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Home My WebLink AboutBLD2019-00259 - 05 STORMWATERo DEPARTMENT OF COMMLTNITY D 621 Sheridan Strcct, l)ort'I'ownscnd, W\ 98368 ' L' cl: 360.37 9.4450 lt ax: 360.37 9.4451 Wcb: www.co.icffcrson.wa.us /communitydcvclopment I')-mail; dcd@co.icffcrson.wa.us STORMWATER CALCUI-ATION WORKSHEET JUN 05 20tg Scan the QR access PARcEL #enorecr/,APPLICANT NAME: DETERMINING STORMWATER MANAGEMENT REQUTREMENTS: 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 permlt application, or other land use approval application that involves sto rmwater review. The basic information will also be helpful for completing a Stormwater Site plan, if requi red. ddivity is any activity that results in movement of earth, or a change in the existing soil cover (both vegetative and and/or the existing soil topography. Land disturbing activities include, but are not limited to clearing, grading, filling, compaction associated with stabilization of structures and road construction. Notive vegetqtion is vegetation comprised of 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. Exa mples 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 flowe r, and fireweed Lond-disturbing non-vegetative) excavation, and a0 re lmperuious surface 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 priorto development. Common impervious surfaces include, 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. stormator c€lc wffksh8et oR ode - REv 2t1no19 p4a 1 or 2 Loab,",""^ffiarefeet.Multiplytheacreagebythisfigure. in square r""tlRQ *165. 6 "qrt '*'-Size of parcel ' Size of parcel i LAND DISTURBING ACTIVITY. CONVERSION OF NATIVE VEGETATION. AND VOLUME OF CUT/FILL Cut Fill_ (cu/yd) 6id sq/ft sq/ft 16 A,fr\ Construction site for structures Well, utilities, etc. Driveway, parking, roads, etc. Other compacted surface, etc. Lawn, landscaping, etc. lndicate Total Volumes of Proposed: (lncludes BMP T5.'13 FillVolume) sq/ft sq/ft sq/ft sq/ft Calculate the total area to be cleared, graded, fllled, 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 proJect convert Y, acres or more of native vegetation to lawn or landscaped areas? Circle: Yes Does the project convert 2 Vz acres or more of native vegetation to pasture? Circle: Yes Temporary construction area Total Land Disturbance Drainfield, septic tank, etc. _ sq/ft Qnt- \\r-o\? STORMWATER CALCULATIONS . IMPERVIOUS SURFACE Structures (all roof area) - _.+__--,*-";*_, Total Exisffng TOTAL NEW + TOTAL EXISTING'*This amount will be used to check total lol coverage. e EXISTING-Fyzcnlxr.:S o sq/ft ,sq/ft Other SidewalksSidewalks Driveway, parking, roads, etc sq/ft Total New 9re Patios _sq/ftPatios -sq/ft .sq/ft sq/ft Solid Decks (without infiltration below) NEW Structures(allroofarea) E/( "qft Driveway, parking, roads, etc _sq/ft Other _sq/ft Solid Decks (without infi ltration below) o Divide the total existinq impervious surface above by the. size of the parcel and convert to a percentage. A,Oq(1 v, o DEVELOPMENT v. REDEVELOPMENT Does the site have > 35o/o or more existinq im oervious surface?->no.) F The proposal is considered redevelopment and Answer questions in Figure 2.4.2. - Proponents of "smal!" projects must comply only with Minimum Requirement #2-Construction Stormwater Pollution Prevention. Please submit the Small Project Certification. 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 (SWPPP) Best Management Plactices (BMPs) Fact Sheet. - Proponents of "medium" projects-those that must meet only Minimum Requirements #1 through #5 must submit Worksheet 41 and 81, a stormwater site plan and a construction stormwater pollution prevention site plan (See Worksheet A2 and 82 for guidance). - "Lalge" projects-those that must meet all 9 Minimum Requirements- must submit Worksheet A1 and 81, a stormwater site plan and a construction stormwater pollution prevention site plan (See Worksheet A2 and 82 for guidance). Large projects also may require engineering. See Worksheet L to determine additional large project requirements. APPTICANT SlGNATURE \ The proposal is considered new development. Answer questions in Figure 2.4.1 Refer to the applicable Flow Chart to determine the Minimum Requirements. srG 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 R OR AUTHORIZED RE} K)R AFF'CE USE ONLY stomtar €lc rcrksheet QR @de - REV Z1DO19 p8p,e2 ol2 --L-i-sq/ft \rQLtO sqfft o o ocD iorr Fact Sheet Volume I - Minimum Technical Reguirements - August 2012 2-t0 StartHere Yec No No Tes No This is a "large" project. Large projects refer to Worksheet L for submittal requirements. At a minimum, all large Project must submit Worksheet Al, ,{2, Bl, and 82 or equivalent. Yec This is a "medium" project. Submit Worksheet Al, A2, Bl and 82 or equivalent. No Con.rplete "Small ect lt Frgure 2.4,1 -Ftow chart ror Determrnlng noquril;il;ildi[i'ii']l]'6dffitbiiiSii,PoilLrtion See Redevelopment Minimum Requirements and Flow Chart (Figure 3.3) Does the sito have 35o/o or more of existing impervious coverage? Does the project convert '/t ADteS Or mOre Of vegetation to lawn or landscaped areas, or convert 2.5 acrrs or more of nativc vcgetationto pasture? Does the project result in 5,000 squsre feet, or greater, of newplus replaccd hard surface area? No Yer Does the projeot rcsult in 2,000 square foct, or greater, of ncwplus rcplaced hard surhco area?All Minimum Requirements apply to thencwand rcplaccd hard surfaces and converted vegctation areas. Does the project have land disturbing activities of 7,000 square feet or greater? Minimum Requirements #1 through #5 apply to thc new and replaced hard surfaces and the land disturbcd. Minimun Requirernent #2 applies. /fiaeryr o O Yer No NcxtQscrtton Ycr NGrt Qucrtloa Ycr No No Flgure 2.4.2- Flow Ghart for Determln lng Requlrements for Redevelopment I No No a pro t.to submittal requirements. At a minirnum, all large Project must submit worksrrT,lAri#'fr];fii^Bh}I,$*yfr;;:;i,"ments-Ausustz0r2 2-I I Does the project rcsult in 2,000 squarc fcet, or more, ofncw plus replaced hard surfacc arca? OR Does the land disturbing activity total 7,000 square feet or greater? Minimum Requircmenb #2 applier.Minimum Requirements #l through #5 apply to the ncw and rcplaced hard surfaces and the land disturbed. Does tho project add 5,000 squarc feet or more ofnow hard surfaces? OR Canvcrl'A acres or morc of vogetation to lawn or landscaped arcas? OR Convort 2.5 acres or morc of nativo vogetation to pastrre? Is this a road rclated project? All Minimum Requircments apply to thc ncw lurd rurfrcee and tre convcrted wgctation arcas. Docs thc project add 5,000 squarc fect or moro ofncw hard surfrpas? Do now hard gurfaces add SV/o or moroto tho cxisting hud surfscGs within thc projcct limiB? Is drc toal ofnew plus rcplaced hard surfaccs 5,000 squarc fcet or morc, AND does thc valuc of thc proposed improvernents - including iatcrior improvcmcntr - cxceed 50% of the asscsscd valuo (or replaccnrcnt value) ofthe oristing site improvcmcnts? No additional rcquiremenB Tcr Ycr Yer No additional requirem€otB All Minimum Rcquhonpnts apply to thc now and rcplaccd hard rurfaccs and coovcrtod vrgotation arcas. o t Worksheet S Small Project Certifi cation Yes Yes no no no This certification may only be used if you answer yes to all of the questions below (circle yes or no) Permanent and temporary drainage on site is designed to divert Stormwater away from my onsite septic system or any neighboring onsite septic system. lf located in a SIPZ zone, I am able to infiltrate stormwater onsite using a drywell or other method (full dispersion, downspout dispersion). My project will not discharge stormwater runoff into a critical area (including but not limited to: geohazard area or its 3O-foot buffer, wetland or Fish and Wildlife Habitat Conservation Area) no My proposal is a small project, which means it will create less than 2,000 square feet of new, replaced, or new plus replaced impervious surface area, and has less than 7,000 square feet of land disturbing activities as defined on the Stormwater Calculation Worksheet. I understand that my project must comply with Minimum Requirement #2 in the Department of Ecology Stormwater Management Manual as amended. I have read the Construction Stormwater Pollution Prevention Fact Sheet and will implement BMP's as applicable to my project. trl w Applicant Signature I as the applicant/owner attest that the information provided herein is true and correct to the best olslrqe By signing the small project of my (uroowrrn oR AUTHoRTZED nepnrse nmrffisre Mrune ) 7\(orref IFIRn*Fwrme 05 20i9 J :*}UI{IYDCI