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621 Sheridan Street, Port Townsend, WA 98368
T el: 360.379.4450 | Fax: 360.379.4451
DEPARTMENT OF CO
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Web: www.co.iefferson.wa.us/communiwdevclooment
E_mail: dcd@co.ieffenon.wa.us JEFFERSON COtrh{Ty
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ST ORMWATER CALCULATI ON WORKSHEET
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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 stormlyater review. The basic information will also be helpful for completing a Stormwater Site Plan, if
required.
Land-dtsturblng octiviirry. 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 lnclude, but are not limited to clearing, grading, filling,
excavation, and compaction associated with stabilization of structures and road construction.
Native trlgetotion 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, bigJeaf maple, and vine maple; shrubs such as willow, elderberry,
salmonberry, and salal; herbaceous plants such as sword fern, foam flower, and fireweed.
lmperulous 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 include,
but are not limited to roof tops, walkways, patiog 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.
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PARCEL SIZE (I.E.. SITE)
An acre contains 43,560 square feet. Multiply the acreage by this figure.
Size of parcel in sq uare feet sq/ft
sizeof parcet 5. tS
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construction site for structures l0' , li6
lao @
O ecOther compacted surface, etc. _
sq/ft
sq/ft
sq/ft
sq/ft
sq/ft
sq/ft
Driveway, parking, roads, etc.
Lawn, landscaping, etc.
Drainfield, septic tank, etc.
Well, utilities, etc.
Total Land Disturbance
lndicate Total Volumes of Proposed:
(cu/yd)
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:
Answer the following two questions related to
conversion of native vegetation:
Does the prolect convert 7o acres or more of
native vegetation to lawn or landscaped areas?
Circle: Yes
Does the project convert 2 lz acres or more of
native vegetation to pasture?
Circle: Yes
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STORMWATER CALCULATIONS . IMPERVIOUS SURFACE
Driveway, parking, roads, etc D sqfft
',4,Other - sq/ft\
Total Existin g {) sqmTotal New
TOTAL NEW + TOTAL EXISTING*
v sqffi
O
"qm6
Other .!sq/ft
Driveway, parking , roads, a"11 ,77\
21 qn q/ft *This amount will be used to check total lot coverage.
NEW
Structures (all roof area)
Sidewalks
Patios
Solid Decks
(without infi ltration below)
EXIST!NG
Structures (all roof area)
Sidewalks
Patios
Solid Decks
(without infi ltration below)
DEVELOPMENT v. REDEVELOPMENT
Divide the total existinq impervious surface above by the size of the parcel and convert to a percentage:
Does the site have 35% or more of existino impervious surface? Circle: Yes
-Q-n@
The following questions will help determine whether the proposed project is considered development or redevelopment.
FURTHER INSTRUCilOilS: 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 Fe-QlfLments 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 f2-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 (SWPP) Best Management Practices (BMPs) Packet. Proponents of "medium"
projects-those that must meet only Minimum Reguirernents #1 through f5-and for "large"meet all 10
\4ininLunRequlEmegts-are required to submit a stormwater Site Plan. DCD has prepa 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 o-r pitipaie i Stormwater Site Plan using the step-by-step guidance in the Stormwa ter Management Manuo!.
APPTICANT SIGNATURE
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 affected
property.
(uroowrrn nerntsrmltrvE srernrune)(DArE)
FOROFFICE USE ONLY
Stormwater Site Plan:LARGE
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DEPARTMENT OF GOMMUNITY DEVEL
621 Sheridan Street, Port Townsend, WA 98368
Tel: 360.379.4450 | Fax: 360.379.4451
Web: www. co. iefferson.wa. us/communitvdevelooment
E-mail: dcd@co jefferson.wa.us JEFFERSON COUNWDCD
1
STORMWATER SITE PLAN SUBMITTAL TEMPI-ATE
uu#pRoJEcr/AppLrcANr NAME: Williamson
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 incorporate 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
Construction of a single family residenep, front North on property with two parking spots. On south front corner we will build a 5,000 sq
[.oullolngwlInflveparKngspotS.ASlngleStorymodularbulI0lng640sqE.uu
Existing Conditions Summary
Qgg.crtlg the existing topography. lndicate contours on the site map2.
Site is generally flat, with a gentle slope South-West to back South-West corner
3. Describe the existing vegetation. lndicate native vegetation areag qq the site map.
The entire parcel currently has dense natural vegetation.
4. Describe the existing soils. I soil type on the site map.
1995 soil samples were taken, see attachment. Mostly 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 acreage of each.
5.
Natural infiltration through soil and natural vegetation.
6. Describe any excess levels of noise generated by the proposed use or activity:
We do not expect to generate any excess level of noise.
7. Describe significant geographic features and critical areas (i.e., environmentally sensitive areas such as wetlands, streams,
etc.) on the site. lndicate location on the site mapsteep slopes,
stomater site da t8trplate - rev. 12nl2015
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No critical areas located on the site.
Describe the general vicinity of the site, including adjacent land uses and structures, utilities, roads, and sensitive/critical areas
fqtreams, wetlands, lakes, steep slopes, etc.).
L
Adjacent properties are zoned rural residential and have no established residences. The back side sets against commercial forest land.
r ne lront ooroers uoyle t(oao. I nere are no senstttve or cfltlcal areas.
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 eompleted.
'Medium" size projects are required to have the totals cal@lated of all impervious surfaces, pollutiongenerating 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 conlrol 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 Gontrol Plan
9.
Storm water will be collected ftom gutters and stored in a tank off of the main building. Any storm water not captured will naturally be
orsperseo rnlo me unolslurDeo naturat vegetaflon
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 from existing facilities. [Ihis is
normally for "large" projeds or projects that involve the potentialfor dispersion of contaminants.l
11. Describe the performance goals and standards applicable to the project.
Our performance goals and standards of the prqect are to have as slight of an impacl on the existing vegtation and overall sit
conotttons as possrDle. our goal rs to not drsturb the natural vegetaton except tor what is lndicatcd oR me stlcmeE
12. Describe the flow control system
N/A
13. Describe the water quality system.
bstom€ter sits plsn tetrplate - rev. 12n 12015
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.
We do not expecl to have any excess fill material leave the site.will be covered by gravel
16. Proposed methods of placement and compaction consistent with the applicable standards on Appendix Chapter 33 of the
Uniform Building Code.
Road surfaces and parking spots will be graveled and compacted with dozer and excavator.
17. Describe the proposed surfacing material
The road will be surfaced 1 1/4 inch crushed basalt.
18. Describe methods for restoration of the site
We plan on keeping the natural vegetation on the lot except where construction is proposed.
19. An Operation and Maintenance Manual is required for each flow control and treatment facility. [-his is normally required for
"large" projecb only and only those for which facilities are required to control flow or treat runoff.l lf included, list the Manuals
here.
N/A
20. List here and include any special reports or studies conducted to prepare the Stormwater Site Plan.
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.
None.
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CoNSTRUCTTON STORMWATER POLLUTTON PREVENTTON PLAN (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 Prcvention (SWPP) Best Management Practices (BMPB) Packet for guidance, particularly with rural residential
development.
SECTION I - CONSTRUCTION SWPPP NARRATIVE
Construction Stormwater Pollution Plan Elements. Describe how each of the Construction SWPPP elements has been or
will be addressed. ldentify the gpe and location of BMPs used to satisfu 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 SecUon 3.3.3 of the Manual
(beginning on page 3-11).
13 Required Elements - Construction SWPPP
'1. Mark Clearing Limits.
The clearing limits are clearly marked on the site plan ad will be implemented in a careful and specific fashion.
2. Establish Construction Access.
Construction access will occur throughout the proposed gravel driveway in order to provide the most proteclion to the native
vegetalon.
3. Control Flow Rates.
Th minimize runoff with weather predictions and strabilizing with straw bales and silt fencing as needed. lf sediment flow occurs
aclcltttonal measured wll be taken
4. lnstall Sediment Controls.
Straw bales and silt fencing will be used.
5. Stabilize Soils.
Ma compaction of road surfaces.
6. Protect Slopes.
Minimal vegetation will be disturbed. No substantial slopes. Land is fairly slat. Vegetation in low areas is not expected to be
orsturDeo.
7. Protect Drain lnlets.
No drain inlets on site.
stomwats site dil tetrplats - rev. 1 2n /20 1 5
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13 Required Elements - Construction SWPPP (continued)
8. Stabilize Channels and Outlets.
None on site.
9. Control Pollutants.
Bark chips and straw will aid in pollution protection, lt can easily be collected, removed, and replaced as necessary. A spill kit
wrll De rn stte to clean up potentral orl; tuel, sprlls, wasn water (on srte) rl avarlable lor contamrnateo rtems.
10. Control De-Watering (the act of pumping groundwater or stormwater away from an active construction site).
ln necessary clean storm water will be pumped to slightly higher ground into existing vegetation and allowed to filter down into
the RaturalVegetatlon floor
11. Maintain Best Management Practices (BMPs).
BMP will be maintained and managed throughout the entire construction process. They will be monitored daily
12. Manage the Project.
I understand all aspects of the projecl and will monitor and will include any additional BMP's as needed.
13. Protect Low lmpact Development BMP's
At least a 25' natural vegetation buffer will be maintained around the parcel. A 43" green belt consisting of dense natural
vegetauon w[ be maintarned on tfle tront 0f tho Bropefy mal faoes theroac
2.Adjacent Areas.
a. Description of the adjacent areas that may be affected by site disturbance (e.9., streams, lakes, wetlands, residential
areas, roads).
No established residences on adjacent properties. Commercial forest borders back. Coyle road borders the front of the
b. Description of the downstream drainage path leading from the site to the receiving body of water (minimum distance of 400
yards).
Drains into natural vegetation.
3.Environmentally Sensitive Areas.
a. Description of environmentally sensitive areas that are on or adjacent to the site.
No enyironmentally sensitive areas on site or on adjacent properties.
Islsmmtar site plil totrplale - rov. 12nno15
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 site is flat to gentle slope. The soil consists of sandy loam. We do not foresee any erosion problems.
5.Construction Phasing.
a. Constructionsequence
Road construction, site prep, power, water, septic instillation, foundation, building construction
b. Construction phasing (if proposed)
None.
6. Construction Schedule. Wet season is October 1 through April 30 (page 2-2O of the Manual).
l. Provide a proposed construction schedule.
January 2019- January 2020
ll. Wet Season Construction Activities.
a. Proposed wet season construction activities.
Clearing, excavating, site prep, and road instillation.
b. Proposed wet season construction activities for environmentrally sensitive areas.
No environmentally sensitive areas.
7 Financial/Ownership Respons ibilities.
a. ldentify the property owner responsible for the initiation of bonds and/or other financial securities.
N/A
b. Describe bonds and/or other evidence of financial responsibility for liability associated with erosion and sedimentation
impacts.
N/A
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
Watenarays.N/A
Runoff/StormwaterDetention Calculations N/A
stommtor site plil lcfiErlat€ - rey . 12n 12015 '10
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. ldentify FEMA base flood boundaries and Shoreline Management boundaries (if applicable).
f. Show existing and proposed contours.
S. lndicate drainage basins and direction of flowfor individual drainage areas.
h. Label final grade contours and identiff 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 typical section views through pond and outlet structure.
e. Provide gpical 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 specifcations and detail for rock check dam(s), if applicable.
j. Specify 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 specifications 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.
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).
7
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.
stmwater site dan tetrdate - ev. 12n12015 11
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 erplains and supports the reason for the change.
Final Corrected Plan Submittal
lf the project included construction of conveyance systems, treatment facitities, flow control facilities, or structural source control BMPs
(not standard on-site stormwater management BMPs), the applicant shall submit a final conected 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 applicanVowner attest that the information provided herein is true and
conect 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 affected propefi.
//'B '2018
REPRESENTATIVE (oArE)
etomwatr site da letrplat6 - rBv. 12nX2015