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HomeMy WebLinkAboutSWP271907s f'kr,lcaci Ms. G ISO, .S G s _7 7PI 935�� vS7 I T !fig a90 3 e+0 q1- ry I N T E R 0 F F I C E hi E M 0 DATE: Gf—%F�r FROM: (114 k SUBJECT: X l /< 1/)-(it�J � f �i - _ -_ � ��17- Lam(,' - COY). _3/6 I Le z r, it. t G--- (rc Y1 — ----- _ _— — — -- — { _ .... ::: : ::::::::: .::::::: ::::::::........... : :::::::. ........ ......... ....:::.. N »...._.»..__......._. _ _ »» ............._.._ _._....-..•.._............ _. . . . . . . . s . . . . . .•� / .�. .,. if ' l 4 . _ ; - i : : : ::.: : ..:...:...:...:...:...: .»._.....................:..� »......- ------ ......... r �t o�� /:.. � .....:'.. .... _...._ ....» . . i� . .. _...........__........... » ......................_ _ »_..._»___.»» i ... __. _._...._.. »._......».. __...... . . . . . . . . X �i - e s ::;:": :j - �'"ti:: 1�0� ►:.:S�f.� �,e� 1 ........-.'''.: `..:; :::::...: . ....:::t::::' :::':::.:. i� ': CC t� { . .�• �IVtN `s'k`I�'�� {(�'�(� r.,,�� .��. ,,1. 4 ......_��1Y1°tl»»...... ., + . . . qgO S �• [ . . • ' . . . : : Tr � t I ( . . . . . . : . . . . . . OEM _ { F _ _ • ""_r' rT-� °% as � I [ 46 .. . . . . . : : . . . . . Cd . C•.: : r'a ran, N T R R n F F T r F uft n TO: I C)Y-V\ DLk-(Yl lDATE: 3 / J FROM: SUBJECT:���1(/ ✓' .. D/^m Lyi ��h 0 GENERAL CONDITION Property Area = 7. i Acres Total Basin Area = 11.9 Acres Land Cover = SPARES TREE C = .10 For S < 5% Developed C = 3.00 - 3.5 DU/GA = 0.40 ALLOWABLE FLOWS A = 11.9 Acres Overland Flow = 1060' @ S = 1.2% V = D .26 fps 170' @ S = 26% V = 1.30 fps TC = 10 + 1060/.26(60) = 170/1.30(60) �) = 10 + 67.95 + 2.18 = 80.13 min I = 0.44 in/h. � �;1 = 1.9) t _ . 524 cfs f. Since Q > .30 cfs, Two Orifices will be used. STORAGE REQUIREMENTS Site Area As = 7.8 Acres Overland Flow = 740' @ S = 1.2% V = .26 fps 170' @ S = 26% V = 1.3 fps T-. = 10 + 740/.26(60) = 170/1.3(60) = 10 + 47.44 + 2.18 = 59.62 min. I = 0.52 in/h. Ts",�, = G, 1/S- �, = CIA (.52)(7.8)(G'•/) 1,j .406 cfs Q,q= Q1CD A = :406/.40(7.8) = .13 cfs/Acre wPlGR 00. Oil VI _ 0, 1 S % �Jtp -> VS U S1,15 3 7 s-1j4 VF - U 17, 5� �-O, yob -1- UT J 70�'f3 T = -25 + ;70L �.9Q _ -25 j 70500 .13 W 29.9 ( ) = 109.675 min 0 0 V = 2820 T - 29.9 Q.T T+25 _ (2820)(109.675) - 29.9(.13)(109.675) 134.675ft = 2296.52 - 426.31 = 1870.21ft3 /Acre V_r = V C j A = 1870.2 (.40)(7.8) = 5835.55 W STORAGE FACIL S WILL CONSIST OF UNDERGROUND PIPES. � 2 x4� LF 0, P-r635 ft /LF = :549-7-� ft 38LF- _ . 6 f t I� S 1-0.72 LF - 54"II,_ ft TOTAL: ..................................= 58S4-►36 ft Available Storage > Required Storage of 583-5.-55 FT. ORIFICE SIZING Two —Orifice Structure is proposed to control outflow. Total Flow Q = ,524 c f s 0.�6 Flow Per Orifice = .262 c f s h, = 5 _*` For Orifice #1 , lrt h,, = 4�72 For Orifice #2 a, = V.p62 _ .262/.62 n _ .9,22 ft� it = 167 £-t" I, A2 419. GIs = 2.00/inches. fig" S-i_%g�� L1 /-. 2 3 135 4-24.ai 410 -2- ay = Q/ . 62 M 2gh,. .262/.62 V64.4(3,-7-2) r 024 ft" U. 0 d = V4.a = U4(.024)(' >> i1 .-w&t f t i7S� 2. D_ inches. DOWN STRL'AM ANALYSIS The drainage from the subject property drain as sheet flow northerly to ditches along the west side of Duvall Ave. Small area of off -site drainage contributes to the subject property. Eventually, the runoff from the Site flows into the May Creek approximately some 1000 feet downstream of the Site. There is no evidence of restrictive structure exit dowmstream of the Site. TEMPORARY EROSION SEDIMENTATION CONTROL FACILITIES Drainage Basin Area = 11.9 Acres 40% of the Site Area will be cleared ....... 3.12 Acres. Balance of Basin Area .......................8.78 Acres. Soil type and classification - Alderwood Gravelly Loam on a 1.2% slope with an average slope length of 1100 feet - type "C" . RUN-OFF VOLUME DETENTION The Ground Cover is Forest (ungrazed) 8.78 X 350 = 3073 ft�5 for undeveloped Portion 3.12 X 1250 = 3900 ft� for cleared Acres. Total Runoff Volume = 6973 ft:1 SEDIMENT VOLUME 2 X 40 XF 3.12 = 249.6 = 250 ft3 TOTAL POND VOLUME 7223 ft3 -3- STORM REPORT FOR RIDGVIEW ESTATES �MwA�ER u11LrN � ,Slow PREPARED BY: TOUMA ENGINEERS 201 SW 41ST STREET RENTON, WA. 98055 ^�«�O'Hee�b• nV,•• OF Wgsh;•, �L ts 4L GENERAL CONDITION Property Area 7.8 Acres Total Basin Area = 11.9 Acres Land Cover = SPARES TREE C = .10 For S < 5% Developed C - 3.00 - 3.5 DU/GA = 0.40 ALLOWABLE FLOWS A = 11.9 Acres Overland Flow = 1060' @ S = 1.2% , V = D .26 fps 170' @ S = 26% , V = 1.30 fps TC = 10 + 1060/.26(60) = 170/1.30(60) = 10 + 67.95 + 2.18 = 80.13 min I = 0.521n/hr Q =( C I A )5y +( C I A) 25yr = (.10)(.52)(4.1) + (.10)(.45)(7.8) = .56 cfs Since Q > .30 cfs, Two Orifices will be used. STORAGE REQUIREMENTS Site Area As = 7.8 Acres Overland Flow = 740' @ S = 1.2% V = .26 fps 170' @ S = 26% V = 1.3 fps T = 10 + 740/.26(60) = 170/1.3(60) = 10 + 47.44 + 2.18 = 59.62 min. I = 0.45 in/hr Q, = CIA = (.10)(.45)(7.8) = .351 cfs Q. = O/CD A = .351/.40(7.8) = .113 cfs/Acre -1- 1- 9-.-07 f t =-2429.5ft -/Acre T -25 + (185-;C-0-- 9.9Q = -25 f81500 29.9(.113) = 134.07 min Vy = 3420 T - 29.9 Qa T T+25 = (3420)(134.07)-29.9(.113)(134.07) 159.07ft = 2429.5ft /Acre Vr = VS Cj A = 2429.5 s(.40)(7.8) = 7580 ft STORAGE FACILITIES WILL CONSIST OF UNDERGROUND PIPES. 11 2 x 135 = 270LF - 72" 0, 28.274 ftZ/LF = 7634 ft TOTAL: ................................= 7634 ft Available Storage > Required Storage of 7580 FT.s ORIFICE. SIZING Two -Orifice Structure is proposed to control outflow. Total Flow Q = .56 cfs Flow Per Orifice .28 cfs hl = 6.68 For Orifice #1 h2 = 5.68 For Orifice #2 a, = Q/.62 (�2gh, .28/.62 V64.4(6.68) = .0217 ftL d, = 1/4.a = j�(.022) rr = .167 ft = 2.00 inches. -2- a., = Q/.62 V2gh,. = .28/.62 V64.4(5.68) = .024 ft .176 ft 2.11 inches Use 2 1/8" DOWN STREAM ANALYSIS The drainage from the subject property drain as sheet flow northerly to ditches along the west side of Duvall Ave. Small area of off -site drainage contributes to the subject property. Eventually, the runoff from the Site flows into the May Creek approximately some 1000 feet downstream of the Site. There is no evidence of restrictive structure exit dowmstream of the Site. TEMPORARY EROSION SEDIMENTATION CONTROL FACILITIES Drainage Basin Area = 11.9 Acres 40% of the Site Area will be cleared ....... 3.12 Acres. Balance of Basin Area .......................8.78 Acres. Soil type and classification - Alderwood Gravelly Loam on a 1.2% slope with an average slope length of 1100 feet - type "C" . RUN-OFF VOLUME DETENTION The Ground Cover is Forest (ungrazed) 8.78 X 350 = 3073 ft for undeveloped Portion 3.12 X 1250 = 3900 ft for cleared Acres. Total Runoff Volume = 6973 ft SEDIMENT VOLUME 2 X 40 XC 3.12 = 249.6 = 250 ft TOTAL POND VOLUME 7223 ft. ZZ �- - �te, 1 TREES T L] L l� x X 433 `0 x 0 TREES n LJ b � 1� i — ` I I 14 20 x I C r ,L-II n H 50 30 20 10 9 s 6 5 4 3 1 � ���WWW/Wlllit uu�uu �• 4VA 0 � q � �tJ•Hfufz �iv���� mWpnti�s • • •r ®W.t�G1119��vWWUW�Wu�� ��r �W���rrrnv��mW�WWnn�u�� � QII�v' �i!/JJui��/ ■W11 � 50 40 911 20 10 9 07 CD I 2 1 5 2 .3 .4 .5 1 2 3 4 5 10 20 i LOCITY !Zl FEET PER SECOND AVERAGE VELOCITIES FOR ESTIMATING TRAVEL TM�E FOR OVERLAND FLOW C = Runoff Coefficient SOIL CONSERvATION SERVILE TECHmCAL RELEASE NO.55 TEMPORARY SEDIMENT PONDS - NOMOGRAPH 2 (SEDLMENT VOLUME FOR DETENTION STORAGE) tn J LL Slaps Lugtn in Feet * BARE GROUND (C = 1.0, P = 1.2, & R = 10) 1/ 60 P.C.F. per Ft.3 EROSION TONS PER ACRE (E = RKLSCP) i i- t i TOUMA ENGINEEF 201 SW 41st Stree. RENTON, WASHINGTON 98055 R-[E-T-Tow -mus -T-mu (206) 251-9000 TO STORM WATER UTILITY DEPARTMENT CITY OF RENTON 200 Mill Ave. South WE ARE SENDING YOU LX Attached i- Under separate cover via_ ❑ Shop drawings EX Prints ❑ Plans ❑ Copy of letter ❑ Change order ❑ DATE 3/25/88 JOB NO, AT NTi ON Ir. Charles Price RE RjdgAp_v_jPw FgtAtPC the following items: ❑ Samples F1 Specifications COPIES DATE NO. DESCRIPTION 3/25/88 4 Revised Copies of Street & Storm Drainage Plans. 11 4 Redmarked Copies " 11 11 11" 1113 1 Revised Portion of Hydrolics Report THESE ARE TRANSMITTED as checked below: EX For approval ❑ Approved as submitted ❑ For your use ❑ Approved as noted ❑ As requested ❑ Returned for corrections ❑ For review and comment ❑ ❑ FOR BIDS DUE 19 REMARKS f_^ Resubmit copies for approval ❑ Submit copies for distribution ❑ Return corrected prints PRINTS RETURNED AFTER LOAN TO US 1ji1LITY .J COPY PRODUCT 240Q2 B Inc.. Gramm. ■m 0I47I SIGNED: Mounir "Tom" Touma, P.E., If enclosures are not as noted, kindly notify us at once. STORM REPORT FOR RIDGVIEW ESTATES PREPARED BY: TOUMA ENGINEERS 201 SW 41ST STREET RENTON, WA. 98055 STCGORA4 WAT-MR UTI T D R CE'V MAR 1 1988 17- GENERAL CONDITION Property Area = 7.9 Acres Total Basin Area = 11.9 Acres Land Cover = SPARES TREE C = .10 For S < 5% Developed C = 3.00 — 3.5 DU/GA = 0.40 ALLOWABLE FLOWS A = 11.9 Acres Overland Flow = 1060' @ S = 1.2% , V = D .26 fps 170' @ S = 26% , V = 1.30 fps 7gp� �Zs, TC = 10 + 1060/.26(60) = 170/1.30(60) `(r = 10 + 67.95 + 2.18 I� 9!l Ac z 1st = 80.13 min O, S. 1 I = 0-OM i n/ h. LS = 0 S 2 y S f Q t, = CI A +� _ (.10)(.")(11.9) .524 cfs Since Q > .30 cfs, Two Orifices will be used. STORAGE REQUIREMENTS Site Area As = 7.8 Acres Overland Flow = 740' @ S = 1.2% V = .26 fps 170' @ S = 26% V = 1.3 fps T, = 10 + 740/.26(60) = 170/1.3(60) = 10 + 47.44 + 2.18 = 59.62 min. I = 0.52 in/h. 09 = CIA _ (.52)(7.8)(a./? _ .406 cfs .406/.40(7.8) .13 cfs/Acre r Zc�'is cfs 03SI /� a yCril Gr. ZJ U29, y�c,i�3) vs = 3 - —z�.9 , T T S 3 vj=VS(7� '5�)G,yO) —1— UT- 704;43 -L r� T = -25 + L 0 29.9Q = -25r7O5OO .9(.13) = 109.675 min V = 2820 T - 29.9 Q.T J T+25 = (2820)(109.675) - 29.9(.13)(109.675) 134.675ft = 2296.52 - 426.31 = 1870.21ft3 /Acre VT = V C,1 A = 1870.2 (.40)(7.8) = 5835.55 W STORAGE FACILITIES WILL CONSIST OF UNDERGROUND PIPES. 2 x 140 = 280LF - 60" 0, 19.635 ft /LF = 5497.80 ft 30LF - 36" 0, 7.0685 ft /LF = 212.06 ft 10.72 LF - 54"0, 15.904 ft /LF = 170.50 ft TOTAL: ..................................= 5880.36 ft Available Storage > Required Storage of 5835.55 FT. ORIFICE SIZING Two -Orifice Structure is proposed to control outflow. Total Flow Q = ,5'4 c f s ©,�� Flow Per Orifice = .262 cfs h, = 5.72 For Orifice #1 h,, = 4.22 For Orifice #2 a, = Q/.62 rghr b, �1� = .-262/.62 V64.4(5.72) .022 ft r - v, LT2��r ` d� = V4ra = V4('.DM r . 16 7 Ir 73. = 2.00 inches. :2,d8"' S� -2 -2- ax = Q/ . 62 Y 2gh-, = .2-62/.62 V64.4(4.72) _" ft` G, Dz� d = 1/4 . a = U4 ( .,0-Z4) n n =.eft - s 2.11 inches. :2-,v"'t�2_y DOWN STREAM ANALYSIS The drainage from the subject property drain as sheet flow northerly to ditches along the west side of Duvall Ave. Small area of off -site drainage contributes to the subject property. Eventually, the runoff from the Site flows into the May Creek approximately some 1000 feet downstream of the Site. There is no evidence of restrictive structure exit dowmstream of the Site. TEMPORARY EROSION SEDIMENTATION CONTROL FACILITIES Drainage Basin Area = 11.9 Acres 40% of the Site Area will be cleared ....... 3.12 Acres. Balance of Basin Area .......................8.78 Acres. Soil type and classification - Alderwood Gravelly Loam on a 1.2% slope with an average slope length of 1100 feet - type "C" . RUN-OFF VOLUME DETENTION The Ground Cover is Forest (ungrazed) 8.78 X 350 = 3073 f 0 3.12 X 1250 = 3900 ft5 for undeveloped Portion for cleared Acres. Total Runoff Volume = 6973 ft SEDIMENT VOLUME 2 X 40 Xg 3.12 = 249.6 = 250 f0 TOTAL POND VOLUME 7223 ft3 -3- 66/A TREES i 1 \ II x 11 00 I� 439 !1 \\ 1 1 II 17aLC I 1�� T ES TH_ ST_----� l is \I I vWi----4�� 1 1 a aye---11 I I Q I ila�c� II�� J\J Ep al �� F7 x 8 ' i 433 k TREES 00 s 50 u (7 30 20 10 8 6 5 4 3 2 � �• sr�,��r�r��:•�nmuu� • Emma .2 .3 .4 .5 1 2 3 4 5 10 Lam? OCITY IZl FEET PER SEC01 5 0 40 30 20 2 5 20 AVERAGE VELOCITIES FOR ESTIMATING TRAVEL T MIE FOR OVERLAND FLOW C = Runoff COOffiCicni SOIL CONSERVATION SERVILE TECHNICAL RELEASE N0.55 ■ Ed ■nil mom r ■ ■■ ..0=11111I EMOMMOMMOMEN l�N� ■��mm�s��:........ �`� ::::::mmm■■■m■■■• i►i �� ■■■■■■ ' ► a ommosoiCls ...Z\a.................=C ■■.■■■■■rA\q ■■■■■■■■■■■ ' • ■■N■■■■1,Lula ■■■■■■■■,■■ ■■■s■■■■■■1ti■► ■E■■■■■■■■■M ■M■■■a■\\\`■► • ■■/SEES■■■ ■■■/■■■■■■�4\� • ■■SEEM■■■■ • SEES■■/q■►1■► ■mEE■■■■■■■ ■■■■■■■■■■E� ■■■■■■moms■ -1 �mE.■■...m. UMSOMEONE IshIMMONNE\\■s■s■ ■■M■■E■E■■ ■■■■mom■■■■■ \■►\■SEEM �M■■■■■■■■■■N■\�■mom\V■./mai■o■ ■■1/■■■■■■■■■■■EEE■■tom■.\o\■mM UNTER0F�F I C'E 1! �0 TO:�r`>�; DATE FROM: SUBJECT: lLa) Y/EW E;T,)' S a SPEED LETTER TO: �d-�_ DATE: PROJECT: SUBJECT: e.r'(_,/,� J Signed STORM WATER UTILI D RECF`v MAR I L.;.i9aa 17-W r► wit R Barbara Y. Shinpoch, Mayor CITY OF RENTON PUBLIC WORKS DEPARTMENT MEMORANDUM DATE: September 11, 1987 TO: Building and Zoning Design/Utility Engineering FROM: Charles E. Price, Storm Water Utility Engineer SUBJECT: Preliminary Plat PP-067-87, Ridgeview Estates Development Application Review I. Consideration shall be given in the calculations to past detention capability of the natural depression on site. 2. The capacity of the downstream drainage course is required to be evaluated for a minimum distance of 1/4 mile from the point of discharge on 138th Ave SE. 3 4 9 I The number and location of catch basins will be determined during design. Inlets should be placed at the radius points at intersections. Arrows indicating drainage direction in all public and private property shall be shown on he construction drawings for all hydraulic conveyance systems. Vehicular access must be provided to the detention pond. When the width of the pond is 20 feet m greater, access must be provided to the bottom of the pond. A drainage easement for maintenance shall be provided for the detention facilities located in '1 rack A. R. C'onstitiction d►mnage plans and profiles should be 1" = 20' scale. 1�� Charles E. Price w\c\tn\ridgview.cep: jlni 200 Mill Avenue South - Renton, Washington 98055 - (206) 235-2631 /7 4O1� �- WAL Barbara Y. Shinpoch, Mayor CITY OF RENTON PUBLIC WORKS DEPARTMENT MEMORANDUM DATE: September 11, 1987 TO: Building and Zoning Design/Utility Engineering FROM: Charles E. Price, Storm Water Utility Engineer SUBJECT: Preliminary Plat PP-067-87, Ridgeview Estates Development Application Review 1. Consideration shall be given in the calculations to past detention capability of the natural depression on site. 2. The capacity of the downstream drainage course is required to be evaluated for a minimum distance of 1/4 mile from the point of discharge on 138th Ave SE. 3. The number and location of catch basins will be determined during design. Inlets should be IV placed at the radius points at intersections. 4. Arrows indicating drainage direction in all public and private property shall be shown on he construction drawings for all hydraulic conveyance systems. 5. Vehicular access must be provided to the detention pond. When the width of the pond is 20 feet or greater, access must be provided to the bottom of the pond. 7. A drainage easement for maintenance shall be provided for the detention facilities located in Track A. 8. Construction drainage plans and profiles should be 1" = 20' scale. Charles E. Price w\c\m\ridgview.cep: jlm 200 Mill Avenue South - Renton, Washington 98055 - (206) 235-2631 PLAN REEVVIEWS L No. / ,-/— 06IEw, Project Name: Building Permit Number: Date to Utility Billing: Business or Use: Site Address: Owner/Billing Address: C o Tax Lot Number(s) Sauare Footage Assessment �' 1-j J�-Q e / 1 Gy-j- 1� 0 a'-, � V 1 HIV VW" 1. 1 I A /"A, IK �A- U• s l /5;57 79 DESCRIPTION ADDRESS DATE DATE - CHUCK'S DATE TO DUE DATE TO BUILDING DATE RCVD. DATE TO RECEIVED REVIEW BERGSTROM BUILDING, DEPT. PLAN NO. PEP -MIT BILLING I F 11L 5'� f 72W --� - i 1 i ' 4 i i f i I ` STORM REPORT FOR RIDGVIEW ESTATES PREPARED BY: TOUMA ENGINEERS 201 SW 41ST STREET RENTON, WA. 98055 GENERAL CONDITION Property Area = 7.9 Acres Total Basin Area = 11.9 Acres Land Cover = SPARES TREE C = .10 For S < 5% Developed C = 3.00 - 3.5 DU/GA = 0.40 ALLOWABLE FLOWS A = 11.9 Acres Overland Flow = 1060' @ S = 1.2% , V = D .26 fps 170' @ S = 26% , V = 1.30 fps TC = 10 + 1060/.26(60) = 170/1.30(60) = 10 + 67.95 + 2.18 = 80.13 min I = 0.44 in/h. Qy = C I A (.10)(.44)(11.9) _ .524 cfs Since Q > .30 cfs, Two Orifices will be used. STORAGE REQUIREMENTS Site Area As = 7.8 Acres Overland Flow = 740' @ S = 1.2% V = .26 fps 170' @ S = 26% V = 1.3 fps T = 10 + 740/.26(60) = 170/1.3(60) = 10 + 47.44 + 2.18 = 59.62 min. I = 0.52 in/h. Qp = CIA = (.52)(7.8) = .406 cfs Q d = QJCD A .406/.40(7.8) .13 cfs/Acre -1- T = -25 + 70500 29.9Q = -25 r7O5OO .9(.13) = 109.675 min V = 2820 T - 29.9 Q.T T+25 = (2820)(109.675) - 29.9(.13)(109.675) 134.675ft = 2296.52 - 426.31 = 1870.21ft'9 /Acre VT =VCdA = 1870.2 (.40)(7.8) = 5835.55 W STORAGE FACILITIES WILL CONSIST OF UNDERGROUND PIPES. 2 x 140 = 28OLF - 60" 0, 19.635 ft /LF = 5497.80 ft 30LF - 36" 0, 7.0685 ft /LF = 212.06 ft 10.72 LF - 54"0, 15.904 ft /LF = 170.50 ft TOTAL: ..................................= 5880.36 ft Available Storage > Required Storage of 5835.55 FT. ORIFICE SIZING Two -Orifice Structure is proposed to control outflow. Total Flow Q = .524 cfs Flow Per Orifice = .262 cfs h, = 5.72 For Orifice #1 h,, = 4.22 For Orifice #2 a, = Q/.62 rghr = .262/.62 V64.4(5.72) = .022 ft� d� = V4 a = V4(.022) V 7� = .167 ft = 2.00 inches. -2- ay = Q/.62 V 2gh,. .262/.62 K64.4(4.72) .024 ft d = I/4.a = F(.024) V r1 = .176 ft = 2.11 inches. DOWN STREAM ANALYSIS The drainage from the subject property drain as sheet flow northerly to ditches along the west side of Duvall Ave. Small area of off -site drainage contributes to the subject property. Eventually, the runoff from the Site flows into the May Creek approximately some 1000 feet downstream of the Site. There is no evidence of restrictive structure exit dowmstream of the Site. TEMPORARY EROSION SEDIMENTATION CONTROL FACILITIES Drainage Basin Area = 11.9 Acres 40% of the Site Area will be cleared ....... 3.12 Acres. Balance of Basin Area .......................8.78 Acres. Soil type and classification - Alderwood Gravelly Loam on a 1.2% slope with an average slope length of 1100 feet - type "C" . RUN-OFF VOLUME DETENTION The Ground Cover is Forest (ungrazed) 8.78 X 350 = 3073 f0 for undeveloped Portion 3.12 X 1250 = 3900 ft5 for cleared Acres. Total Runoff Volume = 6973 fta SEDIMENT VOLUME 2 X 40 Xg 3.12 = 249.6 = 250 ft3 TOTAL POND VOLUME 7223 ft3 -3- i TREES �' II II x I1 i1 439 r I 1 11 111 I I 11 1\ I I TH. ST. I� l�r — — — ----� X — ,1 1 tUJ cWn—n---4 ,�— / � — a� ��I Ia� S66 \x •a TREES ` _ V 350 i \\' 'k.\\ ��- t 17Dc s= �T ti l4vw ."" 433 � � J x a- x El I \S. E. I� 1 420 I Ix I' 42 50 u0 30 20 H z0 9 8 t-: z� 6 5 w CD 4 �j 3 �I CI 0 v 2 3 1 i��t/��/nL��/�I.IlIIt� ���Q�t�niun •... �� �aa=�t� ira.►a�ai��ra�va�at �as��taw■���sa�a���a•�tai�,���a•��aats�� r a ■ • I� �annu • Y uu�nna lu _2 .3 .4 .5 1 2 3 4 5 10 .5 20 % BLOCI T Y IN r EET er_R SECOND AVERAGE VELOCITIES FOR ESTIMATING TRAVEL T IME FOR OVERLAND FLOW C = Runoff Coefficient SO+L CONSER✓ATiON SERVICE TECHNICAL RELEASE NO.55 TEMPORARY SEDIMENT PONDS — NOMOGRAPII 2 (SED LMENT —VOLUME FOR DETENTION STORAGE) ri li ITV lOG• y:: 2.O • I � � I � r.+ -�I O(o .04. _ + • 02 I �jI I • t� 1i x1 1 1 KXJ it• �0 3 �00 c 600 > > t rs» Slope Length in Foot