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Home My WebLink About999700028 Drainage Report STO'~'?"Mr 9RAE~/AGE REPORT FOR TEAL .'t,AK'E VILLAGE .DIVISION II ( dUN -8 I JEFFERSON COUNTY DEPT. OF COMMUNITY DEVELOPMENT Pope :Rez,..:,urces BY JEFFERSON COUNTY DEPT. Attachm~_,nt [.c MACLEARNSBErrY. INC. CIVIL ENGINEEI~$ -- LANE) SURVEYORS -- PLANNERS 15g WYATT WAY NE BAINE~RIE)GE ISLAND, WA 98110 (206) 842-5.~14 STOI~M DRAYAGE REPORT FOR TEAL LAKE VILLAGE DIVISION II (PHASE 1) I. Introduction: Pope Resources is proposing to develop the single-family subdivision of Teal Lake Village Division II, on the south side of Port Ludlow Bay. A Preliminary Plat has been approved by Jefferson County and it is the intent of the Developer to conduct final platting and site improvements in the Spring of 1996 in order to have lots available to the public by the Summer of 1996. II. Site Description: The proposed plat of Teal Lake Village Division II lies, predominately, in the northeast-quarter and the southeast-quarter of Section 21, Township 28 North, Range 1 East, W.M. It is bounded on the north by the plats of Teal Lake Village Division I and Fairwood Village, on the west by the preliminary plat of Springwood, and on the south and east by unplatted Pope Resources lands. The site straddles the Teal Lake Road and contains a total of 110.27 acres of land, 71.84 acres of which lies east of the road in Phase 1, with the remaining 38.38 acres in Phase II, west of the Teal Lake Road. Ground cover consists of small second growth, mixed coniferous and deciduous cover. Phase 1 lies, predominately along a north-south running ridge. The land falls away to the west, toward the Teal Lake Road at slopes of eight to ten percent. The more irregular terrain to the east falls toward a ravine at slopes upwards of eight to twenty percent. The gently sloping rid,zeline rises from an elevation of 310', at the project entrance on the Teal Lake Road, to 480', at the fiat ridgetop.some 2600 feet to the southeast. According to the SCS Soil Survey of Jefferson County the soil type covering the site is Cassolary, which falls in Hydrologic Group C. JEFFERSON III. Project D~cription: The proposal consists of a 36 lot subdivision with the main access off the Teal Lake Road and running along the center of the ridge, and culminating in a mm around at the top of the ridge, some 2750 feet to the southeast. The southerly extension df Crestview Drive will connect to Teal Lake Village Div. I approximately 300 feet in from the entrance and a 450 foot long cul- de-sac extends from the main road at approximately station 10+00. When completed, the 36 1o~ will cover approximately 57 % of the site and range in size from 0.8 acre to 1.6 acres. IV. Existing Drainage Conditions: A. The Drainage Basin: The aforementioned ridge divides storm water runoff from Phase I. Storm water runoff from the east side of the ridge drains to the north-flowing ravine, which runs along the easterly boundary of the plat. Runoff from the west side of the ridge is further divided. The southerly portion of the runoff from the west side of the ridge flows to the Teal Lake Road and thence northwesterly in the roadside ditch to the creek which runs north, through the Port Ludlow Golf Course. The northerly portion of the sub-basin flows, naturally, into the ravine, which runs, northerly, along the east side of Teal Lake Village Division I. . B. Site Drainage: Due to the lay of the land, the large amount of natural open space, the fact the that most of the proposed lots lie along the ridgetop, and size of the lots, most of which will remain in their natural state, the predominance of the project site will not be affected by land clearing activities. Most of the site will continue to drain as in its undeveloped condition. Therefore, only that portion of the site, which will actually be disturbed, will be addressed in the drainage analysis. V. Downstream Drainage Conditions: The primary stream flowing into the Ludlow Bay drainage basin is Ludlow Creek, which drains the bulk of the Chimicum Valley and culminates at the head of Port Ludlow Bay. The north- flowing stream in the valley in which the Port Ludlow Golf Course lies, and a series of steep ravines, drain into the south side of Port Ludlow Bay, east of Ludlow Creek. All of these drainage sub-basins flow through large culverts, under the Port Ludlow - Paradise Bay Road and on into the bay through well defined channels. JEFFERSON COUNT'¢ DEPT. OF :'-n,**J, i:J TV DEVELOP!V, ENT VI. Prgp0$ed Drainage Imprgvcment~: A. OFF-SITE, UPSTREAM Off-site, upstream, draina, ge all flows in from south along the aforementioned easterly ravine and the Teal Lake Road ditches and bypasses the project site. Accordingly, this runoff does not affect the project and will not be addressed further. B. ON-SITE DRAINAGE Jefferson County (by virtue of it's reference to the DOE Manual), requires detention of the 2- year, 10-year and 100-year, 24-hour storm events, with a release rate equal to one-half of the 2-year storm discharge quantity, under undeveloped conditions. In addition, the DOE Manual requires storm water quality control in the form biofiltration, or storage capacity for the 6-mos, 24-hour storm event (0.64 of the 2-year storm event). It is anticipated that the 36, approximately one-acre, lots in the project will be improved to only a distance of about 100-feet back from the street. For purposes of this report it will be assumed that the entire width of each lot will be cleared (actually clearing will probably not be this extensive). This being the case, total lot clearing will amount to 15.69 acres, or 0.436 acre per lot. Furthermore, 4.72 acres of road right-of-way will be cleared, for a total of 20.41 acres to be cleared out of the total 71.89 acres in Phase 1. , Of the 0.44 acre of cleared area per lot, it is anticipated that there will be 4000 square feet, or 0.09 acre of impervious area in the form of buildings, driveways, patios and side walks, this leaves 0.36 acre per lot for lawn and landscaping. The developed site will divide into two sub-basins, each one draining to a separate detention facility. For purposes of this report these sub-basins will be described as Sub-basin A and Sub- basin B. Their characteristics are described as follows: Sub-basin A: Description: 31 lots consisting of Lots 1 through 9 and Lots 15 through 36. Of these lots, drainage from the building sites on Lots 6, 8 and 9, 23 through 34 cannot be intercepted, either directly or indirectly, by the roadside ditch system and will have to have individual infiltration systems designed and constructed at the time of individual house construction on the lots. Therefore, drainage from 28 building sites will be directed to the Sub- basin A detention facility: 0.435 acres/lot x 16 lots = 6.96 acres draining to detention facilities. JU~ - ,~ ,:':~.,~ !,_..., JEFFERSON COUNTY DEPT. OF COMMUNITY DEVELOPMENT 0.09 acre/lot x 16 lots = 1.44 acres combined lot impervious area. 6.96 acres- 1.44 acres = 5.52 acres combined lot pervious area (Developed Conditions). Road System: There are 4.34 acres of road right-of-way in Sub-basin A. of which 1.92 act:es will be paved. Right-of-way area in pervious area = 4.34 - 1.92 = 2.42 acres. Total impervious area = 1.44 acres (lots) + 1.92 acres (roads) = 3.36 acres Total pervious area in lawns landscaping = 5.52 acres + 2.42 acres = 7.94 acres Total natural pervious area (woods) = 4.31 acres. Total existing pervious area within this analysis = 6.96 acres + 4.34 acres + 4.31 acres = 15.61 acres. (1) Time of Concentration Worksheets were prepared for both existing and developed site conditions (see Appendix A-1 and A-2). (2) Four hydrographs were created for: the 2-year, 24-hour storm event and the 100-year, 24-hour storm event, under existing conditions, and the 2-year, 24-hour storm event and the 100-year, 24-hour storm event, under developed conditions (see Appendix A-3 and A-4). (3) The hydrographs for the 2-year, 24-hour storm event and the 100-year, 24-hour storm event, under developed conditions, using one-half the release rate under existing conditions (0.16 cfs) for the 2-year event and the full release rate under existing conditions for the 100-year event (see Appendix A-5 and A-6) were used to size a detention pond for the sub-basin. The resultant pond was determined to be 31,378 cubic feet in volume. The top area of the resultant pond is 13,886.9 square feet, resulting in a rectan=mJlar pond 84 feet wide by 167 feet long. The routing data was filed for reference (A100.Det). (4) Finally, the above mentioned hydrographs for the 2-year and 100-year, 24 hour storm events (for developed conditions) were routed through the design pond using the Reservoir Routing Inflow/Outflow Routine to verify the adequacy of the pond volume. The peak storage calculated out at 31,370 cubic feet. l 1 JEFF'F_.RS ON COUNTY DEPT. OF Cn~'~Ut'.~!%".,,.,~v,,,. DEVEL. OP¢'~ENTj VOL Sub-basir~ B: Description: $ lots consisting of Lots 11 through 14. Of these lots drainage fro.m the building sites on Lots 10 through 13 cannot be intercepted, either directly or indirectly, by the roadside ditch system and will have to have individual infiltration systems designed and constructed at the time of individual house construction on the lots. Therefore, drainage from one building site will be directed !o the Sub-basin A detention facility: 0.436 acres/lot x 1 lots = 0.436 acres draining to detention facilities. 0.09 acre/lot x 1 lots = 0.09 acres combined lot impervious area. 0.436 acres - 0.09 acres = 0.346 acres combined lot pervious area (Dev.) Road System: There is 0.38 acre of road fight-of-way in Sub-basin A. of which 0.24 acre will be paved. Right-of-way area in lawn = 0.38 - 0.24 = 0.14 acres. Total impervious area = 0.09 acres (lots) + 0.24 acres (roads) = 0.33 acres Total pervious area in lawns landscaping = 0.346 acres + 0.14 acres = 0.49 acres Total unimproved area draining to detention = 0.49 acres Total existing pervious area within this analysis = 0.38 acres + 0.49 acres 4- 0.49 acres = 1.36 acres. (1) (2) (3) Time of Concentration Worksheets were prepared for both existing and developed site conditions (see Appendix B-1 and B-2). Four hydrographs were created for: the 2-year, 24-hour storm event and the 100-year, 24,hour storm event, under existing conditions, and the 2-year, 24-hour storm event and the 100-year, 24-hour storm event, under developed conditions (see Appendix B-3 through B-5). The hydrographs for the 2-year, 24-hour storm event and the 100-year, 24-hour storm event, under developed conditions, using one-half the release rate under existing conditions (0.015 cfs) for the 2-year event and the full release rate under existing conditions for the 100-year event (see Appendix B-6 and B-7) were used to size a detention pond for the sub-basin for comparative purposes. The resultant pond was determined to be 2,838 cubic feet in volume. The top area of' the resultant pond is 2,082 square feet, resulting in a rect~.ngular pond 33 feet 1 JEFFERSON COUNTY DEPT. OF COMMUNI'I~' DEVELOPMENT 563 (4) wide by 66 feet long. Finally, the above mentioned hydrographs for the 2-year and 100-year, 24 hour storm events (for developed conditions) were used to determine the required length of a four foot diameter detention pipe. The required pipe lengtti was determined to be 225.4 lineal feet, with a storage capacity of 2829 cubic feet (see Appendix B-8 and B-9). OFF-DRAINAGE DOWNSTREAM Water from the detention pond will discharge into the roadside ditch on the Teal Lake road; thence down the Teal Lake road ditch to the Highland Drive intersection, where it will flow westerly, along the ditch adjacent to Highland Drive and into the main north-flowing stream, which drains the Port Ludlow Golf Course. VII. Conclusion Rules in the current edition of the State Department of Ecology's Storm Water Technical Manual (hereinafter called the Manual) require that, for a project of this magnitude, a Storm Water Site Plan be prepared and implemented. This site plan will have two elements, an Erosion and Sediment Control Plan for temporary control of pollution generated during construction, and a Permanent Storm Water Quality Control Plan for control of pollution from storm water after construction is completed. The Manual lists eleven Best Management Practices which pertain to this project. These requirements and the descriptions their elements are listed in AppendLx C. ,* PE JEFFE,~SON COUNTY DEPT. OF COI~,MIJNITY DEVELOPMENT 563 I/6 SHEET NUMBER 55 (J~n~ ~,4eet $2) Or~ .; jEFFE'RSON COUNTY DEPT. OF COMMUNITY DEVELOPMENT KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 'ABLE 3.52.B SCS W~'ERN WASHINGTON RUNOFF CURVI~ NUMBERS , , , SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS (Published by SCS in 1982} Runoff curve numbers for selected agricultural, suburban and urban land use for Type lA rainfall distribution, 24-hour storm duration. , , _ CURVE NUMBERS BY HYDROLOGIC SOIL GROUP LAND USE DESCRIPTION A B C D Cultivated land(l): winter condition 86 91 94 95 Mountain open areas: Iow growing brush and grasslands 74 82 89 92 , , Meadow or pasture: 65 78 85 89 Wood or forest land: undist0rbed 42 64 76 . 81 Wood or forest land: young second growth or brush 55 72 81 86 Orchard: with cover crop 81 88 92 94 Open spaces, lawns, perks, golf courses, cemeteries, landscaping. good condition: grass cover on 75% or more of the area 68 80 86 90 fair condition: grass cover on 50% to 75% of the area 77 85 90 92 Gravel roads and parking lots 76 85 89 91 Dirt roads and parking lots 72 82 87 89 Impervious surfaces, pavement, roofsl etc. ..9~..,~..-98~.~..~Z:'98~ ..~"'98~.":,' Open water bodies: lakes, wetlands, ponds, etc. 100 100 100 100 Single Family Residential (2) Dwelling Unit/Gross Acre % Impervious (3) 1.0 DU/GA 15 Separate curve number 1.5 DU/GA 20 shall be selected 2.0 DU/GA 25 for pervious and 2.5 DU/GA 30 impervious portion 3.0 DU/GA 34 of the site or basin 3.5 DU/GA 38 4.0 DU/GA 42 5.0 DU/GA 48 5.5 DU/GA 50 6.0 DU/GA 52 6.5 DU/GA 54 7.0 DU/GA 58 Planned unit deYelopments, % impervious JEFFEBSON COU ~ITY condominiums, apartments, must be computedt OEPT. OF COMMUNITY D VELOPMENT commercial business and industrial areas. (1) For a more detailed description of agricultural land use curve numbers refer to National Engineering Handbook, Section 4, Hydrology, Chapter 9, August 1972. (2) Assumes roof and driveway runoff is directed into street/storm system. (3) The remaining pervious areas (lawn) are considered to be in good condition for these curve numbers. 1/90 124 123 122 FRIDAY HARBOR PORT STA 4,~ 15 I, 124 123 dUN - £L;b i DEPT. OF COMMU COUNTY ~ DEVELOPMEN,~J: IDAY HARBOR \ 17.5 122 PO RT STAN ,. 1 7,,. 70 55 45 . .. · TACOMA 30' / / 124 123 122 JEFFERSON COUN' DEPT. OF COMMUNITY DEVE FRIDAY HARBOR ! 45 _.4 L_.__ PO RT STANI 9[ 1 1 9~ 65 ~0 \ i IO0-YEAR 60 55 55 65 ' ' VOL 24-~tOUR PRECIPITATION MacLEARNSBERRY, INC. 159 Wyatt Way NE Bainbridge Island, WA (206) 842-5514 98110 TIME OF CONCENTRATION WORKSHEET BASIN # P2= A (exist) 1.5 SHEETFLOW TYPE Woods ? ? LENGTH 300 ? ? PROJECT: JOB NO.: DATE: Teal Lake Village 95034 ol/1'o/96 Div. II JEFFERSON COUNTY DEPT. OF COMMUNITY DEVELOPMENT~ SLOPE N Tc 0.0567 0.8 86.68 ? ? 0.00 ? ? 0.oo SHALLOW FLOW: LENGTH SLOPE Woods 150 0.1233 ? ? ? . · · K V Tc 3 1.05 2.37 ? 0.00 0.0O ? 0.00 0.00 ? 0.00 0.00 ? 0.00 0.00 ? 0.00 0.00 · INTERMIT: LENGTH SLOPE K V Tc Road Ditch 1400 0.0768 20 5.54 4.21 ? ? ? ? 0.00 0.00 ? ? ? ? 0.00 0.00 ? ? ? ? 0.00 0.00 MacLEARNSBERRY, INC. 15'9 Wyatt Way NE Bainbridge Island, WA (206) 842-5514 98110 TOTAL Tc= 93.2 7 PROJECT: Teal Lake Village Div. II JOB NO.: 95034 DATE: 01/10/96 TIME OF CONCENTRATION WORKSHEET BAS IN # P2= A(exist) 1.5 SHEETFLOW TYPE Woods · SHALLOW Woods FLOW: LENGTH SLOPE 300 0.0567 · N Tc 0.8 86.68 ? 0.00 ? 0.00 LENGTH SLOPE 150 0.1233 . . 563 ~ Tc 1.05 2.37 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 MacLEARNSBERRY, INC. 159 Wyatt Way NE Bainbridge Island, WA (206) 842-5514 98110 TIME OF CONCENTRATION WORKSHEET BASIN A(dev) 1.5 SHEETFLOW TYPE Lawn · · LENGTH 50 ? , PROJECT: JOB NO.: DATE: SLOPE 0.01 ? ? Teal Lake Village Div. 95034 o /lo/96 N 0 ? ? SHALLOW FLOW: LENGTH SLOPE K Lawn 50 0.01 ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? II jEFFERSON COUN'T'Y DEPT. OF COM,."',4UNI~' DEVELOPMENT INTERMIT: LENGTH SLOPE Road Ditch 800 0.0375 Road Ditch 800 0.0163 Road Ditch 800 0.169 K ? .15 11 17 17 17 V 1.10 0.00 0.00 0.00 0.00 0.00 V 3.29 2.17 6.99 0.00 TOTAL Tc= Tc 10.85 Tc 0.76 Tc 4.05 6.14 23.70 MacLEARNSBERRY, INC. 159 Wyatt Way NE Bainbridge Island, WA (206) 842-'5514 98110 PROJECT: JOB NO.: DATE: Teal Lake Village Div. 95034 Ol/lO/96 II TIME OF CONCENTRATION WORKSHEET BASIN # P2= A (dev) 1.5 SHEETFLOW TYPE Lawn · LENGTH 5O 9 · · SHALLOW FLOW- LENGTH Lawn 50 SLOPE N 0.01 0.15 · SLOPE K 0.01 11 · , 563,,,..,,1.83 1.10 0 .00 0.00 0 .00 Tc 10.85 Tc 0.76 "~,1 1 ' ~ ..¢':.:"::~' .('~'~' :'":';:~" '.].C ~. ,~)~"-',"~ O['.]':;'~,'~l'Jl'l]()N ~'~'~.~.~~'~~ ~ x. ~-~... '" ':- ' '~..: YEAR 24-..HOUR STORM .*-~** ] . 50" TOTAl.. PREC I P . *~**~**** -.-N'I'ER: A( PEI!'..' )~ Cl'.l( r)'-..RU ), 15.61,81,0,98,93.3 DATA PRINT-OUT: A( IPlPERU ), CN( ] M~L-.RU ), TC FOR BASIN NO 1 A~:A (ACRES) PERVIOUS A CN 15.6 15.6 81.0 IMPERVIOUS TC (MINUTES) A CN .0 98.0 93.3 PEAK-Q(C, FS) T-PEAK(HRS) ~ d./(, 12.50 17666 ENTER [d:][path]Eilename[.ex%] FOR STO:{AGE OF CGMPU~.'~{D ~YOROGRAPH: b: a2ex .hyd SPECIFY: C - CON?INUE, N - NEWSTO!.:N, P - PRINT, S - STOP L00,24,3.2 k,z***~************* S.C.S. 'rIPE-iA DES'CRIBO'{'[ON ******************** **=~***** 100-YEAR 24-}]oUR STORM **** 3.20" TOTAL PRECIP. ******~*, ENTER' A(PERV), CN(PERV), A(IMPERV), 15.61,81,0,98,93,39 CN ( ] ~4PERV ), TC FOR BASIN NO. 1 ~iA'PA PRINT-OUT: AREA(ACRES) PERVIOUS IMPi~:RV IOUS A CN A CN 15.6 15.6 81.0 .0 98.0 TC<MINUTES) 93.3 PEAK Q(C::'S) · T -PE.~.K(HRS) VOL (CU-FT) 2.05 8.50 82189 · r'~.ER I:,i'][path]filename[.-;<t] FOR STORAGE OF COMPUTED HYDROGRAPH: b: al00ex, hyd 563 :,., 184 2,24,1.5 · ********************** ****x**** 2-YEAR S.C.S. TYP;:: Ia 0ISTRIB ***************** 24-HOIJR ST~.::I~ **** 1.50" TO'l'~i. vRECI?. ********* · A( F. aV), ,.... 25,84,3.36,9::~, 9..3.7 ~m A(IMPE]{V), CN(IMPERV), TC FOR BASIN NO. 1 DATA PRINT-OUT: AREA ( AC~ ,,: ;'4 ) PERVIOUS A CN 15.6 12.3 84.0 IMPERVIOUS TC(MINUTES ) A CN 3.4 98.0 2~.7 : ' :': A K..-.Q (_CF_.S_) .... T- PEAK (, '{~.;,S) 1.47 7.83 33877 ENTER Id: ] [ 9ath ~ !' i !,:name[ .ext] FOR STORAGE OF COt.tL:UT":~:. :~.'¢OROGRAPH: b' a2dev.hyd SPECIFY: C - CONTINUE: N - NEWSTORM, P - PRINT, S - STOP 100,24,3.2 ******************** S.C.S. TYPE-].A DI.{'r;{[SUTION ***'****~'~.~********* ********* 100..YEAR 24-HOUR STORM **** 3.20" TO'[',~,. PRECIP. ********* : ENTER: A(P}.:RV), CN(PERV), A(~v.:~ERV), CN(IMPERV), TC f'O}-, BASIN NO. i2,25 84,3 . 26,98,23 . 7 b,.£A PRINT-Ob"i · AR);:;, ( A CR.F:-: ) PEI{'; ~ OUS IMPERVIOUS TC (MINUTES) A CN A CN 15.5 12.3 84.0 3.3 98.0 23.7 PEAK-Q(CFS ) T-PEAK(HRS) VO~, (CU-FT) 5 . 81 7 . 83 109295 ENTER [d'][.pat]:]~'i.[ename(.exk] ::'()R STORAGe{ OF '.':4~?UTED HYDROGRAPH: b' a].00dev .'~,~ ~. SPE~"~;;'Y: C - CONTIN!~t<, N -NEWSTORM, P - PRINT, S - S'1'(,~ JEFF~R.$GN GOUNTY DEPT. OF COMMUI'ilTY r:-~-, p ~ 563 1 VOL"~'-,~' · ENTER' POND SIDE SLOPE (HORIZ. COMPONENT) 3 ENTER: EFFECTIVE S'J'ORAG?. DEPTH(ft) BEFORE OVERFLOW 3 .. ENTER [d:][path]f.~]ename[.ext] b:al00dev.hyd PRIMARY DESIGN INFLOW PEAK = OF PR 1MARY 5.81 CFS DES'[GN INFLOW HYDROGRAPH: 'EN.';~.R ?~{.'MARY DESIGN RELEASE RATE(cfs): 2.05 ENTER NUMB;<~ OF INFLOW HYDROGRAPHS TO BE TESTED F~;~.' PERFORMANCE 1 ENTER [cl:][path]f%lename[.ext] OF HYDROGRAPH 1: b:a2dev.hyd ENTER TARGET RE.~,E^SE RATE(cfs): 0.16 ENTER' NUMBER OF ORIFICES, RISER-HEAD(ft), 2,3,18 R I SF.R- DIAMETER ( i.~ ~ RISER OVERFLOW DEPTH FOR PRIMARY PEAK INFLOW = .54 FT ITERATION DISPLAY: Y - YES, N - NO ( 5 MA.'.( '[MUM ): SPEC/FY' R - REVIEW/REV.[S~< INPUT, C - CONTINUE c INITIAL STORAGE VALUE FOR ITERATION BOTTOM ORIFICE: a ENTER Q-MAX(cf s) BOTTOM ORIFICE: ENT~:k Q-MAX(cfs) DIA.= 1.96 INCHES TOP OR[FI. CE: KNT:~.R HEIGHT(ft) 2.5 DIA.= ').:]8 INCHES PURPOSES: 346.] 4 CU-FT JEFFERSON COUNTY DEPT. OF COMMUNI'i~ DEVELOPMENT PERFORMANCE: DESCGN HYO: TEST HYD 1: INFLO%.~ TARGET-OUTFLOW ACTUAL-OUTFLOW 5.81 ~.05 2.04 1.47 .16 .16 PK- STAGE STORAGE 3.00 3 [378 2.48 25120 :~SECIgY' d P=RFOR/4ANCF. · 'S[(:N HY0' q'EST ~IY]) 1' D - 0OCUMENT, R - REVISE, A - ADJUST ORIF, INFLOW TARGET-OU'.:'FLOW ACTUAL-OUTFI.~w 5.8i 2.05 ~.04 1.47 .16 .16 E - ENLARGE,. S - STOP PK-STAGE 3.00 2.48 STORAGE 31378 25120 ','o,. 563 R I S~:R-I1EAD 3-00 F'I,' POND-BOTTOM-AREA "8591'~ 8 1.3886.9 SQ FICE RESTRICTOR: BOTTOM ORI }.' [¢,~: TOP ORIFICE: STOR-DEPTH 3 .'00 'FT ' ROUTING OA'lTA: STAGE ( FT ) D I SCHA ~,'. ,. ( CFS ) .00 .00 .3O .06 .60 .08 · 90 .10 1.20 .11 1.50 .13 1.80 .~4 2.10 .15 2.40 .L6 2.50 .16 2.70 1..35 3.00 2.05 3.10 2.69 3.20 3.71 '~. 30 4.95 3.40 6.40 3.50 8.00 D I A ( :[ NCHES ) HT ( FEET ) Q-MAX ( CFS ) 1.96 .00 .180 9.88 2.50 1.870 STORAGE ( CU-FT ) .0 2631.0 5370.0 8219.2 11180.3 14255.5 17446.5 20755.3 24184.0 25353.8 27734.4 31408.4 32660.9 33927.4 35).08.1 36502.9 3781]..9 PERM-AREA ( SQ-FT ) .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 AVERAGE VERTICAL PK;<MEA~:.:,.TTY: · 0 MINUTES/INCH FILE, N - NEWJOB, P - ?1-'~,.~'1.' [F/OF, R - REVISE, EN'I'ER [d:][path]fJ]ename[.ext] FOR STORAGE OF ROUTIN,,' .. :.TA' S~ECIFY: F - FILE, N - NEWJOB, P - PRINT IF/OF, R - REVISE, STORAOE-WO~,u~. S - STOP S - STOP · SON COUN,TY DEPT. OF COMMUNI'FY DEVELOPMENT RESERVOIR ROUTING INFLOW/OUTFLOW ROUTINE ~,IFY [d'][path]fllename[.ext] OF ROUTING DATA A.,, 100. DET DISPLAY ROUI~ING DATA {Y or N)? ROUTING DATA: STAGE(FT) DISCHARGE(CFS) STORAGE(CU-FT) .00 .00 .0 .30 .06 2631.0 .60 .08 5370.0 .90 .10 8219.2 1.20 .11 11180.3 1.50 .13 14255.5 1,80 .14 17446,5 2.10 .15 20755,3 2.40 .16 24184.0 2.50 ,16 25353.8 2.70 1.35 27734.4 3.00 2.05 31408.4 3.10 2.69 32660,9 3.20 3.71 33927.4 3.30 4.95 35208.1 3.40 6.40 36502,9 3.50 8.00 37811.9 3.60 9.56 39135.3 PERM-AREA(SQ-FT) .0 .0 .0 .0 .0 .0 .0 ,0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 AVERAGE PERM-RATE: .0 MINUTES/INCH ENTER [d:][path]filename[.ext] OF COMPUTED HYDROGRAPH- A: AE)SEV. HYD INFLOW/OUTFLOW ANALYSIS: PEAK-INFLOW(CFS) 1.47 PEAK-OUTFLOW(CFS) .16 OUTFLOW-VOL (CU-FT) 31847 INITIAL-STAGE( FT ) TIME-OF-PEAK(HRS) .00 24.33 PEAK-STAGE-EL EV { FT ) 2.48 PEAK STORAGE: 25120 CU-FT ENTER [d'][path]filename[.ext] FOR STORAGE OF COMPUTED HYDROGRAPH: ^C C:\HYO> JEFFERSON COUNTY DEP"f,,'. OF CO~',,~ML!Ni'FY DEVELOPMENT ,,'o,. 563 .,,.,18§ ""$E:,'v~)IR ROUTING INI"I,OW/OUTFLOW ROUTINE b:al00.det SPLAY ROUTING DATA (? or N)? ROUTING DATA R~DUTI NG DATA: STAr.:E (FT) DISCHARGE (CFS) STOh: .::('.:E ( ,,:t- FT) .00 .00 .0 .30 .06 2631.0 .60 .08 5370.0 .90 .10 8219.2 1.20 .11 i I. L80.3 1.50 .13 14255.5 1.80 .14 17446.5 2.10 .15 20755.3 2.40 . 1.6 24184.0 2.50 .16 25:3:,3.8 2.70 l. 35 27734.4 3.00 2.05 3]408.4 3.10 2.69 32660.9 3.20 3.71 33927.4 3.30 4.95 '~5).08.1 3.40 6.40 36502.9 3 . 50 8. O0 378 L1 . 9 3 . 60 9.56 39135 . 3 PERM-AREA(SQ-FT) .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 A:;' -i : ,.' :%G ~2 PERM-~A'$E: .0 MINUTES/INCH ENTER [d:][path]f~ lenam~.[.ex%.] O:' COMT.'UTED HYDROGRAPH: ,, al ..-0dev. ',.~ ~'~LOW/OUTFLOW ANA[,Y': ~. .",: PEAK- l N ;-" ' ' CF~: ) 5.81 PEAK-OUTFLOW ((:.'$) 2.04 OUTFLOW - V' :.!. ,[ CU- PT ) 107043 INITIAl.-S'!';. ~E(FT) TIME-OF-PEAl< (.~,:S) .00 9.50 PEAK-STAGE-ELEV ( FT ) 3. O0 PEAK STORAGE: 313'7(~ CU-F' ' ' ~ L t,~,aame[ . ~,xt ] ',:'{)R STORAGE OF COP, ::, ,'r:,:I) HYDROGRAPH: ENTER Id: ~acLEARNSBERRY, INC. 159 Wyatt Way NE Bainbridge Island, WA (206) 842-5514 98110 PROJECT. JOB NO. DATE Teal Lake Village Div. 95034 Ol/lO/96 II TIME OF CONCENTRATION WORKSHEET BAS IN # P2= B (exist) 1.5 SHEETFLOW TYPE Woods ? ? LENGTH 300 ? ? SLOPE 0.1389 ? ? N 0.8 ? ? SHALLOW FLOW: LENGTH SLOPE K V Woods 250 0.08 11 3.11 ? ? ? ? 0.00 ? ? ? ? 0.00 ? ? ? ? 0.00 ? ? ? ? 0.00 ? ? ? ? 0.00 INTERMIT: LENGTH SLOPE K V ? ? ? ? 0.00 ? ? ? ? 0.00 ? ? ? ? 0.00 ? ? ? ? 0.00 TOTAL Tc= Tc 60.57 Tc 1.34 61.91 jUN 8 i:ff.!'i i~ jEFFERSON COUNTY DEPT. OF COMMUNITY DEVELOPMENT .acLEARNSBE~Y, INC. 159 Wya~ Way NE Bainbridge Island, WA (206) 842-5514 98110 PROJECT: JOB NO.: DATE: Teal Lake Village Div. 95034 ol/ o/96 II TIME OF CONCENTRATION WORKSHEET BAS IN # P2= B (dev) 1.5 SHEETFLOW TYPE Lawn ? ? LENGTH 180 ? ? SHALLOW FLOW: LENGTH ? ? · · ? ? · · ? ? INTERMIT: LENGTH Road Ditch 250 . · · · . · SLOPE 0.1389 ? ? N 0.15 ? ? SLOPE K V ? ? 0..00 ? ? 0.00 ? ? 0.00 ? ? 0.00 ? ? 0.00 ? ? 0.00 SLOPE K V 0.08 17 4.81 ? ? 0.00 ? ? 0.00 ? ? 0.00 Tc 10.55 Tc Tc 0.87 TOTAL Tc= 11.42 JEFFERSON COUNTY DEPT. OF COMMUNITY DEVELOPMENT ,,,o,. 563,,,,.,191 ~, .S. TYPE-iA RAINFALL DISTRIBUTION ENTER: FREQ(YEA~{), OURATIC~(HOI'fR), ~RECIP(~NCHES) 2,24,1.5 .. mm m mm -- m mmm mm mmmmmmmmmmmmmmmmmm ************************* S.C. S . TYP',' - I.A.. DISTRIBUTION ******************..+., :['******** 2-YEAR 24-HOUR STORM **** 1.50" TOTAL PRECIP. ********* ENT;'R'.~ A(PERV), CN(PERV), 1.36,81,0,9:3,6l. 9~ A(IMPERV), CN (I PERV), TC FOR BASIN NO. 1 DATA PRINT-OUT: AREA.( ACRES ) PE]~V I OUS · .. . cN 4 1.4 81.0 · ., PEAK-Q(CFS) '[' · PS:AK(HRS ) ~ o. 0,~- /i2.50 / .,L~NTER Id: ][~ath]-,.'~.l..:name[.ext] b: b2"ex, hyd · IMPERVIOUS TC (MINU']'E:. ]. A CN .0 98.0 61.9 Vo r, ( CU- PT ) 1544 ~?OR STORAGE OF COMPUTED SPECIFY' C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP JEFFERSON COUNTY DEPT. OF COMMUNITY DEVELOPMENT HYDR' ,;:~A:?H: S.C.S. EN'~'~;R: 2,10,2 TYPE-lA RAINFALL DISTRIBUTION FREQ(YEAR), DURATION(HOUR), ,?REC~:?{ rNCHES) ************************ S.C.S. '~:YP~-IA DISTRIBUTION ********* 2-YEAR 10-HOUR STORM **** 2.00" ENTER' A(PERV), CN(PERV), A(IMI'ERV), CN(IMPERV), TC FOR ].. 36,:~i,0,98,2 DA'VA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERV ] (~US TC (MINUTES) A CN A CN 1.4 1.4 86.5 .0 98.7 2.0 PEAK-Q(CFS) T-BEAK(HRS) VOL(CU-FT) · 63 3.08 4136 ENTER ~.,:['][,.:al:h]~.iXename[.e:¢t] ;."';R STORAGE OF COMPUTED 'b' bl0ex, hyd B;'-- .41 N NO. 1 HYDROGRAPH: .S.C.S. TYPE-lA RAINFAi.}. DT~T;{IBUTION 100,24,3.9 m m -- . mmmm mmmmmmmmmmmmmmmm mmmmmmm m mmmm mmmmmmmmmmmm~ ~****** 100-Y~:A~ 24-]]OUR STO~ **** ~ 20" TOTAL PREOIP. ********* ENTER: A(PERV), CN(PE~V), ~.36,81,0,98,61.91 · I I ! I I I . t IIIIIIIiI Iill~IIi i I Ii IlII! I IIiI Ifil ( MPERV), CN(1MP RV), ?C FOR ASIN NO. DATA ~':~[NT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS A CN A CN 1.4 1.4 81.0 .0 98.0 P EAK-Q ( C~J )' '['- .~EAK ( HRS ) i .22 8.00 ~iNT:,:R [d:][pat"h]f~1ename[.ext] · . /b: b].00ex.h~d CU- T) 7181 6]..9 FOR STORAG;{ OF COMPUTED HYDROGRAPH: SPECIFY: C - CONTINUE, N - NEWSTORM, P - PRINT, S - STOP 1 S.C.S. TYPE-lA RAINFALL DISTRIBUTION .~NTER' ['~REQ(YEAR), DURATION([{OUR), 2,24,1.5 / I I I I I I i IiImIIlImmIII .... .. I I I ! i -- .. ! ! I i I i I i ...... IimI II IIllI I I i liimIImi I Ii ********'***'****** S C.S. TY:~:~. lA DISTRIBUTION ****~** -:~;~******** ********* 2-YEAR 24-HOUR STORM **** 1.50" TOTAL PR]::-'.:~P. ********* ENTER: A(PERV), CN(PERV), '..03,86,0.33988,11.42 A(IMPERV), CN(IMPERV), TC FOR BA.'-;~N NC.. 1 DATA-PRINT-OUT: · . AREA(ACRES) PERVIOUS A CN 1.4 1.0 86.0 /:-'.PERVIOUS TC(MINUTES) A CN .3 98.0 1]..4 PEAK-Q(CFS) T-PEAK(HRS) .20 7.83 3369 i ~"::~,R [~]: ][path]fL[ename[.ext] b2dev.hyd FOR :~'['ORA,;:,; OF COMP(ITE0 563 1.93 . ~'~ :~ROGRAPH: 1 ENTER' POND SIDE SLOPE (HORIZ. COMPONENT) 3 E" 'R' EFFECTIVE STORAGE DEPTH(ft) BEFORE OVERFLOW 3 ENTER [d.][path]filename[.ext.] OF PRIMARY DESIGN INFLOW HY~)ROGRAPH: A- B IO00EV. HYD PRIMARY DESIGN INFLOW PEAK = .69 CFS ENTER PRIMARY DESIGN RELEASE RATE(cfs)' 0.22 ENTER NUMBER OF INFLOW HYDROGRAPHS TO BE TESTED FOR PERFORMANCE (5 MAXIMUM)' 1 ENTER [d'][path]filename[.ext] OF HYDROGRAPH l- A: B2DEV. HYD ENTER TARGET RELEASE RATE{cfs}' 0.015 ENTER' NUMBER OF ORIFICES, RISER-HEAD(ft), RISER-DIAMETER(in) 2,3,12 RISER OVERFLOW DEPTH FOR PRIMARY PEAK INFLOW : .17 F'r SPECIFY ITERATION DISPLAY' Y - YES, N - NO N Sr.CIFY' R - REVIEW/REVISE INPUT, C - CONTINUE C INITIAL STORAGE VALUE FOR ITERATION PURPOSES: BOTTOM ORIFICE' ENTER Q-MAX(cfs) A 3255 CU-FT JEFFERSON COUNTY DEPT. OF COMMUNITY DEVELOPMENT BOTTOM ORIFICE: ENTER Q-MAX(cfs) 0,025 DIA.: .73 INCHES TOP ORIFICE: ENTER HEIGHT(ft) 2.47 0IA.= 3.1~ INCHES PERFORMANCE' INFLOW TARGET-OUTFLOW ACTUAL-OUTFLOW PK-STAGE STORAGE DESIGN HYD' ,69 ,22 ,22 3,00 2838 TEST HYD 1' ,20 ,01 ,02 2,47 2080 SPECIFY' O - DOCUMENT, R - REVISE, A - ADJUST ORIF, E - ENLARGE, S - STOP 0 PERFORMANCE' INFLOW TARGET-OUTFLOW ACTUAL-OUTFLOW PK-STAGE ..~TORAGE OES[GN HYD' .6g .22 .22 3.00 2838 'T HYD 1' .20 .01 .02 2.~7 2080 563 s.c'.S. ,.:N'L'E~{ · 10,24,2 TYPE-iA RAINF^LL DISTRIBUTIO~I FR:,:Q(YF..%~), DURATKON(HOUI{), ~:RECIP([N,:HES) ********************* S. .S. TY~,: ~A DISTRIBUTION *~ ~**************** '****** 10-YEAR 24-HOUR STORM **** 2.00" TOTA,. PRECIP. ********* ENTER: A(PERV), CN(PERV), [ . 03,86,0.33,98,11.42 A(IMPERV}, CN(IMPERV), TC FO~ ~%ASIN NO. 1 DATA PRINT-OUT: AREA ( ACRES ) 1.4 PERVIOUS IMPERVIOUS A CN A CN 1.0 86.0 .3 98.0 'rC( INUTES) 11.4 PEAK-Q(CFS) '1.' · :.':':&K (HRS) VOl, (C.U-FT) .33 7.83 5294 [,~R. [d.][.oath]f~.ie~ame[.ext] FOR STO'RAGE "b: bl0dev.hyd SPECIFY: C - CONTINUE, N - NEWSTORM P - PRINT S - STOP S.C.S. TYPE-lA RAINFALL DISTRIBUTION ENTER' FREQ(Y:<AR), DURAT[(}N(J{OUR), PRECIP(INCHES) 100,24,3.2 ;**'~****~******* S.C.S. TYP:.:.I.A OISTRIBUTION ******************** ********* 100-YEAR 24-HOUR STORM **** 3.20" TOTAL PRECIP. ***~***** E~.'.;'ER: A (PERV), CN (PERV), ~.03,86,0.33,98,[] .42 A(IM}:ERV), CN(IMPERV), TC FOR BASIN NO. 1 DATA.P)<]NT-OUT: AREA(ACRES) PERVIOUS A CN 1.4 1.0 86.0 PEAK-Q(~,o.S) T-PEAK([~RS) .69 7.83 IHPERV] OUS A CN .3 98.0 VOL(CU-FT) 10406 TC(M] NUTES) ].1.4 ~iNTER Id: ]l]pathl~i!ename[.ext] FOR STO~.AGE ()F COMPUTED HYDROGRAPH: -'~ 1,].00dev. hyd ' SP}<CIFY: C - CONTINUE, N NEWSTORM, P - P;{rNT, S - STOP ~SERTHEAD 3.00 POND-8OTTON-AREA 439.1 SQ-FT TOP-AREACel 'F.B. ) 2081. g $g-FT STOR-OEPTH 3.00 FT STORAGE-VOLUME 2838 CU-FT OOUBLE ORIFICE RESTRICTOR: BOTTON ORIFICE: i TOP ORIFICE: DIA(INCHES) HT(FEET) Q'-NAXCCFS) .73 .00 .025 3.14 2.47 . 195 ROUTING DATA: STAGE(FT) DISCHARGE(CFS) 'STORAGE(CU-FT) PERM-AREA (SQ-FT) .00 .00 .0 .0 · 30 .01 144.0 .0 · 60 .01 314.0 .0 : · 90 .01 511.9 .0 1.20 .02 739.6 .0 1.50 .02 999.1 .0 1.80 .02 1292.3 .0 2,10 ,02 1621,2 ,0 2,40 · 02 1987,7 · 0 2.47 , 02 2078,9 · 0 2.70 . 15 2393.8 · 0 3.00 · 22 2841.3 , 0 3.10 .55 3000.1 .0 3.20 1.13 3163.7 .0 3.30 1.87 3332.3 .0 3.40 2.68 3506.0 .0 3.50 2.97 3684.7 .0 AVERAGE VERTICAL PERMEABILITY: .0 MINUTES/INCH $~-C!FY: F - FILE, N - NEWJ08, P - PRINT IF/OF, R - REVISE, S - STOP ENTER [d:][path]filename[.ext] FOR STORAGE OF ROUTING DATA: A:BlOO.DET SPECIFY: F - FILE, N - NEWJOB, P - PRINT IF/OF, R - REVISE, S - STOP 563 ENTER' TANK DIAMETER (ft), EFFECTIVE STORAGE DEPTH (ft) 4,4 E .R [d'][path]fllename[.ext] OF PRIMARY DESIGN INFLOW HYDROGRAPH: A' B IOODEV. HYD PRIMARY DESIGN INFLOW PEAK = .69 CFS ENTER PRIMARY DESIGN RELEASE RATE{cfs)' 0.22 ENTER NUMBER OF INFLOW HYDROGRAPH8 TO BE TESTED FOR PERFORMANCE (5 MAXIMUM)' 1 ENTER [d-][path]filename[.ext] OF HYDROGRAPH 1' .A: @2DEV. HYD ENTER TARGET RELEASE RATE(cfs). . 0.015 ENTER' NUMBEi~ OF ORIFICES, RISER-HEAD(ft), RISER-DIAMETER(in) 2,4,12 RISER OVERFLOW DEPTH FOR PRIMARY PEAK INFLOW = .17 FT SPECIFY ITERATION DISPLAY' Y - YES, N - NO 8OTTOM ORIFICE: ENTER Q-MAX(cfs) O.. .= .74 INCHES TOP ORIFICE: ENTER HEIGHT(ft) 2.68 DIA.= 2.47 INCHES JEFFERSON COUN'W DEPT. OF C,O!'.~,~?UN!TY~ ~ ~.,,,_~,n~v.r- F~PME~',J,T PERFORMANCE' INFLOW TARGET-OUTFLOW ACTUAL-OUTFLOW PK-STAGE STORAGE OESIGN HYD' .69 .22 .22 3.99 2829 TEST HYD 1' .20 .01 .02 2.66 1990 SPECIFY' D - DOCUMENT, R - REVISE, A - ADJUST ORIF, E - ENLARGE, S - STOP D PERFORMANCE: INFLOW TARGET-OUTFLOW ACTUAL-OUTFLOW PK-STAGE STORAGE DESIGN HYD' .69 .22 .22 3.99 2829 TEST HYD 1' .20 .01 .02 2.66 1990 5fi3 : . 197 [SER-~EAD · TANK-DIAN STOR-DEPTN TANK-LENGTH 4.00 FT 4.00 FT 4.00 FT 225,4 FT 30UBLE ORIFICE RESTRICTOR' OIA(INCHES) FIT(FEET) BOTTOH ORIFICE: .74 .00 TOP ORIFICE: 2.47 2.68 qOUTING DATA- STORAGE-VOLUME 2829 CU-FT Q-MAX(CFS) .030 .190 STAGE(F'r) DISCHARGE(CFS) STORAGE(CU-FT) PERH-AREA (S~-FT) .00 .00 .0 .0 .40 .01 147.4 .0 · 80 .01 403.3 .0 1.20 .02 714.7 .0 1.80 .02 1058.1 .0 2.00 .02 1416.3 .0 2.40 . 02 1774.5 . 0 2.68 .02 2017.4 .0 2.80 .08 2117.9 .0 3.20 . 15 2429.3 .0 3.80 . 19 2885.2 .0 4. O0 . 22 2832.5 .0 4.10 .54 2832.6 .0 4.20 1.11 2832.6 .0 4.30 1.84 2832.6 .0 4.40 2.84 2832.6 .0 4.50 2.93 2832.6 .0 AVERAGE VERTICAL PERMEABILITY- MINUTES/INCH 27 ~FY- F - FILE, N - NEW JOB, P - PRINT IF/OF R - REVISE, S STOP ENTER [d'][path]filename[.ext] FOR STORAGE OF ROUTING DATA' A'S1OO,TNK SPECIFY- F - FILE, N - NEWJO8, P - PRINT IF/OF, R - REVISE, S - STOP JEFFERSON COUNTY DEPT. OF COMMUNITY DEVELOPMENT APPEN'DIX C I. Erosion and Sediment Control , 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. Stabilization and Sediment Trapping Delineate'Clearing and Easement Limits Protection of Adjacent Properties Timing and Stabilization of Sedimentation measures Cut and Fill Slopes Controlling Off-site Erosion JEFFERSON COUNTY DEPT. OF COMM JNITY DEVE~.O, .,,tNT Stabilization of Temporary Conveyance Channels and Outlets Storm Drain Inlet Protection Underground Utility Construction Construction Access Routes Removal of Temporary BMPs De-watering Construction Sites Control of Pollutants Other than Sediment on Construction Sites Maintenance Financial Liability II. Preservation of Natural Drainage Systems o Maintain natural drainage patterns to maximum extent practicable. , Discharges from site should occur at natural location to maximum extent practicable. III. Source Control of Pollution IV. . Apply approved source control BMPs to maximum extent practicable. Basin Plan (see Large Parcel Minimum Requirement #9) may be used to develop source control BMPs tailored for a specific basin. Runoff Treatment BMPs . . Provide treatment of stormwater. Size treatment BMPs for water quality design storm (6-month, 24-hour return period). Use infiltration to fullest extent practicable. Use treatment BMPs as described in an approval manual. BMPs shall not be built within natural vegetated buffer, except for necessary conveyance systems as approved. Basin Plan (see Large Parcel Minimum Requirement #9) may be used to develop stormwater treatment requirements tailed for a specific basin. V, Streambank Erosion Control . o . . . Limit peak rate of runoff from developed site to 50 percent of existing condition 2-year, 24-hour design storm. Maintain existing condition peak runoff rates from developed sit for the 10-, and 100-year, ~24-hour design storms. Use infiltration to fullest extent practicable. Stormwater must be treated before direct discharge into groundwater. Use streambank erosion control BMPs as 'described in an approved manual. BMPs shall not be built within natural vegetated buffers, except for necessary conveyance systems as approved. Basin Plan ( see Large Parcel Minimum Requirement//9) may be used to develop streambank erosion control requirements tailored for a specific basin. Wetlands VII. , o . o . Control and treat stormwater discharges to wetlands to meet State Water Quality Standards and Ground Water Quality Standards. Discharge to wetland only after evaluation alternative discharge locations' Discharges shall maintain hydroperiod and flows of existing conditions to extent necessary to protect characteristic uses. Constructed wetlands used for treatment must be constructed in non-wetland area and managed for stormwater treatment. Discharges are regulated. , No stormwater discharge to create wetlands used for mitigation. Stormwater treatment BMPs shall not be built within natural vegetated buffer, except for necessary conveyance systems as approved. Basin Plan (see Large Parcel Minimum Requirement//9) may be used to develop wetlands requirements tailored for a specific basin. Water Quality Sensitive Areas . 2~ . More stringent controls may be required by the local government for protection of water quality sensitive areas. Stormwater treatment BMPs shall not be built within natural vegetated buffers, except for necessary conveyance systems as approved. Basin Plan (see Large Parcel Minimum Requirement//9) may be used to develop water quality sensitive areas requirements tailored for a specific basin. VIII. Off-site Analysis and Mitigation . Conduct analysis of off-site water quality impacts resulting from the project and mitigate these impacts. Analysis shall extend a minimum, of one-fourth mile · · JEFFERSON COUNTY DEPT. OF COh!MUN!-R" DEVELOPMIENT IX. X. , downstream from project. Existing or potential impacts include, but are not limited to, excessive sedimentation, streambank erosion, discharges to groundwater, violations of water quality standards, spills and discharges of priority pollutants. .. Basin Planning . , Minimum Requirements #3-7 may be modified by adopted and implemented basin plans, provided the level of protection for sUrface or ground water achieved will equal or exceed that produced by implementation of the Minimum Requirements. Basin plans shall be developed in accordance with an approved manual, and may include retrofitting of BMPs for watershed wide pollutant reduction. Operation and Maintenance , Identify responsible party, and provide schedule of operation and maintenance activities for all proposed stormwater facilities and BMPs. " Financial Liability , Performance bonding or other appropriate financial instruments to ensure compliance with these standards. t'~og6 966~ 'g;~ ~380100 H¥O 0 ~,,, Zn nv z 0 n 0 n,- II 14.1 · I--Z 966[ 11¥130 (]NOd NOIIN313Q mo1 'IVnCIIAIQNI 830~NO~3~ 3dOd J'ISG';~'8 (90~) :HNOHd ~ 01186 V,4t 'QNY'I$I H(XIIWgNlYll HN AY& ,,LI,YA_AI 65'I 9JOUU~Id o gJOKOAJnS p~ o SJoOlXtguH [iAi[~ A V V Ot~ O'LU A II Z LiJ rn U) .d A V · o A Z z ~ 0