HomeMy WebLinkAboutMS 13-02; King Property; Minor Subdivision (MS) (3)STORM WATER MITIGATION PLAN
FOR
KING TENTATIVE PARCEL MAP
1600 BUENA VISTA WAY, CARLSBAD
PROJECT NO. MS 13-02
APN 156-142-40
PREPARED FOR
Bill and Robin King
5120 Avenida Encinas #100
Carlsbad, CA 92008
PREPARED BY
The Sea Bright Company
Robert Sukup RCE 28302
4322 Sea Bright Place
Carlsbad, CA 92008
760 - 720 - 0098
August 26, 2013
Rev. December 6, 2013
RECEiVED
DEC 1 0 2013
CITY OF CARLSBAD
PLANNING DIVISION
1.0 Project Setting
The existing site Is located in the northwest quadrant in the City of Carlsbad. The
attached Vicinity Map shows it location. The site has a gross area of 1.517 acres
with an existing single family house. The house occupies the western 20% of the
property and slopes westerly. The remaining property slopes easterly to James
Drive with an average slope of about 10%. The land is primarily vegetated with
non native grasses. There are only 2 palm trees to speak of on the site along
Buena Vista Way. They are projected to be removed. There are existing single
family homes along the northern boundary. The western, southern and eastern
boundaries are bounded by streets, namely Arland Road, Buena Vista Way and
James Drive, respectively. Arland Road will remain as is. Buena Vista Way and
James Drive are to be widened to meet City Standards.
The existing site is zoned for residential development with a density of
0 to 4 DU/Ac. with a minimum Lot size of 7,500 S.F. The proposed land use is to
remain the same. The existing house will remain, be remodeled, and sit on its
own lot. Four additional new lots are proposed for an ultimate total of 5 lots. The
site has a gross area of
1.517 acres. Required road dedications will take up .148 acres leaving a net area
of 1.369 for development.
The anticipated activities that could affect storm water are house construction,
runoff from the roofs, flatwork and driveways, minor erosion, pesticides,
fertilizers, and pet waste.
The comfortable grade ofthe property (about 10%), provides the opportunity to
install bio retention basins with engineered soil and gravel bottoms, with french
drain gravity outlets to minimize standing water within the basins. The
comfortable grade of the property equally creates a bit of a problem in capturing
driveway runoff due to their steepness. On Parcel 1 we have proposed the
driveway drainage to flow into a 5' wide planter that has 6"vertical drops
accommodated by masonry blocks in order to get flat areas for filtration. Parcels
2 and 3 will possibly do the same or as minimum install a grass swale on the
downhill side.
The 2 nearest water bodies are the Buena Vista Lagoon and the Pacific Ocean
which ultimately receive the projects waters. For the most part, the drainage
waters from the existing house flow westerly off the site then northerly on Arland
Road about 500 ' to an existing City storm drain system. The runoff from the
remaining portion of the site flows easterly to James Drive where it enters into
the City Storm Drain System. From there it is basically piped all the way to the
Buena Vista Lagoon.
2.0 Applicable Storm Water Standards
The completed Storm Water Standards Questionnaire is attached at the end of
this report. The project is exempt from Hydromodification (See Section 8.0 of this
report).
3.0 Pollutants of Concern
The pollutants of concern associated with detached residential housing
developments are sediments, nutrients, trash and debris, oxygen demanding
substances, oil and grease, bacteria and viruses, and pesticides.
The subject project is located in the Carlsbad Hydrologic Unit and more
particularly in the Buena Vista Creek Hydrologic Sub Area (904.2 ). The primary
receiving water for this project is the Buena Vista Lagoon. The drainage waters
for this project ultimately get to the lagoon via the City's existing storm drain
system.
The project does not directly discharge to an impaired water body per the 2010
303d list. The pollutants of concern are bacteria, nutrients, and sedimentation/
siltation.
The beneficial uses of the receiving waters for the 904.2 HSA are Agricultural
Supply, Industrial Supply, Contact Water Recreation, Non Contact Water
Recreation, Warm Freshwater Habitat, Wild Habitat, Marine Habitat, and
Preservation of Biological Habitats of Special Significance.
The pollutants of concern listed in the first paragraph of this section will be
primarily "treated" by the use of bioretention basins. The preliminary grading plan
associated with the TPM has identified potential areas for these basins. When a
final development plan is put together for each lot, specific locations and sizes
will be determined. At this point in time the general design cross section would
be to have 18" of engineered soil underlain by 2' of gravel. The gravel layer
would have a French drain within it and have a gravity flow outlet. The receiving
basin would have a depth of 12" and a ponding depth of 10" with a standpipe
inlet set 10" above the engineered soil.
4.0 Source Control Measures
This is a residential project so the sources of pollutants are derived from
everyday activities of the inhabitants.
Sediments can be controlled by sweeping, sediment basins in the bottom ofthe
area drain inlets, good ground cover, and mulch in planting beds.
Nutrients can be controlled by minimizing fertilizers and using more natural
based fertilizers along with more indigenous plants. Proper watering and
elimination of irrigation runoff goes a long way in nutrient control.
Trash and debris mitigation occurs with common sense sweeping, litter pick up,
covered garbage qans and the like.
Oil and grease can be controlled by making sure no leaks occur in your vehicles
as well as good clean up practices if you are using those substances around the
house. Also, driveways should be swept and not hosed off.
Bacteria and viruses can be minimized again by good common sense clean up
as well as clean up of pet waste.
Pesticide release can be minimized by proper application, utilizing more natural
products, and elimination of irrigation runoff. Driveways should be swept and not
hosed off.
5.0 Low Impact Design
This project is a small infill parcel with no real unique topographical features or
drainage courses that exist and therefore cannot be saved.
In flnal design the following recommendations can be applied to each lot:
1. Utilize a 2 story structure to reduce the size of the footprint.
2. Have the roof drainage go to landscape areas.
3. Have all hard surfaces (flatwork, driveways, etc.) drain to bio-retention
basins where possible. Multiple bio-basins may be necessary. Consider
pavers with wider joints for flatwork or driveways.
4. Use efflcient irrigation systems.
5. Use drought tolerant plants.
6. Have refuse containers always covered.
6.0 Integrated Management Practices (IMP's)
The exact size of the houses and driveway configurations are not known at this
time. On the Tentative Parcel Map I have indicated 200 S.F. basins on each
parcel for filtration purposes. Each of these basins could service up to 5,000 S.F.
of impervious area (.04 x 5000 S.F. = 200 S.F.) The soils engineer is reviewing
their application. If they determine they want them lined, I have adequate grade
to line them and provide the gravel layer with a combination French drain/ stand
pipe outlet system to the street.
7.0 Treatment Control BMP's
At this stage of design no specific TCBMP's are proposed. This is a residential
development where good stewardship of one's property is extremely important in
conjunction with the proposed bio retention basins.
No treatment to the widening areas of Buena Vista Way and James Drive are
proposed due to the small total area (about 2800 S.F.) The project has non
contiguous sidewalks which would allow for low flows from the street to enter into
the parkways. Buena Vista Way would not be practical because of its steep
grade.
The project is proposing porous concrete sidewalks on James Drive to mitigate
impervious areas.
8.0 Hydromodification
I have "completed" the HMP Applicability Determination flow chart and included a
copy in this report. The project is actually exempt from Hydromodification
requirements per "Hydromodification Exemption Analysis for Select Carlsbad
Watersheds" by Wayne W. Chang, dated June 19, 2013.
9.0 Storm Water Design Calculations
The proposed project is a Tentative Parcel Map with proposed pads but no
specific house design, patios, or final driveway configurations. I have shown that
bio retention basins will be utilized (see Section 6.0) but no design calculations
have been done because of the preliminary status.
10.0 Maintenance
Depending on the final design of each lot, it is anticipated that bio retention
basins of some design will be on each lot and a standard maintenance
agreement that holds the owners responsible will be executed with the City. Prior
to any sale of lots or finished houses, the maintenance of any treatment facilities
utilized will be the responsibility of the present or future owners.
The proposed porous sidewalk on James Drive is in the City R.O.W. and is to be
maintained by the City. "Normal landscaping" between the curb and sidewalk will
be maintained by the owner along their specific frontage. This includes Buena
Vista Way. If the aforemenfioned parkways become treatment areas, then they
will be maintained by the City.
Typical maintenance of the bio basins includes removal of trash, removal of silt,
fixing any erosion issues, making sure the drain pipes are working if they have
drain pipes, and assuring good plant growth within the basins.
11.0 Certifications
I hereby declare I am the Engineer of Work for this project and that I have
exercised responsible charge over the design of the project as defined in the
Business and Professions Code, and the design is consistent with current
standards. I understand and acknowledge that the check of this Storm Water
Mifigafion Plan by the City of Carlsbad is confined to a review and does not
relieve me, as Engineer of Work, of my responsibility for project design.
By: ^ailOd'O. ^XjLfi^ iZjcl 13
F^obfert O. Sukup ^ RCE 28602 Date'
The Sea Bright Company
4322 Sea Bright Place
Carlsbad, CA 92008
760 720 0098
I certify that, as owner of the property described herein, I have read and
understand the requirements of this Storm Water Management Plan (SWMP)
and that I am responsible for ensuring that all storm water treatment measures
described within said SWMP will be properly implemented, monitored, and
maintained.
By:
Bill King - owner Date
Attachments
The following figures are attached:
Vicinity Map
Storm Water Quality Standards Questionnaire [attached hereon]
HMP Applicability Determination
Preliminary BMP Exhibit for the Future Pads
VICINITY MAP
NO SCALE
^ CITY
CARLSBAD
O F
STORM WATER
STANDARDS
QUESTIONNAIRE
E-34
Development Services
Land Devetopment Engineering
1635 FaradayAvenue
760-602-2750
www.carlsbadca.gov
INSmUCTIONtf ••.i.a'.jri
To address post-development pollutants that may be generatsd from development projects, the City requires ttiat new development and
significant redevetopment priority projects inootponrte Pennanent Storm Water Best Management Practk»s (BMP's) into the project
design per the City's Standard Urban Stomiwater Management Plan (SUSMP). To view the SUSMP, refer to ttie Engineering Standards
(Volume 4, Chapter 2) at www.car1sbadca.gov/standards.
Initially ttiis questtonnaine must be completed by ttie applicant in advance of submitting for a development appllcatton (subdivision,
discretionary permits and/or construction permrts). The results of ttie questionnaire determine ttie level of stomri water standarcis ttiat
must be applied to a proposed development or redevetopment project Depending on ttie outcx>me, your project will eittier be subject to
'Standard Stormwater Requirements' or be subject to additional criteria called 'Priority Development Project Requirements'. Many
aspects of project site design are dependent upon ttie storm watar standards applied to a project
Your reeponses to the questionnaire represent an initial assessment of the proposed project conditions and impacts. City staff has
responsibility for maldng the final assessment after submlsston of the devetopment appltoatton. If staff detennines that the questionnaire
was incorrectty filled out and is subject to more stringent storm water standards ttian initially assessed by you, ttiis will result in the retum
of the development appltoatton as incomplets. In this case, please make ttie changes to ttie questionnaire and resubmit to the City.
If you are unsure about ttie meaning of a question or need help in determining how to respond to one or more of ttie questions, ptoase
seek assistance from Land Devetopment Engineering staff.
A separate completed and signed questionnaire must be submitted fbr each new devetopment appltoatton submlsston. Only one
completed and signed questionnaire is required when muittpto development applicattons for the same project are submitted concurrentiy.
In addition to this questionnaire, you must also complete, sign and submit a Project Threat Assessment Fomri wtth construction permits
for the project
Phaaa atari by comp/effng Step 1 and follow tha inatnictiona. Whan comphtad, sign the fomt at tha and and submif this with your
application to Oie dty.
To determine if your project is a priority development project, piease answer the foltowing questions:
YES NO
1. Is your project UMITED TO constiiicting new or retrofitting paved sidewalks, bicycle lanes or trails ttiat meet
ttie following criteria: (1) Designed and constructed to direct storm water runoff to adjacent vegetated areas, or
other non-erodible permeabto areas; OR (2) designed and consttucted to be hydraulically disconnected from
paved staeeto or roads; OR (3) designed and constructed witti permeabto pavements or aurfiaces in
accordance wfth USEPA Green Streeto guidance?
/
2. Is your project UMITED TO rettvfitting or redevetoping existing paved alleys, sb«ete, or roads ttiat are
designed and consttucted in accordance with the USEPA Green Streete guidance?
If you answered 'yes' to one or more of the above questions, ttwn your project is NOT a priority devetopment project and therefore is
NOT subject to the storm water criteria required for priority devetopment projecte. Go to stap 4, mark the last box stitlna "my
project does not meat PDP raqulraments" and completa applicant Information.
If you answered 'no' to both questions, ttien go to Step 2.
E-34 Page 1 of 3 Effective Sr27/13
^ CITY
CARLSBAD
O F
STORM WATER
STANDARDS
QUESTIONNAIRE
E-34
Development Services
Land Oevelopment Engineering
1635 Faraday Avenue
760-602-2750
www.carlsbadca.gov
TO BR COMPUmEDroil AUll^rai REOeVBLOfWENT PRtUECT^
To determine if your project is a priority devetopment project, please answer ttie following questions: YES NO
1. Is your project a new development ttiat creates 10,000 square feet or more of impervtoue suribces coltocttvely
over the entire project site? 77>/s indudas commarcial, industrial, rasidantial, mixed-use, and public
davelopmant projects on public or private land. /
2. Is your project creating or repladng 5,000 square feet or more of impervious surfece collectively over the entire
project site on an existing eite of 10,000 scKJare feet or more of impen/ious suriiace? 77>« includes commarcial,
Industrial, rasidantial, mixad-usa, and public davalopmant projects on public or private land.
3. Is your project a new or redevetopment project that creates 5,000 square feet or more of impen/ious surfece
coltocttvely over the entire project site gQ^I supports a restaurant? A restaurant ia a fatuity that sella prepared
foods and drinks for conaumpdon, indudmg stationary /uncfi counters and refrashnwnt stands saKIng prepared
foods and drinks for immediate consurrvOon.
/
4. Is your project a new or redevetopment project that creates 5,000 square feet or more of impennous surfece
coltoctivsly over the entire project site and supporte a hillsids development project? A hitskle devetopment
projed Includes development on any natural slope tfiaf cs twenty-five percent or greater. /
5. Is your project a new or redevetopment project that creates 5,000 square feet or more of impervious surfece
coltoctively over the entire project site and eupporte a paridng tot A parking tot is a land araa or facility for tha
tentporery paridng or storage of motor vehicles used personally fbr buainess or fbr corrmerce.
6. Is your project a new or redevetopment project that creates 5,000 square feet or more of impervious surfece
coltoctively over ttie entire project site and supporte a sbeet road, highway freeway or driveway? A street,
road, highway, leeway or driveway is any paved impenrious surface used fbr Oie transportation of
automobSes, trucks, motorcydes. end other vehides.
/
7. Is your project a new or redevelopment project that creates or replaces 2,500 square feet or more of
impervious surfece collectively over the entire site, and dischargee direcUy to an Environmentally Sensitive
Area (ESA)? 'Dischargirtg Dkectly to" indudes ftow thM is conveyed overiand a distance of 200 teet or lass
from tha project to tlie ESA, or conveyed in a pipe or open channel any distance as an isolated How fmm the
projed to the ESA (i.e. not commingles with fhws from atgacent lands).*
8. Is your project a new development that eupporte an automotive repair shop? An automotive repair shop is a
fadlity ffiat is c^gorized in any ona of ffie foltowkig Standard Industrial Classiftoation (SIC) codes: 5013,
SOU, 5541. 7532-7534. or 7536-7539.
9. is your project a new devetopment ttiat supporte a retail gasoline outiet (RGO)? TTiis category indudes RGO'a
that meet the foltowing criteria: (a) 5,000 squan feat or mora or (b) a projed Average Daily Traffic (ADT) of
100 or mora vehides per dey.
10. Is your project a new or redevetopment project that results In ttie disturbance of one or more acres of land and
are expected to generate poilutante post construction? /
11.1s your project tocated within 200 feet of the Pacific Ocean and (1) creates 2,500 square feet or more of
impervtous surfece or (2) increases impervtous surfece on the property by more than 10%?
If you answered 'yea' to one or more of Ifie above questtons, you ARE a priority devetopment project and are therefore sub
implementing structural Best Management Practices (BMP's) in addition to imptomenting Standard Storm Water Requirement!
as source conttol and tow impact devetopment BMP's. A Storm Water Management Pton (SWMP) must be submitted witt
application(s) for devetopment Go to step 3 for radevetopmant projects. For new projects, go to step 4 at tiM end o
quasflonnirire, checlt tha "my project meets PDP requlramanto" box and complete applicant Information.
petto
such
your
f this
If you answered 'no' to all of the above questions, you ARE NOT a priority development project and are ttierefore subjsct to
implementing only Standard Stonn Water Reqinrementa such aa source control and tow impact devetopment BMP's required for all
development projecte. A Stomi Water Management Plan (SWMP) is not required witti yoir applicatton(s) for devetopment Go to step
4 at tha end of this quastionnaira, check tha "my project does not meat PDP raqulraments" box and complate applicant
Information.
E-34 Page 2 of 3 Eflective 8^7/13
CITY OF
CARLSBAD
STORM WATER
STANDARDS
QUESTIONNAIRE
E-34
Development Services
Land Development Engineering
1635 Faraday Avenue
760-602-2750
www.carisbadca.gov
Comptete ttie questions betow regardinfl your redevelopment project
Does the redevelopment project result in the creation or replacement of impennous suriiace in an amount of less than
50% ofthe surface area ofthe previously existing development?
If you answered 'yes,' the sbxictural BMP's required for Priority Devetopment Projecte apply only to tiie creation or replacement of
impervious surfece and not ttie entire devetopment Go to step 4, check the "my project maeto PDP raqulremanto" box and
complate applicant Information.
if you answered 'no,' ttie sttuctoral BMP's required for Priority Devetopment Projecte apply to the entire development Go to step 4,
check tha "my project maete PDP raqulramente" box and comptete applicant Infonnatton.
WT 1 CHBCK THt APPWOFWATE BOX Mtt COHWJti APPUCANT mfQHMKIM^
My project meete PRIORITY DEVELOPMENT PROJECT (PDP) requiremente and must comply with addittonal stomiwater
criteria per ttie SUSMP and I understand I must prepare a Storm V\fetor Management Plan for submittal at time of application.
I understand flow control (hydromodification) requiremente may apply to my project Refer to SUSMP for detaite.
My project does not meat PDP requiremente and must only comply witti STANDARD STORMWATER REQUIREMENTS per
the SUSMP. As part of tfiese requiremente, I will incorporate tow impact development sttategies throughout my project
Applicant Infomiation and Signature Box ^^-'pR^^X£C~V
Applicant Signature: Date: ^13
This Box fbr City Use Only
City Concurrence: YES NO
By:
Date:
Project ID:
* Environmentally Sensitive Areas include but are not limited to all Clean Wator Act Section 303(d) impaired water bodies; areas
designated ae Areas of Special Btological Significance by the State Water Resources Conbol Board (VSfeter Quality Control Plan for ttie
San Diego Basin (1994) and amendmente); water bodtos designated wHh ttie RARE beneficial use by the State V\feter Resources
ConttQl Board (VVater Quality Conttol Plan for ttw San Diego Basin (1994) and amendmente); areas destgnatod as preserves or ttwir
quivalent under ttw Multi Species Conservation Program within ttw Cities and County of San Oiego; and any ottier equivatont
environmentally sensittve areas which have been identified by the Copermitteea.
E-34 Page 3 of 3 Effective 6/27/13
SCCTION t: lOKNTirV POLLUTANTS, BMP SIZIN0 AND SILICTION
FIGURE 2-1. HNfP Applicability Detennination'^
•refer to acptnded HMP gmnption critcM below tbr justifieatioiM tequired on each node
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