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HomeMy WebLinkAbout9591 STORK DRAINA'-3:E ANALYSIS FOR: WI LL. IAZ►SS 13�.�E :� E APARTME13g S CLIENT: C.J . CJNSTRUCTJC1y 11015 -- 142ND AV7. S.E. RENTON, WASHINGTON 98056 PHONE: i2C6) 229 -i261 PREPARED BY: TOWNSEND-CHASTA:N OF REWON & ASSOC. �E I V E 409 SOUTH 3rD AVENUE D KEHT, WASHINGTON 9803? DEC 2 8 1992 PHONE: (206) 854-2043 BULDINQ DIVISION 1 r '�\N Sk s�N PROJECT NUMBER: 90086 SEPTEMBER 25 , 1991 :Wi 1 ;4a,s .REOISt .••���v OFF-SITE ANALYSIS WILLIAMS AVENUE APARTMENTS Our Project No . 90086 Williams Ave . - Between So . 5th St . & Grady Way September 24, 1991 LEVEL I DOWNSTREAM DRAINAGE ANALYSIS The site of the proposed 7- unit apartment complex is locat- ed on the east side of Williams Ave . between So . 5th St . and Grady Way, in the City of Renton . The existing site con- tains two existing single family house . The site is basi- cally flat , with land sloping slightly to the western cor- ner . There is presently no piped drainage system along Williams Ave . in the immediate vicinity of the site . Storm drainage from the site sheet flows to the roadway and then flows south in the gutter to Grady Way to an existing shallow drainage inlet at the northeast corner of the intersection . Storm water is then carried in a 6 inch concrete pipe south- east 12 feet to a brick catch basin along Grady Way. Water then flows southwest along the northwest side of Grady Way in an 18 inch concrete pipe . Per the attached "Memorandum" dated December 6 , 1989 , Grady Way was experiencing flooding problems . The City ' s remark made reference to "beauty bark clogging CB ' s" . However , the existing storm system is also referenced as being under- sized . Current discussions with City Personnel indicate that this entire section of the city still has occasional flooding problems . Much of this is due to previous develop- ments within the area which do not have retention/detention facilities . It is anticipated that the proposed development will have a negligible impact on existing flooding because the project is proposing to provide detention facilities . If additional developments along Williams Ave . are also required to pro- vide retention/detention facilities , then the future flood- ing impacts along Grady Way would be kept to a minimum. File No : WS6/ENGR/90086 . 924 September 24, 1991 i CITY OF RENTON MEMORANDUM DATE: December 6, 1989 TO: Chuck Price, Storm Water Utility Engineer FROM: Kim Scattarella, Stormwater Engineering Specialist SUBJECT: MAPPING & INDEXING OF RENTONS' DRAINAGE PROBLEMS MAP NUMBER LOCATION AND NATURE OF PROBLEM �1-84�'-'y Talbot Rd./Shattuck Av. S. - Drainage/Rat Complaints. A storm drain needed on private property. 1-85 Black River- Drainage west of SW 7th and SW I0th Streets inadequate. System inadequate; outfall points clogged. Drainage channel not maintained. 2-85 1301 N. 26th. Drainage from CB's by city flows onto property of R.E. Deitrich; considers City liable for foundation damage._,_ 1-1286 Grady Way Flooding- Undersized system, with beauty bark clogging CB's; 1-387 814 N.32nd- Basement has flooded 7-8 times during winter 1987. 1-1087 1406 Shattuck Av.- Open ditch maintenance problem. 2-1087 247 Pelly Av. N.- Dirt alley built up higher than residents' property so water drains onto property and is rotting the foundation. No drainage in alley. 3-1087 1825 NE 3rd (Monterrey Apts.)- Ponding problem in parking lot. 4-1087 645 Shattuck Av. S. -Flooding of S.7th & Shattuck. 5-1087 3623 Park Av. N.-Water runs off the road onto private property below road grade. 6-1087 3501 NE 11 th Pl. - Flooding of Sunset Blvd. in front of Community Bank. 1-1287 2125 & 2803 NE 24th- Yards under water. 2-1287 2324 Aberdeen Av. NE.,- Overflow flooding T A ear Y STORK DRAINAGE ANALYSIS I f x., tyti t t., r j 17` 1 s r• t. . �..... fV r I 1 I ':> ..�tr. 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The site is virtually flat , with a slight slope to the west to Williams Avenue . Williams Avenue , adjacent to the project site , is paved with concrete curb , gutter and sidewalk . There presently is no upstream off-site drainage contributed to the site . DOWNSTREAM DRAINAGE : There presently is no piped drainage system in the vicinity in Williams Avenue . Drainage to Williams Ave . flows south by gutter flow to Grady Way to an existing shallow drainage inlet at the northeast corner of the intersection . Storm- water then is carried in a 6 inch concrete pipe southeast 12 feet to a brick catch basin on Grady Way . Drainage then flows southwest along the northwest side of Grady Way in an 18 inch concrete pipe . PROPOSED DEVELOPMENT: It is proposed to construct a 7-unit apartment complex on the site , together with as paved parking lot adjacent to Williams Avenue . Drainage from the parking lot as well as from PVC roof and footing drainage will be collected in three Type I catch basins and conveyed by 15 inch CMP to a Type II 54 inch detention control manhole with orifice control located in a landscaped area at the southwest corner� of the site . Approx- imately 172 cubic feet of stormwater detention storage is provided in the 15 inch detention pipes as well as the poten- tial live storage in the control structure . The detention system design is based on a 10 year storm for storage and release rate , using the Yrjanainen and Warren Method . Discharge from the site will be through a 12 inch concrete pipe that will run along Williams Avenue , and connect to the existing catch basin in the intersection with Grady Way. The 12 inch line is covered under the proposal of Dennis & Lois Hyland . 409 SO. 3RD AVENUE SUITE "A" RENT, WA 98032-5898 PHONE 206/854-2043 FAX 206/854-2053 CITY OF RENTON — So., 4m M ST FND. LEAD PLUG W CONC. MONr' `\560 00•(P) SHORT PLAT NO. IN CASE 0.4'OWN. ,�559.82'(M) LEGAL DESCRIPTION — So. 5M ST.. — N89-32.40-W300. — — LOT 9. BLOCK 18, TOWN OF RENTON, ACCORDING TO THE 300:>7 M) FND. PUNCH IN- PLAT RECORDED iN VOLUME 1. OF PLATS, PAGE 135. FND. -X-IN 2- BRASS CAP IN- C R/R SPIKE RECORDS OF KING COUNTY,WASHINGTON_ 10- DIA_ CONC. MON. OWN. 0.4' i LOT 10. BLOCK 18, TOWN OF RENTON, ACCORDING TO THE PLAT RECORDED IN VOLUME 1, OF PLATS. PAGE 135. RECORDS OF KING COUNTY, WASHINGTON. THAT PORTION OF THE SOUTHWEST QUARTER OF THE SOUTH- WEST QUARTER OF SECTION 17, TOWNSHIP 23 NORTH, RANGE — — — — — — — — — — — — — — — — — — — — — — — — — 5 EAST, W.M., BEING DESCRIBED AS FOLLOWS: BEGINNING AT A POINT WHICH IS 270 FEET EAST OF THE SOUTHWEST CORNER OF BLOCK 28 OF THE TOWN OF RENTON, KING COUNTY, WASHINGTON. THENCE EAST 150 FEET; THENCE SOUTH 7 FEET; THENCE WEST 150 FEET: — — — — — — — — — — — — — — — — — — — — — — — — — THENCE NORTH 7 FEET TO THE POINT OF BEGINNING; - ALL SITUATE IN SECTION 17. TOWNSHIP 23 NORTH, RANGE 5 EAST, W.M., KING COUNTY, WASHINGTON; EXCEPT THAT PORTION LYING WITHIN WILLIAMS STREET. I MERIDIAN: ASSUMED I S. ath ST. BASIS OF BEARING: MONUMENTED CENTERLINE BETWEEN 4 SO. 4th ST. AND SO. 5th ST. { — — — — — — — — — — — — — — — — — — — — — — — — — I� I �I I VI �I14LEGEND rn ' !Il- FOUND MONUMENT AS NOTED UnLITY POLE FIRE HYDRANT 13 13 I ^ I-CI �30.00'- N B9'52'40- A'" °6 - - - - - —I 120.00• a - - - - - - - - - ZI .n: i x ,�_ m srl' _��. , I ^�* I LI 0 T 9 PROPOSED 1=!o NOTES BUILDING I' p EXISTING STRUCTURES TO BE REMOVED ------------------- :�I Wf I II b — — —� — — — — — — — — — ,:' PROPOSED L T 10 BUILDING _ •1 J I - i. pQ L V� 30.00)- — — aL 120.DO' �ials' _ -21aa"_ — — — — — — — — — j 4 v NE, 8552'4 uM Paz. • ZONED R-3 ON COMPREHENSIVE PUN 60.00' �-EX Y SAN.SEW. ESM'T AS PER RECORDING 0691673 VICINITY A/AP - - - - - i — — — — — — — — — — — yy_1/4__-X 1/4 SEC.,2_. 7WP._23_N., RGE_5_£,W.M. GRAPHIC SCALE GRAPHIC SCALE TOWNSEND - CHASTAIN & ASSOC.. INC. C.J. CONSTRUCTION • • ' J` Srmvsroxs - M�CrnFX'xs DEVE'LOPA44'NT co1�s12.rANrs —WILLIAMS A VE S0. APARTMENTS l a�T l09 SOUTH duo .I X T AI PRELIMINARY SHORT PLAT I loch - '_'00 It 1 Ineb• 30 M1 XEN7. WASHINGTON 9803. ERP I � : N(0i _DUALS 3G FEE V '706) 95s-10+3 I" OC- '990 I`^'90086 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 1.2.3 CORE REQUIREMENT #3: RUNOFF CONTROL Proposed must projects provide runoff control through a combination of peak rate runoff control facilities and on-site biofiltration measures as described below. Peak Rate Runoff Control Proposed projects must provide peak rate runoff control to limit the developed conditions peak rates of runoff from specific design storm events not to exceed the pre-development peak rates for the proposed project site "existing conditions" as described below. Three basic methods for peak rate runoff control are possible: detention, retention, and infiltration. Detention is the collection and temporary storage of surface water (typically over several hours) with the outflow rate restricted—usually to the pre-developed outflow rate. Retention is the collecting and holding of surface and stormwater with effectively no surface outflow (outflow occurs by evapotranspiration). Infiltration is the soaking of surface water into the ground (typically for several hours or days). Infiltration not only reduces or eliminates surface runoff, but also helps to maintain the hydrologic balance of the surface water system. Infiltration can limit erosion and recharge groundwaters that supply water to wetlands, streams, and wells. Preserving infiltration after development is by far the most effective mechanism in preventing adverse impacts to the surface water system. Because of these benefits, King County encourages the use of infiltration systems for runoff control where the appropriate soil conditions exist. Proposed project peak rate runoff control must be located on-site. An exemption from on-site peak rate runoff control may be granted for the special conditions specified at the end of this core requirement section. Biofiltration Proposed project runoff resulting from more than five thousand square feet of impervious surface, and subject to vehicular use or storage of chemicals, shall be treated prior to discharge from the project site by on-site biofiltration measures as described in Section 4.6.3 in Chapter 4. The biofiltration design flow rate shall be the peak rate of runoff for the 2-year 24-hour duration design storm event. Note, biofiltration facilities installed following peak rate runoff control facilities may be sized to treat the allowable release rate (pre-developed) for the 2-year 24-hour duration design storm event for the peak rate runoff control facility. 8iofiitration facilities installed prior to peak rate runoff control facilities shall be sized based on the developed conditions. Proposed Project Site "Existing Conditions" In performing the analysis for the design of runoff control, it is essential to first determine the proposed project site "existing conditions" from which the pre-development runoff rates can be computed for - -_ specific design storms. Existing conditions are not always synonymous with those of the natural, totally undeveloped site. In some instances substantial modifications (such as diversions, piping, clearing, and grading) have already increased and'altered surface water runoff leaving the site, but no permit, nor accompanying engineering plan, was ever approved. In other instances, an approved drainage system exists and the existing system must be analyzed for its performance. There are two definitions for proposed project site "existing conditions" depending on the site. Sites with Existing Approved Drainage Systems: The proposed project site "existing conditions" are defined as those that occur with the existing drainage facilities constructed per approved permits and engineering plans. The current performance of existing drainage and detention facilities shall be determined by using the analysis methods described in Section 3.5 in Chapter 3. Sites with No Existing Approved Drainage Systems: The "existing conditions" are defined as those that existed prior to May 1979, which is the date of publication of "Requirements and Guidelines for Storm Drainage Control in King County" by the King County Public Works Department's Hydraulics Division, the 1.2.3-1 1/90 D E T E N T I O N F AC I L = T Y D E S = G N J. L__ L_J l� ♦ 1. I IV 00,00,00" E 107.00 x X - - - - - - - -� K. 3 X I. C. o x o OJR_ I FIN. Q O EL.=29. 3 i Q� o�� I 4 - PLEX FIN. FL. I �1 EL.=28.7��� 28-53 FL 28.53 FL o 28.22 FL 29.03 TC ;., 28.2 29.03 TC'.•. 28.72 TC X2_8_7 Yaw 1 .41 FL 8:20 FL cz 8.91 TiG TC =� co 28.37 FL �- �T BLDG. 8.87 .07 FL x 28.20 ,FL 8 7.;. TC 28-35 FL - 28.70 't:C �° <28.07 F1 ::. 28.85 TC MAIL 28.57 TC— 28.20 2 . 84 TC 28.64, FLY- BOXE '28.1. FL°= 28 2$ --......28 ® $ 64 FL2 ' EX. 8"WAFl X. 12"Sp 10 28.20 FL/\ G G 8 SS s cn SSMH WILLIAMS A VE. S. " M=28.� SCA�• � s ,.�I.E. 8"(N, T I.E. 12 Joe 414, ^'' ��, 1)OOg` d TOWNSEND-CHASTAIN & ASSOC., INC. SHEET NO. OF 409 South 3rd Avenue KENT, WASHINGTON 98032, CALCULATED BY DATE (206) 854-2043 CHECKED BY DATE SCALE _............__........ ..........:...._- - ._ _.. _.. _.. -_ - - .... ..... _ - - - i : ; i � ..«.....«-..............._...«_........:...........:.....__.n...........e................ _._ ... .._ _.. .... .... .... __ ... .... ... .... -... - .... .... ..... .... ......... ...._ .... i - �..or ! xL ai -----------r --- O.,Q55... ..... --- o - ot9 �....._..�................. .. . _ _ _ --.. ..._ _ . i ; D- 23 O.'2a { g t ; p OA7 . r ,�o : ..3 3 : _ __ _ _ -t-l-t-' ........... . - .«....------_._._. - - ...._ -... _... _ o .o ........... ........... - - - - _}-_............._ i ...l..�t...-.b o _ram•N:. �_._ ..I..... ---.--------- . ............ ........................_ _ ....... V+++ LAL-41-1. ............................. 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PRODUCT 204-1(Single SWM)205-1(Padded)Qelnc,Grow,Mass.01471.To Order PHONE TOLL FREE 1-8*225-M 5 0'1 5 10 40 50 40 30 30 20ZI-T 20 N ti 19 i� 8 - _-� _ - - - 90 z 6 _ 7 vl fJ44 r•r 3 �vI --r_ r Q20v - --- . r•r �''' v 2 4 1. -- .5 1 .2 .3 .4 .5 1 '2 3 !r 5 5 10 20 VELOCITY IN I'EET PER SECOND AVERAGE VELOCITIES FOR ESTIMATING TRAVEL TIME FOR OVERLAND FLOW SOIL. CONSERVATION SERVICE I �I, i� p TABLE 1 STORAGE REQUIREMENTS FOR MULTIPLE ORIFICES Type* and— 0-YearDesi nn torm - ear ees g_n_ Storm AREA Number of Peak Maximum torage eaStorage Maximum o age Outlets Time(Minutes) Volume (Cu•Ft/Ac) Time(Minutes) Volume (Cu.Ft/Ac) Seattle/ One T = -25+ 1762 Vs = 2820T - 40QoT T = -25+ 2138 Vs = 3420T - 40QoT Renton T_ Seattle/ Two T = -25+ 70500 Vs = 282OT-29.9QoT T = -25+ 05500 Vs = 3420T-29.9QoT Renton 1 .9Qo '1 f�� o T+-2 - Seattle/ Three T = -25+V64 Vs = 282OT-26.4QoT T - -25+ 85500 Vs = 3420T-26.4QoT Renton o T-a25 26.4Qo T+25 Seattle/ Four T = -25+ 70500 Vs = 282OT-25.1QoT T = -25+ Q5500 Vs - 3420T-25. 1QoT Renton 25,IQo T4 2571Qo 5- Seattle/ Five T = -25+ 70500 Vs = 282OT-24.1QoT T = -25+ 85500 Vs = 3420T-24.lQoT Renton4.TQo � "o T+2 - * Orifices with equal head pressure between adjacent orifices. M.Tseng/L.Gibbons/7/19/85 TABLE 1 RUNOFF FACTORS FOR STORM SEWERS FLAT ROLLING 0-5% >51 UNDEVELOPED LAND Wood f Forest . . . . . . . . . . . 0 . 05 0 . 10 Sparse Trees F Ground Cover 0 . 10 0 -15 Light Grass to Bare Ground . . . . . . 0 . 15 0 A 0 DEVELOPED AREA Pavement & Roofs . . . . . . . . . . . 0 . 90 0 . 90 Gravel Roads & Parking Lots . . . . . . 0 . 75 0 . 80 City Business . . . . . . . . . . . 0 . 85 0 . 90 Apartment Dwelling Areas . . . . . . . 0 . 80 0 . 85 Industrial Areas (Heavy) . . . . . . . 0 . 70 0 . 80 Industrial Areas (Light) . . . . . . . 0 . 60 0 . 70 Earth Shoulder . . . . . . . . . . . . 0 . 50 0 . 50 Playground . . . . . . . . . . . . . . 0 . 25 0 . 30 Lawns , Meadows & Pastures . . . . . . . 0 . 20 0 . 25 Parks & Cemetery . . . . . . . . . . . 0 .15 0 . 20 SINGLE FAMILY RESIDENTIAL (Dwelling Unit/Gross Acre) 1 . 0-1 . 5 DU/GA . . . . . . . . . . . . . . 0 . 30 1 . 5-3 . 0 DU/GA . . . . . . . . . . . . . 0 . 35 3. 0-3 . 5 DU/GA . . . . . . . . . . . . . . . 0 . 40 3 . 5-4 . 0 DU/GA . . . . . . . . . . . . . . . 0 . 45 4 . 0-6 . 0 DU/GA . . . . . . . . . . . . . . . 0 . 50 6 . 0-9 . 0 DU/GA . . . . . . . . . . . . . . . 0 . 60 9 . 0-15 . 0 DU/GA . . . . . . . . . . . . . . . 0 . 70