HomeMy WebLinkAboutNOA - Stormwater Calculation WorksheetGtrfiVtrDEPARTMENT OF COMMUNITY DEVELO
621 Sheridan Street, Pon Townsend, WA 98368
Tel: 360.379.4450 | Fa* 360.379.4451
Web: www.co.ieffersoa.wa.us /communitydevelopment
E-mail: dcd@.co.iefft rson.wa.us
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JEFTERSON COUNIY
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STO RMWATER CALCULATION WO RI$HEET
MIA#PRorEcr/APPLTcANT NAME:J
DETERMINING STORMWATER MANAGEMENT REqUIREMENTS: fhis stormwater calculation worksheet should be completed first to
classifo 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.
Lond4lsturbing octivity 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.
Notiye t egetation is vegetation comprised on plant species, other than noxious weeds, that are indigenous to tfie 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.
tmpmlous sutloce is a hard surface that either prevents or retards the entry of water into the rcil mande as under natural
conditlons 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 impeMous surfaces include,
but are not limited to roof tops, walkways, patios, driveways, parking lots or storage areas, concrete or asphah paving, grarel 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.
sq/ftSize of parcel in square feet 29620.8
size of p"r""t 0'68 u"r""
Construction site for "trr"trr""
N/A
N/A o
b
300
300
sq/ft
sq/ft
sq/ft
sq/ft
sq/ft
sq/ft
Drainfield, septic tank, etc.
Well, utilities, etc.N/A
Total Land Disturbance
Other compacted surface, etc.
Lawn, landscaping, etc.N/A
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:
lndlcate Total Volumes of Proposed:
"rrfu- Fiu 35 (curyo)
Does the project convert 7o acres or more of
native vegetation to lawn or landscaped areas?
Circle: Yes
Does the project convert 2lz acres or more of
native vegetation to pasture?
Circle: Yes
Driveway, parking, roads, etc. N/A
"qrn
1
STORMWATER CALULATIONS - IMPERVIOUS SURFACE
EXISTING
4730TOTAL NEW + TOTAL EXISTING.*This amount will be used to check total lot coverage.
sq/ft
NEW
Structures (all roof area)N/A Structures (all roof area)1562
N/APatios
1 168N/A
Other
Driveway, parking, roads, etc 1 500
TotalExisting 4430
Sidewalks Sidewalks
Patios 200
Other 300
Solid Decks
(without infiltration below)
Solid Decks
(without inliltration below)
TotatNew 300
Driveway, parking, r"oao", "t"
N/A
"qltt
N/A
DEVELOPMENT v. REDEVELOPMENT
Divide the total existino impervious surface above by the size of the parcel and convert to a percentagu, 15 oro
Does the site have 350/o or more of existinq impervious surface? Circle:NoYes
The following questions will help determine whether the proposed project is considered development or redevelopment.
FURTHER INSTRUCTIONS: lf the answer is yes, the proposal is considered redevelopment and the attached Flgure 2 should be used
to determine the applicable Minimum Requirements. lf the answer is no, the proposal is considered na danelopment 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 verifo 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 Practace (BMPsl Packet. Proponents of 'medium'
projects-those that must meet only Minimum Requirements #1 through #5-and tor "large" projects-those that must meet all 1O
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 lnstructbns and Submittal
Template or prepare a Stormwater Site Plan using the step-by-step guidance inthe Stormwoter Monogement Manuol.
APPLICANT SIGNATURE
By signing the Stormwater Calculation Worksheet, I as the applicant/owner attest that the information provided herein is true and correct to tlre
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.
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slormwaler €lc worksheet - REV. 1Ol2Ol2O14 2
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