HomeMy WebLinkAboutCT 16-10; HOME AVENUE CONDOMINIUMS; STORM WATER QUALITY MANAGEMENT PLAN (SWQMP); 2015-05-14CITY OF CARLSBAD
PRIORITY DEVELOPMENT PROJECT (PDP)
STORM WATER QUALITY MANAGEMENT PLAN (SWQMP)
FOR
HOME AVENUE CONDOMINIUMS
CT 16 -10, PUD 16 -12
DWG XXX-XX
SWQMP NO. XX-XX
ENGINEER OF WORK:---7
7„ ,,,,,......6,..„.„..._L„.._.2_/,,,.
B E RI .E RCE 60676 EXP 12-31-2018 DATE
PREPARED FOR:
EDMOND T. SHEHAB
800 GRAND MMKLC, LLC Ov'C
.EoF SSial.
800 GRAND AVENUE, SUITE C16 GE L.l'.
'4'4%.S1 'r‘c(sl
CARLSBAD, CA 92008
icu9 M858-342 -9725 cc
C 60676
,tEXP./2---
3/,PREPARED BY:
dj:it_oCivl\
-4N-
b h A Inc1
CAl
land pallri ng, civi engineky ng, survey Ina
5115 AVENIDA ENCINAS, SUITE L
CARLSBAD, CA 92008 -4387
(760) 931 -8700
DATE:
DECEMBER 21, 2016
W.O. 1026 -1383 -400
TABLE OF CONTENTS
Certification Page
Project Vicinity Map
FORM E -34 Storm Water Standard Questionnaire
Site Information
FORM E-36 Standard Project Requirement Checklist
Summary of PDP Structural BMPs
Attachment 1:Backup for PDP Pollutant Control BMPs
Attachment la: DMA Exhibit
Attachment 1 b:Tabular Summary of DMAs and Design Capture Volume Calculations
Attachment lc: Harvest and Use Feasibility Screening (when applicable)
Attachment ld: Categorization of Infiltration Feasibility Condition (when applicable)
Attachment le: Pollutant Control BMP Design Worksheets / Calculations
Attachment 2: Structural BMP Maintenance Thresholds and Actions
Attachment 3: Single Sheet BMP (SSBMP) Exhibit
Attachment 4: Geotechnical Reference
2
CERTIFICATION PAGE
Project Name: Home Avenue Condominiums
Project ID: CT 16-10,PUD 16-12
I hereby declare that I am the Engineer in Responsible Charge of design of storm water BMPs for
this project, and 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 the
requirements of the BMP Design Manual, which is based on the requirements of SDRWQCB
Order No. R9-2013 -0001 (MS4 Permit) or the current Order.
I have read and understand that the City Engineer has adopted minimum requirements for
managing urban runoff, including storm water, from land development activities, as described in
the BMP Design Manual.I certify that this SWQMP has been completed to the best of my ability
and accurately reflects the project being proposed and the applicable source control and site
design BMPs proposed to minimize the potentially negative impacts of this project's land
development activities on water quality.I understand and acknowledge that the plan check review
of this SWQMP by the City Engineer is confined to a review and does not relieve me,as the
Engineer in Responsible Charge of design of storm water BMPs for this project,of my
responsibilities for project design.
R.C.E. 60676 Exp.12/31/2018
LE veer of Work's Signature, PE Number & Expiration Date
Bruce Rice
Print Name
b [lA Inc c<;FESiofv4.
land planning ,civil e 1...0.ngineering, surveying
L.,s./<(./„C<<‘
I CO
.Z;2/
Date
we6(9,1.
6.74Ex:06jcv6:0„
3
PROJECT VICINITY MAP
\SITE**r oo \i...
p.,
3/44.
0 No iz.5c3 9
i‘P
-4-
77
;..CNo-ab
tP 1 1
NNW
VICINITY I\4AP
4
tv of STORM WATER STANDARDSs
QUESTIONNAIRE
Devq/opment
Land Development Engineering
Cads'bad E-34
1635 Faraday Avenue
(760) 602 -2750
www.carlsbadca.gov
r INSTRUCTIONS:
To address post-development pollutants that may be generated from development projects,the city requires that new
development and significant redevelopment priority projects incorporate Permanent Storm Water Best Management
Practices (BMPs) into the project design per Carlsbad BMP Design Manual (BMP Manual).To view the BMP Manual,
refer to the Engineering Standards (Volume 5).
This questionnaire must be completed by the applicant in advance of submitting for a development application
(subdivision,discretionary permits and/or construction permits).The results of the questionnaire determine the level of
storm water standards that must be applied to a proposed development or redevelopment project.Depending on the
outcome,your project will either be subject to 'STANDARD PROJECT'requirements or be subject to 'PRIORITY
DEVELOPMENT PROJECT' (PDP) requirements.
Your responses to the questionnaire represent an initial assessment of the proposed project conditions and impacts.City
staff has responsibility for making the final assessment after submission of the development application.If staff
determines that the questionnaire was incorrectly filled out and is subject to more stringent storm water standards than
initially assessed by you, this will result in the return of the development application as incomplete.In this case,please
make the changes to the questionnaire and resubmit to the city.
If you are unsure about the meaning of a question or need help in determining how to respond to one or more of the
questions, please seek assistance from Land Development Engineering staff.
A completed and signed questionnaire must be submitted with each development project application.Only one
completed and signed questionnaire is required when multiple development applications for the same project are
submitted concurrently.
PROJECTMFORMATJON •
PROJECT NAME: Home Avenue Condominiums PROJECT ID:
ADDRESS: Home Avenue, Carlsbad, CA 92008 APN: 203 -202 -03
The project is (check one):gi New Development 0 Redevelopment
The total proposed disturbed area is:18,097 ft2 (
0.415 )acres
The total proposed newly created and/or replaced impervious area is:8,601 ft2 (
0.20 )acres
If your project is covered by an approved SWQMP as part of a larger development project,provide the project ID and the
SWQMP # of the larger development project:
Project ID SWQMP #:
Then,go to Step 1 and follow the instructions.When completed,sign the form at the end and submit this with your
application to the city.
E-34 Page 1 of 4 REV 02116
STEP 1
i•TO BE COMPLETED FOR ALL PROJECTS
To determine if your project is a "development project", please answer the following question:
YES NO
Is your project LIMITED TO routine maintenance activity and/or repair/improvements to an existing building 0or structure that do not alter the size (See Section 1.3 of the BMP Design Manual for guidance)?
If you answered "yes" to the above question,provide justification below then go to Step 5,mark the third box stating "my
project is not a 'development project' and not subject to the requirements of the BMP manual" and complete applicant
information.
Justification/discussion: (e.g. the project includes only interior remodels within an existing building):
If you answered "no" to the above question, the project is a 'development project', go to Step 2.
STEP 2
TO BE COMPLETED FOR ALL DEVELOPMENT PROJECTS
To determine if your project is exempt from PDP requirements pursuant to MS4 Permit Provision E.3.b.(3),please answer
the following questions:
Is your project LIMITED to one or more of the following:
YES NO
1.Constructing new or retrofitting paved sidewalks, bicycle lanes or trails that meet the following criteria:
a)Designed and constructed to direct storm water runoff to adjacent vegetated areas, or other non -
erodible permeable areas;
b)Designed and constructed to be hydraulically disconnected from paved streets or roads;
c)Designed and constructed with permeable pavements or surfaces in accordance with USEPA
Green Streets guidance?
2.Retrofitting or redeveloping existing paved alleys, streets, or roads that are designed and constructed in 0accordance with the USEPA Green Streets guidance?
3.Ground Mounted Solar Array that meets the criteria provided in section 1.4.2 of the BMP manual?
If you answered "yes" to one or more of the above questions, provide discussion/justification below, then go to Step 5,mark
the second box stating "my project is EXEMPT from PDP ..." and complete applicant information.
Discussion to justify exemption (e.g.the project redeveloping existing road designed and constructed in accordance with
the USEPA Green Street guidance):
if you answered "no" to the above questions, your project is not exempt from PDP, go to Step 3.
E-34 Page 2 of 4 REV 02116
,STEP 3 ,4 4*.
BE COMP,LEIEDLFOR ALL NEW OR REDEVELOP ,Ort -
Imre*••.„,
To determine if your project is a PDP, please answer the following questions (MS4 Permit Provision E.3.b.(1)):
YES NO
1.Is your project a new development that creates 10,000 square feet or more of impervious surfaces
collectively over the entire project site?This includes commercial,industrial,residential,mixed-use,El 0
and public development projects on public or private land.
2.Is your project a redevelopment project creating and/or replacing 5,000 square feet or more of
impervious surface collectively over the entire project site on an existing site of 10,000 square feet or El 121more of impervious surface?This includes commercial,industrial,residential,mixed-use,and public
development projects on public or private land.
3.Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious surface collectively over the entire project site and supports a restaurant?A restaurant is
•a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and I:I 0
refreshment stands selling prepared foods and drinks for immediate consumption (Standard Industrial
Classification (SIC) code 5812).
4.Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious
surface collectively over the entire project site and supports a hillside development project?A hillside El 0
development project includes development on any natural slope that is twenty -five percent or greater.
5.Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
•of impervious surface collectively over the entire project site and supports a parking lot? A parking lot is
I=1alandareaor facility for the temporary parking or storage of motor vehicles used personally for
business or for commerce.
6.Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious surface collectively over the entire project site and supports a street,road,highway El 0freeway or driveway?A street,road,highway,freeway or driveway is any paved impervious surface
used for the transportation of automobiles, trucks, motorcycles, and other vehicles.
•7.Is your project a new or redevelopment project that creates and/or replaces 2,500 square feet or more
of impervious surface collectively over the entire site,and discharges directly to an Environmentally
Sensitive Area (ESA)?"Discharging Directly to" includes flow that is conveyed overland a distance of D 0
200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an
isolated flow from the project to the ESA (i.e. not commingled with flows from adjacent lands).*
•8.Is your project a new development or redevelopment project that creates and/or replaces 5,000 square
feet or more of impervious surface that supports an automotive repair shop?An automotive repair El 0shop is a facility that is categorized in any one of the following Standard Industrial Classification (SIC)
codes: 5013, 5014, 5541,7532-7534, or 7536-7539.
•9.Is your project a new development or redevelopment project that creates and/or replaces 5,000 square
feet or more of impervious area that supports a retail gasoline outlet (RGO)?This category includes
RGO's that meet the following criteria:(a)5,000 square feet or more or (b)a project Average Daily
Traffic (ADT)of 100 or more vehicles per day.
10.Is your project a new or redevelopment project that results in the disturbance of one or more acres of land
and are expected to generate pollutants post construction?El 0
11.Is your project located within 200 feet of the Pacific Ocean and (1) creates 2,500 square feet or more of
impervious surface or (2)increases impervious surface on the property by more than 10%?(CMC El 10
21.203.040)
If you answered "yes" to one or more of the above questions, your project is a PDP.If your project is a redevelopment
project, go to step 4.If your project is a new project, go to step 5, check the first box stating "My project is a PDP ..."
and complete applicant information.
•If you answered "no" to all of the above questions, your project is a 'STANDARD PROJECT.'Go to step 5,check the
second box stating "My project is a 'STANDARD PROJECT'..." and complete applicant information.
E-34 Page 3 of 4 REV 02/16
•
,
••STEP 4
TO BE COMPLETED FOR REDEVELOPMENT PROJECTS. THAT ARE PRIORITY DEVELOPMENT PROJECTS (PDP)
Complete the questions below regarding your redevelopment project (MS4 Permit Provision E.3.b.(2)):
YES NO
Does the redevelopment project result in the creation or replacement of impervious surface in an amount
of less than 50%of the surface area of the previously existing development?Complete the percent
impervious calculation below:
Existing impervious area (A) =sq. ft.
Total proposed newly created or replaced impervious area (B) =sq. ft.
Percent impervious area created or replaced (B/A)*100 =
If you answered "yes",the structural BMPs required for PDP apply only to the creation or replacement of impervious
surface and not the entire development.Go to step 5, check the first box stating "My project is a PDP ..." and complete
applicant information.
If you answered "no," the structural BMP's required for PDP apply to the entire development.Go to step 5, check the
check the first box stating "My project is a PDP ..." and complete applicant information.
STEP75'.1'1
•"''::'"
ci-j(cK THE APPROpRIATE BOX AND COMPLETE APPLICANT
LO My project is a PDP and must comply with PDP stormwater requirements of the BMP Manual.I understand I must
prepare a Storm Water Quality Management Plan (SWQMP) for submittal at time of application.
ID My project is a 'STANDARD PROJECT' OR EXEMPT from PDP and must only comply with 'STANDARD PROJECT'
stormwater requirements of the BMP Manual.As part of these requirements,I will submit a "Standard Project
Requirement Checklist Form E-36" and incorporate low impact development strategies throughout my project.
Note: For projects that are close to meeting the PDP threshold, staff may require detailed impervious area calculations
and exhibits to verify if 'STANDARD PROJECT' stormwater requirements apply.
D My Project is NOT a 'development project' and is not subject to the requirements of the BMP Manual.
Applicant Information and Signature Box
Applicant Nam .
Grand N11011c1-G,4.C.Applicant Title:(.7/...0
Applicant Signature:.Date:t/76./4
119.1\/C1-0 6+
•Environmentally Sensitive Areas include but are nbt limited to all Clean Water ct Section 303(d) impaired water bodies; areas designated as Areas of Special
Biological Significance by the State Water Resources Control Board (Water Quaity Control Plan for the San Diego Basin (1994) and amendments); water bodies
designated with the RARE beneficial use by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994)and
•amendments); areas designated as preserves or their equivalent under the Multi Species Conservation Program within the Cities and County of San Diego; Habitat
Management Plan; and any other equivalent environmentally sensitive areas which have been identified by the City.
This Box for City Use Only
YES NO
City Concurrence:
r.By:
Date:
Project ID:
E-34 Page 4 of 4 REV 02/16
SITE INFORMATION CHECKLIST
frpject Stmprary InforrOation
Project Name Home Avenue Condominiums
Project ID CT 16 -10, PUD 16 -12
Project Address Home Avenue, Carlsbad, CA 92008
Assessor's Parcel Number(s) (APN(s))203 -202 -03
Project Watershed (Hydrologic Unit)[E]Carlsbad 904
Project Hydrologic Unit Hydrologic Area Select One:
O Loma Alta 904.1
111 Buena Vista Creek 904.2•Agua Hedionda 904.3
Encinas 904.4
El San Marcos 904.5
0 Escondido Creek 904.6
Parcel Area
(total area of Assessor's Parcel(s)0.415 Acres (18,097 Square Feet)
associated with the project)
Area to be disturbed by the project
(Project Area)0.415 Acres (18,097 Square Feet)
Project Proposed Impervious Area
(subset of Project Area)0.20 Acres (8,601 Square Feet)
Project Proposed Pervious Area
(subset of Project Area)0.22 Acres (9,496 Square Feet)
Note: Proposed Impervious Area +Proposed Pervious Area =Area to be Disturbed by the
Project.
This may be less than the Parcel Area.
6
Description of Existing Site Condition and Drainage Patterns
Current Status of the Site (select all that apply):
Z Existing development
Z Previously graded but not built out
Agricultural or other non -impervious use
Vacant,undeveloped/natural
Description / Additional Information:
The existing site is approximately 0.405 acres and has been previously graded.The site is
currently an impervious parking lot.
Existing Land Cover Includes (select all that apply):
Vegetative Cover
Non -Vegetated Pervious Areas
Z Impervious Areas
Description / Additional Information:
The site is currently an impervious parking lot.
Underlying Soil belongs to Hydrologic Soil Group (select all that apply):
NRCS Type A
Z NRCS Type B
NRCS Type C
NRCS Type D
The on -site soil classification is Type-B from USGS Web Soil Survey.
Approximate Depth to Groundwater (GW):
GW Depth <5 feet
5 feet <GW Depth <10 feet
Z 10 feet <GW Depth < 20 feet
GW Depth >20 feet
See Geotechnical Reference by Advanced Geotechnical Solutions (Attachment 5).
7
Existing Natural Hydrologic Features (select all that apply):
Watercourses
Seeps
Springs
Wetlands
Z None
Description / Additional Information:
There are no existing natural hydrologic features.
8
Description of Existing Site Topography and Drainage [How is storm water runoff conveyed
from the site?At a minimum, this description should answer (1)whether existing drainage
conveyance is natural or urban; (2) describe existing constructed storm water conveyance
systems, if applicable; and (3) is runoff from offsite conveyed through the site? if so, describe ]:
Storm flows affecting the site are limited to the rainfall that lands directly on the property.Surface
runoff sheet flows west across the impervious parking lot to Home Street.Runoff that drains to
Home Street will be conveyed southwest via existing curb and gutter to the storm drain system
on Home Street.Approximately 100% of the existing site is impervious.
The on -site soil classification is Type -B from USGS Web Soil Survey.
A 9
Description of Proposed Site Development and Drainage Patterns
Project Description / Proposed Land Use and/or Activities:
The project proposes the development of five (5)condominiums and a driveway.Proposed
drainage improvements consist of five (5)flow -through planter BMPs to provide stormwater
treatment and maintain the pre -developed runoff characteristics.The proposed driveway will be
comprised of permeable pavement to reduce the DCV and provide additional stormwater
treatment.The project drains to one (1)Point of Compliance (POC) located to the northwest
corner of the project site.
List/describe proposed impervious features of the project (e.g., buildings, roadways, parking
lots, courtyards, athletic courts, other impervious features):
The proposed impervious features of the project include the 5 proposed condominium
residences.
List/describe proposed pervious features of the project (e.g., landscape areas):
The proposed pervious features of the project include landscape areas surrounding the
proposed residences, the proposed flow -through planters, and the proposed permeable
pavement driveway.
Does the project include grading and changes to site topography?
Ei Yes
No
Description / Additional Information:
Project grading will occur on approximately 0.415 acres of the project.Storm water flows from
impervious roof areas will be conveyed via surface flow to the proposed flow -through planters
located adjacent to the proposed residences.The flow -through planters will outlet to a proposed
storm drain system underneath the permeable pavement driveway.The storm drain system will
require excavation and installation of underground storm drains.Post-development site flow will
mimic existing drainage conditions, and will discharge from the site at below historical flow rates.
See the "Drainage Report for Home Avenue Condominiums" by BHA, Inc. dated October 31, 2016
for post -development drainage calculations.Impervious surfaces have been minimized where
feasible.
10
Does the project include changes to site drainage (e.g., installation of new storm water
conveyance systems)?
1:S]Yes
No
Description / Additional Information:
Storm water runoff from the proposed project site is routed to a single POC located at the
northwest of the project site.The proposed drainage pattern will be similar to the existing
drainage pattern with some modifications to incorporate the Best Management Practices (BMPs)
into the project design to mimic the impacts on storm water runoff and quality.Runoff from the
developed project site is drained to five (5) onsite flow-through planter BMPs (WQ -BMPs) and a
permeable pavement driveway for water quality purposes (the project is not subject to
hydromodification requirements).Once flows are routed via the proposed WQ -BMPs,all flows
are then conveyed via storm drain to the aforementioned POC.
DMA-1 —DMA-5 encompasses runoff from the proposed buildings.Roof drains will collect runoff
and discharge into proposed flow -through planters,FTP -1 —FTP -5,located adjacent to the
proposed buildings.The flow -through planters will provide stormwater treatment and flow
detention.Treated water will discharge via storm drain pipes to a proposed storm drain system
underneath the permeable pavement driveway.
Runoff from the proposed concrete sidewalks and landscape areas of the amenity site will be
44 directed to yard drains and will discharge onto the proposed permeable pavement driveway.The
permeable pavement will provide stormwater treatment and flow detention.Treated water will
discharge via a perforated underdrain pipe underneath the driveway.The underdrain pipe will
outlet over rip rap in a landscape area and flow northwest to POC -1.The drainage area, SR-1,
is considered a Self-retaining DMA per Section 5.2.3 of the BMP DM.The permeable pavement
is used as a site design BMP (SD -6B) and designed to be self-retaining.The ratio of total drainage
area (including permeable pavement)to area of permeable pavement is 1.5:1 or less,in
accordance with Section 5.2.3 of the BMP DM.
The landscape areas in the back of the proposed residences will flow onto permeable pavement
patio areas.The drainage areas are also considered to be self-retaining per Section 5.2.3 of the
BMP DM, and shown on the DMA Exhibit as SR -2 —SR -6.
The drainage areas adjacent to Home Street that are unable to gravity flow towards the permeable
pavement driveway will flow directly to Home Street.Areas defined as Self-mitigating DMAs will
be designed with native or drought tolerant species in accordance with Section 5.2.1 of the BMP
DM.Sidewalk areas and the driveway apron classified as De Minimis DMAs are not considered
to be a significant contributor of pollutants and are less than 250 square feet per Section 5.2.2.
The proposed drainage patterns will not alter the existing flow pattern and will discharge from
the site at the historic discharge points.
11
Identify whether any of the following features, activities, and/or pollutant source areas will be
present (select all that apply):
E1 On -site storm drain inlets
Interior floor drains and elevator shaft sump pumps
Interior parking garages
E]Need for future indoor & structural pest control
Z Landscape/Outdoor Pesticide Use
Z Pools, spas, ponds, decorative fountains, and other water features
Food service
Refuse areas
Industrial processes
Outdoor storage of equipment or materials
Vehicle and Equipment Cleaning
Vehicle/Equipment Repair and Maintenance
Fuel Dispensing Areas
Loading Docks
Fire Sprinkler Test Water
Miscellaneous Drain or Wash Water
Z Plazas, sidewalks, and parking lots
12
Identification of Receiving Water Pollutants of Concern
Describe path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or
reservoir, as applicable):
From the project site, runoff flows to the Buena Vista Lagoon and to the Pacific Ocean.
List any 303(d) impaired water bodies within the path of storm water from the project site to the
Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable), identify the
pollutant(s)/stressor(s) causing impairment, and identify any TMDLs for the impaired water
bodies:
303(d) Impaired Water Body Pollutant(s)/Stressor(s)TMDLs
Indicator bacteria N/a
Buena Vista Lagoon (904.21)Nutrients N/a
Sedimentation/siltation N/a
Identification of Project Site Pollutants
Identify pollutants expected from the project site based on all proposed use(s) of the site (see
BMP Design Manual Appendix B.6):
Not Applicable to the Expected from the Also a Receiving
Project Site Project Site Water Pollutant of
Pollutant Concern
Sediment
Nutrients [SI
Heavy Metals
Organic Compounds
Trash & Debris
Oxygen Demanding
Substances
Oil & Grease
Bacteria & Viruses
Pesticides IS ]
13
•.
Hydromodification Management. Requirements
Do hydromodification management requirements apply (see Section 1.6 of the BMP Design
Manual)?
Yes,hydromodification management flow control structural BMPs required.
No,the project will discharge runoff directly to existing underground storm drains
discharging directly to water storage reservoirs, lakes, enclosed embayments, or the
Pacific Ocean.
E No, the project will discharge runoff directly to conveyance channels whose bed and bank
are concrete -lined all the way from the point of discharge to water storage reservoirs,
lakes, enclosed embayments, or the Pacific Ocean.
No,the project will discharge runoff directly to an area identified as appropriate for an
exemption by the WMAA for the watershed in which the project resides.
Description / Additional Information (to be provided if a 'No' answer has been selected above):
Storm water runoff from the project site flows southwest along Home Street and enters a storm
drain on Grand Ave, and ultimately discharges to the Buena Vista Lagoon.Based on Section
1.6 of the City of Carlsbad BMP Design Manual, the City has the discretion to exempt a PDP
from hydromodification management requirements if discharge is conveyed via a concrete lined
system to an encased embayment (i.e. lagoon).Pursuant to the study approved by the City of
Carlsbad titled "Hydromodification Exemption Analyses for Select Carlsbad Watersheds" dated
September 17, 2015 prepared by Chang Consultants, the hydrologic and hydraulic analyses
performed showed that the hardened system downstream of the project draining to the lagoon
conveys the 10 -year storm event, the discharge point has proper energy dissipation and the
outlet is within the 100 -year flood limits.
Critical Coarse Sediment Yield Areas*
*This Section only required if hydromodification management requirements apply ji
Based on the maps provided within the WMAA, do potential critical coarse sediment yield
areas exist within the project drainage boundaries?
Yes
El No, No critical coarse sediment yield areas to be protected based on WMAA maps
If yes, have any of the optional analyses presented in Section 6.2 of the BMP Design Manual
been performed?
6.2.1 Verification of Geomorphic Landscape Units (GLUs) Onsite
6.2.2 Downstream Systems Sensitivity to Coarse Sediment
6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite
No optional analyses performed, the project will avoid critical coarse sediment yield areas
identified based on WMAA maps
If optional analyses were performed, what is the final result?
No critical coarse sediment yield areas to be protected based on verification of GLUs
onsite
14
Critical coarse sediment yield areas exist but additional analysis has determined that
protection is not required. Documentation attached in Attachment 8 of the SWQMP.
Critical coarse sediment yield areas exist and require protection. The project will implement
management measures described in Sections 6.2.4 and 6.2.5 as applicable, and the areas
are identified on the SWQMP Exhibit.
Discussion / Additional Information:
Hydromodification requirements are not required for this project.
15
Flow Control for Post-Project Runoff*
L *This Section only required if hydromodification management requirements apply _01
List and describe point(s) of compliance (POCs) for flow control for hydromodification
management (see
Section 6.3.1). For each POC, provide a POC identification name or number correlating to the
project's HMP Exhibit and a receiving channel identification name or number correlating to the
project's HMP Exhibit.
Hydromodification requirements are not required for this project.
Has a geomorphic assessment been performed for the receiving channel(s)?
0 No, the low flow threshold is 0.1Q2 (default low flow threshold)
0 Yes, the result is the low flow threshold is 0.1Q2
0 Yes, the result is the low flow threshold is 0.3Q2
0 Yes, the result is the low flow threshold is 0.5Q2
If a geomorphic assessment has been performed, provide title, date, and preparer:
Discussion / Additional Information: (optional)
16
Other Site Requirements and Constraints 1
When applicable, list other site requirements or constraints that will influence storm water
management design, such as zoning requirements including setbacks and open space, or
local codes governing minimum street width, sidewalk construction, allowable pavement
types, and drainage requirements.
Several factors are considered while assessing the feasibility and desirability of infiltration
related to geotechnical conditions.A review of the soil survey maps indicate Type -B soils at
the location of the project site.According to the NRCS web survey, Type -B soils are generally
rated for moderate infiltration capacity.
Additional field and laboratory investigations were performed by Advanced Geotechnical
Solutions, Inc. to further assess the geological impacts of storm water infiltration.The purpose
of the study was to evaluate the general infiltration rate of earth materials in the location of the
proposed stormwater facilities.Infiltration testing was performed using the borehole percolation
test method,in general conformance with City of Carlsbad BMP Design Manual Guidelines.An
analysis of the field test data is included in the Geotechnical Investigation and Foundation
Design Recommendations by Advanced Geotechnical Solutions,Inc.,October 21,2016
(Attachment 4).
Infiltration testing indicated that the soils located in the areas of the proposed biofiltration basins
have relatively high infiltration rates when thoroughly wet, similar to typical Type B soils.The
geotechnical engineer has stated that partial or full infiltration of stormwater is feasible.
Based upon the proposed location of the pervious driveway,it is not anticipated that partial
infiltration will affect the proposed improvements.The permeable pavement will not include an
impermeable liner below the aggregate storage layer.
However, based upon the location of the proposed flow -through planters, it is not recommended
infiltration be allowed due to the proximity to the proposed residences.Foundations and
retaining walls can be impacted by increased water infiltration into the subsurface as a result of
potential increases in lateral pressures and potential reductions in soils strength.Because of
these factors, the flow -through planters will be designed with no infiltration and will be lined with
an impermeable liner.
.final Aloitippal intvration or Cont141.1ation of Previous Sections AS Needed 1
Additionally,Home Avenue lacks an underground storm drain system.This requires the
proposed WQ -BMPs and storm drain pipes to discharge flows onto Home Avenue.Because
the existing and proposed slope of the site is relatively flat, the depth of the storm drain system
is very limited.
17
STANDARD PROJECT(City of REQUIREMENT
Development 5ervlces
Land Development Engineering
Carlsbad CHECKLIST 1635 Faraday Avenue
(760) 602 -2750E-36 www.carlsbadca.gov
Project Informa#0
Project Name: Home Avenue Condominiums
Project ID:
DWG No. or Building Permit No.:
Source Control BMPs
All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible.See
Chapter 4 and Appendix E.1 of the BMP Design Manual for information to implement source control BMPs shown in this
checklist.
Answer each category below pursuant to the following.
• "Yes" means the project will implement the source control BMP as described in Chapter 4 and/or Appendix E.1 of the
Model BMP Design Manual.Discussion/justification is not required.
• "No" means the BMP is applicable to the project but it is not feasible to implement.Discussion/justification must be
provided.Please add attachments if more space is needed.
• "N/A"means the BMP is not applicable at the project site because the project does not include the feature that is
addressed by the BMP (e.g.,the project has no outdoor materials storage areas).Discussion/justification may be
provided.
Source Control Requirement Applied?
SC-1 Prevention of Illicit Discharges into the MS4
I
l Yes No N/A
Discussion/justification if SC -1 not implemented:
Acknowledge that an illicit discharge is any discharge to the MS4 that is not composed entirely of wash water.
Provide educational materials to prevent illicit discharges as a component of the Operation and Maintenance Plan (O&M
Plan).
SC-2 Storm Drain Stenciling or Signage Yes No 121 N/A
Discussion/justification if SC -2 not implemented:
No onsite storm drain inlets proposed.
SC-3 Protect Outdoor Materials Storage Areas from Rainfall,Run-On,Runoff,and Wind Yes No ®N/ADispersal
Discussion/justification if SC -3 not implemented:
No outdoor materials storage areas proposed.
E -36 Page 1 of 4 Revised 03/16
•
kgkitit*VitittOROqui rementiOntinued)Applied?
SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall,Run-On,Runoff,and 0 Yes No 0 N/AWind Dispersal
Discussion/justification if SC -4 not implemented:
No materials stored outdoors proposed.
SC-5 Protect Trash Storage Areas from Rainfall, Run -On, Runoff, and Wind Dispersal Yes No QJ N/A
Discussion/justification if SC-5 not implemented:
No trash storage areas proposed.
SC-6 Additional BMPs based on Potential Sources of Runoff Pollutants must answer for each source listed below and
identify additional BMPs. (See Table in Appendix E.1 of BMP Manual for guidance).
On -site storm drain inlets Yes No 0 N/A
Interior floor drains and elevator shaft sump pumps Yes No l N/A
Interior parking garages Yes No 0 N/A
Need for future indoor & structural pest control 0 Yes No N/A
0 Landscape/Outdoor Pesticide Use 0 Yes No N/A
Pools,spas, ponds, decorative fountains, and other water features 0 Yes No N/A
Food service Yes No 0 N/A
Refuse areas Yes No 0 N/A
Industrial processes Yes No 0 N/A
Outdoor storage of equipment or materials Yes No 0 N/A
Vehicle and Equipment Cleaning Yes No 0 N/A
Vehicle/Equipment Repair and Maintenance Yes No 0 N/A
Fuel Dispensing Areas Yes No 0 N/A
Loading Docks Yes No 0 N/A
Fire Sprinkler Test Water Yes No 0 N/A
Miscellaneous Drain or Wash Water Yes No I N/A•Plazas, sidewalks, and parking lots 0 Yes No N/A
For "Yes" answers, identify the additional BMP per Appendix E.1.Provide justification for "No" answers.
•Plant pest-resistant or well -adapted plant varieties such as drought tolerant and/or native plants in landscape areas.
•Irrigation systems will be designed for the specific water requirements of each landscape area.Landscaping will be
designed to minimize irrigation and runoff, to promote surface infiltration where appropriate, and to minimize the use of
fertilizers and pesticides that can contribute to storm water pollution.
•Acknowledgment that swimming pool water is chlorine and should never be discharged to the storm drain system.Pools
or fountains should be drained to the sanitary sewer if permitted to do so.
•Plazas, sidewalks, and parking lots must be swept regularly to prevent the accumulation of litter and debris.Debris from
pressure washing must be collected to prevent entry into the storm drain system.
E-36 Page 2 of 4 Revised 03/16
Site Design BNIPs
All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible.See
Chapter 4 and Appendix E.2 thru E.6 of the BMP Design Manual for information to implement site design BMPs shown in
this checklist.
Answer each category below pursuant to the following.
• "Yes" means the project will implement the site design BMPs as described in Chapter 4 and/or Appendix E.2 thru E.6 of
the Model BMP Design Manual. Discussion /justification is not required.
• "No"means the BMPs is applicable to the project but it is not feasible to implement.Discussion/justification must be
provided. Please add attachments if more space is needed.
• "N/A"means the BMPs is not applicable at the project site because the project does not include the feature that is
addressed by the BMPs (e.g., the project site has no existing natural areas to conserve). Discussion/justification may be
provided.
Source Control Requirement Applied?
SD-1 Maintain Natural Drainage Pathways and Hydrologic Features 0 Yes I No I N/A
Discussion/justification if SD -1 not implemented:
The project will maintain the overall cross lot drainage.
SD-2 Conserve Natural Areas, Soils, and Vegetation Yes No LZ N/A
Discussion/justification if SD -2 not implemented:
The site is 100% impervious pre -development and 45% impervious post-development.Although the project cannot
conserve natural areas, the project will create vegetated areas.
SD-3 Minimize Impervious Area 0 Yes No N/A
Discussion/justification if SD -3 not implemented:
Project will incorporate permeable pavement to minimize impervious area.
SD-4 Minimize Soil Compaction Yes No N/A
Discussion/justification if SD -4 not implemented:
Project site has been previously graded.
SD-5 Impervious Area Dispersion 0 Yes No N/A
Discussion/justification if SD -5 not implemented:
Runoff from the impervious walkway areas of the amenity site will be directed onto the adjacent permeable pavement
driveway.The permeable pavement will be designed to effectively receive, retain and treat runoff from impervious areas
prior to discharging to the MS4.
E -36 Page 3 of 4 Revised 03/16
ittgirco Coiitiametoififfiedt (cdtliffi44)
-
/Wilted?
SD-6 Runoff Collection 0 Yes
1
No 1 N/A
Discussion/justification if SD -6 not implemented:
Permeable pavement will be used in low traffic areas.Permeable pavement contains small voids to effectively receive
runoff and allow filtration, storage, and evaporation, prior to discharge to the storm drain system.
SD-7 Landscaping with Native or Drought Tolerant Species 0 Yes No N/A
Discussion/justification if SD -7 not implemented:
Landscape or pervious areas will incorporate native or drought tolerant landscape design.Final selection of plant material
needs to be made by a landscape architect experienced with LID techniques.
SD-8 Harvesting and Using Precipitation Yes No 0 N/A
Discussion/justification if SD -8 not implemented:
Harvest and use is considered to be infeasible for the project site.Project will utilize other LID strategies such as
minimizing impervious area to reduce the overall DCV of the site.See Form 1 -7 in Attachment 1c.
E -36 Page 4 of 4 Revised 03/16