HomeMy WebLinkAboutBLD2018-00420 - 05 STORMWATERoov
DEPARTMENT OF COMMUNITY DEVE
621 Sheridan Strcet, Pon Torvnsend, WA 98368
'Icl: 36t1.379.445() | Fax: 360.379.,1451
\\,'eb: s'wrr'.co.icff crson.s'a.us /cunmuniqrlcr-clopmc nr
E-mail: dcd(@co.ic ftcrsr:n.s,a.us q,tj ?0b
STORMWATER CALCULATION WO
DETERMINING STORMWATER MANAGEMENT REQUIREMENTS: This stormwater calculation worksheet should be completed first to
classify the proposal as "small," "medium," or "large." The size determines whether a Stormwater Site Plan is required in
conjunction with a stand-alone stormwater management permit application, building permit application, or other land use approval
application that involves stormwater review. The basic information will also be helpful for completing a Stormwater Site Plan, if
required.
Landdisturbing adiv@ is any activity that results in movement of earth, or a change in the existing soil cover (both vegetative and
non-vegetative) and/or the existing soil topography. Land disturbing activities include, but are not limited to clearing, grading, filling,
excavation, and compaction associated with stabilization of structures and road construction.
Native vegetation is vegetation comprised on plant species, other than noxious weeds, that are indigenous to the coastal region of
the Pacific Northwest and which reasonably could have been expected to naturally occur on the site. Examples include species such
as Douglas fir, western hemlock, western red cedar, alder, big-leaf maple, and vine maple; shrubs such as willow, elderberry,
salmonberry, and salal; herbaceous plants such as sword fern, foam flower, and fireweed.
lmpervious surfoce is a hard surface that either prevents or retards the entry of water into the soil mantle as under natural
conditions prior to development. A hard surface area which causes water to run off the surface in greater quantities or at an
increased rate of flow from the flow present under natural conditions prior to development. Common impervious surfaces inclu de,
but are not limited to roof tops, walkways, patios, driveways, parking lots or storage areas, concrete or asphalt paving, gravel roads,
packed earthen materials, and oiled, macadam or other surfaces which similarly impede the natural infiltration of stormwater.
MtA #nnor ecr/leelrclrut rarur :
PARCEL SIZE fl.E.. SITE)
An acre contains 43,560 square feet. Multiply the acreage by this figure.
Size of parcel in square teet I 2,1 9 T sqltt
size of p rnt O.Z I ".r*
8,ooo
+
Well, utilities,sq/ft
sq/ft
sq/ft
sq/ft
sq/ft
sq/ft
Driveway, parking, roads, etc.
Drainfield, septic tank, etc.+Construction site for structures
lndicate Total Volumes of Proposed:
cut I I \t Fiil .? + (cu/yd)
Circle: Yes
"r". 8n 0
Other compacted surface, etc.
Total Land Disturbance
Lawn,landscaping, etc. ?, fO C
Does the project @nvert 2Yzacres or more of
native vegetation to pasture?
Answer the following two questions related to
conversion of native vegetation:
Does the project convert Y.acres or more of
native vegetation to lawn or landscaped areas?
Circle: Yes
Calculate the total area to be cleared, graded, filled,
excavated, and/or compacted for proposed development
project. lnclude in this calculation the area to be cleared for:
slommter clc rcrkshel - REV. 1Ol2OnO14
LAND DISTURBING ACTIVITY. CONVERSION OF NATIVE VEGETATION. AND VOLUME OF CUT/FILL
@
STORMWATER CALULATIONS - IMPERVIOUS SURFACE
Solid Decks 6 sqltt
(without infi ltration below)
Driveway, parking, roaos, etc * I * sq6
other & sqttt
TOTALNEW+TOTALEX|STTNG. 3 *a 8 rr*'This amount will be used to check total lot coverage.
€- sqltt+
€-
-q)-
-e-
Other
Total New
NEW
Structures (all roof area)
Sidewalks
Patios
EXISTING
Structures (all roof area)
Sidewalks
Patios
Solid Decks
(without inf ltration below)
Driveway, parking, p6s6s, dg G sq/ft
TotalExisting + sq/ft
56 sq/ft
o
The following questions will help determine whether the proposed project is considered development or redevetopment.
FURTHER INSTRUCTIONS: lf the answer is yes, the proposal is considered redevelopment and the attached Figure 2 should be used
to determine the applicable Minimum Requirements. lf the answer is no, the proposal is considered new development and the
attached Figure 1 should be used. At this juncture, the applicant should refer to the applicable Flow Chart to determine the
Minimum Requirements for stormwater management. DCD staff will help verify the classification of the project and the application
requirements.
For proponents of "small" projects who must comply only with Minimum Requirement #2-Construction Stormwater Pollution
Prevention-an additional submittal is not required. The proponent is responsible for employing the 12 Elements to control erosion
and prevent sediment and other pollutants from leaving the site during the construction phase of the project. Pick up the
Construction Stormwater Pollution Prevention (SWPPI Best Management Practices (BMPs) Packet. Proponents of "medium"
projects-those that must meet only Minimum Requirements #1 through #5-and for "large" projects-those that must meet all 10
Minimum Requirements-are required to submit a Stormwater Site Plan. DCD has prepared a submittal template of a Stormwater
Site Plan, principally for rural residential projects. Complete the template in the Stormwater Site Plan lnstructions and Submittal
Template or prepare a Stormwater Site Plan using the step-by-step guidance in the Sformwoter Monogement Monuol.
APPLTCANT SIGNATURE
o
DEVELOPMENT v. REDEVELOPMENT
Divide the total existinq impervious surface above by the size of the parcel and convert to a percentrage: #
"
By signing the Stormwater Calculation Worksheet, I as the applicant/owner attest that the information provided herein is true and correct to the
best of my knowledge. I also certify that this application is being made with the full knowledge and consent of all owners of the affeaed
property.
G 7/o /t I
(utrtoowr,rtR on nuTHoRtzED REpREsEurmvr sretnrunr)(oere)
stomreter €lc mrkshet - REV. 1Ol2Ol2O14
FOB OFFIG USE ONLY
SMAU MEDTUM_LARGE_REDEyELoPMEIiIT- Stormwater Slte Plan:Y€s_ No_
2
qO + q' sq/ft
/ 0d sq/ft
3rA O I 'qt*
Does the site have 35% or more of existing impervious surface? Circle: "* E No
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1
DEPARTMENT OF COMMUNITY DEV
621 Sheridan Street, Port Townsend, WA 98368
Tel: 360.379.4450 | Fax: 360.379.4451
Web: www. co. iefferson.wa. us/commu nitvdevelopment
E-mail: dcd@co. iefferson.wa.us
STORMWATER SITE PLAN SUBMITTAL
ur.a #PRoJEcr/APPLtcANT NAME:
Please answer all of the following questions to the best of your ability. Where the question calls for depiction on a site map, the
applicant may choose to either incnrporate the elements into the general plot plan for the Master Land Use Application or to submit a
separate stormwater site plan map.
Project Overview
Describe the proposed developed conditions of the site. lndicate position and relative size of proposed improvements on the
site m
5
Development to the site will be a 2,105SF single family residence with a two car attached garage. House will be positioned on the West
eno or rne ror, raqng Ine street (Katnter Lane). tne oullotng looIpnnl ts z,5/5til-
Existing Conditions Summary
Describe the existinq topoqraphy. lndicate contours on the site map.2.
The lot gradually slopes downward from West to East (slopes down away from Rainier Lane). Elevation change is roughly 7' over the
t5u oeptn oI Ine tot. uontours are orawn on tne sttemap.
3. Describe the existinq veqetation. lndicate native veoetation areas on the site map.
Native vegetation are ferns, berry bushes, large maples, large cedars and a few fir trees.
4. Describe the existinq soils. lndicate soil tvpe on the site map.
USDA Soil conservation soil survey shows site as AlC, Alderwood series Gravelly Sandy Loam
Describe the existing site hydrology (i.e., drainage; behavior of water on the site-above, below, and on the ground). lndicate
existing stormwater drainage to and from the site on the site map. Depict separate drainage basins on the site map, if
applicable, and indicate acreaoe of each.
5.
The existing storm water pattern consists of drainage in the street with ditches paralleling the pavement intercepting the storm water
Trom up street ano sneet flow across tne lot.
6. Describe any excess levels of noise generated by the proposed use or activity:
Noise will be generated from excavator, dump truck, generator, air compressor, nail gun, saw and other typical construction equipment
Describe significant geographic features and critical areas (i.e., environmentally sensitive areas such as wetlands, streams,
steep slopes, etc.) on the site. lndicate location on the site map.
7
stomwater site plan ternplate - rev. 121712015
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N/A
Describe the general vicinity of the site, including adjacent land uses and structures, utilities, roads, and sensitive/critical areas
(streams, wetlands, lakes, steep slopes. etc.).
8.
Site is located in the North Bay Development of Port Ludlow on Rainier Lane which is located off of Swansonville Road. There is
poweuwale7sewericaDle locateo aI tne west eno o1 tne srte. lne adjacent propenres on the street are used tor stngle tamtly restdence.
This portion of the Stormwater Site Plan consists of the selection and installation of the appropriate stormwater control BMPs
and facilities to remain in place after construction of the project is completed.
"Medium" size projects are required to have the totals calculated of all impervious surfaces, pollution-generating impervious
surfaces, and pollution-generating pervious surfaces to verify that the thresholds for treatment facilities and flow control
facilities are not exceeded.
Describe the developed site hydrology, as proposed. lndicate whether stormwater will be fully dispersed (i.e., per BMP T5.30
in the Manual) or, if not, what types of stormwater flow control will be utilized for the site or specific threshold discharge areas
within the site. Locate these facilities on the site plan and differentiate proposed facilities from existing facilities.
Permanent Stormwater Control Plan
o
Site hydrology will remain the same as is...the street water will remain in the street...the storm water on-site will be captured by roof
oownspouls ano connecteo to tne ratn garoen on-stte.
'10. lf the project requires the use of stormwater treatment facilities, describe the types of stormwater treatment facilities proposed
for use on the site. Locate these facilities on the site plan and differentiate proposed facilities ftom existing facilities. [his is
normally for "large" projects or projects that involve the potential for dispersion of contaminants.l
11. Describe the performance goals and standards applicable to the project.
lnfiltration via the rain garden to comply with the Rain Garden Handbook for Western Washington
12. Describe the flow control system
The roof drains will be 4" minimum tight lines to the rain garden. The foundation drain will also be 4" dia and slope to daylight.
13. Describe the water quality system
6stomater site dan template - rev. 12n12O15
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same
14. Describe the conveyance system analysis and design.
'15. Describe the source of fill material, physical characteristics of fill material, and deposition of excess material
Excess material will be removed from the site with a dump truck. Fill material will be pit run or the soil that was excavated initially
16. Proposed methods of placement and compaction consistent with the applicable standards on Appendix Chapter 33 of the
Uniform Building Code.
Fill material will be placed using a skid steer or mini excavator and compacted with the machine or a plate compactor as it is
17. Describe the proposed surfacing material.
The final surfaci material will either be mulch, rocks or wood chips.
18. Describe methods for restoration of the site.
The final grade will be the same as the existing grade. Grass or small native plants will be planted around the house.
19. An Operation and Maintenance Manual is required for each flow control and treatment facility. [This is normally required for
"large" projects only and only those for which facilities are required to control flow or treat runoff.l lf included, list the Manuals
here.
NA
20. List here and include any special reports or studies conducted to prepare the Stormwater Site Plan.
21 . List other necessary permits and approvals as required by other regulatory agencies. lf those permits or approvals include
conditions that affect the drainage plan or contain more restrictive drainage-related requirements, describe those conditions or
restrictions here.
PLDD reviews the drainage plan and provides input but the county gives the final decision/approval.
7slomater site plan template - rev. 127/2015
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CoNSTRUCTION STORMWATER POLLUTTON PREVENTTON pt-AN (Swppp)
The Construction SWPPP addresses sediment and erosion control during construction. The BMPs indicated by the applicant in the
template that follows must be installed on the ground during all construction phases of the project. The proponent is responsible for
preventing sediment and erosion impacts to environmentally sensitive areas and off-site areas. Consult the Construction Stormwater
Pollution Prevention (SWPP) Best Management Practices (BMPs) Packet for guidance, particularly with rural residential
development.
SECTION I- CONSTRUCTION SWPPP NARRATIVE
8
Construction Stormwater Pollution Plan Elements. Describe how each of the Construction SWPPP elements has been or
will be addressed. ldentify the type and location of BMPs used to satisfy the required element. lf an element is not applicable to
the proposal, justify in writing. Detailed descriptions of the 13 Elements are found at Volume ll Section 3.3.3 of the Manual
(beginning on page 3-11).
13 Required Elements - Construction SWPPP
1. Mark Clearing Limits.
50' of native vegetation will be left on the East end of the lot. Most of the West half of the lot will be cleared for the house while
a tew trees may remarn based on BfaCmCm
2. Establish Construction Access.
Construction access will be established at the proposed driveway
3. Control Flow Rates.
The flow will be contained in the storm water pipes shown.
4. Install Sediment Controls.
A sediment fence will be established along the native vegetation.
5. Stabilize Soils.
All areas disturiced by the new construction will be covered with straw during construction and replaced with new landscaping
to be marntarned by owner
6. Protect Slopes.
No slopes to be constructed.
7. Protect Drain lnlets.
No drains affected by this proposed work.
stormwater site dan template - rev. 127 f2O15
1.
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13 Required Elements - Construction SWPPP (continued)
8. Stabilize Channels and Outlets.
Not applicable to this project.
9. Control Pollutants.
No pollutant generation anticipated
10. Control DeWatering (the act of pumping groundwater or stormwater away from an active construction site)
No de-watering planned.
'l 1. Maintain Best Management Practices (BMPs).
The project will comply with all the requirements of the DOE Manual
12. Manage the Project.
The project will be managed during construction by the principal contractor and the owner on completion of work.
13. Protect Low lmpact Development BMP's
Silt fence will be placed around rain garden after completion and removed once the construction/landscaping is complete.
2.Adjacent Areas.
a. Description of the adjacent areas that may be affected by site disturbance (e.9., streams, lakes, wetlands, residential
areas, roads).
The roadside ditch.
b. Description of the downstream drainage path leading from the site to the receiving body of water (minimum distance of 400
yards).
The roadside ditch draisn to the roadside ditch on Oak Bay Road which eventually drains into the bay.
3 Envi ronmenta!!y Sensitive Areas.
a. Description of environmentally sensitive areas that are on or adjacent to the site.
N/A
Istmater site plan template - rev. 12n2015
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b. Description of special requirements for working in or near environmentally sensitive areas.
N/A
4 Erosion Problem Areas. Description of potential erosion problems on site in the context of the characteristics of the on-site
soils (e.9., erodibility, settleability, permeability, depth, texture, soil structure).
The on-site soils have been described as free draining...no problems are anticipated.
5 Construction Phasing.
a. Constructionsequence
Clearing, excavation, foundation, grading, framing and roof.Wndows, plumbing, HVAC, Electrical, siding.
lnsulatron, drywall, patnttng, Intenor t-tntshes ancl dnveway.
b. Construction phasing (if proposed)
6 Construction Schedule. Wet season is October 1 through April 30 (page2-2O of the Manual).
l. Provide a proposed construction schedule.
Construction will begin immediately upon receipt of building permit. Therefore, construction work may or may not be performed
dunng tne wet season.
ll. Wet Season Construction Activities.
a. Proposed wet season construction activities.
Could be all or none. Depends on when building permit is received.
b. Proposed wet season construction activities for environmentally sensitive areas.
None
7 Financial/Ownership Responsibilities.
a. ldentify the property owner responsible for the initiation of bonds and/or other financial securities
Michael Casal
b. Describe bonds and/or other evidence of financial responsibility for liability associated with erosion and sedimentation
impacts.
Owner of property is licensed and bonded general contractor.
8. Engineering Calculations. Provide Design Calculations on a separate sheet for the following, if applicable.
a.
b.
c.
d.
Sediment Ponds/Traps.N/A
Diversions N/A
Watenrays.N/A
RunoffiStormwaterDetentionCalculations N/A
stmwater site dan template - rev. 121712015 10
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SECTION II. EROSION AND SEDIMENT CONTROL PLAN
Sediment and erosion control measures may be depicted on the master land use application plot plan, a stormwater site plan, and/or a
separate Construction SWPPP site plan. This is a checklist to ensure that the following are depicted on a site plan:
1 General.
a. Vicinity Map
b. Jefferson County Approval Block
c. Erosion and Sediment Control Notes
2. Site Plan.
a. Legal description of subject property.
b. North arrow.
c. lndicate boundaries of existing vegetation (e.9., tree lines, pasture areas, etc.).
d. ldentify and label areas of potential erosion problems.
e. Identifr FEMA base flood boundaries and Shoreline Management boundaries (if applicable).
f. Show existing and proposed contours.
S lndicate drainage basins and direction of flow for individual drainage areas.
h. Label final grade contours and identify developed condition drainage basins.
i. Delineate areas that are to be cleared and graded.
j. Show all cut and fill slopes indicating top and bottom of slope catch lines.
3. Conveyance Systems.
a. Designate locations for swales, interceptor trenches, or ditches.
b. Show all temporary and permanent drainage pipes, ditches, or cut-off trenches required for erosion & sediment control.
c. Provide minimum slope and cover for all temporary pipes or call out pipe inverts.
d. Shows grades, dimensions, and direction of flow in all ditches, swales, culverts and pipes.
e. Provide details for bypassing off-site runoff around disturbed areas.
f. lndicate locations and outlets of any dewatering systems.
4. Location of Detention Best Management Practices (BMPs). ldentify location of detention BMPs.
5. Erosion and Sediment Control Facilities.
a. Show the locations of sediment trap(s), pond(s), pipes and structures.
b. Dimension pond berm widths and inside and outside pond slopes.
c. lndicate the trap/pond storage required and the depth, length, and width dimensions.
d. Provide gpical section views through pond and outlet structure.
e. Provide typical details of gravel cone and standpipe, and/or other filtering devices.
f. Detail stabilization techniques for outleUinlet.
S. Detail control/restrictor device location and details.
h. Specify mulch and/or recommended cover of berms and slopes.
i. Provide rock specificatlons and detail for rock check dam(s), if applicable.
j. Speciff spacing for rock check dams as required.
k. Provide front and side sections of typical rock check dams.
l. lndicate the locations and provide details and specif,cations for silt fabric.
m. Locate the construction entrance and provide a detail.
6. Detailed Drawings. Any structural practices used that are not referenced in the Ecology Manual should be explained and
illustrated with detailed drawings.
7. Other Pollutant BMPs. lndicate on the site plan the locations of BMPs to be used for the control of pollutants other than
sediment (e.9., concrete wash water).
8. Monitoring Locations. lndicate on the site plan the water quality sampling locations to be used for monitoring water quality on
the construction site. Sampling stations should be located upstream and downstream of the project site.
stomater site plan lemplale - rey. 'l2lll2o15 11
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Stormwater Site Plan Changes
lf the designer wishes to make changes or revisions to the originally approved Stormwater Site Plan, the proposed revisions shall be
submitted to DCD prior to construction. The submittal shall include substitute pages that include all proposed changes, revised
drawings showing any structural changes, and any other supporting information that explains and supports the reason for the change.
Final Corrected Plan Submiftal
lf the project included construction of conveyance systems, treatment facilities, flow control facilities, or struclural source control BMPs
(not standard on-site stormwater management BMPs), the applicant shall submit a final corrected plan ("as-builts") when the project is
completed. These should be engineering drawings (stamped by a licensed civil engineer) that accurately represent the project as
constructed.
APPLICANT SIGNATURE
THIS SPACE MAY BE USED FOR ADDITIONAL NOTES, IF NEEDED:
By signing the Construction SWPPP worksheet, I as the applicanUowner attest that the information provided herein is true and
correct to the best of my knowledge. I also certify that this application is being made Wth the full knowledge and consent of all
owners of the affected property
?/to t?
oR AUTHoRTZED REPRESENTATIVE STGNATURE)(DATE)
stomater site plan lemplale -rcv.'l2I7l2O'15 12
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Cir-.y &- C)"|)ot'ra.,' It.r.
CONSULTING ENGINEERS
October 19,2018
Mr. David W. Johnson
Planner
Jefferson County Department of Community Development
621 Sheridan Street
Port Townsend, Washington 98368
SUBJECT:STTE PLAN REVIEW, BUILDING PERMIT
APPLICATION BLDl8.OO42O, 55 RAINTER LANE
PORT LUDLOW DRAINAGE DISTRICT, JEFFERSON COLINTY,
WASHINGTON
G&O #18418.00
Dear Mr. Johnson:
Thank you for the opportunity to review the Stormwater Calculation Worksheet and Site
Plan for the proposed single-family residential structure at 55 Rainier Lane
(Permit BLD l8-00420). Drainage from this property flows to the east toward the
properties located on the west side of Camano Lane,
We have the following comments regarding the information provided.
STORMWATER CALCULATION WORKSHEET
The proposed new impervious surface is 3,708 square feet and proposes
8,000 square feet of land-disturbing activity. Per Figure I (attached) the
project is classified as a "Medium" project. Minimum Requirements #l
through #5 apply to the new and replaced impervious surfaces and the land
disturbed.
SITE PLAN
Minimum Requirement #2 requires Construction Stormwater Pollution
Prevention (SWPP) measures. The Construction Stormwater Pollution
Prevention Plan worksheet indicates a "sediment" fence will be installed
along the native vegetation, The fence should be shown on the final site
plan submitted with the building plan. The clearing limits should be
clearly shown on the final site plan. In addition to the silt fence, the
1130 Rainier Avenue S., Suite 300 Seattle, Washington 98144 (206) 284-0860 Fax (206) 283-3206
S Printcd on tccYdcd PoPcr
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Mr. David W. Johnson
October 19, 2018
Page2
applicant should implement BMPs to prevent transport of sediment off
site, including but not limited to preventing erosion by limiting soil
exposure, minimize tracking sediment onto roads, and protection of
slopes.
2.Minimum Requirement #5, On-Site Stormwater Management, is applied
to this lot, BMPs meeting the Low Impact Development BMPs are
included in List #1 (Ecology 2012 Manual as amended 2014, Volume I,
page2-29). The Site Plan indicates two rain gardens (BMP T5.14) will bc
installed at the east side of the building. Overflow from the rain gardens
will be dispersed tkough 50 feet of undisturbed vegetation. This is an
acceptable method of handling stormwater runoff on this properly.
3 Any areas dcsignated for infiltration should be protected from compaction
during construction.
Please contact me if you have any questions regarding this review
Sincerely,
GRAY & OSBORNE, INC.
rl
foq{tfu'uut
Nancy'f. Lockett, P.E.
NEL/hh
Encl.
cc:Commissioners, Port Ludlow Drainage District
@ Prhtoaon recydea papor
Yes
Does the site have
35Y, or more of
oxisting impervious
covcrage?
Scc Redevelopment
Minirnum
Requirements and
Flow Chart
(Figure 2)
I)oes the projeot add
5,000 square feet or
more of new
impervious surfaces?
Does the project convert3/q
acfes or more of native
vegetation to lawn or
landscaped areas, or
convert 2.5 acres or more
of native vegetation to
pasture?
Yes Yes
Does the projcct havc
2,000 square feet or
rnore of new, replaced,
or new plus replaced
impervious surfaces?
..LARGE" PROJECT
All Minimum Requirements
apply to the new impervious
surfaces and converted
pervious surfaces.
Does the project have
land-disturbing
activities of 7,000
square feet or more?
"MEDIUM" PROJECT
Minimum Requirements #1
through #5 apply to the new
and replaced impervious
surfaces and tlie land
disturbed.
*SMALL" PROJECT
See Minimum
Rcquirement #2,
Construction Stonnwater
Pollution Prevention
Oa o
BLDl 8-00420
FIGURE 1: NEW DEVELOPMENT
Yes
No
Yes
No
Start Here
IJased oo Vig.2.2 frcrn 20Ol Ecology Stormwater Mondgement |vlurual for Western Washinglon
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No