L=302'
69'
L=40'
L=75'
L=192'
L=9'
L=82'
L=290' L=290' L=210'
L=100'
L=343' L=74'L=30' L=52'
L=30'
L=162'
L=100'
L=100'
L=63'
P1.10.47
P1.30.18
P3.00.10
P2.10.36
P2.20.44 P2.40.07 P2.50.10
P2.30.07 AC
P1.20.05
P4.00.03 P4.20.32 P5.00.13
P6.00.01
P1.00.04
P3.10.05P2.00.08
P3.20.26 P4.10.15
P5.10.16
NODE #335ELEV=519.94 IE
L=14'
PROP. WEIRBYPASSSTRUCTURE 2
J:\ACTIVE JOBS\3527 MAYER-SOUTH SANTA FE AVE\CIVIL\REPORTS\HYDROLOGY\TOWNHOME SITE PLAN\Appendix C - Existing and Proposed Condition Hydro ExhibitsGRAPHIC SCALE: 1" = 20' 020'40'60'
PROPOSED CONDITION HYDROLOGY EXHIBITSOUTH SANTA FE TOWNHOMESCITY OF SAN MARCOS
PROPOSED CONDITION HYDROLOGY EXHIBITSOUTH SANTA FE TOWNHOMES
LEGENDRIGHT OF WAYPROJECT BOUNDARYBASIN BOUNDARYSUB-BASIN BOUNDARYEXISTING CONTOURSLIMITS OF EXISTING BUILDINGLIMITS OF PROPOSED BUILDING
STREET CENTER LINE
LIMITS OF PROPOSED PAVEMENT
SURFACE DRAINAGE PATHUNDERGROUND PROPOSED PIPE DRAINAGE PATHUNDERGROUND EXISTING PIPE DRAINAGE PATH P##HYDROLOGIC SUB-BASIN NUMBERHYDROLOGIC AREA (ACRES)
LIMITS OF EXISTING PAVEMENT