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HomeMy WebLinkAboutSWP272871(1) R.C.AMUITHUM TECHNICAL INFORMATION 1 REPORT fnr: FIRSTBUILDERS CITY OF RENTON Date: December 1999 1 ' Robert Miller Blaine Miller First Builders PO Box 6487 Kent, WA 98064 (253) 630-8265 1 c� RCA/Huitt-Zollars,Inc. 1 EXPIRES 3/17/0 814 East Pike Street Seattle,WA 98122 (206)324-5500 i ' 15-0275.01 First Builders at Renton TABLE OF CONTENTS ' DRAINAGE REPORT I. PROJECT OVERVIEW p. 3 II. PRELIMINARY CONDITIONS SUMMARY p. 5 ' III. OFF-SITE ANALYSIS p. 6 IV. RETENTION/DETENTION ANALYSIS AND DESIGN p. 7 ' A. Existing Site Hydrology p. 7 B. Developed Site Hydrology p. 8 C. Hydrologic Analysis - P. g i. Detention Facility Sizing P. 9 ii. Water Quality Treatment Vault Sizing P. 10 D. Retention/Detention System p. 10 V. CONVEYANCE SYSTEMS ANALYSIS AND DESIGN P. 10 ' VI. SPECIAL REPORTS AND STUDIES P. 11 VII. BASIN AND COMMUNITY PLANNING AREAS P. 11 ' VIII. OTHER PERMITS P. 11 ' IX. EROSION / SEDIMENTATION CONTROL DESIGN P. 11 X. BOND QUANTITIES, WORKSHEET, RETENTION/DETENTION FACILITY ' SUMMARY SHEET AND SKETCH, AND DECLARATION OF COVENANT P. 11 XI. MAINTENANCE AND OPERATIONS MANUAL p. 12 ' J',\1507]501\d\wortl\report\tllattMl.tloc ' 15-0275.01 First Builders at Renton ' FIGURE 1 TIR WORKSHEET FIGURE 2 SITE LOCATION FIGURE 3A AREA DRAINAGE BASIN MAP ' FIGURE 3B AREA SITE CHARACTERISTICS — CONTOURS FIGURE 3C EXISTING SITE SUBBASIN MAP ' FIGURE 3D DEVELOPED SITE SUBBASIN MAP FIGURE 3E SITE CONVEYANCE SYSTEM MAP 1 FIGURE 4 SOILS MAP/ GEOTECHNICAL REPORT APPENDIX 1 DOWNSTREAM FLOW PATH SCHEMATICS ' APPENDIX 2 SYSTEM CALCULATIONS AND DESIGN Isopluvial Maps ' Detention Pipe Sizing for the 2, 10 and 100-Year Events Water Quality Treatment Vault Sizing Calculations ' Conveyance Calculations for the 25-Year Event Backwater Analysis for the 25 and 100-Year Events ' APPENDIX 3 WATER QUALITY TREATMENT DOCUMENTATION APPENDIX 4 BOND QUANTITIES WORKSHEETS APPENDIX 5 RETENTION/DETENTION FACILITY SUMMARY SHEET AND ' SKETCH APPENDIX 6 DECLARATION OF COVENANT ' APPENDIX 7 MAINTENANCE AND OPERATIONS References • City of Renton Design and Construction Standards and Specifications revised May 1997. • Washington State Department of Ecology, Storm Water Management Manual for the Puget Sound Basin, February 1992. ' • King County, Washington, Surface Water Design Manual, November 1994 and September 1998. • WaterWorks Ver.4.13c, Storm Drainage Analysis Software, 1996. ' J:\1-1111\c11-11d111PW1drattMI d— 2 ' 15-0275.01 First Builders at Renton ' SECTION I. PROJECT OVERVIEW ' This Drainage Report documents the design of the storm drainage system for First Builders' Proposed Subdivision along NE 24`h Street in Renton. The proposed subdivision is located between Jones Avenue NE and Aberdeen Avenue NE, and is situated in the East Lake Washington drainage basin, ' southwest of May Creek. The attached Figure 1 is a copy of the Technical Information Report (TIR) worksheet (from Reference 10- ' B of the Surface Water Design Manual). Figure 2 contains a map showing the general location of the site with roads and significant geographic features identified. Figures 3A and 3B contain additional site characteristics. The project consists of clearing, grubbing, grading, and hydroseeding 4.35 acres on the south side of ' NE 24t' Street directly across from Monterey Avenue NE. The existing project site contains two existing houses, a garage, and a concrete pad that may have served as a foundation for a former garage. The existing impervious area adds up to approximately 7,820 SF or 0.18 acres. The remainder of the site ' consists of a dense cover of blackberries and Alder trees as well as several native Douglas Firs. The proposed subdivision will contain approximately 28 units. The average footprint of each proposed ' unit is 2,400 SF or 0.055 acres. The subdivision will contain approximately 700 LF of public road with a cul-de-sac at the end of it. Surface water from small amounts of the existing property drain toward NE 24`h Street that contains no curbs, gutters or sidewalks on the south side of the street. It does, however, contain a series of catch basins that convey storm water both east and west along NE 24' Street. The portion of the street where ' the subdivision will connect to happens to be the high point of the street that is why some runoff will flow in each direction. The existing storm drainage system along NE 24`h Street does not appear to ' meet the minimum storm drainage requirements outlined in the City's Standard Specifications for Municipal Construction and Standard Details manual. As part of our project we propose to construct half street wide improvements to that portion of NE 241h Street that adjoins the proposed development. ' The half street wide improvements include extending a sewer main, paving and installing curb and gutter. After the storm water is collected and conveyed in a public conveyance system to an underground detention vault at the south end of the property, the entire storm event will pass through a "Stormwater Management" water treatment vault. Following treatment, the storm water will be released through a level spreader over the southwestern property line and continue along it's predeveloped route over private property, toward Jones Avenue NE and NE 201h Street. ' The proposed detention and treatment facilities will be located in the public right-of-way and have been designed to detain and treat storm water which reaches the proposed street/ right-of-way as well as the alley behind the northernmost lots. This excludes all roof drains and some portions of private ' landscaping, private walkways and private driveways. Based on the soils information available, the soils are Indianola soils, known for high degrees of infiltration. For this reason, roof drains will be directed ' toward dry wells on individual lots. ' 1'\15027501\01\wortl\report\tlrattM l.tlOC 3 ' 15-0275.01 First Builders at Renton ' In the post-developed condition, storm runoff from the northwest portion of the site will continue draining to the west, storm water from the east portion of the site will continue draining to the east, and ' storm water runoff from the remaining site will drain to the southwest. The proposed drainage system will collect the runoff from the proposed street, alley and portions of the surrounding lots. The collected storm water will be conveyed to the detention and treatment facilities at the south end of the site. See ' Figures 3C, 3D and 3E. The approximate size of the drainage basin draining into the proposed street and into the detention vault includes 1.52 acres, 0.66 acres of which is impervious. The remainder is runoff from landscaping. In an effort to mitigate the impacts of development, the project proposes to meet the standards t established by the City of Renton Design and Construction Standards and Specifications, revised May 1997. While there is an increase in the volume of storm water runoff due to the reduction in pervious surface, the detention system will detain storm water to pre-developed rates. The use of a storm water treatment vault downstream of the site reduces the potential for introducing pollutants from the proposed street into the downstream system. ' There is no existing storm water system at the proposed site. Storm water primarily infiltrates on site, flows as surface and near surface water onto neighbor's properties, or drains into the drainage system along the street. The storm water leaving the south and west portions of the property flow overland to ' Jones Avenue NE and NE 20th Street. From there the storm water is collected into a storm drain system and conveyed north. The storm water leaving the east end of the property flows overland toward ' Aberdeen Avenue NE where it is collected and conveyed in an existing storm system. The proposed storm water system for First Builders' proposed subdivision consist of the following elements: Collection: Catch basins will be spaced to limit surface flow and shall conform to City of Renton requirements. Conveyance: ' A piped system along the proposed street has been designed to convey the 25-year event into the proposed detention vault system and treatment vault at the south end of the proposed street without causing any backwater. See Section V, Conveyance System Analysis and Design for additional information. Detention: Detention is proposed to be provided for in the proposed detention vault that has been designed to accommodate the 2, 10 and 100 year, 24 hour events. A 30% factor of safety has been added to obtain ' a final vault size of 8 feet deep x 20 feet wide x 90 feet long. ' 8.UE41]501\M\wortl\report\tlrattM 1.loc 4 ' 15-0275.01 First Builders at Renton ' Treatment: Treatment is proposed to be provided by a water quality treatment vault manufactured by Stormwater Management and located on the south portion of the property. See Appendix 2 for Water Quality ' Treatment Vault,Sizing Calculations and Appendix 3 for documents in support of Stormwater Management's water quality treatment system. ' Discharge: The drainage then exits the site by way of a level spreader located at the southwest corner of the site. ' SECTION IL PRELIMINARY CONDITIONS SUMMARY The project site is located within a developed neighborhood with ground surface elevations ranging from approximately 306 to 266 feet. See Appendix 1. Two small ponds exist adjacent to Jones Avenue NE, directly west of the proposed site. There is also an existing drainage ditch approximately 200 feet east of Jones Avenue NE that parallels the avenue. There also exist numerous drainage ditches on the edge of the streets surrounding the block that occasionally contain standing water as most of the storm drainage around the block is conveyed in open ditches. No apparent water bodies or surface water drainage courses have been observed on the proposed site. Neither have surface waters been observed discharging onto the site from adjacent areas since the central portion of the proposed site is at a relative high point with respect to the elevations throughout ' the block. NE 241h Street contains a storm drainage system which conveys storm water east and west from the proposed site. There are moderately steep slopes that range from approximately 17 - 28% along the southern and southwestern portions of the property. Otherwise, slopes range from 5 — 13% throughout. There is no apparent drainage system at the proposed project site. Surface runoff leaving the property eventually flows to the existing drainage swale across Jones Avenue NE and is conveyed northward through additional swales that parallel SR-405 for approximately 1,000 feet. Drainage maps obtained at the City ' of Renton indicate that the storm water is then conveyed under the highway and flows west to Lake Washington. Existing Blackberry vines, Alder trees, and Douglas Fir form the principal vegetation on the site. We did not observe any creeks downslope of the proposed site although we did find numerous swales that conveyed up to two or three inches of water. There is an existing blueberry farm on the south side of ' NE 120' Street, between Jones Avenue NE and Aberdeen Avenue NE that contains various swales throughout. Between the blueberry farm and the proposed site, there appears to be an area that could hold water but no standing water was observed during our field visit other than what was observed ' within the drainage Swale. See Appendix 1, Downstream Flow Path Schematics. 5 ' 15-0275.01 First Builders at Renton ' Figures 3A though 3E show the drainage basins, subbasins and site characteristics for the project including the acreage of subbasins, existing discharge points to and from the site, existing construction and future flows at all discharge points. Figure 4 shows the soils within the project site,the area ' draining to the site, and the drainage system downstream of the site for the distance of the Downstream Analysis. See the geotechnical report for additional information. A CN value of 55 for the group A Indianola soils was used for the preliminary conditions calculations. See Figure 4 for additional information. SECTION III. OFF-SITE ANALYSIS A. Upstream Analysis ' From our observations, it does not appear as if storm water from an upstream basin is conveyed onto or through the site since the proposed site is at a relative high point with respect to the elevations ' throughout the block. B. Downstream Analysis, see Appendix 1. ' The proposed site runoff will release in three general directions, to the east,to the west and to the southwest. See Figures 3C and 3D. ' Except for runoff from roofs which will be directed to dry wells, storm water runoff from the east portion of the site will continue draining overland to the east. This runoff is strictly from the landscaped areas of homes on the east side of the development and not from the street. ' Again, with the exception of roof runoff, storm water runoff from the west portion of the site will continue draining to the west to Jones Avenue NE and toward SR-405. This runoff, like runoff on the ' east side, is strictly from the landscaped areas of homes on the west side of the development and not from the street. Storm water runoff from the remainder of the site will drain to the southwest. The proposed drainage system will collect the runoff from the proposed street and the portions of the surrounding proposed lots and convey it to the detention and treatment facilities at the south end of the site. After the storm ' water is collected and conveyed to a series of underground detention vaults at the south end of the property, the entire discharge will pass through a water quality treatment vault manufactured by "Stormwater Management". Because the flows leaving the site are so small,the 100-year outflow is 0.08cfs,we propose to convey the entire runoff through the treatment system rather than just the 6- month event. Following treatment,the storm water will be released through a level spreader over the ' southwest property corner and continue along it's predeveloped route over private property and then toward Jones Avenue NE and NE 20`h Street. The 2, 10 and 100-year release rates at the property corner are 0.01, 0.04 and 0.08 cfs respectively. 6 15-0275.01 First Builders at Renton ' Once the storm runoff is collected in the existing drainage system along a swale, approximately 200- feet east of Jones Avenue NE and paralleling it, the storm water is conveyed north and routed through two ponds located on private property. The ponds are on the property of those residents living at 1725 ' NE 24th Street and 2216 Jones Avenue NE. Storm water flows out of the ponds through a 24-inch culvert across Jones Avenue NE and again enters another swale on the west side of the road. From here, the storm water flows northwest through a 1 —3 foot wide swale that meanders through thick ' blackberries. When the swale reaches NE 24t' Avenue, it is combined with storm drainage being routed from the east. The combined flows are conveyed north under NE 24t' Street and enter yet another ' swale. From this point, the swale continues it's northern journey along the east side of SR-405. When the storm drainage reaches the west end of NE 271h Court, it is conveyed west under the highway through a storm drain pipe to the west side of SR-405. The storm water is then conveyed an additional ' 2,000 feet west of the highway before it enters Lake Washington. The drainage basin is the East Lake Washington drainage basin, south of the May Creek drainage basin and north of the Cedar River drainage basin; see Figures 3A, 3B, 3C, 3D and Section V, Conveyance System Analysis and Design for additional information. C. Review of Pertinent Resources ' The site was checked for sensitive areas using the December 1990 Sensitive Areas Map Folio. We did not observe or uncover any information that would indicate that there are sensitive areas at or adjacent to the site. The King County Soil Survey indicates the site has Indianola Series soils (see attached soils map in Figure 4). ' SECTION IV. RETENTION/DETENTION ANALYSIS AND DESIGN A. Existing Site Hydrology The existing site is made up of three drainage subbasins. It was analyzed using WaterWorks. For this site, P2 = 1.97 inches, P,o = 2.87 inches, P25 = 3.4 inches, and P,00 = 3.87 inches (see Appendix 2 for ' Isopluvial Maps). The Santa Barbara Urban Hydrograph Method (SBUH) was used in the hydrology analysis which is an acceptable method recognized by the City of Renton and the Washington State Department of Ecology. The basin consists of 4.35 acres containing two residences with associated garages and sheds, blackberry vines, and a scattering of Alder and Douglas Fir trees. The basin has a CN value of 55 for the group A Indianola soils; see Figure 4. It is proposed that the 4.35 acres be mass graded and converted to a residential subdivision. The existing time of concentration for the entire site is 56 minutes. The existing 100-year peak flow is 0.08 cfs,which produces a peak volume 4,069 CF (0.093 Acre-feet). Peak runoff rates for the existing and developed conditions are tabulated below. Note that the largest of the three existing subbasins, subbasin "South", contains the lowest peak flows. One might expect this subbasin to have the greatest peak flows of the three. This is attributed to the "South" subbasin having no impervious surface, a greater time of concentration and denser landscaping. The other two subbasins have 8 and 11% of impervious surface areas. 7 1 15-0275.01 First Builders at Renton ' B. Developed Site Hydrology The developed basin for the proposed subdivision consists of the same 4.35 acres. The subbasins that drain to the east and west will not contain any roadway runoff and will therefore not be detained or treated. Most of the runoff from these two subbasins will be from roofs that will be conveyed to dry wells. The remainder of the lots consisting of runoff from landscaping will either drain into the roadway or off-site to the east and west. What flows into the roadway is ultimately conveyed to the south end of the property. ' The subbasin that drains to the south and is detained and treated consists of 0.86 acres of landscaped area (CN = 68) and 0.66 acres of impervious surface (CN = 98). The developed time of concentration for the entire site is 10 minutes. The developed 2-year peak flow is 0.26 cfs which produces a volume of 4,792 CF (0.11 Acre-ft). The developed 100-year peak flow is 0.69 cfs which produces a volume of 12,197 CF (0.28 Acre-ft). Hydrograph Summary (Existing) ' Qpeak WS) Existing Conditions Basin Area (ac) 2-year 10-year 25-year 100-year East 1.40 0.04 0.07 ------ 0.09 rWest 0.61 0.03 0.04 ------ 0.06 South 2.34 0.01 0.04 ------ 0.08 J:\150275011M\wortl\report\tlratflN l.tloc H 15-0275.01 First Builders at Renton Hydrograph Summary (Developed) ' Qpeak (CfS) ' Developed Conditions Basin Area (ac) 2-year 10-year 25-year 100-year ' South 0.26 0.44 0.57 0.69 C131 0.09 0.10 ' CB2 0.06 0.08 CB3 0.03 0.03 CB4 0.05 0.06 ' CB5 0.02 0.02 C136 0.06 0.07 CB7 0.05 0.05 CB8 0.01 0.01 CB9 0.01 0.01 CB10 0.05 0.05 CB11 0.06 0.07 CB12 0.04 0.05 CB13 0.17 0.19 ' C. Hydrologic Analysis i. Detention Facility Sizing ' The proposed detention facility consists of a 90 LF detention vault that has been modeled to restrict the developed 2, 10, and 100-year runoff to the pre-developed 2, 10 and 100-year rates. Because the 2-year ' predeveloped rate is so small, 0.01 cfs, we are unable to model half of that rate and have designed the system to release the entire existing 2-year event. Appendix 2 contains pertinent system calculations for the detention facility analysis including Isopluvial maps. The following explains in detail the sizing of the system. 9 15-0275.01 First Builders at Renton ' The detention system will restrict storm runoff from all of the street, sidewalk, alley, as well as landscaped areas from individual lots that may drain toward the right-of-way. To size it, the existing and developed hydrographs for the south subbasin were compared using WaterWorks. The required ' detention volume is 8,787 ft'for a 68 LF long, 20-foot wide detention vault (see attached computer output). As a factor of safety the detention vault has been increased 30% to 88 LF and rounded up to 90 LF. ill (y� (�A\14 II. Water Quality Treatment Vault Sizing The water quality treatment system was sized based on the full 2-year release rate from the detention system using the SBUH model. Using WaterWorks for computing the storm event, the required design flow was computed to be 0.01 cfs. Since this release rate is so small, and because of the treatment ' system we are using, we have opted to treat the full 100-year release rate which is 0.08cfs. We propose to treat the runoff with a storm treatment system developed by Stormwater Management and which has been recently accepted by the Department of Ecology as an acceptable BMP for storm water treatment, BMP 5.8. The vault is approximately 7 ft wide x 9 ft long and 6 ft deep and contains 4 filter cartridges. Appendix 2 contains backup information regarding the water quality treatment system. ' Typically, the filter cartridges are serviced by Stormwater Management and a certification of inspection would typically be provided to the Storm Water Division to show that the treatment facility has been maintained and is in compliance. ' D. Retention/Detention System The detention storage requirements are explained above in Section N.C. Applicable calculations have been included, see appendix 2. SECTION V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN The developed site consists of one basin the South basin for conveyance calculations. This is because p � Y ' the East and Northwest subbasins are relatively small in comparison to the South basin and because the existing topography is such that the south end of the property has the lowest elevation. This allows us to construct one detention facility and one treatment facility and capture all of the stormwater that ' comes from the proposed streets and alleys. Portions of the Northwest basin still flow to the northwest but only those portions that are not part of the proposed right-of-way. The same goes for the East basin. Only those portions of the East subbasin that drain into the right-of-way are conveyed to the ' treatment and detention facilities. The developed peak flows were calculated for the 25 and 100 year storm events, see Appendix 2. Using WaterWorks, the reach summary shows all pipe reaches to be ' flowing well below capacity when the 25-year event is routed through. The greatest design depth is shown at the most downstream pipe run with a 25-year design depth of 0.60 (7.2 inches). Conveyance calculations were performed based on the 25-year events per the King County Surface Water Design Manual. ' J..\15027501\ct\watl\repot\\tlrallMl.tloc 10 ' 15-0275.01 First Builders at Renton The backwater analysis method was used to analyze the capacity of the proposed pipe system to ' convey the peak rate of runoff for the 25, and 100-year design storm events, see Appendix 2. The report demonstrates that the proposed pipe system provides a minimum of 0.5 feet of freeboard between the ' headwater surface (hydraulic grade line) and the top of the structure for the 25-year peak rate of runoff. The report also demonstrates that the 100-year peak rate of runoff does not overtop any structures. Tables listing pipe flow, profiles, nomographs, charts, graphs, and detailed drawings are provided in order to confirm performance of the conveyance system. The calculations verify the capacity and performance of each element of the on-site conveyance system. Backwater calculations were checked ' and show no adverse affect using 8-inch diameter pipe throughout. SECTION VI. SPECIAL REPORTS AND STUDIES A geotechnical report was prepared by GeoEngineers, Inc. in December 1999 and has been included as an attachment with this report SECTION VII. BASIN AND COMMUNITY PLANNING AREAS The site is located in King County's East Lake Washington Basin Plan as noted on the 1998 King County Flow Control Application Maps. ' SECTION VIII. OTHER PERMITS Preliminary and Final Plat Approval, and Grading Permit with SEPA Review. SECTION IX. EROSION/ SEDIMENTATION CONTROL AND DESIGN ' It is anticipated construction of the development will take place during the summer of 2000. Existing catch basins along NE 241h Street will be protected with filter fabric inlet filters. A construction entrance will be constructed for all construction equipment to pass through. Perimeter runoff will be controlled ' by silt fence installed-at the limits of clearing and along property lines, as needed. Other approved BMPs will be used as required. ' SECTION X. BOND QUANTITIES, WORKSHEET, RETENTION/DETEN ITION FACILITY SUMMARY SHEET AND SKETCH, AND DECLARATION OF COVENANT The Bond Quantities Worksheet is attached. See Appendix 5. The R/D Facility Summary Sheet and Sketch are attached. See Appendix 6. A Declaration of Covenant is provided in Appendix 7. 15-0275.01 First Builders at Renton SECTION XI. MAINTENANCE AND OPERATIONS MANUAL The following tables listed in Appendix 8 contain the required Operation and Maintenance Standards established by the City of Renton. They include required action regarding the cleaning of catch basins, detention pipe, control structure, conveyance pipes, et.al. ' With respect to the treatment facility, Stormwater Management typically services the filter cartridges and a certification of inspection would be provided to the City's Storm Water Division to show that the treatment facility has been maintained and is in compliance. ' The detention system contains one 90-foot long, 20-foot wide detention vault at the south end of the proposed site. Storm water is first conveyed into the detention vault from the series of catch basins and storm pipes along the proposed street. It is then released into a water quality treatment vault. Lastly,the treated storm water is then released through a level spreader. During a rain event, storm water is collected inside the detention vault. The detention vault is connected to a 54-inch diameter manhole by a 36-inch diameter pipe. The manhole contains a control structure that detains the storm water so that it leaves the detention vault at the pre-developed flow rate. Storm water being released from the control ' structure later enters the water quality vault followed by a level spreader and then it flows over land until it reaches the City of Renton's drainage system along Jones Avenue NE. It is recommended that Vactor trucks be used to clean out drainage facilities such as catch basins/ manholes when the basin exceeds 1/3 the depth from the bottom of the basin to invert of the lowest pipe. The Operation and Maintenance Standards table lists other less common reasons and requirements for cleaning catch basins/ manholes. The project lists the trees and shrubbery that are to be planted on site. The Contractor shall notify the ' Owner's representative prior to any deviation from the provided the planting list as the City of Renton prohibits the planting of certain species. 12 Page 1 of 2 ' King County Building and Land Development Division TECHNICAL INFORMATION REPORT (TIR) WORKSHEET PROJECTPART 1 PROJECT OWNER AND PART 2 PROJECT LOCATION • ' ProjectOwner Project Name FIF-5 i 'JLb L---0-_S Address 2,0.$c'x E�f�, � cN►L A cl6nL4-0 0 Location Phone ZST-2�, 6c-S0, 6Zt;-_5' Township Project Engineer Cv�--J-e? Range Company RCA Z HQ il Section Project Size q,3� AC Address Phone t4 ti KE. 5i Upstream Drainage Basin Size AC zo& 3 -SS"oa PART 37YPE OF ' Subdivision 0 DOF/G HPA = Shoreline Management 0 Short Subdivision = COE 404 = Rockery Grading = DOE Dam Safety 0 Structural Vaults ' 0 Commercial 0 FEMA Floodplain = Other Other COE Wetlands = HPA COMMUNITYPART 5 SITE D- Community i Drainage Basin �/t-S L,4 V-C Eli ON :�PART 6 .SITE-CHARACTERISTICS River 0 Floodplain ' Stream Wetlands Critical Stream Reach Seeps/Springs 0 Depressions/Swales 0 High Groundwater Table ' 0 Lake Groundwater Recharge Steep Slopes Other Lakeside/Erosion Hazard PART 7 SOILS Soil Type Slopes., Erosion Potential Erosive Velocities `r cIA i — 7.s7 h en�fe ' Additional� Ad a!Sheets Attatched FIGURE 1 1/90 ' King County Building and Land Development Division Page 2 of 2 TECHNICAL INFORMATION REPORT (TIR) WORKSHEET PARTS DEVELOPMENT LIMITATIONS ' REFERENCE LIMITATION/SITE CONSTRAINT (� Ch.4-Downstream Analysis El ' o 0 Additional Sheets Attatched ESCREQUIREMENTS ' MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION FOLLOWING CONSTRUCTION 0 Sedimentation Facilities = Stabilize Exposed Surface 0 Stabilized Construction Entrance = Remove and Restore Temporary ESC Facilities 0 Perimeter Runoff Control = Clean and Remove All Silt and Debris Clearing and Grading Restrictions = Ensure Operation of Permanent Facilities Cover Practices = Flag Limits of NGPES Construction Sequence = Other Other PART 10 SURFACE WATER SYSTEM L_J Grass Lined Channel Tank = Infiltration Method of Analysis Q Pipe System �_K] Vault 0 Depression _ SaLi t-+ Open Channel 0 Energy Dissapator 0 Flow Dispersal Compensation/Mitigation 0 Dry Pond Wetland 0 Waiver of Eliminated Site Storage 0 Wet Pond Stream = Regional Detention Brief Description of System Operation rr, ;��.?c ��-� t-� V cI C r X ZC I�, ,!5r ' Facility Related Site Limitations Reference -Facility Limitation 0 Additional Sheets Attatched PART 11 STRUCTURAL ANALYSIS PART 12 EASEMENTS/TRACTS (May require special structural review) Drainage Easement 0 Cast Place Vault C] Other C] Access Easement Retaining Wall Native Growth Protection Easement x�J Rockery>4'High Tract 1 Structural on Steep Slope Other PART 14 SIGNATURE OF -• • 1 I or a civil engineer under my supervision have visited the site. 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Y� , ��. � a _ -- -•� ;W � •rzs � 1 � rze �,,• - �. `, �. ��_�'-� -"��� �� is ' B8' 4k n •��\,.i•'�.: _ _ ��g -2�r: _ , _ , <tiF; .� 16N )I \'�., t z� \_ co 1\ i•.' /� Epp --��.- �'��/'M1 ?�I_ ., \ I •1 / l pEN � �- �'. ` ,, i . 150 '\ �\\ y' I , -I , �..\ \\ � / \\ - "R �:}•Ir _ r �l.#r 'Li Power ra I ^r - -1-�... 1�• ( �• I ° I _t C' - / 99 NE a 1 �. -% °I r / ,N' f- :\° \ •7railer w61 \ \` %1 _?s ti�\�e R7 np / / . ♦ •oR R o ' '• I B n, _ �• pk_:. � �i Q�at' -, . �a 1 1 S sta' �♦, - � i• t .1 r / \\ �.r// \ �I \ \ \ .l�• __,�-, �\L / / Pk \V •+ 1\ r •�Q` • : T )Sta .��;. u \ `►S I jh Sdi ' KCA/HUITT-ZDUARS FIGURE 3B e i z E ISTING SITE SU ASIN MAP W I _ Z - wl- - _ M _ _ - - -- - - Q GI 5'• 89'0T20'W iJ24.9S• � 4- JONES AVE.TO ABERDEEN AVE)-D D '4 '•`: r ,� ti�� �'°'� �'' x -.. j - w I N.E. 24TH STREET a - - - " O - - - -- - - o- - - - ^e N y89.07'20 E 213. I LEGAL DESCRIPTION 5' ENCE � ' LEGEND ' PORTIONS OF TRACT 262 AND 273 OF C.H. I n HILLMAN'S LAKE WASHINGTON GARDEN OF EDEN GARAGE I I \ \ ID HOUSE B LIGHT PULL 80% o DIVISION NO. 4 ACCORDING TO PLAT RECORDED IN / I CHAIN U `-' I� ' - � / I m VOLUME 11 OF PLATS AT PACE 82. IN KING COUNTY, LIGHT STANDARD W ARM WASHINCTON, DESCRIBED AS FOLLOWS: THE EAST 63 I FEET OF THE NORTH 200 FEET OF TRACT 27}. FENCE I I N 89'07�20" E ® MONUMENT IN CASE t THAT PORTION OF TRACT 262 COMMENCING AT A NW BASIN ^! H ! HOUSE ` ` 102.63' ■ HUB AND TACK POINT 60 FEET EAST OF THE NORTHWEST CORNER ' 0 IRON PIPE OF SAID TRACT 252; THENCE SOUTH 135 FEET / \ PARALLEL WITH THE WEST BOUNDARY OF SAID TRACT; PK NAIL N THENCE EAST 90 FEET PARALLEL WITH THE NORTH ' LINE OF SAID TRACT; THENCE NORTH 135 FEET HOUSE I \ I \ \ \ I LL PARALLEL WITH SAID WEST LINE,* THENCE WEST 90 PI a ® NATURAL GAS METER I FEET TO THE POINT OF BEGINNING. I\ \ 1 \ \ 5 POWER POLE WITH DROPLINE TRACT 262 EXCEPT THE SOUTH 238.72 FEET o SEP. I\ l I \ \ 1 \ N '¢ a THEREOF AND; EXCEPT THAT PORTION OF TRACT 262, o TANK ii DESCRIBED AS FOLLOWS; COMMENCING 60 FEET EAST 1 \ 1 p I POWER POLE WITH DROPLINE, AND TRANSFORMER o OF THE NORTHWEST CORNER THEREOF; THENCE OL �1 h SOUTH FOLLOWING THE WEST LINE OF SAID TRACT ARAG \ I ` ` , I I i �'IQ POWER POLE WITH LIGHT I 135 FEET; THENCE FOLLOWING THE NORTH LINE OF I I I I >1 1 1 I I c n SAID TRACT 90 FEET; THENCE NORTH FOLLOWING THE 5.5' WOOD O w STORM DRAIN CATCH BASIN a WEST LINE OF SAID TRACT 135 FEET TO THE NORTH I C, LINE THEREOF; THENCE WEST ALONG THE NORTH LINE ' 89'07'20" E FENCE 189.60 I I I I I \ \ ` 90 FEET TO THE POINT OF BEGINNING AND LESS THE z STORM DRAIN MANHOLE oro MAIL BOX NORTH 100 FEET OF THE EASTERLY 102.3 FEET I / ( I I \ I I a STREET SIGN ' FEET THER ANDEOF TRACT 273 EXCEPT THE NORTH 200 I I I I I I 1 I I I I II ` I 1 1 ! 1 \ \ \ I I R SANITARY SEWER MANHOLE m BASIS OF BEARINGS I I I I ' I , I \ \ I I I I I I \ 1 \ \ I \ \ r I ® TELEPHONE RISER/PEDISTAL w BEARINGS HEREON ARE BASED ON CITY OF RENTON CONIFER TREE I II I 1 I \\ I O M CPS SURVEY CONTROL NETWORK MONUMENTS. \ DECIDUOUS TREE�1 m - I I I \ I I (D SHRUB Z BASIS OF ELEVATION ELEVATIONS HEREON ARE BASED ON CITY OF RENTON r I I I I I I I I \ ® TELEVISION JUNCTION BOX 2 5 3 D ' CPS SURVEY CONTROL NETWORK MONUMENTS. I ' r / / I I I I I I ( \ '` / / ' I 1 I It, FIRE HYDRANT m BENCHMARK #334 TOP OF BRASS NAIL SET IN + ` CONCRETE MONUMENT AT INTERSECTION OF JONES I I I ' I / 1 \ f / / J \2 C AVENUE N.E. AND N.E. 247H STREET, ELEVATION 1 M HOSE BIB Z 244.34 NAGVD 1988 US FOOT. I I I ' ' ' / / J I I I ^ / / / I / / I I I ¢ I �' � � I � 83 WATER METER fn - N 89'13 58 / 252 8 I pG WATER VALVE_ i "CI) I UTILITY NOTES HOG WARE I I I 1 I �- 3oa / v In O STORM DRAINAGE CATCH BASIN FENCE l p' / \ ` I I I / 02 300i � 1' NATURAL GAS LINE TAG PNT# RIM EL INVERT EL I ' I I I I I I " D STORM DRAIN LINE 1 1001 300.72 IE 12 CONC W-299.01 I �� ' 1 I 1 ( `p -- ' IE 6 CONC SW-299.29 I I I I I 1 aR i w WATER LINE IE 12 CONIC E-299.04 �ii < < I i I o EAST BASIN DP 'BURIED POWER2 10 2 . IE 12 CUP E-291.27 TELEPHONE J 1024 289.18 IE 12 PVC NE-285.53 II \ \ \ I ` ni - AREA CONTAINED WITHIN DELINEATED BOUNDARY 4 1582 285 AREA IE 12 PVC W-285.48 I \ \ \ \ I I I I I 1 \ / / .70 IE 8 PVC H-283.70 I \ \\ \ \ v OVERHEAD POWER LINE ' EQUALS 4.35 ACRES. 8 CMP 5-282.97 - - - STORM DRAINAGE MANHOLE NHOLE s 'SANITARY SEWER UhE PAVEMENT TAG PNT RIM EL INVERT EL III \ \ \ \ I I ` I \\ / '- A'�•' ""'�'�'•" 1 1000 302.65 IE 12 PVC N-293.05 I \ \ \ \ \ ��� \ 2'^� / _ CONCRETE OR IE PVC W-293.03 1 ' IE 12 CONE .45 Al 1026 286.33 IE 8 CONE N-281.3281.33 USE ENCROACHMENT, AREA BEING USED BY ADJACENT IE 12 PVC W-280.55 OWNER TO THE NORTH. O SANITARY SEWER MANHOLE TAG PNTJ RIM EL INVERT EL 1 1003 294.08 IE 8 PVC S-285.06 ' 2 101. IE 12 PVC W-291.45 II 1I1 \ 1` ` \ \\\� 1 \ SOUTH BASIN 3 1025 25 29 291,6868 IE 12 PVC W-282.55 l 4IE 12 PVC IE 8- PVC -277.761 (JI 4 1350 284.70 IE B PVC E-277.63 � `\ \ \ \� ` " 13'S6"r, � -Z52.55',, 280- FIGURE 3C - - NOT FOR CONS RU TION APPROVALS JOB No. 15-0275-01 revlsbne RCA/HUl-ff-ZXLAf6 PRELIMINARY PLAT DATE ►T,DOBr 12,1999 TOPOGRAPHIC SURVEY DRAWING No. DCSICMD CT,DOB PORTION OF TRACT 282 AND 273 Investment Properles, LLC DRAFTED DBB SEC 5, T23N, R5E, W.M. PP-3 land Pl-"•OW E,g;n.wirg.l ad.o94 A littc4r..Suv. q.Tnhrawnenl.l SarAcp CAI,LV- CHECKED 51TC ADDRL55 1917 AND 1929 NORTHEAST 24TH STREET t e14 E.P'i.SI. . SealU.,wa 9e122 PM,w(xoa)J24-ssao Foc(xoe)32e-laeD SCALE 1'-40' SHEET NO. .w..huiH-rollora.com Relrton,WA 98056 D.C. 1917, 1929 NORTHEAST 24TH STREET �'-� RENTON, WA 96056 3 OF 4 Av.r-w Ew. 0 20 40 60 FEET f t MGuRE 3D DEVELOPED SITE SUBBASIN MAP t NOKM ...... .' --•t--�— ........ ...-,:: ........... . ............ ..... ........ .......... ..... 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'`'�n I ,i i, » 'I i �7a,a-.�••� 1 �'f:'4a• t _ I• _t^ _ . -its;% .- 'Sri'' .��1•'� �?ta�,., � •:��' r i+, 1 , � Ag'�• •t s', EvC:.. •.f I t' E � '.�•: r' �'•- :'•' r.' t'hra •r.' •a aFa / s-:'9-cR• � ►' EvB -�s:`.' � i tt �a �•� t '1_Y' + t`yi, ."' F(tYggCgo •• �'� �,: r '/� � • O �x �/�'•� e TS \,i '+7 s f: t�: .i.'. .' ••� +-'� hyi .a r<,�` , ��. Y i •i:� • B 11`*J.t1Qr 1.S .M + !+tljy�' s - t'f '—_— ••' 1+ 1 •r.�, - �•t: 1' :tr -�"�e 33.{' •. p 'Z,.is �i•- �, �' �J SN. t'�ir•+s``+t.•+.t, Z •..s7q,,. ;;`L+ - ">"' 4F •:,! •-� Ur 1 1 r 1.. rat. a o' ' ••e, !� n4'a•Sui• :':!=.r:Y.?°'�' . k 1 ai x" �fi' Dc'c ,1 i 'C.::1.' f]� •F✓ .f1t-•.P. - i•' i_• .- .I r TU�mv w "- _•t � ' •i ,4m <Y� C' Ar w • r' `S•� +"3:S- ys y * t �i. �J. O• -q�. �r. a - rrt'4 ur '1,,. *'-�'. � '�`i � .� �y M -.<:'� �1 tI r R®®ry ir. -c�� �r ,!• f� vyl- :•1 !7• 9 Tiailer ark }, d � Y { -• +n - BDY ' 'fl s_ti_ �`: ♦ i i.1 I i •f�: i•i► 't_i } gM Lt Wp •: BM ti i• r:�c t BM RdC Q Plant .S. �'•3•. •t- ,. '1:t .7 r t J ,:3r� .A$C` ''r,•�; :' .� +, ,�., +�� 1' •� t^;1 '. J i v i•.�.• C' t '�k,�� S •.,'. '��••t3� .. .. AgC I tv '$• L Ii , p, .` `• 9 • r �r tis �_,• n; _ ,. , i- •x. .1. ';:fir+.�� l—Jl-�/ -. ••,i ' I .•,,'�..1 _ ._ CGS AgC�ji R.4 E. R.5 E. RENTON 1.9 MI. 1290" (Joins sheet 1 1) Roc 10, 47030' ' RENTON 1.7 Ml. 122007'30" Scale 1:24 000 N Orthophotobase compiled in 1970 by USGS. Planimetric 1 3/4 1/z 1/4 0 1 2 Miles detail obtained from USGS 7V2*minute series maps. 5000 4000 3600 2000 1000 0 5000 10000 Feet Polyconic projection. 1927 North American datum. - _ ---------- ---- __ ___ _ 101000-foot grid based on Washington coordinate system, KCA/HU11T-,7DLM SOILS MAP FIGURE 4 3.2.2 KCRTSIRUNOFF FILES METHOD—GENERATING TIME SERIES ' TABLE 3.2 2.13 EQUIVALENCE BETWEEN SCS SOIL TYPES AND KCRTS SOIL TYPES SCS Soil Type SCS KCRTS Soil Notes Hydrologic Group ' Soil Group Alderwood (AgB, AgC, AgD) C Till Arents, Alderwood Material (AmB, AmC) C Till Arents, Everett Material (An) B Outwash 1 Beausite (BeC, BeD, BeF) C Till 2 Bellingham (Bh) D Till 3 Briscot (Br) D Till 3 Buckley (Bu) D Till 4 Earlmont (Ea) D Till 3 Edgewick (Ed) C Till 3 Everett (EvB, EvC, EvD, EwC) A/B Outwash 1 --� Indianola (InC, InA, InD) A Outwash 1 Kitsap (KpB, KpC, KpD) C Till Klaus (KsC) C Outwash 1 Neilton (NeC) A Outwash 1 Newberg (Ng) B Till 3 Nooksack (Nk) C Till 3 Norma (No) D Till 3 Orcas (Or) D Wetland Oridia (Os) D Till 3 Ovall (OvC, OvD, OvF) C Till 2 Pilchuck (Pc) C Till 3 Puget (Pu) D Till 3 Puyallup (Py) B Till 3 Ragnar(RaC, RaD, RaC, RaE) B Outwash 1 Renton (Re) D Till 3 ' Salal (Sa) C Till 3 Sammamish (Sh) D Till 3 Seattle (Sk) D Wetland Shalcar(Sm) D Till 3 Si (Sn) C Till 3 Snohomish (So, Sr) D Till 3 Sultan (Su) C Till 3 Tukwila (Tu) D Till 3 Woodinville (Wo) D Till 3 Notes: 1. Where outwash soils are saturated or underlain at shallow depth (<5 feet) by glacial till, they should be treated as till soils. 2. These are bedrock soils, but calibration of HSPF by King County DNR shows bedrock soils to have similar hydrologic response to till soils. 3. These are alluvial soils, some of which are underlain by glacial till or have a seasonally high water table. In the absence of detailed study, these soils should be treated as till soils. ' 4. Buckley soils are formed on the low-permeability Osceola mudflow. Hydrologic response is assumed to be similar to that of till soils. 1998 Surface Water Design Manual 9/1/98 3-25 gravelly coarse sand to very gravelly loamy sand. the presence of a consolidated substratum at a depth ' Depth to the IIC horizon ranges from 18 to 36 of 7 to 20 feet. This substratum is the same mate- inches. rial as that in the Alderwood soils. Some areas are up to 5 percent included Alderwood Some areas are up to 5 percent included Norma, soils, on the more rolling and undulating parts of Seattle, and Tukwila soils, all of which are poorly ' the landscape; some are about 5 percent the deep, drained. sandy Indianola soils; and some are up to 25 percent Runoff is slow to medium, and the erosion hazard Neilton very gravelly loamy sands. Also included is slight to moderate. in mapping are areas where consolidated glacial till, Most of the acreage is used for timber. Capabil- ' which characteristically underlies Alderwood soils, ity unit VIs-1; woodland group 3f3. is at a depth of 5 to 15 feet. Permeability is rapid. The effective rooting depth is 60 inches or more. Available water capac- Indianola Series ity is low. Runoff is slow, and the erosion hazard is slight. The Indianola series is made up of somewhat This soil is used for timber and pasture and for excessively drained soils that formed under conifers urban development. Capability unit IVs-1; woodland in sandy, recessional, stratified glacial drift. group 3f3. These undulating, rolling, and hummocky soils are on terraces. Slopes are 0 to 30 percent. The annual Everett gravelly sandy loam, 5 to 15 percent precipitation is 30 to 55 inches, and the mean slopes (EvC) .--This soil is rolling. Areas are annual air temperature is about 50° F. The frost- irregular in shape, have a convex surface, and range free season is 150 to 210 days. Elevation ranges from 25 acres to more than 200 acres in size. Run- from about sea level to 1,000 feet. off is slow to medium, and the erosion hazard is In a representative profile, the upper 30 inches slight to moderate. is brown, dark yellowish-brown, and light olive- Soils included with this soil in mapping make up brown loamy fine sand. This is underlain by olive no more than 25 percent of the total acreage. Some sand that extends to a depth of 60 inches or more areas are up to 5 percent Alderwood soils, which (pl. I, right) . overlie consolidated glacial till; some are up to Indianola soils are used for timber and for urban ' 20 percent Neilton very gravelly loamy sand; and development. some are about 15 percent included areas of Everett soils where slopes are more gentle than 5 percent Indianola loamy fine sand, 4 to 15 percent slopes and where they are steeper than 15 percent. (InQ --This undulating and rolling soil has convex This Everett soil is used for timber and pasture slopes. It is near the edges of upland terraces. and for urban development. Capability unit VIs-1; Areas range from 5 to more than 100 acres in size. woodland group 3f3. Representative profile of Indianola loamy fine sand, 4 to 15 percent slopes, in forest, 1,000 feet ' Everett gravelly sandy loam, 15 to 30 percent west and 900 feet south of the northeast corner of slopes (EvD) .--This soil occurs as long, narrow sec. 32, T. 25 N. , R. 6 E. : areas, mostly along drainageways or on short slopes between terrace benches. It is similar to Everett 01--3/4 inch to 0, leaf litter. gravelly sandy loam, 0 to 5 percent slopes, but in B21ir--0 to 6 inches, brown (10YR 4/3) loamy fine most places is stonier and more gravelly. sand, brown (10YR 5/3) dry; massive; soft, Soils included with this soil in mapping make up very friable, nonsticky, nonplastic; many no more than 30 percent of the total acreage. Some roots; slightly acid; clear, smooth boundary. areas are up to 10 percent Alderwood soils, which 4 to 8 inches thick. overlie consolidated glacial till; some are up to 5 B22ir--6 to 15 inches, dark yellowish-brown (10YR percent the deep, sandy Indianola soils; some are 4/4) loamy fine sand, brown (10YR 5/3) dry; up to 10 percent Neilton very gravelly loamy sand; massive; soft, very friable, nonsticky, non- and some are about 15 percent included areas ,of plastic; common roots; slightly acid; clear, Everett soils where slopes are less than 15 percent. smooth boundary. 6 to 15 inches thick. Runoff is medium to rapid, and the erosion hazard C1--15 to 30 inches, light olive-brown (2.5Y 5/4) is moderate to severe. loamy fine sand, yellowish brown (10YR 6/4) Most of the acreage is used for timber. Capa- dry; massive; soft, very friable, nonsticky, bility unit VIe-1; woodland group 3f2. nonplastic; common roots; slightly acid; gradual, smooth boundary. 12 to 17 inches Everett-Alderwood gravelly sandy loams, 6 to 15 thick. ' percent slopes (EwC) .--This mapping unit is about C2--30 to 60 inches, olive (5Y 5/4) sand, light equal parts Everett and Alderwood soils. The soils brownish gray (2.5Y 6/2) dry; single grain; are rolling. Slopes are dominantly 6 to 10 percent, loose, nonsticky, nonplastic; few roots; but range from gentle to steep. Most areas are slightly acid. Many feet thick. irregular in shape and range from 15 to 100 acres or more in size. In areas classified as Everett There is a thin, very dark brown Al horizon at soils, field examination and geologic maps indicate the surface in some places. The B horizon ranges 16 from very dark grayish brown to brown and dark and the mean annual air temperature is about 500 F. yellowish-brown. The C horizon ranges from dark The frost-free season is 150 to more than 200 days. grayish brown to pale olive and from loamy fine sand Elevation ranges from about sea level to 500 feet. to sand. Thin lenses of silty material are at a In a representative profile, the surface layer depth of 4 to 7 feet in some places. and subsoil are very dark brown and dark yellowish- Soils included with this soil in mapping make up brown silt loam that extends to a depth of about 24 no more than 25 percent of the total acreage. Some inches. The substratum is olive-gray silty clay areas are up to 10 percent Alderwood soils, on the loam. It extends to a depth of 60 inches or more. more rolling and undulating parts of the landscape; Kitsap soils are used for timber and pasture. - some are up to 8 percent the deep, gravelly Everett and Neilton soils; some are up to 15 percent Kitsap Kitsap silt loam, 2 to 8 percent slopes (KpB).- soils, which hav%%platy lake sediments in the sub- This undulating soil is on low terraces of the major soil; and some are up to 15 percent Ragnar soils, valleys of the Area. Areas range from 5 acres to which have a sandy substratum. more than 600 acres in size and are nearly circular Permeability is rapid. The effective rooting to irregular in shape. Some areas are one-eighth to depth is 60 inches or more. Available water capac- a half mile wide and up to 3 or 4 miles long. ity is moderate. Runoff is slow to medium, and the Representative profile of Kitsap silt loam, 2 to erosion hazard is slight to moderate. 8 percent slopes, in pasture, 820 feet west and 330 This soil is used for timber and for urban devel- feet south of east quarter corner of sec. 28, T. 25 opment, Capability unit IVs-2; woodland group 4s3. N. , R. 7 E. : Indianola loamy fine sand, 0 to 4 percent slopes Ap--O to 5 inches, very dark brown (10YR 2/2) silt (InA) .--This soil occupies smooth terraces in long loam, dark grayish brown (lOYR 4/2) dry; mod- narrow tracts adjacent to streams. Areas range from erate, medium, granular structure; slightly ' about 3 to 70 acres in size. hard, very friable, nonsticky, nonplastic; Soils included with this soil in mapping make up many roots; medium acid; abrupt, smooth bound-, no more than 20 percent of the total acreage. Some ary. areas are up to 5 percent Alderwood soils, on the B2--5 to 24 inches, dark yellowish-brown (IOYR 3/4) more rolling and undulating parts of the landscape; silt loam, brown (10YR 5/3) dry; 2 percent some are about 10 percent the deep, gravelly Everett iron concretions; weak, coarse, prismatic and Neilton soils; some are up to 10 percent Indian- structure; slightly hard, friable, slightly ola loamy fine sand that has stronger slopes; and sticky, slightly plastic; many roots; slightly some areas are up to 10 percent the poorly drained acid; abrupt, wavy boundary. 18 to 21 inches Norma, Shalcar, Tukwila soils. thick. Runoff is slow, and the erosion hazard is slight. IIC--24 to 60 inches, olive-gray (5Y 5/2) silty clay This soil is used for timber. Capability unit loam, light gray (5Y 7/2) dry; many, medium IVs-2; woodland group 4s3. and coarse, prominent mottles of dark yellowish brown and strong brown (10YR 4/4 and 7.5YR Indianola loamy fine sand, 15 to 30 percent 5/8) ; moderate, thin and medium, platy struc- slopes (InD) .--This soil is along entrenched streams. ture; hard, firm, sticky, plastic; few roots Soils included with this soil in mapping make up to a depth of 36 inches, none below; strongly no more than 25 percent of the total acreage. Some acid. areas are up to 10 percent Alderwood soils; some are about 5 percent the deep, gravelly Everett and Neil- The A horizon ranges from very dark brown to dark ton soils; some are up to 15 percent Kitsap soils, brown. The B horizon ranges from dark yellowish which have platy, silty lake sediments in the sub- brown to dark brown and from silt loam to silty clay soil; and some are up to 15 percent Indianola loamy loam. "The platy IIC horizon ranges from grayish fine sand that has milder slopes. brown to olive gray and from silt loam to silty clay Runoff is medium, and the erosion hazard is moder- loam that has thin lenses of loamy fine sand in ate to severe. places. Brownish mottle: are common in the upper This soil is used for timber. Capability unit part of the IIC horizon. VIe-1; woodland group 4s2. Some areas are up to 10 percent included Alderwood gravelly sandy loam; some are up to 5 percent the ' very deep, sandy Indianola soils; and some are up to Kitsap Series 5 percent the poorly drained Bellingham, Tukwila, and Seattle soils. The Kitsap series is made up of moderately well Water flows on top of the substratum in winter. drained soils that formed in glacial lake deposits, Permeability is moderate above the substratum and under a cover of conifers and shrubs. These soils very slow within it. The effective rooting depth is are on terraces and strongly dissected terrace about 36 inches. Available water capacity is moder- fronts. They are gently undulating and rolling and ate to moderately hi;h. Runoff is slow to medium, moderately steep. Slopes are 2 to 70 percent. and the erosion hazard is slight to moderate. Platy, silty sediments are at a depth of 18 to 40 This soil is used for timber and pasture. Capabil- inches. The annual precipitation is 35 to 60 inches, ity unit IIIe-1; woodland group M. ' 17 1 TABLE 2.--ESTIMATED PROPERTIES Classification Coarse Percentage Depth to Depth fraction passing Soil series and map seasonal from greater sieve-- symbols high water surface than 3 table USDA texture Unified AASHO inches in No. 4 diameter (4.7 mm,) Feet Inches Percent *Everett: EvB, EVC, EvD, 0-17 Gravelly sandy loam-- SM A-1 0-10 60-90 EwC. For Alderwood part of 17-32 Very gravelly sandy GM A-1 5-10 45-55 EwC, see Alderwood loam. series. 32-60 Very gravelly coarse GW or GP A-1 5-20 35-45 sand. =Ind�ilanola: nA, InC, (�) 0-30 Loamy fine sand------ SM A-2 0 9G-100 '� 30-60 Sand----------------- SP-SM A-3 0-5 90-100 Kitsap: KpB, KpC, KpD--- 12-3 0-24 Silt loam------------ ML A-4 0 95-100 24-60 Silty clay loam------ MH A-6 0 95-100 ' Klaus: KsC-------------- 0-60 Very gravelly loamy CP-GM A-1 20-40 4G-50 sand and very grav- elly sand. Mixed alluvial land: Ma. Properties are too variable to rate. Seasonal high water table is at the surface. Neilton: NeC------------ 0-18 Very gravelly loamy r,P-GM A-1 0-15 40-50 sand. 18-60 Very gravelly sand---- GW or GP A-1 5-15 35-45 Newberg: Ng------------- 3-4 0-60 Very fine sandy loam-- ML A-4 0 100 Nooksack: Nk------------ 3-4 0-60 Silt loam------------- ML A-4 0 100 Norma: No--------------- 0-1 0:760 Sandy loam------------ SM A-2 0 9;-100 Orcas: Or--------------- 0-1 0-60 Sphagnum peat--------- Pt A-8 ----- ------ Oridia: Os-------------- 1-2 0-64 Silt loam------------- ML A-6 or A-7 0 100 Oval1: OvC, OvD, OvF---- 0-36 Gravelly loam--------- SC or SM A-4 0-5 70-80 36 Weathered andesite. Pilchuck: Pc, Pk-------- 2-µ 0-38 Loamy fine sand------- SM A-2 0 85-100 (Fine sandy loam surface layer in Pk) 38-60 Gravelly sand-------- SP A-1 0-15 55-95 rSee footnotes at end of table. 38 OF THE SOILS--Continued Percentage passing sieve--Cont. Corrosivity Available Shrink-swell Permeability water Reaction potential Uncoated No. 10 No. 40 No. 200 capacity steel Concrete (2.0 mm.) (0.42 mm.) (0.074 mm. Inches/hr. Inches in pH of soil 50-85 35-50 15-25 2.o-6.3 0.08-0.10 5.1-6.5 Low---------- High--------- Moderate to high. 40 50 20-30 10 15 6.3-20.0 o.06-0.08 5.1-6.5 Low---------- Low---------- Moderate to high. 20-35 5-15 0-5 >20.0 0.02-0.04 5.6-6.5 Low---------- Low---------- Moderate. 85-100 60-75 20-30 6.3-20.0 0.09-0.11 6.1-6.5 Low---------- Low---------- Moderate. 75-90 55-75 5-10 >20.0 0.04-0.06 6.1-6.5 Low---------- Low---------- Moderate. 90-100 90-100 85-95 0.63-2.0 0.20-0.24 5.5-6.5 Low---------- Moderate----- Low to moderate. 95-100 95-100 90-100 <.06 0.04-0.06 5.1-6.5 Moderate----- High--------- Low to moderate. 30-40 10-20 5-10 6.3-20.0+ 0.03-0.05 4.o-6.0 Low---------- Moderate to Moderate to high. high. i E 30-40 10-20 5-10 6.3-20.0 0.03-0.05 5.1-5.0 Low---------- Moderate----- Moderate to high. 20-35 5-15 0-5 >20.0 0.02-0.04 5.6_6,5 Low---------- Low---------- Moderate. 100 85-95 50-6o o.63-2.0 o.16-o.18 5.6-7.3 Low---------- Moderate----- Low to moderate. i 100 95-100 95-100 0.63-0.0 0.20-0.24 5.6-6.5 Low----------- Moderate----- Low to moderate. 85-100 ------ 35-55 -? =. -' •S 0.12-0.14 5.6-6.5 Low----------- High--- Moderate. ------ ----- ----- 120.0 0.30-0.40 4.0-).0 High shrink, High--------- Etigh. low swell. 95-100 95-1oo 9o-loo j.2-2.0 0.20-0.24 4.5-7.3 Low---------- High--------- Low to high. 05-75 50-60 35-50 6.3-2.0 0.12-0.14 5.1-6.5 Low---------- Moderate----- Low to moderate. 80-100 60 20-30 .3-=0.0 0.08-0.10 0.1-7.3 Low----------- Low---------- Low to moderate. 50-90 30-40 0-5 >20.0 0.03-0.05 6.6-7.3 Low----------- Low---------- Low. 39 i E eTABLE 4.--DEGREE OF LIMITATIONS FOR TOWN AND COUNTRY PLANNING--Continued Soil series and map Foundations for Shallow Septic tank symbols low buildings excavations filter fields Sewage lagoons Briscot: Br------------- Severe: seasonal Severe: seasonal Severe: flood hazard; Severe: flood high water table; high water table. seasonal high water hazard. flood hazard. table. Buckley: Bu------------- Severe: seasonal Severe: seasonal Severe: slow perme- Severe: OL soil; high water table. high water table. ability; seasonal organic matter. high water table. Coastal beaches: Cb----- Severe: tidal Severe: tidal Severe: tidal Severe: tidal flooding. flooding. flooding. flooding. Earlmont: Ea------------ Severe: seasonal Severe: seasonal Severe: flood Severe: flood high water table; high water table. hazard; seasonal hazard. flood hazard; low high water table. shear strength. i Edgewick: Ed------------ Severe: flood Severe: flood Severe: flood Severe: flood hazard. hazard. hazard. hazard; rapid permeability in substratum. *Everett: EvB-------------------- None to slight---- Severe: very None to slight: Severe: G61 soil; gravelly. possible rapid perme- pollution hazard. ability. EvC, EwC--------------- Slight and moderate: Severe: very Slight and moderate: Severe: GM soils; For Alderwood part of moderate if slope gravelly. moderate if slope slope; rapid EwC, see AgC. is more than 8 is more than 8 permeability. percent. percent; possible pollution hazard. EvD-------------------- Severe: slope---- Severe: slope; Severe: slope; Severe: GM soil; very gravelly. possible pollution slope; rapid hazard. permeability. Indianola: Ind---------------- None to slight---- Severe: coarse None to slight: Severe: SP-Sht texture. possible pollution soil; rapid hazard. permeability. InC-------------------- Slight and moderate: Severe: coarse Slight and moderate: Severe: SP- Sm moderate if slope texture. moderate if slope soil; rapid is more than 8 is more than 8 permeability. percent. percent; possible pollution hazard. InD-------------------- Severe: slope; Severe: slope; Se%rere: slope-------- Severe: slope; slippage. coarse texture. rapid perme- ability. Kitsap: KpB-------------------- Moderate: seasonal Moderate: seasonal Severe: very slow Moderate: slope, high water table; high water table; permeability. low shear moderately well strength. _ drained. KpC-------------------- Severe: seasonal Moderate: slope; Severe: very slow Severe: slope. high water table; seasonal high permeability. low shear strength; water table. moderate slippage potential. KpD-------------------- Severe: seasonal Severe: slope; Severe: slope; very Severe: slope. high water table; seasonal high slow permeability. low shear strength; water table. severe slippage potential. 58 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TABLE 3.5.213 SCS WESTERN WASHINGTON RUNOFF CURVE 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 1 A rainfall distribution, 24-hour storm duration. CURVE NUMBERS BY HYDROLOGIC SOIL GROUP LAND USE DESCRIPTION A B C D Cultivated land(1): winter condition 86 91 94 95 Mountain open areas: low growing brush and grasslands 74 82 89 92 Meadow or pasture: 65 78 85 89 Wood or forest land: undisturbed or older second growth 64 76 81 Wood or forest land: vouna second arowth nr b= 55 72 81 86 Orchard: with cover crop 88 92 94 Open spaces, lawns, parks, golf courses, cemeteries, landscaping. good condition: grass cover on 75% or more of the area O 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, roofs, etc. 98 98 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 4.5 DU/GA 46 5.0 DU/GA 48 5.5 DU/GA 50 6.0 DU/GA 52 6.5 DU/GA 54 7.0 DU/GA 56 Planned unit developments, % impervious condominiums, apartments, must be computed ' 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. 3.5.2-3 11/92 2Nor— ,1 - 6- '. r -- �.,..a� a. . ` � •_f �r� YY y,j/,Yw",;,. •�wr. -�\< tc- v �:,\ \ `�\`..\\ •`(a- '�tC1• (T� , I -.i/ '� ��♦ "q♦... ^.. w � II yY J%r � r:: .L..a }* \.\ p ♦ `•. v,• ;lut`i'4,v �\•``�\^'i^. !, � \\` _, _ ti �'�Y a`�`�. %� cw�rf' ,. i r,. •- \\h �•4iR\1 11 .�♦�ZL�_r a , �1.�., ♦ ♦�♦;a •'� ` '. ` 7• -mac 7 -�C `���- ,�^' i+ ,Tr �,i�. � ♦�v �'!b"a�Q\\\��'kNt\ r�� ,�a ` ♦ `;.���I t �, fit'•,..,a �,\ �;` \\`•,.\.` (�J 2 th'Ct. , 7 ),I:z-7 l' - ,/ `�'�•* ���•\�♦� _ , ral �, ice.-\` '`�'.,'� _ - i W _.�• nd w, All WC 1. ,.�-•,- \ --] ,EI f0 - ._ 14-9 , 6 I, ,1. NE. L� t $t 1-7 714-5 Sly' _ ! I '✓ \t ,. I• I t �! 1 =' 'e .G,.2 •U, ¢ ` .. 8.1+-2 } ` I I 7.6+ . NE •'\ 7.C3-2 "� ,' t1�1 I l 7 )•GS- Q77.G I l' \ �\..� r _, � ¢ 1�1 \` i' I t As 12 It''•l4L _ ` •� „ 1`� 1 - /.. .cs 7, :'. ' � J+ li J,'.I i, •` 7J 6- ".Ir3-° ,.,\ I l�t ,)W ' 7.3G'1 w ®4G r lr, .. ✓ i i \ p, a„ > \ '''\\ Q Qr. ' ,.:r,l S,' r /,/,.:/ \ ;' t NE 19 h Liut,t ee6_il �r, E; S 71 nt L \a 1 C. 41 9-10; \t6.99-1 la a-�--� ��— \\\"t�.\•` Iz s: \ lob >� i��`. 12J2� t�N��`.�\♦1,1 �> ,'V _ th t \ � 11,'' \ `,\ '` \. E4 8 T23N R5E E 1/2 +;T y a Q zoo 400 lk UTILITIES DIVISION Renton City Limits �1'4e004. \� P/B,/PW TP---�mau. 'vim, Comm Ia wwak C i or LJ taBltt m DOWNSTREAM FLOW PATH SCHEMATIC oi i t I l Y .' It I ' `\ \ a` 1` ♦ -_ ,i1 ' (i it ` :i t`�SI 702-' i�/•, � i 7.E2. ' .r Yer9. ,wn`; >;' , `` 1 ; j \"'\ 2 th Ct I w. \, \, :•`,\ \\y���\, Wit. 1.� -_� 'L .; ) 1 \\,\., \>j �� \'1 7 1 t`4 � -:1.: I 1 \ 1,•t 1 ,/� .� ` 1•� ; sl ,1 4-6 a s , �1� t,t� l •• , xix y^�',,a \\�\l�`�,�♦`\\ rllli ! ll T`-`�y� .\ llW — — — — l�\ \'•` �'><'_� �"...7.m 16 :1,.4 ��; `of �,, i/�i/ ,ti , �IL'a N 7.D3-17it: N\, ♦ \\r \\t1,,1 1'1 ` x,. •'' :i I W 3-0': + llA ut�� 7 t. .\\ ,\� `\; : t1.11.0 1 rr \;,u,. / ,.�•i-t 4„ , i� � \ i M 9 " >x lr I f r!," J✓fir ,r \' \ \ fit' 1 t \ -i 3 'Vlrp.r r t.l lul 11 i,lAl1 7; h' i Zrr 11/�ftit ,�i,t plr � 1�dt( �.✓\. \\. "•_�i.,r; �'\J ,06- I 11lil,tll L,II "riG 77Kr + -Yt' xr. , ' -.V if iI• AA h ` . �.os- .,;lwaxv}+.= �11Jkr' �\•kill � � 1 1, , 1 .axa - __ (, \\ •..\ - d,1 .11%?j1r`f,llli�.�14 A i ll�)� '4t' - � �.706 3 �• i ary rf}}��f iQ�rt�9ljf' ' i1�111�/ t .r - t,.._ . - Y .` \i ,. ..If:r .`jll Il�f,�r(/\�'•"t r'I��. / \ I Z` ''\,` I '� . _� __ \r� 1 " /. � ! / �ry�1 rr -err r'� 1\' , �• l r - -- \ •' , �/�• 1. ':!'.1 k!7,\I\ '�� ` ,1 i, ' \,: ,o �'� NE !6 - ' \:.' •C , �`�° '�i.WMl,�1lk rll l\.IC \��. t 7y'7-6'�. Nit w •• \\`jj'� e •\•' `ll'tt +�- w yl `4 '\ F779 j .POND 3INS - ` , � .. \ '-•\\,.�� .:.r x111 _: `�,.' f ,h, ��: i. 1. ' ;POND A.i - , 1. V Q'~r�f-j�•4:fX.l ,1\ t, , \` •\ � I .. ,\ 0 3 12.02- / r_`' „ y •! \'•: �\` `\\ 12l2t w.�� ti1 o 12.0J-I POND Zh `4 - tJ T23N R5E W 1/2 Y _ +~.A. ��+ UTILITIES DI'' NION �.�e_ Renton City mite R 14a00 4QO4 P/B/PW 1TXHMCAY, LZIC3tLTE Concuvr IIaEor..lz 0.5 or 41J attars 04/06/98 DLM= NAVD 1M Mouts 5 T23N R5 1/2 DOWNSTREAM FLOW PATH SCHEMATIC u • . . r- - --- -- - ' t ''�'A. 7 '; , J NORTH L 7,E4-, , • . s -C F 64 t S t- \7 7�4" 1 7,E4-7 7,E4—S 4—G �'; 4—( f ` Is N. WALE ' ;';:� `r ` 1 ► .�1725 NE: 24 1 - 3 WID P N S ,jj q; i SITE f 2411 DI C, LVERT r ' ' > 2216 ', I'+, '\►� ' , te 7.E4-1 NE LE�f 'L S ABADE" �l Q,t 7�4 I•.G -I0 1 E - II1 7. 7,G5— �. i << ',:� 4 1. • • .• :'� ,�ti .:•� ,t. �; . , .. � G - r WE. M TA.'.t WAL 7 , 5�.•;1 1 I L1J r \. 1 I J i f I\ •I, I'1.I \ICJ• '�' - •7 ! 6. + ` J-Y • j ' •�' \ ! ` - 7,✓\J-� LU ' ► _ ,! • 73 rs_ NE 19 h Q, 1 �. �- • ,�•�: •; +1 ,+I ' BLUE E ' •�� � 7,rs-• 7 KCA/HUITT-ZOLM DOWNSTREAM FLOW PATH SCHEMATICS Appendix 2 APPENDIX 2 SYSTEM CALCULATIONS AND DESIGN 1 a O i� , 'ki �\ 1 PAP!_ �.�...� fit w��`VAN�r��l�i�� ■Y�A�A In CAI ��► ��; ��� �� �� � •1ST"=; ,. S Wv 0 1p s . RID M It ago �� „ .111 •• G C lllYw.ac � ' � � l I � � . -%141 MIN bmkbi • • ���r . y. l -allte '�Ci`/► . 1"'ilk'► . � '�' -- ILI E o < it* So Wyly A �� u�� , wri MA • • M,AI i DETENTION PIPE SIZING FOR THE 21 10& 100-YEAR EvENTS 11/12/99 8 :4 : 52 am RCA - Seattle page 1 First Builders - Renton 2, 10 & 100 yr Event for Detention DETAIL BASIN SUMMARY .raw-1 BASIN ID' • Ex2yrNW NAME : Predev 2 yr event F Basin SBUH METHODOLOGY TOTAL AREA. . . . . . . 0 . 61 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 1 . 97 inches AREA. . : 0 . 54 Acres 0 . 07 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 55 . 00 98 . 00 TC. . . . : 11 . 92 min 5 . 00 min ABSTRACTION COEFF: 0 .20 TcReach - Sheet L: 130 . 00 ns : 0 . 1500 p2yr: 1 . 97 s : 0 . 0380 PEAK RATE: 0 . 03 cfs VOL: 0 . 01 Ac-ft TIME: 480 min TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) 10 310 0.0057 610 0.0071 910 0.0048 1210 0.0044 1510 20 320 0.0069 620 0.0068 920 0.0048 1220 0.0044 1520 30 330 0.0070 630 0.0068 930 0.0048 1230 0.0045 1530 40 340 0.0071 640 0.0068 940 0.0048 1240 0.0046 1540 50 350 0.0072 650 0.0068 950 0.0048 1250 0.0046 1550 60 360 0.0073 660 0.0068 960 0.0048 1260 0.0046 1560 70 370 0.0071 670 0.0061 970 0.0037 1270 0.0047 1570 80 0.0003 380 0.0068 680 0.0054 980 0.0028 1280 0.0047 1580 90 0.0007 390 0.0068 690 0.0054 990 0.0028 1290 0.0048 1590 100 0.0009 400 0.0069 700 0.0055 1000 0.0027 1300 0.0049 1600 110 0.0012 410 0.0070 710 0.0054 1010 0.0028 1310 0.0049 1610 120 0.0014 420 0.0070 720 0.0054 1020 0.0028 1320 0.0049 1620 130 0.0018 430 0.0112 730 0.0055 1030 0.0034 1330 0.0046 1630 140 0.0022 440 0.0154 740 0.0054 1040 0.0042 1340 0.0041 1640 150 0.0024 450 0.0156 750 0.0054 1050 0.0042 1350 0.0041 1650 160 0.0025 460 0.0216 760 0.0055 1060 0.0043 1360 0.0041 1660 170 0.0027 470 0.0277 770 0.0055 1070 0.0044 1370 0.0042 1670 180 0.0029 480 0.0279 780 0.0055 1080 0.0044 1380 0.0042 1680 190 0.0030 490 0.0200 790 0.0048 1090 0.0042 1390 0.0042 1690 ' 200 0.0031 500 0.0120 800 0.0041 1100 0.0038 1400 0.0042 1700 210 0.0033 510 0.0121 810 0.0041 1110 0.0039 1410 0.0043 1710 220 0.0033 520 0.0114 820 0.0041 1120 0.0053 1420 0.0043 1720 230 0.0034 530 0.0108 830 0.0041 1130 0.0040 1430 0.0043 1730 240 0.0035 540 0.0108 840 0.0041 1140 0.0027 1440 0.0044 1740 250 0.0039 550 0.0091 850 0.0044 1150 0.0041 1450 0.0025 1750 260 0.0042 560 0.0074 860 0.0048 1160 0.0041 1460 0.0005 1760 270 0.0043 570 0.0074 870 0.0048 1170 0.0042 1470 0.0002 1770 280 0.0044 580 0.0075 880 0.0048 1180 0.0043 1480 1780 290 0.0044 590 0.0074 890 0.0048 1190 0.0043 1490 1790 300 0.0045 600 0.0074 900 0.0048 1200 0.0043 1500 1800 11/12/99 8 :4 : 52 am RCA - Seattle page 3 First Builders - Renton 2, 10 & 100 yr Event for Detention --------------------------------------------------------------------- --------------------------------------------------------------------- DETAIL BASIN SUMMARY �E BASIN Ib '. ExXyrNW NAME : Predev 10 yr event NW Basin SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 61 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPE1A PERV IMP PRECIPITATION. . . . : 2 . 87 inches AREA. . : 0 . 54 Acres 0 . 07 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . 55 . 00 98 . 00 TC . . . . : 12 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE: 0 . 04 cfs VOL: 0 . 02 Ac-ft TIME : 480 min TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) 10 310 0.0091 610 0.0109 910 0.0139 1210 0.0129 1510 20 320 0.0110 620 0.0108 920 0.0142 1220 0.0129 1520 30 330 0.0111 630 0.0112 930 0.0144 1230 0.0130 1530 40 340 0.0111 640 0.0115 940 0.0145 1240 0.0132 1540 50 350 0.0112 650 0.0120 950 0.0147 1250 0.0132 1550 60 0.0003 360 0.0113 660 0.0125 960 0.0149 1260 0.0132 1560 70 0.0008 370 0.0109 670 0.0117 970 0.0125 1270 0.0134 1570 80 0.0015 380 0.0105 680 0.0107 980 0.0097 1280 0.0134 1580 90 0.0020 390 0.0105 690 0.0109 990 0.0092 1290 0.0135 1590 100 0.0024 400 0.0105 700 0.0113 1000 0.0089 1300 0.0137 1600 110 0.0028 410 0.0106 710 0.0114 1010 0.0090 1310 0.0136 1610 120 0.0031 420 0.0106 720 0.0117 1020 0.0090 1320 0.0137 1620 130 0.0037 430 0.0169 730 0.0120 1030 0.0107 1330 0.0128 1630 140 0.0043 440 0.0233 740 0.0122 1040 0.0129 1340 0.0117 1640 150 0.0045 450 0.0234 750 0.0125 1050 0.0134 1350 0.0114 1650 160 0.0047 460 0.0324 760 0.0128 1060 0.0137 1360 0.0112 1660 170 0.0050 470 0.0414 770 0.0130 1070 0.0139 1370 0.0113 1670 180 0.0052 480 0.0415 780 0.0133 1080 0.0141 1380 0.0114 1680 190 0.0053 490 0.0297 790 0.0121 1090 0.0133 1390 0.0113 1690 200 0.0055 500 0.0179 800 0.0107 1100 0.0123 1400 0.0114 1700 210 0.0056 510 0.0179 810 0.0106 1110 0.0121 1410 0.0115 1710 220 0.0056 520 0.0169 820 0.0107 1120 0.0156 1420 0.0114 1720 230 0.0058 530 0.0160 830 0.0108 1130 0.0128 1430 0.0116 1730 240 0.0059 540 0.0160 840 0.0109 1140 0.0092 1440 0.0117 1740 250 0.0064 550 0.0135 850 0.0118 1150 0.0119 1450 0.0073 1750 260 0.0069 560 0.0110 860 0.0129 1160 0.0122 1460 0.0022 1760 270 0.0070 570 0.0110 870 0.0132 1170 0.0124 1470 0.0009 1770 280 0.0071 580 0.0110 880 0.0133 1180 0.0126 1480 0.0004 1780 290 0.0071 590 0.0110 890 0.0136 1190 0.0127 1490 0.0002 1790 300 0.0072 600 0.0111 900 0.0138 1200 0.0127 1500 1800 11/12/99 8 :4 : 52 am RCA - Seattle page 2 First Builders - Renton 2 , 10 & 100 yr Event for Detention - DETAIL BASIN SUMMARY �o BASIN ID':' ExCyrNW NAME : Predev 100 yr event ( WW) Basin SBUH METHODOLOGY �� TOTAL AREA. . . . . . . 0 . 61 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 54 Acres 0 . 07 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 55 . 00 98 . 00 TC . . . . : 12 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE: 0 . 06 cfs VOL : 0 . 04 Ac-ft TIME: 480 min TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) 10 310 0.0128 610 0.0287 910 0.0288 1210 0.0247 1510 20 320 0.0154 620 0.0282 920 0.0292 1220 0.0247 1520 30 330 0.0155 630 0.0287 930 0.0295 1230 0.0248 1530 40 0.0001 340 0.0155 640 0.0291 940 0.0296 1240 0.0251 1540 50 0.0005 350 0.0156 650 0.0299 950 0.0300 1250 0.0250 1550 60 0.0011 360 0.0157 660 0.0305 960 0.0302 1260 0.0251 1560 70 0.0020 370 0.0151 670 0.0287 970 0.0256 1270 0.0254 1570 80 0.0031 380 0.0145 680 0.0263 980 0.0201 1280 0.0253 1580 90 0.0038 390 0.0145 690 0.0261 990 0.0187 1290 0.0254 1590 100 0.0044 400 0.0145 700 0.0264 1000 0.0180 1300 0.0257 1600 110 0.0048 410 0.0146 710 0.0266 1010 0.0180 1310 0.0257 1610 120 0.0052 420 0.0146 720 0.0269 1020 0.0180 1320 0.0257 1620 130 0.0060 430 0.0232 730 0.0274 1030 0.0211 1330 0.0241 1630 140 0.0068 440 0.0320 740 0.0277 1040 0.0252 1340 0.0220 1640 150 0.0071 450 0.0321 750 0.0280 1050 0.0264 1350 0.0214 1650 160 0.0073 460 0.0442 760 0.0286 1060 0.0270 1360 0.0210 1660 170 0.0076 470 0.0564 770 0.0288 1070 0.0274 1370 0.0211 1670 180 0.0078 480 0.0571 780 0.0291 1080 0.0276 1380 0.0212 1680 190 0.0079 490 0.0425 790 0.0268 1090 0.0262 1390 0.0210 1690 200 0.0081 500 0.0284 800 0.0238 1100 0.0242 1400 0.0213 1700 210 0.0082 510 0.0308 810 0.0232 1110 0.0238 1410 0.0214 1710 220 0.0082 520 0.0315 820 0.0231 1120 0.0299 1420 0.0212 1720 230 0.0084 530 0.0319 830 0.0231 1130 0.0252 1430 0.0215 1730 240 0.0085 540 0.0337 840 0.0233 1140 0.0183 1440 0.0216 1740 250 0.0092 550 0.0306 850 0.0248 1150 0.0228 1450 0.0140 1750 260 0.0098 560 0.0266 860 0.0269 1160 0.0235 1460 0.0047 1760 270 0.0099 570 0.0268 870 0.0276 1170 0.0239 1470 0.0019 1770 280 0.0101 580 0.0276 880 0.0279 1180 0.0243 1480 0.0008 1780 290 0.0100 590 0.0282 890 0.0284 1190 0.0243 1490 0.0003 1790 300 0.0101 600 0.0290 900 0.0287 1200 0.0244 1500 0.0001 1800 11/12/99 8 : 5 : 11 am RCA - Seattle page 1 ' First Builders - Renton 2 , 10 & 100 yr Event for Detention --------------------------------------------------------------------- --------------------------------------------------------------------- DETAIL BASIN SUMMARY BASIN ID '- Ex2yrE NAME : Predev 2 yr event East Basin SBUH METHODOLOGY r TOTAL AREA. . . . . . . : 1 .40 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE . . . . : TYPElA PERV IMP PRECIPITATION. . . . : 1 . 97 inches AREA. . : 1 .29 Acres 0 . 11 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 55 . 00 98 . 00 TC . . . . : 40 .28 min 5 . 00 min ABSTRACTION COEFF: 0 .20 TcReach - Sheet L: 70 . 00 ns : 0 .4000 p2yr: 1 . 97 s : 0 . 0150 TcReach Sheet L: 130 . 00 ns : 0 . 4000 p2yr. 1 . 97 s : 0 . 1080 PEAK RATE: 0 . 04 cfs VOL: 0 . 02 Ac-ft TIME: 480 min TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) 10 310 0.0090 610 0.0112 910 0.0075 1210 0.0074 1510 0.0007 20 320 0.0109 620 0.0107 920 0.0076 1220 0.0074 1520 0.0006 30 330 0.0111 630 0.0107 930 0.0076 1230 0.0076 1530 0.0004 40 340 0.0112 640 0.0106 940 0.0075 1240 0.0078 1540 0.0003 50 350 0.0113 650 0.0107 950 0.0076 1250 0.0078 1550 0.0003 60 360 0.0115 660 0.0107 960 0.0076 1260 0.0079 1560 0.0002 70 0.0001 370 0.0111 670 0.0096 970 0.0059 1270 0.0081 1570 0.0002 80 0.0005 380 0.0107 680 0.0085 980 0.0043 1280 0.0082 1580 0.0001 90 0.0010 390 0.0107 690 0.0085 990 0.0043 1290 0.0083 1590 100 0.0015 400 0.0108 700 0.0086 1000 0.0043 1300 0.0085 1600 110 0.0019 410 0.0109 710 0.0085 1010 0.0043 1310 0.0085 1610 120 0.0022 420 0.0109 720 0.0086 1020 0.0043 1320 0.0087 1620 130 0.0028 430 0.0175 730 0.0086 1030 0.0054 1330 0.0082 1630 140 0.0034 440 0.0242 740 0.0086 1040 0.0065 1340 0.0076 1640 150 0.0037 450 0.0244 750 0.0086 1050 0.0066 1350 0.0076 1650 160 0.0040 460 0.0339 760 0.0086 1060 0.0067 1360 0.0075 1660 170 0.0043 470 0.0435 770 0.0086 1070 0.0068 1370 0.0076 1670 180 0.0045 480 0.0438 780 0.0086 1080 0.0069 1380 0.0077 1680 190 0.0047 490 0.0314 790 0.0075 1090 0.0065 1390 0.0076 1690 200 0.0049 500 0.0189 800 0.0064 1100 0.0060 1400 0.0077 1700 210 0.0051 510 0.0190 810 0.0064 1110 0.0061 1410 0.0078 1710 220 0.0052 520 0.0179 820 0.0064 1120 0.0084 1420 0.0078 1720 230 0.0054 530 0.0169 830 0.0064 1130 0.0065 1430 0.0079 1730 240 0.0055 540 0.0170 840 0.0065 1140 0.0045 1440 0.0080 1740 250 0.0061 550 0.0143 850 0.0070 1150 0.0066 1450 0.0054 1750 260 0.0066 560 0.0117 860 0.0075 1160 0.0067 1460 0.0025 1760 270 0.0067 570 0.0117 870 0.0076 1170 0.0068 1470 0.0020 1770 280 0.0069 580 0.0117 880 0.0075 1180 0.0070 1480 0.0015 1780 290 0.0069 590 0.0117 890 0.0076 1190 0.0071 1490 0.0012 1790 300 0.0070 600 0.0117 900 0.0076 1200 0.0072 1500 0.0009 1800 11/12/99 8 : 5 : 11 am RCA - Seattle page 3 First Builders - Renton 2 , 10 & 100 yr Event for Detention --------------------------------------------------------------------- --------------------------------------------------------------------- DETAIL BASIN SUMMARY 0 BASIN IDI" ExXyrE NAME : Predev 10 yr event 'East! Basin SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1 .40 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 2 . 87 inches AREA. . : 1 . 29 Acres 0 . 11 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 55 . 00 98 . 00 TC . . . . : 40 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE : 0 . 07 cfs VOL: 0 . 04 Ac-ft TIME : 480 min TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) 10 310 0.0143 610 0.0169 910 0.0262 1210 0.0261 1510 0.0035 20 320 0.0172 620 0.0166 920 0.0268 1220 0.0262 1520 0.0028 30 330 0.0174 630 0.0171 930 0.0272 1230 0.0264 1530 0.0021 I 40 340 0.0175 640 0.0177 940 0.0276 1240 0.0267 1540 0.0017 50 350 0.0176 650 0.0186 950 0.0282 1250 0.0268 1550 0.0013 60 0.0004 360 0.0177 660 0.0194 960 0.0286 1260 0.0270 1560 0.0010 70 0.0013 370 0.0171 670 0.0185 970 0.0256 1270 0.0273 1570 0.0008 80 0.0023 380 0.0165 680 0.0174 980 0.0221 1280 0.0274 1580 0.0006 90 0.0031 390 0.0165 690 0.0180 990 0.0211 1290 0.0276 1590 0.0005 100 0.0038 400 0.0165 700 0.0187 1000 0.0203 1300 0.0279 1600 0.0004 110 0.0044 410 0.0167 710 0.0192 1010 0.0199 1310 0.0280 1610 0.0003 120 0.0049 420 0.0166 720 0.0198 1020 0.0195 1320 0.0281 1620 0.0002 130 0.0058 430 0.0266 730 0.0205 1030 0.0214 1330 0.0271 1630 0.0002 140 0.0067 440 0.0366 740 0.0210 1040 0.0241 1340 0.0257 1640 0.0001 150 0.0071 450 0.0368 750 0.0216 1050 0.0250 1350 0.0252 1650 0.0001 160 0.0074 460 0.0509 760 0.0223 1060 0.0257 1360 0.0247 1660 170 0.0078 470 0.0650 770 0.0229 1070 0.0264 1370 0.0246 1670 180 0.0081 480 0.0653 780 0.0235 1080 0.0269 1380 0.0244 1680 190 0.0083 490 0.0467 790 0.0222 1090 0.0263 1390 0.0242 1690 200 0.0086 500 0.0281 800 0.0205 1100 0.0252 1400 0.0243 1700 210 0.0088 510 0.0281 810 0.0204 1110 0.0251 1410 0.0243 1710 220 0.0089 520 0.0266 820 0.0205 1120 0.0294 1420 0.0241 1720 230 0.0091 530 0.0251 830 0.0206 1130 0.0262 1430 0.0243 1730 240 0.0092 540 0.0251 840 0.0208 1140 0.0217 1440 0.0244 1740 250 0.0100 550 0.0212 850 0.0220 1150 0.0249 1450 0.0191 1750 260 0.0108 560 0.0172 860 0.0235 1160 0.0250 1460 0.0125 1760 270 0.0109 570 0.0172 870 0.0241 1170 0.0252 1470 0.0097 1770 280 0.0111 580 0.0173 880 0.0246 1180 0.0255 1480 0.0075 1780 290 0.0111 590 0.0172 890 0.0252 1190 0.0256 1490 0.0059 1790 300 0.0112 600 0.0173 900 0.0258 1200 0.0258 1500 0.0046 1800 11/12/99 8 : 5 : 11 am RCA - Seattle page 2 ' First Builders - Renton 2, 10 & 100 yr Event for Detention --------------------------------------------------------------------- --------------------------------------------------------------------- DETAIL BASIN SUMMARY BASIN ID?: ExCyrE NAME : Predev 100 yr event{ East Basin SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1 . 40 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 1 . 29 Acres 0 . 11 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 55 . 00 98 . 00 TC . . . . : 40 . 00 min 5 . 00 min ABSTRACTION COEFF : 0 . 20 PEAK RATE : 0 . 09 cfs VOL: 0 . 08 Ac-ft TIME: 480 min TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) 10 310 0.0201 610 0.0527 910 0.0587 1210 0.0526 1510 0.0075 20 320 0.0242 620 0.0528 920 0.0597 1220 0.0527 1520 0.0059 30 330 0.0243 630 0.0540 930 0.0604 1230 0.0529 1530 0.0046 40 0.0002 340 0.0244 640 0.0551 940 0.0609 1240 0.0534 1540 0.0036 50 0.0008 350 0.0245 650 0.0566 950 0.0618 1250 0.0535 1550 0.0028 60 0.0017 360 0.0246 660 0.0580 960 0.0625 1260 0.0537 1560 0.0021 70 0.0032 370 0.0237 670 0.0562 970 0.0573 1270 0.0542 1570 0.0017 80 0.0049 380 0.0228 680 0.0537 980 0.0505 1280 0.0543 1580 0.0013 90 0.0060 390 0.0227 690 0.0535 990 0.0477 1290 0.0545 1590 0.0010 100 0.0068 400 0.0228 700 0.0539 1000 0.0454 1300 0.0550 1600 0.0008 ' 110 0.0076 410 0.0230 710 0.0540 1010 0.0439 1310 0.0551 1610 0.0006 120 0.0082 420 0.0229 720 0.0545 1020 0.0427 1320 0.0553 1620 0.0005 130 0.0094 430 0.0365 730 0.0552 1030 0.0454 1330 0.0535 1630 0.0004 140 0.0107 440 0.0502 740 0.0557 1040 0.0499 1340 0.0510 1640 0.0003 150 0.0112 450 0.0504 750 0.0563 1050 0.0518 1350 0.0498 1650 0.0002 160 0.0115 460 0.0695 760 0.0573 1060 0.0534 1360 0.0487 1660 0.0002 170 0.0119 470 0.0887 770 0.0579 1070 0.0547 1370 0.0482 1670 0.0001 180 0.0122 480 0.0893 780 0.0586 1080 0.0558 1380 0.0478 1680 0.0001 190 0.0124 490 0.0656 790 0.0562 1090 0.0549 1390 0.0472 1690 200 0.0127 500 0.0427 800 0.0525 1100 0.0530 1400 0.0472 1700 210 0.0129 510 0.0461 810 0.0514 1110 0.0524 1410 0.0471 1710 220 0.0130 520 0.0475 820 0.0507 1120 0.0594 1420 0.0468 1720 230 0.0132 530 0.0490 830 0.0503 1130 0.0544 1430 0.0469 1730 240 0.0133 540 0.0528 840 0.0500 1140 0.0466 1440 0.0470 1740 250 0.0144 550 0.0499 850 0.0516 1150 0.0510 1450 0.0383 1750 260 0.0155 560 0.0459 860 0.0541 1160 0.0511 1460 0.0265 1760 270 0.0156 570 0.0473 870 0.0553 1170 0.0513 1470 0.0206 1770 280 0.0158 580 0.0491 880 0.0561 1180 0.0518 1480 0.0160 1780 290 0.0158 590 0.0506 890 0.0572 1190 0.0519 1490 0.0125 1790 300 0.0159 600 0.0523 900 0.0581 1200 0.0521 1500 0.0097 1800 11/12/99 8 :4 : 12 am RCA - Seattle page 4 First Builders - Renton 2 , 10 & 100 yr Event for Detention --------------------------------------------------------------------- --------------------------------------------------------------------- DETAIL BASIN SUMMARY BASIN ITDt: Ex2yrS NAME : Predev 2 yr event Sout Basin SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2 . 34 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 1 . 97 inches AREA. . : 2 . 34 Acres 0 . 00 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 55 . 00 0 . 00 TC. . . . : 55 . 99 min 0 . 00 min ABSTRACTION COEFF: 0 . 20 TcReach - Sheet L: 175 . 00 ns : 0 .4000 p2yr: 1 . 97 s : 0 . 0280 TcReach - Sheet L: 125 . 00 ns : 0 .4000 p2yr: 1 . 97 s : 0 . 0920 TcReach - Shallow L: 65 . 00 ks : 5 . 00 s : 0 . 0750 PEAK RATE : 0 . 01 cfs VOL: 0 . 00 Ac-ft TIME : 1440 min TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) 10 310 610 910 1210 0.0032 1510 0.0020 20 320 620 920 1220 0.0034 1520 0.0017 30 330 630 930 1230 0.0036 1530 0.0014 40 340 640 940 1240 0.0039 1540 0.0012 50 350 650 950 1250 0.0041 1550 0.0010 60 360 660 960 1260 0.0043 1560 0.0008 70 370 670 970 1270 0.0045 1570 0.0007 80 380 680 980 1280 0.0047 1580 0.0006 90 390 690 990 1290 0.0049 1590 0.0005 100 400 700 1000 1300 0.0052 1600 0.0004 110 410 710 1010 1310 0.0054 1610 0.0003 120 420 720 1020 1320 0.0056 1620 0.0003 130 430 730 1030 1330 0.0057 1630 0.0002 140 440 740 1040 1340 0.0057 1640 0.0002 150 450 750 1050 0.0002 1350 0.0057 1650 0.0002 160 460 760 1060 0.0003 1360 0.0057 1660 0.0001 170 470 770 1070 0.0004 1370 0.0058 1670 0.0001 180 480 780 1080 0.0006 1380 0.0059 1680 190 490 790 1090 0.0008 1390 0.0059 1690 200 500 800 1100 0.0010 1400 0.0060 1700 210 510 110 1110 0.0012 1410 0.0061 1710 220 520 820 1120 0.0015 1420 0.0062 1720 230 530 830 1130 0.0017 1430 0.0063 1730 240 540 840 1140 0.0017 1440 0.0065 1740 250 550 850 1150 0.0019 1450 0.0060 1750 260 560 860 1160 0.0021 1460 0.0050 1760 270 570 870 1170 0.0023 1470 0.0042 1770 210 580 810 1110 0.0026 1480 0.0035 1780 290 590 890 1190 0.0028 1490 0.0029 1790 300 600 900 1200 0.0030 1500 0.0024 1800 r r 11/12/99 8 :4 : 12 am RCA - Seattle page 7 1 First Builders - Renton 2, 10 & 100 yr Event for Detention DETAIL BASIN SUMMARY i BASIN ID? ExXyrS NAME : Predev 10 yr event South Basin SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2 . 34 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 2 . 87 inches AREA. . : 2 . 34 Acres 0 . 00 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 55 . 00 0 . 00 TC. . . . : 56 . 00 min 0 . 00 min ABSTRACTION COEFF : 0 . 20 PEAK RATE: 0 . 04 cfs VOL: 0 . 03 Ac-ft TIME : 1320 min TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) 10 310 610 0.0005 910 0.0262 1210 0.0325 1510 0.0103 so 20 320 620 0.0011 920 0.0271 1220 0.0328 1520 0.0086 1//4be 30 330 630 0.0019 930 0.0279 1230 0.0331 1530 0.0072 40 340 640 0.0029 940 0.0217 1240 0.0335 1540 0.0060 50 350 650 0.0041 950 0.0296 1250 0.0338 1550 0.0050 60 360 660 0.0054 960 0.0304 1260 0.0341 1560 0.0042 70 370 670 0.0065 970 0.0299 1270 0.0345 1570 0.0035 80 380 680 0.0074 980 0.0284 1280 0.0348 1580 0.0029 90 390 690 0.0084 990 0.0272 1290 0.0352 1590 0.0025 100 400 700 0.0094 1000 0.0261 1300 0.0356 1600 0.0021 110 410 710 0.0105 1010 0.0253 1310 0.0359 1610 0.0017 120 420 720 0.0115 1020 0.0247 1320 0.0362 1620 0.0014 130 430 730 0.0126 1030 0.0251 1330 0.0359 1630 0.0012 140 440 740 0.0137 1040 0.0264 1340 0.0351 1640 0.0010 150 450 750 0.0147 1050 0.0276 1350 0.0345 1650 0.0008 160 460 760 0.0158 1060 0.0287 1360 0.0339 1660 0.0007 170 470 770 0.0169 1070 0.0296 1370 0.0335 1670 0.0006 180 480 780 0.0180 1080 0.0306 1380 0.0332 1680 0.0005 190 490 790 0.0186 1090 0.0309 1390 0.0330 1690 0.0004 200 500 800 0.0187 1100 0.0308 1400 0.0329 1700 0.0003 210 510 810 0.0189 1110 0.0307 1410 0.0328 1710 0.0003 220 520 820 0.0191 1120 0.0327 1420 0.0327 1720 0.0002 230 530 830 0.0194 1130 0.0324 1430 0.0327 1730 0.0002 240 540 840 0.0198 1140 0.0304 1440 0.0328 1740 0.0002 250 550 850 0.0205 1150 0.0307 1450 0.0301 1750 0.0001 260 560 860 0.0215 1160 0.0310 1460 0.0252 1760 0.0001 270 570 870 0.0225 1170 0.0312 1470 0.0210 1770 280 580 880 0.0234 1180 0.0316 1480 0.0176 1780 290 590 890 0.0244 1190 0.0319 1490 0.0147 1790 300 600 0.0001 900 0.0253 1200 0.0322 1500 0.0123 1800 11/12/99 8 :4-: 12 am RCA - Seattle page 5 1 First Builders - Renton 2 , 10 & 100 yr Event for Detention --------------------------------------------------------------------- DETAIL BASIN SUMMARY BASIN ID'=-: ExCyrS NAME : Predev 100yr event South Basin SBUH METHODOLOGY TOTAL AREA. . . . . . . : 2 . 34 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 2 . 34 Acres 0 . 00 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 55 . 00 0 . 00 TC. . . . : 56 . 00 min 0 . 00 min ABSTRACTION COEFF : 0 . 20 PEAK RATE: 0 . 08 cfs VOL: 0 . 09 Ac-ft TIME: 960 min TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN TIME DESIGN RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF RUNOFF (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) (min) (cfs) 10 310 610 0.0499 910 0.0778 1210 0.0756 1510 0.0220 20 320 620 0.0522 920 0.0792 1220 0.0759 1520 0.0184 30 330 630 0.0546 930 0.0805 1230 0.0763 1530 0.0154 40 340 640 0.0570 940 0.0116 1240 0.0768 1540 0.0129 50 350 650 0.0595 950 0.0829 1250 0.0772 1550 0.0107 60 360 660 0.0621 960 0.0841 1260 0.0776 1560 0.0090 70 370 670 0.0634 970 0.0820 1270 0.0781 1570 0.0075 80 380 680 0.0635 980 0.0772 1280 0.0785 1580 0.0063 90 390 690 0.0638 990 0.0733 1290 0.0789 1590 0.0053 100 400 700 0.0645 1000 0.0699 1300 0.0795 1600 0.0044 110 410 710 0.0652 1010 0.0672 1310 0.0799 1610 0.0037 120 420 720 0.0661 1020 0.0651 1320 0.0803 1620 0.0031 130 430 730 0.0672 1030 0.0655 1330 0.0794 1630 0.0026 140 440 740 0.0683 1040 0.0682 1340 0.0774 1640 0.0021 150 450 750 0.0695 1050 0.0706 1350 0.0757 1650 0.0018 160 460 760 0.0708 1060 0.0728 1360 0.0743 1660 0.0015 170 470 770 0.0721 1070 0.0747 1370 0.0732 1670 0.0013 180 480 0.0006 780 0.0735 1080 0.0764 1380 0.0724 1680 0.0010 190 490 0.0027 790 0.0732 1090 0.0768 1390 0.0716 1690 0.0009 200 500 0.0062 800 0.0715 1100 0.0760 1400 0.0712 1700 0.0007 210 510 0.0110 810 0.0701 1110 0.0754 1410 0.0708 1710 0.0006 220 520 0.0163 820 0.0692 1120 0.0794 1420 0.0704 1720 0.0005 230 530 0.0217 830 0.0685 1130 0.0784 1430 0.0703 1730 0.0004 240 540 0.0276 840 0.0681 1140 0.0733 1440 0.0703 1740 0.0004 ' 250 550 0.0320 850 0.0688 1150 0.0736 1450 0.0644 1750 0.0003 260 560 0.0348 860 0.0705 1160 0.0738 1460 0.0539 1760 0.0003 270 570 0.0377 870 0.0721 1170 0.0740 1470 0.0450 1770 0.0002 280 580 0.0408 880 0.0736 1180 0.0745 1480 0.0376 1780 0.0002 290 590 0.0439 890 0.0751 1190 0.0747 1490 0.0315 1790 0.0001 300 600 0.0471 900 0.0765 1200 0.0751 1500 0.0263 1800 0.0001 11/18/99 5 :27 :26 pm RCA - Seattle page 1 First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- BASIN SUMMARY BASIN ID . cbl-Cyr NAME : Area draining into cb#1 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 19 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 09 Acres 0 . 11 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . . 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE: 0 . 10 cfs VOL: 0 . 04 Ac-ft TIME: 480 min BASIN ID: cb10-Cyr NAME : Area draining into cb#10 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 07 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 00 Acres 0 . 07 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 0 . 00 98 . 00 TC. . . . : 0 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE : 0 . 05 cfs VOL: 0 . 02 Ac-ft TIME : 480 min BASIN ID: cbll-Cyr NAME: Area draining into cb#11 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 16 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 09 Acres 0 . 07 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . . 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE : 0 . 07 cfs VOL : 0 . 03 Ac-ft TIME : 480 min BASIN ID: cb12-Cyr NAME : Area draining into cb412 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 08 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP ' PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 02 Acres 0 . 06 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF : 0 . 20 PEAK RATE: 0 . 05 cfs VOL: 0 . 02 Ac-ft TIME : 480 min 11/18/99 5 : 21 :26 pm RCA - Seattle page 2 First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- BASIN SUMMARY BASIN I t- cbl3-Cyr NAME: Area draining into cb#13 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 29 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 06 Acres 0 . 23 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE: 0 . 19 cfs VOL: 0 . 07 Ac-ft TIME : 480 min BASIN ID: cb14-Cyr NAME : Area draining into cb#14 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 00 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 00 Acres 0 . 00 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . 68 . 00 98 . 00 TC. . . . . 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE: 0 . 00 cfs VOL: 0 . 00 Ac-ft TIME : 480 min BASIN ID: cb2-Cyr NAME: Area draining into cb#2 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 15 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 07 Acres 0 . 08 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . . 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE: 0 . 08 cfs VOL: 0 . 03 Ac-ft TIME: 480 min BASIN ID: cb3-Cyr NAME : Area draining into cb#3 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 05 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 01 Acres 0 . 04 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . . 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE : 0 . 03 cfs VOL : 0 . 01 Ac-ft TIME : 480 min 11/18/99 5 :27 : 26 pm RCA - Seattle page 3 First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- BASIN SUMMARY BASIN ID:= cb4-Cyr NAME : Area draining into cb#4 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 11 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 05 Acres 0 . 06 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . . 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE: 0 . 06 cfs VOL: 0 . 02 Ac-ft TIME : 480 min BASIN ID: cb5-Cyr NAME : Area draining into cb#5 SBUH METHODOLOGY TOTAL AREA. . . . . . . • 0 . 03 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 00 Acres 0 . 03 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . 0 . 00 98 . 00 TC. . . . . 0 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE : 0 . 02 cfs VOL: 0 . 01 Ac-ft TIME: 480 min BASIN ID: cb6-Cyr NAME : Area draining into cb#6 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 17 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 10 Acres 0 . 07 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE : 0 . 07 cfs VOL: 0 . 03 Ac-ft TIME : 480 min BASIN ID: cb7-Cyr NAME : Area draining into cb#7 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 08 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 01 Acres 0 . 07 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . . 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE : 0 . 05 cfs VOL: 0 . 02 Ac-ft TIME : 480 min t 11/18/99 5 :27 : 26 pm RCA - Seattle page 4 ' First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- BASIN SUMMARY BASIN ID7'. cb8-Cyr NAME : Area draining into cb#8 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 02 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 01 Acres 0 . 01 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF : 0 . 20 PEAK RATE : 0 . 01 cfs VOL: 0 . 00 Ac-ft TIME : 480 min BASIN ID: cb9-Cyr NAME : Area draining into cb#9 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 03 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 02 Acres 0 . 01 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE : 0 . 01 cfs VOL: 0 . 00 Ac-ft TIME: 480 min t11/12/99 9 : 14 :25 am RCA - Seattle page 1 First Builders - Renton 2 , 10 & 100 yr Event for Detention BASIN SUMMARY BASIN ID: Dev100yr NAME : Dev 100 yr event South Basin SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1 . 52 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 0 . 86 Acres 0 . 66 Acres TIME INTERVAL. . . . . 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE: 0 . 69 cfs VOL: 0 . 28 Ac-ft TIME: 480 min BASIN ID: Dev10yr NAME: Dev 10 yr event South Basin SBUH METHODOLOGY TOTAL AREA. . . . . . . . 1 . 52 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 2 . 87 inches AREA. . : 0 . 86 Acres 0 . 66 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE: 0 . 44 cfs VOL: 0 . 19 Ac-ft TIME: 480 min BASIN ID: Dev2yr NAME : Dev 2 yr event South Basin SBUH METHODOLOGY TOTAL AREA. . . . . . . : 1 . 52 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 1 . 97 inches AREA. . : 0 . 86 Acres 0 . 66 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF. 0 .20 PEAK RATE: 0 . 26 cfs VOL: 0 . 11 Ac-ft TIME : 480 min ' 11/12/99 8 : 28 : 15 am RCA - Seattle page 1 First Builders - Renton 2 , 10 & 100 yr Event for Detention STAGE STORAGE TABLE RECTANGULAR VAULT ID No. 1 Description: Detention Vault Length: 68 . 00 ft . Width: 20 . 00 ft . voids : 1 . 000 STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> (ft) ---cf--- --Ac-Ft- (ft) ---Cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- ` , 100 50 0.0000 0.0000 103.00 3400 0.0781 105.50 6800 0.1561 108.00 10200 0.2342 4- S y QUI�) 100.60 136.00 0.0031 103.10 3536 0.0812 105.60 6936 0.1592 08.10 10336 0.237 100.70 272.00 0.0062 103.20 3672 0.0843 105.70 7072 0.1624 1 8.20 10472 0.2 4 100.80 408.00 0.0094 103.30 3808 0.0874 105.80 7208 0.1655 10 .30 10608 0. 35 100.90 544.00 0.0125 103.40 3944 0.0905 105.90 7344 0.1686 108.40 10744 0 466 101.00 680.00 0.0156 103.50 4080 0.0937 106.00 7480 0.1717 108. 0 10880 .2498 101.10 816.00 0.0187 103.60 4216 0.0968 106.10 7616 0.1748 108.6 11016 0.2529 101.20 952.00 0.0219 103.70 4352 0.0999 106.20 7752 0.1780 108.70 11152 0.2560 101.30 1088 0.0250 103.80 4488 0.1030 106.30 7888 0.1811 108.80 1128 0.2591 101.40 1224 0.0281 103.90 4624 0.1062 106.40 8024 0.1842 108.90 114 4 0.2623 101.50 1360 0.0312 104.00 4760 0.1093 106.50 8160 0.1873 109.00 1 60 0.2654 101.60 1496 0.0343 104.10 4896 0.1124 106.60 8296 0.1904 109.10 1 696 0.2685 101.70 1632 0.0375 104.20 5032 0.1155 106.70 8432 0.1936 109.20 1 32 0.2716 101.80 1768 0.0406 104.30 5168 0.1186 106.80 8568 0.1967 109.30 /119 8 0.2747 101.90 1904 0.0437 104.40 5304 0.1218 106.90 8704 0.1998 109.40 1210 0.2779 102.00 2040 0.0468 104.50 5440 0.1249 107.00 8840 0.2029 109.50/ 12240 0.2810 102.10 2176 0.0500 104.60 5576 0.1280 107.10 8976 0.2061 11 12376 .2841 102.20 2312 0.0531 104.70 5712 0.1311 107.20 9112 0.2092 109. 0 12512 0 2872 102.30 2448 0.0562 104.80 5848 0.1343 107.30 9248 0.2123 109 80 12648 0. 904 102.40 2584 0.0593 104.90 5984 0.1374 107.40 9384 0.2154 10 .90 12784 0.2 35 102.50 2720 0.0624 105.00 6120 0.1405 107.50 9520 0.2185 1X0.00 12920 0.29 6 102.60 2856 0.0656 105.10 6256 0.1436 107.60 9656 0.2217 h0.00 12920 0.296 102.70 2992 0.0687 105.20 6392 0.1467 107.70 9792 0.2248 102.80 3128 0.0718 105.30 6528 0.1499 107.80 9928 0.2279 102.90 3264 0.0749 105.40 6664 0.1530 107.90 10064 0.2310 11/12/99 8 :4 : 12 am RCA - Seattle page 9 First Builders - Renton 2 , 10 & 100 yr Event for Detention STAGE DISCHARGE TABLE MULTIPLE'ORIFICE ID No. 01 ' Description: Orifice Control Outlet Elev: 100 . 50 Elev: 98 . 50 ft Orifice Diameter: 0 . 3633 in. - 3Ae� Elev: 103 . 80 ft Orifice 2 Diameter: 0 . 8994 in. Elev: 105 . 60 ft Orifice 3 Diameter: 1 . 0664 in. _ STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> (ft) ---Cfs-- ------- (ft) ---Cfs-- ------- (ft) ---Cfs-- ------- (ft) ---Cfs-- ------- ------------------------------------------------------------------------------- 100.50 0.0000 102.10 0.0045 103.70 0.0064 105.30 0.0347 100.60 0.0011 102.20 0.0047 103.80 0.0065 105.40 0.0357 100.70 0.0016 102.30 0.0048 103.90 0.0135 105.50 0.0366 100.80 0.0020 102.40 0.0049 104.00 0.0165 105.60 0.0375 100.90 0.0023 102.50 0.0051 104.10 0.0188 105.70 0.0482 101.00 0.0025 102.60 0.0052 104.20 0.0208 105.80 0.0531 101.10 0.0028 102.70 0.0053 104.30 0.0225 105.90 0.0570 101.20 0.0030 102.80 0.0054 104.40 0.0241 106.00 0.0605 101.30 0.0032 102.90 0.0055 104.50 0.0255 106.10 0.0636 101.40 0.0034 103.00 0.0057 104.60 0.0269 106.20 0.0665 101.50 0.0036 103.10 0.0058 104.70 0.0282 106.30 0.0692 101.60 0.0038 103.20 0.0059 104.80 0.0294 106.40 0.0717 101.70 0.0039 103.30 0.0060 104.90 0.0305 106.50 0.0741 ' 101.80 0.0041 103.40 0.0061 105.00 0.0316 101.90 0.0042 103.50 0.0062 105.10 0.0327 102.00 0.0044 103.60 0.0063 105.20 0.0337 11/12/99 8 :4 : 13 am RCA - Seattle page 10 First Builders - Renton 2 , 10 & 100 yr Event for Detention --------------------------------------------------------------------- --------------------------------------------------------------------- ' LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- <-PEAK-> OUTFLOW STORAGE t <-__=====DESCRIPTION--------->--(cfs)--(cfs)---id----id--<=STAGE>-id (cfs)_VOL_(cf) 2 yr Event .................. . 0.01 0.26 1 01 103.75 1 0.01 4419.44 cf ' 10 yr Event .................. 0.04 0.44 1 01 105.45 2 0.04 6738.28 cf 100 yr Event ................. 0.08 0.69 1 01 106.96 3 0.08 8787.42 cf OY- 1 ' WATER QUALITY TREATMENT VAULT SIZING CALCULATIONS ' 11/12/99 12 : 26 : 53 am RCA - Seattle page 1 First Builders - Renton ' 2 , -10-&-100-yr-Event-for-Detention ----------------------------------- BASIN SUMMARY ' BASIN ID: Ex2yrS NAME: Predev 2 yr event South Basin SBUH METHODOLOGY ' TOTAL AREA. . . . . . . : 2 . 34 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE . . . . : TYPElA PERV IMP PRECIPITATION. . . . : 1 . 97 inches AREA. . : 2 .34 Acres 0 . 00 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 55 . 00 0 . 00 TC . . . . : 55 . 99 min 0 . 00 min ABSTRACTION COEFF: 0 .20 TcReach - Sheet L: 175 . 00 ns : 0 . 4000 p2yr: 1 . 97 s : 0 . 0280 TcReach - Sheet L: 125 . 00 ns : 0 .4000 p2yr: 1 . 97 s : 0 . 0920 TcReach - Shallow L: 65 . 00 ks : 5 . 00 s : 0 . 0750 PEAK RATE: 0 . 01 cfs VOL: 0 . 00 Ac-ft TIME: 1440 min ' BASIN ID: ExCyrS NAME: Predev 100yr event South Basin SBUH METHODOLOGY ' TOTAL AREA. . . . . . . : 2 . 34 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 3 . 87 inches AREA. . : 2 . 34 Acres 0 . 00 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 55 . 00 0 . 00 ' TC. . . . : 56 . 00 min 0 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE: 0 . 08 cfs VOL: 0 . 09 Ac-ft TIME: 960 min ' CONVEYANCE CALCULATIONS FOR THE 2 S-YEAR EVENT NORTH ............ ------ .. --- ------- ......... 2N. 7T IL C13#5 a Lbl P5 GB#1 G5#.G 6B#3 c5#2 P7 p p pq/RG GB#7 c5#8 CB#q P2/Rl P /R3 C B#4 Plo/R7 C,5#12 P12/Rq C5#14 P13/ 10 rc,B#1 ---- ---------- NOT TO 5(:�ALE FIGLWE FCVHUTT-ZAM ROUTING SCHEMATIC ' 11/18/99 5 :26 : 34 pm RCA - Seattle page 1 First Builders - Renton ' Preliminary Drainage Report BASIN SUMMARY ' BASIN ID: cbl-25yr NAME : Area draining into cb#1 SBUH METHODOLOGY ' TOTAL AREA. . . . . . . : 0 . 19 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 .40 inches AREA. . : 0 . 09 Acres 0 . 11 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . . 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE: 0 . 09 cfs VOL: 0 . 03 Ac-ft TIME: 480 min BASIN ID: cb10-25y NAME : Area draining into cb#10 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 07 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 40 inches AREA. . : 0 . 00 Acres 0 . 07 Acres TIME INTERVAL. . . . . 10 . 00 min CN. . . . : 0 . 00 98 . 00 TC. . . . : 0 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE: 0 . 05 cfs VOL: 0 . 02 Ac-ft TIME : 480 min BASIN ID: cb11-25y NAME: Area draining into cb#11 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 16 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 40 inches AREA. . : 0 . 09 Acres 0 . 07 Acres ' TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 ' PEAK RATE : 0 . 06 cfs VOL: 0 . 02 Ac-ft TIME : 480 min BASIN ID: cb12-25y NAME : Area draining into cb#12 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 08 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 40 inches AREA. . : 0 . 02 Acres 0 . 06 Acres ' TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE : 0 . 04 cfs VOL: 0 . 02 Ac-ft TIME: 480 min 11/18/99 5 :26 : 34 pm RCA - Seattle page 2 ' First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- ' BASIN SUMMARY BASIN IJD . cb13-25y NAME : Area draining into cb#13 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 .29 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 3 .40 inches AREA. . : 0 . 06 Acres 0 . 23 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE: 0 . 17 cfs VOL: 0 . 06 Ac-ft TIME : 480 min BASIN ID: cb14-25y NAME: Area draining into cb#14 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 00 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP ' PRECIPITATION. . . . : 3 .40 inches AREA. . : 0 . 00 Acres 0 . 00 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . . 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE : 0 . 00 cfs VOL: 0 . 00 Ac-ft TIME: 480 min BASIN ID: cb2-25yr NAME : Area draining into cb#2 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 15 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP ' PRECIPITATION. . . . : 3 .40 inches AREA. . : 0 . 07 Acres 0 . 08 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF : 0 . 20 PEAK RATE : 0 . 06 cfs VOL : 0 . 03 Ac-ft TIME : 480 min BASIN ID: cb3-25yr NAME : Area draining into cb#3 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 05 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 . 40 inches AREA. . : 0 . 01 Acres 0 . 04 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE : 0 . 03 cfs VOL: 0 . 01 Ac-ft TIME : 480 min 11/18/99 5 :28 : 34 pm RCA - Seattle page 3 ' First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- BASIN SUMMARY BASIN ID':'. cb4-25yr NAME : Area draining into cb#4 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 11 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP ' PRECIPITATION. . . . : 3 .40 inches AREA. . : 0 . 05 Acres 0 . 06 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE: 0 . 05 cfs VOL: 0 . 02 Ac-ft TIME: 480 min BASIN ID: cb5-25yr NAME : Area draining into cb#5 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 03 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 .40 inches AREA. . : 0 . 00 Acres 0 . 03 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 0 . 00 98 . 00 TC. . . . . 0 . 00 min 5 . 00 min ' ABSTRACTION COEFF: 0 . 20 PEAK RATE: 0 . 02 cfs VOL: 0 . 01 Ac-ft TIME : 480 min BASIN ID: cb6-25yr NAME: Area draining into cb#6 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 17 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP ' PRECIPITATION. . . . : 3 .40 inches AREA. . : 0 . 10 Acres 0 . 07 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE: 0 . 06 cfs VOL: 0 . 03 Ac-ft TIME : 480 min BASIN ID: cb7-25yr NAME: Area draining into cb#7 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 08 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 .40 inches AREA. . : 0 . 01 Acres 0 . 07 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . : 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE : 0 . 05 cfs VOL : 0 . 02 Ac-ft TIME : 480 min 11/18/99 5 :26 : 34 pm RCA - Seattle page 4 ' First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- BASIN SUMMARY BASIN fDt- cb8-25yr NAME: Area draining into cb#8 ' SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 02 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERV IMP PRECIPITATION. . . . : 3 .40 inches AREA. . : 0 . 01 Acres 0 . 01 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC . . . . . 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 .20 PEAK RATE: 0 . 01 cfs VOL: 0 . 00 Ac-ft TIME: 480 min BASIN ID: cb9-25yr NAME : Area draining into cb#9 SBUH METHODOLOGY TOTAL AREA. . . . . . . : 0 . 03 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERV IMP PRECIPITATION. . . . : 3 .40 inches AREA. . : 0 . 02 Acres 0 . 01 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 68 . 00 98 . 00 TC. . . . . 5 . 00 min 5 . 00 min ABSTRACTION COEFF: 0 . 20 PEAK RATE : 0 . 01 cfs VOL: 0 . 00 Ac-ft TIME : 480 min 11/16/99 4 : 10 : 54 pm RCA - Seattle page 1 First Builders - Renton Preliminary-Drainage-Report ------------------------------------------ STRUCTURE REPORT PROPOSED STRUCTURE REACH ID No. CB1 Location North 1425 . 0000 Str Type TYPE 1 East 1365 . 0000 Str Cat Catch Basin Rim Elev 300 . 2500 Area/sump: 0 . 00 sf/1 . 50 ft Bottom El : 296 . 0800 Cont Area: cbl-25yr Hgrade El : 0 . 0000 ft Bend. . . . . : No special shape Ent type . : Area/sump: Ent Loss : 0 . 000 Exit : 0 . 000 App Vel : 0 . 000 Junct : 0 . 000 Bend: 0 . 000 Reach <Invert> <Diam> < n > <End> P1 297 . 580 8 . 00 0 . 012 Upper PROPOSED STRUCTURE REACH ID No . CB10 Location : North 1305 . 0000 Str Type : TYPE 1 East 1115 . 0000 Str Cat : Catch Basin Rim Elev 294 . 0000 Area/sump: 0 . 00 sf/1 . 50 ft Bottom El : 289 . 8300 Cont Area: cb10-25y Hgrade El : 0 . 0000 ft Bend. . . . . : No special shape Ent type . : Area/sump: Ent Loss : 0 . 000 Exit : 0 . 000 App Vel : 0 . 000 Junct : 0 . 000 Bend : 0 . 000 Reach <Invert> <Diam> < n > <End> P9 291 . 330 8 . 00 0 . 012 Upper PROPOSED STRUCTURE REACH ID No . CB11 Location : North 1180 . 0000 Str Type TYPE 1 East 1145 . 0000 Str Cat Catch Basin Rim Elev 289 . 5000 Area/sump: 0 . 00 sf/1 . 50 ft Bottom El : 284 . 8500 Cont Area: cb11-25y Hgrade El : 0 . 0000 ft Bend. . . . . : No special shape Ent type . : Area/sump: Ent Loss : 0 . 000 Exit : 0 . 000 App Vel : 0 . 000 Junct : 0 . 000 Bend: 0 . 000 Reach <Invert> <Diam> < n > <End> P10 286 . 350 12 . 00 0 . 012 Lower P11 286 . 680 8 . 00 0 . 012 Lower P12 286 . 350 12 . 00 0 . 012 Upper i 11/16/99 4 : 10 : 54 pm RCA - Seattle page 2 First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- STRUCTURE REPORT PROPOSED'STRUCTURE REACH ID No . CB12 Location : North 1180 . 0000 Str Type TYPE 1 East 1115 . 0000 Str Cat Catch Basin Rim Elev 289 . 5000 Area/sump: 0 . 00 sf/1 . 50 ft Bottom El : 285 . 3300 Cont Area : cb12-25y Hgrade El : 0 . 0000 ft Bend. . . . . : No special shape Ent type . : Area/sump: Ent Loss : 0 . 000 Exit . 0 . 000 App Vel . 0 . 000 Junct . 0 . 000 Bend: 0 . 000 Reach <Invert> <Diam> < n > <End> P11 286 . 830 8 . 00 0 . 012 Upper PROPOSED STRUCTURE REACH ID No. C213 Location : North 1085 . 0000 Str Type TYPE 1 East 1150 . 0000 Str Cat Catch Basin Rim Elev 287 . 0000 Area/sump: 0 . 00 sf/1 . 50 ft Bottom El : 282 . 8300 Cont Area : cb13-25y Hgrade El : 0 . 0000 ft Bend. . . . . : No special shape Ent type . : Area/sump: Ent Loss : 0 . 000 Exit : 0 . 000 App Vel : 0 . 000 Junct : 0 . 000 Bend: 0 . 000 Reach <Invert> <Diam> < n > <End> P13 284 . 330 8 . 00 0 . 012 Upper PROPOSED STRUCTURE REACH ID No. CB14 Location South End of Detention Vault North 1100 . 0000 Str Type TYPE 2-54 East 1150 . 0000 ' Str Cat Catch Basin Rim Elev 288 . 0000 Area/sump: 0 . 00 sf/1 . 50 ft Bottom El : 281 .4200 Cont Area: Hgrade El : 0 . 0000 ft Bend. . . . . : No special shape Ent type . : Area/sump: Ent Loss : 0 . 000 Exit : 0 . 000 App Vel : 0 . 000 Junct : 0 . 000 Bend: 0 . 000 Reach <Invert> <Diam> < n > <End> P13 284 . 250 8 . 00 0 . 012 Lower P14 282 . 920 24 . 00 0 . 012 Upper 11/16/99 4 : 10 : 54 pm RCA - Seattle page 3 i First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- STRUCTURE REPORT PROPOSED-STRUCTURE REACH ID No . C22 Location : North 1425 . 0000 Str Type : TYPE 1 East 1395 . 0000 Str Cat : Catch Basin Rim Elev 300 . 2500 Area/sump: 0 . 00 sf/1 . 50 ft Bottom El : 295 . 9300 Cont Area: cb2-25yr Hgrade El : 0 . 0000 ft Bend. . . . . : No special shape Ent type. : Area/sump: Ent Loss : 0 . 000 Exit . 0 . 000 App Vel . 0 . 000 Junct . 0 . 000 Bend: 0 . 000 Reach <Invert> <Diam> < n > <End> P1 297 .430 8 . 00 0 . 012 Lower P2 297 . 430 8 . 00 0 . 012 Upper PROPOSED STRUCTURE REACH ID No. CB3 Location : North 1380 . 0000 Str Type TYPE 1 East 1320 . 0000 Str Cat Catch Basin Rim Elev 299 . 5000 Area/sump: 0 . 00 sf/1 . 50 ft Bottom E1 : 295 . 3300 Cont Area: cb3-25yr Hgrade E1 : 0 . 0000 ft Bend. . . . . : No special shape Ent type. : Area/sump: Ent Loss : 0 . 000 Exit : 0 . 000 App Vel : 0 . 000 Junct : 0 . 000 Bend: 0 . 000 Reach <Invert> <Diam> < n > <End> P3 296 . 830 8 . 00 0 . 012 Upper PROPOSED STRUCTURE REACH ID No. CB4 Location : North 1350 . 0000 Str Type : TYPE 1 East 1320 . 0000 Str Cat : Catch Basin Rim Elev 299 . 5000 Area/sump: 0 . 00 sf/1 . 50 ft Bottom El : 294 . 3333 Cont Area: cb4-25yr Hgrade El : 0 . 0000 ft Bend. . . . . : No special shape Ent type . : Area/sump: Ent Loss : 0 . 000 Exit : 0 . 000 App Vel : 0 . 000 Junct : 0 . 000 Bend: 0 . 000 Reach <Invert> <Diam> < n > <End> P2 296 . 830 8 . 00 0 . 012 Lower ' P3 295 . 833 8 . 00 0 . 012 Lower P4 296 . 570 12 . 00 0 . 012 Upper 11/16/99 4 : 10 : 54 pm RCA - Seattle page 4 i First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- STRUCTURE REPORT PROPOSED4STRUCTURE REACH ID No . CB5 Location : North 1490 . 0000 Str Type TYPE 1 East 1190 . 0000 Str Cat Catch Basin Rim Elev 303 . 0000 Area/sump: 0 . 00 sf/1 . 50 ft Bottom El : 298 . 8300 Cont Area : cb5-25yr Hgrade E1 : 0 . 0000 ft Bend. . . . . : No special shape Ent type . : Area/sump: Ent Loss : 0 . 000 Exit . 0 . 000 App Vel . 0 . 000 Junct . 0 . 000 Bend: 0 . 000 Reach <Invert> <Diam> < n > <End> P5 300 . 330 8 . 00 0 . 012 Upper PROPOSED STRUCTURE REACH ID No. CB6 Location : North 1380 . 0000 Str Type TYPE 1 East 1190 . 0000 Str Cat Catch Basin Rim Elev 298 . 0000 Area/sump: 0 . 00 sf/1 . 50 ft Bottom El : 293 . 5000 Cont Area: cb6-25yr Hgrade El : 0 . 0000 ft Bend. . . . . : No special shape Ent type. : Area/sump: Ent Loss : 0 . 000 Exit : 0 . 000 App Vel : 0 . 000 Junct : 0 . 000 Bend: 0 . 000 Reach <Invert> <Diam> < n > <End> P5 295 . 330 8 . 00 0 . 012 Lower P6 295 . 000 12 . 00 0 . 012 Upper PROPOSED STRUCTURE REACH ID No. CB7 Location : North 1350 . 0000 Str Type TYPE 1 East 1190 . 0000 Str Cat Catch Basin Rim Elev 298 . 0000 Area/sump: 0 . 00 sf/1 . 50 ft Bottom El : 293 . 3500 Cont Area : cb7-25yr Hgrade El : 0 . 0000 ft Bend. . . . . : No special shape Ent type . : Area/sump : Ent Loss : 0 . 000 Exit : 0 . 000 App Vel : 0 . 000 Junct : 0 . 000 Bend: 0 . 000 fReach <Invert> <Diam> < n > <End> P4 294 . 850 12 . 00 0 . 012 Lower P6 294 . 850 12 . 00 0 . 012 Lower P7 294 . 850 12 . 00 0 . 012 Upper 11/16/99 4 : 10 : 54 pm RCA - Seattle page 5 First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- STRUCTURE REPORT PROPOSED�`STRUCTURE REACH ID No . CB8 Location : North 1335 . 0000 Str Type : TYPE 1 East 1155 . 0000 Str Cat : Catch Basin Rim Elev 296 . 0000 Area/sump: 0 . 00 sf/1 . 50 ft Bottom El : 291 . 5000 Cont Area: cb8-25yr Hgrade E1 : 0 . 0000 ft Bend. . . . . : No special shape Ent type. : Area/sump: Ent Loss : 0 . 000 Exit . 0 . 000 App Vel . 0 . 000 Junct . 0 . 000 Bend. 0 . 000 Reach <Invert> <Diam> < n > <End> P7 293 . 000 12 . 00 0 . 012 Lower P8 293 . 000 12 . 00 0 . 012 Upper PROPOSED STRUCTURE REACH ID No. C29 Location : North 1305 . 0000 Str Type TYPE 1 East 1145 . 0000 Str Cat Catch Basin Rim Elev 294 . 0000 Area/sump: 0 . 00 sf/1 . 50 ft Bottom El : 288 . 8333 Cont Area: cb9-25yr Hgrade El : 0 . 0000 ft Bend. . . . . : No special shape Ent type . : Area/sump: Ent Loss : 0 . 000 Exit : 0 . 000 App Vel : 0 . 000 Junct : 0 . 000 Bend: 0 . 000 Reach <Invert> <Diam> < n > <End> P8 291 . 000 12 . 00 0 . 012 Lower P9 290 . 333 8 . 00 0 . 012 Lower P10 291 . 000 12 . 00 0 . 012 Upper PROPOSED STRUCTURE REACH ID No. CSl Location : Control Structure Entrance North 1152 . 0000 Str Type : TYPE 2-54 East 1154 . 0000 Str Cat : Catch Basin Rim Elev 289 . 0000 Area/sump: 0 . 00 sf/1 . 50 ft Bottom El : 282 . 9200 Cont Area: Hgrade El : 0 . 0000 ft Bend. . . . . : No special shape Ent type . : Area/sump : Ent Loss : 0 . 000 Exit : 0 . 000 App Vel : 0 . 000 Junct : 0 . 000 Bend: 0 . 000 Reach <Invert> <Diam> < n > <End> P12 282 . 920 12 . 00 0 . 012 Upper BACKWATER ANALYSIS FOR THE 25-YEAR EVFNT i i i 1 i i i 1 i i i irst Builders-Renton,WA Backwater Analysis ackflow Calculations Existing and-Proposed Storm Drain for First Builders-Renton,WA _ I _ i _ _ - 1 __ (18) (19) (20) Up- p Segment (1) (2) (3) (4) Invert Elevation l (7) (8) (9) (10) (11) (12) (13) (14) Outlet Stream Depth for Inlet Inlet Approach Kb Stream 16 Pipe S - - PP Down- U Down- U I Full-flow Full-flow VelocityTailwater Friction Entrance Ke Entrance F. Control Rim Smooth 1 control or Velocity (from Bend Jur?dtion Headwater Rim Stream Stream 9 P Length Pipe m Q Len Size Stream Stream Area Velocity A Veloci Head Elevation Loss HGI_ from Head Loss Head Loss Elevation Elevation I Int.Culvert Elevation Outlet Head Chart,f',g Head Loss Head Loss Elevation I Elevation � Structure Structure (cfs) (ft) (in) I (ft) "n" (ft) (ft) (sf) (fps) (ft) (ft) (ft) I (ft) I Table) (ft) (ft) (ft) (ft) 1 (ft) (ft) Control? (ft) 4.3.4.E) (ft) Q3 Q1 Kj (ft) (ft) (ft) ROPOSED CONDITIONS-Open Outlet 25 year event) - - --- - - Outlet CB#11 0 46 15 8 0.667 0.012 286.20 286.35 0 35 1.33 0.03 286.20 0.02 286.22 0.20 0.01 0,03 286.25 288.00 0.60 286.95 286.95 0.02 0.06 0.00 0.00 0.52 0A 0.00 286.93 289.50 - -- - - - - - - 0.012 286.35 291.00 0 35 1.20 0.02 286.93 0.13 287 06 0.20 0.00 0.02 287.08 289.50 0.60 i 291.60 1 291.60 0.02 0.06 0.00 0.04 0.42 l 0.08 0.00 291.59 294.00 CB#11 CB#9 0.42 125 8 0.667 _ ! 0.10 .I 0.00 CB#8 CB#7 0.36 38 8 0 667 0 012 291 00.00 293.00 0.35 1.04 0,02 291.59 0.02 291 61 0.20 0.00 0.02 291.63 294.00 0.60 293.60 293.60 0,02 0.06 000 0.05 036 293.59 296.00 0.03 293 61 0.20 0.00 I 0.02 293.63 296.00 0.60 294.85 0.35 I I 0.01 0.06 000 0.00 i 0.35 0.00 0.00 ' 295.44 298.00 0.012 294.85 296.57 0.35 0.66 0.01 295.44 0.04 295.48 0.20 0.00 6.01 295.49 298.00 0.40 296.97 296.97 0.00 0.06 0.00 0.08 0.23 0.25 0.00 296.97 299.50 l B#7 B#4 0.23 130 8 0.667 C C CB#4 CB#2 0.15 106 8 0.667' 0.012 296.83 297.43 0.35 0.43 0.00 I 296.97 001 296.98 0.20 0.00 0.00 296.99 299.50 0.40 297.83 297.83 0 00 0.40 0.00 0.03 0.15 0.15 0.00 297.83 300.25 CB#2 CB#1 0.09 30 --8 0 667 I 0.012 297.43 I 297.58 0.35 0.25 0.00 297.83 0.00 297.83 6.20 ! 000 C.00 297.83 - 300.25 0.40 297.98 297.98 0.00 -1.32 0.00 0.00 I 0.09 0.00 0.00 297.98 300.25 ii"ROPOSED CONDITIONS-Open Outlet(1100 year event) ! I Outlet CB#11 0.62 15 8 10.667 0.012 286.20 286.35 0.35 1.77 0.05 286.20 0 03 1 286.23 0.20 0.01 0.05 286.29 288.00 0.60 286.95 286.95 0 03 0.06 0.00 000 0.62 0.00 0.00 286.92 289.50 CB#11 CB#9 0.50 125 8 0 667 0.012 286.35 291.00 0.35 1.42 11 0.03 286.92 0.18 287.10 0.20 I 0.01 0.03 287.14 289.50 0.60 291.60 291.60 0.02 0.06 0.00 0.05 0.50 0.08 0.00 291.58 294.00 CB#9 CB#8 0.43 32 8 0 667 0.012 291.00 293.00 0.35 1.23 0.02 291.58 0.03 291 61 0.20 0.00 0.02 291.64 294.00 0.60 293.60 293.60 0.02 0.06 0.00 0.05 0.43 0.10 0.00 293.58 296.00 CB#8 CB#7 0.42 38 8 0.667 0.012 293.00 294.85 0.35 1.20 0.02 293.58 0.04 293.62 0.20 I 0.00 0.02 293.65 296.00 0.60 295.45 295.45 0.01 0.06 0.00 0.00 0.42 0.00 0.00 295.44 298.00 CB#7 CB#4 I 0.27 130 B 0.667 0.012 294.85 296.57 1 0.35 0.77 0.01 295.44 0.05 295.50 0,20 0.00 0.01 295.51 298.00 0.40 296.97 296.97 0 00 0.06 0.00 0.10 I 0.27 0.26 0.00 296.97 299.50 -- I - - - CB#4 I CB#2 0.18 106 8 0.667I 0.012 296.83 297.43 ', 0.35 051 0.00 296.97 0.02 296.99 0.20 0.00 0.00 296.99 299.50 0.40 297.83 297.83 0.00 0.40 I, 0.00 , 0.03 0.18 015 0.00 297.83 300.25 CB#2 CB#1 0.10 30 8 0.667 0.012 297.43 297.58 0.35 0.30 0.00 297.83 0.00 297.83 0 20 0 00 0.00 297.84 300.25 0.40 297.98 297.98 0.00 1.32 0.00 0.00 0.10 0.00 j 0.00 297.98 300.25 Choosey 4�,. _ �^ e zc�1 case \Projects\Excel\backwtr1.XLS Page 1 11/22/99 KING COUNTY, W ASHINGTON, SURFACE WATER DESIGN MANUAL FIGURE 4.3.4E* BEND HEAD LOSSES IN STRUCTURES 1.4 i 1.2 , I 1.0 r 1 0.8 Y Bend at Manhole, no Special Shaping _ I a� 0 y 0.6 Deflector 0 Curved I I Bend at Manhole, l Curved or Deflector) 0.4 - I tCurved Sewer r/D=2 I 0.2 r I Sewer r//D>6 I 0.0 4a 00 200 400 1 600 800 900 1000 Deflection Angle Y , Degrees 'From"Modern Sewer Design', copyright 1980,American Iron and Steel Institute I 1 4.3.4-22 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL FIGURE 4.3.4F JUNCTION HEADLOSS IN STRUCTURES 3.4 3.2 Ot O: Q3 3.0 — I00 _.8 O, 2.6 Typical junction chamber Qt - 130.41, 4 195.U) 65 VI - 13.5, Vj-- 12.3 14 �+Q =0.50(50%) eadIAss=0.94' 2.2 2.0 Q1 = 507 o 1.8 :J — 1.6 — 1.4 Q3 = 307 Q1 12 I 0 Graphic Example .8 .6 Q3 = 10 C�t 1101, .4 r 0 2 4 6 8 10 12 14 16 18 20 Velocity in upstream pipe, V(fps) L V p I �Ource: Baltimore County Department of Public Works 1 4.3.4-23 1/90 11/17/99 11 : 6 : 1 am RCA - Seattle page 1 First Builders - Renton Preliminary Drainage Report HYDROGRAPH SUMMARY LS-`lu- EVEN T z s-Yz 't vim-r PEAK TIME VOLUME HYD RUNOFF OF OF Contrib i2Dv7 F- NUM RATE PEAK HYDRO Area -r►+zcoj G`' _-_-------cfs min. _-_cf\AcFt_--__-Acres- 1��Ac14 1 0 . 150 480 2621 cf 0 . 34 2 0 . 029 480 490 cf 0 . 05 TZ Z. µvD t+Wb,2 3 0 .227 480 3931 cf 0 . 50 23 4 0 . 080 480 1421 cf 0 .20 2 4 µYD3+wfDq = 5 0 . 364 480 6293 cf 0 . 79 25 6 0 . 047 480 759 cf 0 . 07 }�YpS, H`iyb= 7 0 .419 480 7212 cf 0 . 88 8 0 . 044 480 736 cf 0 . 08 Q 8 vD :7+ 4 ft) 6= 9 0 . 521 480 8994 cf 1 . 11 �q 10 0 . 168 480 2799 cf 0 .29 rz�a N`lD 9+HY���=11 0 . 689 480 11792 cf 1 .40 N`1D n + PYD 10 11/22/99 11 : 59 : 57 am RCA - Seattle page 2 ' First Builders - Renton Preliminary Drainage Report REACH SUMMARY zs-1{7 Cv&u-- PIPE REACH ID No. P1 From: CB1 To : CB2 Pipe Diameter: 0 . 6667 ft n: 0 . 0120 Pipe Length 30 . 0000 ft s : 0 . 0050 Up invert 297 . 5800 ft down invert : 297 . 4300 ft Collection Area : 0 . 1930 Ac . Design Flow 0 . 0863 cfs Dsgn Depth: 0 . 14 ft Pipe Capacity 0 . 9984 cfs Design Vel 1 . 6642 fps Travel Time . 0 . 30 min Pipe Full Vel 2 . 9355 fps PIPE REACH ID No. P10 From: CB9 To: CB11 Pipe Diameter: 1 . 0000 ft n: 0 . 0120 Pipe Length 125 . 0000 ft s : 0 . 0372 Up invert 291 . 0000 ft down invert : 286 . 3500 ft Collection Area: 0 . 8790 Ac . Design Flow 0 .4191 cfs Dsgn Depth: 0 . 16 ft Pipe Capacity 8 . 0295 cfs Design Vel 5 . 1248 fps Travel Time : 0 . 41 min Pipe Full Vel 10 .4921 fps PIPE REACH ID No. P11 From: CB12 To : CB11 Pipe Diameter: 0 . 6667 ft n: 0 . 0120 Pipe Length 30 . 0000 ft s : 0 . 0050 Up invert 286 . 8300 ft down invert : 286 . 6800 ft Collection Area: 0 . 0750 Ac . Design Flow 0 . 0442 cfs Dsgn Depth: 0 . 10 ft Pipe Capacity 0 . 9984 cfs Design Vel 1 . 3638 fps Travel Time : 0 . 37 min Pipe Full Vel 2 . 9355 fps PIPE REACH ID No . P12 From: CB11 To : CS1 Pipe Diameter: 1 . 0000 ft n: 0 . 0120 Pipe Length 29 .4109 ft s : 0 . 0050 Up invert 286 . 3500 ft down invert : 286 . 2029 ft Collection Area: 1 . 1110 Ac . Design Flow 0 . 5211 cfs Dsgn Depth: 0 . 30 ft Pipe Capacity 2 . 9437 cfs Design Vel 2 . 6827 fps Travel Time : 0 . 18 min Pipe Full Vel 3 . 8466 fps 11/22/99 11 : 59 : 57 am RCA - Seattle page 3 First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- REACH SUMMARY PIPE REACH ID No. P13 From: CB13 To: CB14 Pipe Diameter: 0 . 6667 ft n: 0 . 0120 Pipe Length 15 . 0000 ft s : 0 . 0053 Up invert 284 . 3300 ft down invert : 284 . 2500 ft Collection Area : 0 . 2860 Ac . Design Flow 0 . 1680 cfs Dsgn Depth: 0 . 19 ft Pipe Capacity 1 . 0312 cfs Design Vel 2 . 0656 fps Travel Time : 0 . 12 min Pipe Full Vel 3 . 0318 fps PIPE REACH ID No. P14 From: CS1 To : Pipe Diameter: 1 . 0000 ft n: 0 . 0120 Pipe Length 15 . 0000 ft s : 0 . 0050 Up invert : 286 .2000 ft down invert : ft Collection Area: Ac . Design Flow cfs Dsgn Depth: ft Pipe Capacity cfs Design Vel fps Travel Time : min Pipe Full Vel fps PIPE REACH ID No. P2 From: CB2 To : CB4 Pipe Diameter: 0 . 6667 ft n: 0 . 0120 Pipe Length 106 . 0660 ft s : 0 . 0057 Up invert 297 .4300 ft down invert : 296 . 8300 ft Collection Area : 0 . 3380 Ac . Design Flow 0 . 1504 cfs Dsgn Depth: 0 . 18 ft Pipe Capacity 1 . 0620 cfs Design Vel 2 . 0436 fps Travel Time : 0 . 87 min Pipe Full Vel 3 . 1224 fps PIPE REACH ID No. P3 From: CB3 To: CB4 Pipe Diameter: 0 . 6667 ft n: 0 . 0120 Pipe Length 30 . 0000 ft s : 0 . 0332 Up invert : 296 . 8300 ft down invert : 295 . 8333 ft ' Collection Area : 0 . 0500 Ac . Design Flow 0 . 0295 cfs Dsgn Depth: 0 . 05 ft Pipe Capacity 2 . 5737 cfs Design Vel 2 . 3379 fps Travel Time : 0 . 21 min Pipe Full Vel 7 . 5668 fps 11/22/99 11 : 59 : 57 am RCA - Seattle page 4 ' First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- REACH SUMMARY PIPE REACH ID No. P4 From: CB4 To: CB7 Pipe Diameter: 1 . 0000 ft n: 0 . 0120 Pipe Length 130 . 0000 ft s : 0 . 0132 Up invert 296 . 5700 ft down invert : 294 . 8500 ft Collection Area: 0 .4960 Ac . Design Flow 0 .2267 cfs Dsgn Depth: 0 . 15 ft Pipe Capacity 4 . 7886 cfs Design Vel 2 . 9694 fps Travel Time : 0 . 73 min Pipe Full Vel 6 . 2572 fps PIPE REACH ID No. P5 From: CB5 To : C116 Pipe Diameter: 0 . 6667 ft n: 0 . 0120 Pipe Length 110 . 0000 ft s : 0 . 0455 Up invert 300 . 3300 ft down invert : 295 . 3300 ft Collection Area: 0 . 0270 Ac . Design Flow 0 . 0191 cfs Dsgn Depth: 0 . 04 ft Pipe Capacity 3 . 0104 cfs Design Vel 2 . 2976 fps Travel Time : 0 . 80 min Pipe Full Vel 8 . 8508 fps PIPE REACH ID No. P6 From: CB6 To: C37 Pipe Diameter: 1 . 0000 ft n: 0 . 0120 Pipe Length 30 . 0000 ft s : 0 . 0050 Up invert : 295 . 0000 ft down invert : 294 . 8500 ft Collection Area: 0 . 1970 Ac . Design Flow 0 . 0803 cfs Dsgn Depth: 0 . 12 ft Pipe Capacity 2 . 9437 cfs Design Vel 1 . 5484 fps Travel Time : 0 . 32 min Pipe Full Vel 3 . 8466 fps PIPE REACH ID No. P7 From: CB7 To: CB8 Pipe Diameter: 1 . 0000 ft n: 0 . 0120 Pipe Length 38 . 0789 ft s : 0 . 0486 Up invert 294 . 8500 ft down invert : 293 . 0000 ft Collection Area : 0 . 7680 Ac . Design Flow 0 . 3541 cfs Dsgn Depth: 0 . 14 ft Pipe Capacity 9 . 1761 cfs Design Vel 5 . 3579 fps Travel Time : 0 . 12 min Pipe Full Vel 11 . 9904 fps 11/22/99 11 : 59 : 57 am RCA - Seattle page 5 First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- REACH SUMMARY PIPE REACH ID No. P8 From: CB8 To : CB9 Pipe Diameter: 1 . 0000 ft n: 0 . 0120 Pipe Length 31 . 6228 ft s : 0 . 0632 Up invert : 293 . 0000 ft down invert : 291 . 0000 ft Collection Area: 0 . 7880 Ac . Design Flow 0 . 3636 cfs Dsgn Depth: 0 . 13 ft Pipe Capacity 10 . 4696 cfs Design Vel 5 . 9231 fps Travel Time : 0 . 09 min Pipe Full Vel 13 . 6806 fps PIPE REACH ID No. P9 From: CB10 To: CB9 Pipe Diameter: 0 . 6667 ft n: 0 . 0120 Pipe Length 30 . 0000 ft s : 0 . 0332 Up invert : 291 . 3300 ft down invert : 290 . 3333 ft Collection Area: 0 . 0660 Ac . Design Flow 0 . 0467 cfs Dsgn Depth: 0 . 06 ft Pipe Capacity 2 . 5737 cfs Design Vel 2 . 6950 fps Travel Time : 0 . 19 min Pipe Full Vel 7 . 5668 fps iNetwork Reach R1 REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C_Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P1 0.19 0.67 30.00 0.0050 0.0120 0.09 8.64 0.14 20.60 1.66 2.94 cbl-25yr P2 0.34 0.67 106.07 0.0057 0.0120 0.15 14.17 0.18 26.38 2.04 3.12 cb2-25yr Network Reach R10 REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C_Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P13 0.29 0.67 15.00 0.0053 0.0120 0.17 16.29 0.19 28.33 2.07 3.03 cb13-25y Network Reach R2 ' REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C_Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P3 0.05 0.67 30.00 0.0332 0.0120 0.03 1.14 0.05 7.80 2.34 7.57 cb3-25yr 11/22/99 11 : 59 : 58 am RCA - Seattle page 6 ' First Builders - Renton Preliminary Drainage Report ' REACH SUMMARY ' Network Reach R3 REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q 8 PIPE Ndepth %Depth Vact Vfull C_Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P4 0.50 1.00 130.00 0.0132 0.0120 0.23 4.74 0.15 15.35 2.97 6.26 cb4-25yr ' Network Reach R4 REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C_Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P5 0.03 0.67 110 00 0.0455 0.0120 0.02 0.63 0.04 5.89 2.30 8.85 cb5-25yr P6 0.20 1.00 30.00 0.0050 0.0120 0.08 2.73 0.12 11.76 1.55 3.85 cb6-25yr Network Reach R5 ' REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q 8 PIPE Ndepth %Depth Vact Vfull C_Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P7 0.77 1.00 38.08 0.0486 0.0120 0.35 3.86 0.14 13.89 5.36 11.99 cb7-25yr ' P8 0.79 1.00 31.62 0.0632 0.0120 0.36 3.47 0.13 13.20 5.92 13.68 cb8-25yr ' Network Reach R6 - REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P9 0.07 0.67 30.00 0.0332 0.0120 0.05 1.81 0.06 9.68 2.69 7.57 cb10-25y ' Network Reach R7 REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q W PIPE Ndepth %Depth Vact Vfull C_Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P10 0.88 1.00 125.00 0.0372 0.0120 0.42 5.22 0.16 16.09 5.12 10.49 cb9-25yr ' Network Reach R8 REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C_Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P11 0.08 0.67 30.00 0.0050 0.0120 0.04 4.43 0.10 14.86 1.36 2.94 cb12-25y 1 11/22/99 11 : 59 : 58 am RCA - Seattle page 7 ' First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- ' REACH SUMMARY ' Network Reach R9 REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C_Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) ' P12 1.11 1.00 29.41 0.0050 0.0120 0.52 17.70 0.30 29.57 2.68 3.85 cb11-25y 11/22/99 11 :37 :41 am RCA - Seattle page 1 ' First Builders - Renton Preliminary Drainage Report ' HYDROGRAPH SUMMARY (00_y?- CvE14T 06 ry r N 7- PEAK TIME VOLUME HYD RUNOFF OF OF Contrib ' NUM RATE PEAK HYDRO Area cfs min. cf\AcFt Acres --------------------------------------------- --------------------------------------------- 1 0 . 006 1470 936 cf 1 . 52 2 0 . 036 1460 3586 cf 1 . 52 9—z ' -14YL 7-3 0 . 084 1450 7217 cf 1 . 52 P-3 4 0 . 096 480 1688 cf 0 .20 Q-4 5 0 . 431 480 7408 cf 0 . 79 RS 6 0 . 053 480 871 cf 0 . 07 U 14�D 6=7 0 . 495 480 8472 cf 0 . 88 2--�L 8 0 . 051 480 853 cf 0 . 08 R-$ S=9 0 . 617 480 10577 cf 1 . 11 P-`► 10 0 . 195 480 3245 cf 0 .29 1K� q + H4go ID11 0 . 811 480 13822 cf 1 . 40 11/22/99 11 :23 : 10 am RCA - Seattle page 2 ' First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- ' REACH SUMMARY 1 0 0-�2 EvE*rT� PIPE REAM ID No. P1 From: CB1 To: CB2 Pipe Diameter: 0 . 6667 ft n: 0 . 0120 Pipe Length 30 . 0000 ft s : 0 . 0050 Up invert : 297 . 5800 ft down invert : 297 .4300 ft Collection Area: 0 . 1930 Ac . Design Flow 0 . 1026 cfs Dsgn Depth: 0 . 15 ft Pipe Capacity 0 . 9984 cfs Design Vel 1 . 7518 fps Travel Time : 0 .29 min Pipe Full Vel 2 . 9355 fps ' PIPE REACH ID No. P10 From: CB9 To: CB11 Pipe Diameter: 1 . 0000 ft n: 0 . 0120 Pipe Length 125 . 0000 ft s : 0 . 0372 Up invert 291 . 0000 ft down invert : 286 . 3500 ft Collection Area : 0 . 8790 Ac . Design Flow 0 .4951 cfs Dsgn Depth: 0 . 17 ft Pipe Capacity 8 . 0295 cfs ' Design Vel 5 . 3859 fps Travel Time : 0 . 39 min Pipe Full Vel 10 .4921 fps ' PIPE REACH ID No. P11 From: CB12 To: CB11 Pipe Diameter: 0 . 6667 ft n: 0 . 0120 ' Pipe Length 30 . 0000 ft s : 0 . 0050 Up invert 286 . 8300 ft down invert : 286 . 6800 ft Collection Area: 0 . 0750 Ac . ' Design Flow 0 . 0512 cfs Dsgn Depth: 0 . 11 ft Pipe Capacity 0 . 9984 cfs Design Vel 1 .4275 fps Travel Time : 0 . 35 min ' Pipe Full Vel 2 . 9355 fps PIPE REACH ID No. P12 ' From: C1111 To : CS1 Pipe Diameter: 1 . 0000 ft n: 0 . 0120 Pipe Length 29 . 4109 ft s : 0 . 0050 Up invert 286 . 3500 ft down invert : 286 . 2029 ft ' Collection Area: 1 . 1110 Ac . Design Flow 0 . 6167 cfs Dsgn Depth: 0 . 32 ft Pipe Capacity 2 . 9437 cfs Design Vel 2 . 8134 fps Travel Time : 0 . 17 min Pipe Full Vel 3 . 8466 fps 11/22/99 11 :23 : 10 am RCA - Seattle page 3 ' First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- REACH SUMMARY PIPE REAM ID No. P13 ' From: CB13 To : CB14 Pipe Diameter: 0 . 6667 ft n: 0 . 0120 Pipe Length 15 . 0000 ft s : 0 . 0053 Up invert : 284 . 3300 ft down invert : 284 .2500 ft Collection Area: 0 . 2860 Ac . ' Design Flow 0 . 1947 cfs Dsgn Depth: 0 . 20 ft Pipe Capacity 1 . 0312 cfs Design Vel 2 . 1534 fps Travel Time : 0 . 12 min Pipe Full Vel 3 . 0318 fps PIPE REACH ID No. P14 From: CS1 To: ' Pipe Diameter: 1 . 0000 ft n: 0 . 0120 Pipe Length 15 . 0000 ft s : 0 . 0050 Up invert : 286 . 2000 ft down invert : ft ' Collection Area: Ac . Design Flow cfs Dsgn Depth: ft Pipe Capacity cfs ' Design Vel fps Travel Time : min Pipe Full Vel fps ' PIPE REACH ID No. P2 From: CB2 To: C34 Pipe Diameter: 0 . 6667 ft n: 0 . 0120 Pipe Length 106 . 0660 ft s : 0 . 0057 Up invert 297 . 4300 ft down invert : 296 . 8300 ft Collection Area: 0 . 3380 Ac . ' Design Flow 0 . 1790 cfs Dsgn Depth: 0 . 19 ft Pipe Capacity 1 . 0620 cfs Design Vel 2 . 1472 fps Travel Time : 0 . 82 min ' Pipe Full Vel 3 . 1224 fps PIPE REACH ID No. P3 ' From: CB3 To: CB4 Pipe Diameter: 0 . 6667 ft n: 0 . 0120 Pipe Length 30 . 0000 ft s : 0 . 0332 Up invert 296 . 8300 ft down invert : 295 . 8333 ft ' Collection Area: 0 . 0500 Ac . Design Flow 0 . 0341 cfs Dsgn Depth: 0 . 06 ft ' Pipe Capacity 2 . 5737 cfs Design Vel 2 .4437 fps Travel Time : 0 . 20 min Pipe Full Vel 7 . 5668 fps 11/22/99 11 :23 : 10 am RCA - Seattle page 4 1 First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- 1 REACH SUMMARY PIPE REACH ID No. P4 ' From: CB4 To: CB7 Pipe Diameter: 1 . 0000 ft n: 0 . 0120 Pipe Length : 130 . 0000 ft s : 0 . 0132 ' Up invert : 296 . 5700 ft down invert : 294 . 8500 ft Collection Area : 0 .4960 Ac . Design Flow 0 . 2690 cfs Dsgn Depth: 0 . 17 ft Pipe Capacity 4 . 7886 cfs Design Vel 3 . 1247 fps Travel Time : 0 . 69 min Pipe Full Vel 6 . 2572 fps PIPE REACH ID No. P5 From: CB5 To: CB6 Pipe Diameter: 0 . 6667 ft n: 0 . 0120 Pipe Length 110 . 0000 ft s : 0 . 0455 Up invert 300 . 3300 ft down invert : 295 . 3300 ft 1 Collection Area : 0 . 0270 Ac . Design Flow 0 . 0218 cfs Dsgn Depth: 0 . 04 ft Pipe Capacity 3 . 0104 cfs ' Design Vel 2 . 3900 fps Travel Time : 0 . 77 min Pipe Full Vel 8 . 8508 fps ' PIPE REACH ID No. P6 From: CB6 To: CB7 Pipe Diameter: 1 . 0000 ft n: 0 . 0120 Pipe Length 30 . 0000 ft s : 0 . 0050 Up invert 295 . 0000 ft down invert : 294 . 8500 ft Collection Area: 0 . 1970 Ac . Design Flow 0 . 0965 cfs Dsgn Depth: 0 . 13 ft Pipe Capacity 2 . 9437 cfs Design Vel 1 . 6357 fps Travel Time : 0 . 31 min ' Pipe Full Vel 3 . 8466 fps PIPE REACH ID No. P7 ' From: CB7 To: CB8 Pipe Diameter: 1 . 0000 ft n: 0 . 0120 Pipe Length 38 . 0789 ft s : 0 . 0486 Up invert : 294 . 8500 ft down invert : 293 . 0000 ft iCollection Area : 0 . 7680 Ac . Design Flow 0 . 4198 cfs Dsgn Depth: 0 . 15 ft 1 Pipe Capacity 9 . 1761 cfs Design Vel 5 . 6350 fps Travel Time : 0 . 11 min Pipe Full Vel 11 . 9904 fps i 1 11/22/99 11 :23 : 10 am RCA - Seattle page 5 ' First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- ' REACH SUMMARY PIPE REACH ID No. P8 ' From: CB8 To: CB9 Pipe Diameter: 1 . 0000 ft n: 0 . 0120 Pipe Length 31 . 6228 ft s : 0 . 0632 Up invert : 293 . 0000 ft down invert : 291 . 0000 ft Collection Area : 0 . 7880 Ac . Design Flow 0 .4310 cfs Dsgn Depth: 0 . 14 ft Pipe Capacity 10 .4696 cfs Design Vel 6 . 2312 fps Travel Time : 0 . 08 min Pipe Full Vel 13 . 6806 fps PIPE REACH ID No. P9 From: CB10 To: CB9 Pipe Diameter: 0 . 6667 ft n: 0 . 0120 Pipe Length 30 . 0000 ft s : 0 . 0332 Up invert : 291 . 3300 ft down invert : 290 . 3333 ft Collection Area : 0 . 0660 Ac . Design Flow 0 . 0533 cfs Dsgn Depth: 0 . 07 ft Pipe Capacity 2 . 5737 cfs ' Design Vet 2 . 8104 fps Travel Time : 0 . 18 min Pipe Full Vel 7 . 5668 fps ' Network Reach R1 REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C_Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P1 0.19 0.67 30.00 0.0050 0.0120 0.10 10.28 0.15 22.44 1.75 2.94 cbl-Cyr P2 0.34 0.67 106.07 0.0057 0.0120 0.18 16.86 0.19 28.84 2.15 3.12 cb2-Cyr Network Reach R10 ' REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q W PIPE Ndepth %Depth Vact Vfull C_Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P13 0.29 0.67 15.00 0.0053 0.0120 0.19 18.88 0.20 30.57 2.15 3.03 cb13-Cyr Network Reach R2 ' REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C_Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P3 0.05 0.67 30.00 0.0332 0.0120 0.03 1.33 0.06 8.36 2.44 7.57 cb3-Cyr 11/22/99 11 : 23 : 10 am RCA - Seattle page 6 First Builders - Renton Preliminary Drainage Report --------------------------------------------------------------------- --------------------------------------------------------------------- REACH SUMMARY ' Network Reach R3 REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P4 0.50 1.00 130.00 0.0132 0.0120 0.27 5.62 0.17 16.67 3.12 6.26 cb4-Cyr Network Reach R4 REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C_Area ID====(Ac)===(ft)=====(ft)--ft/ft=========(cfs) (ft) (fps)===(fps)====___ P5 0.03 0.67 110.00 0.0455 0.0120 0.02 0.72 0.04 6.27 2.39 8.85 cb5-Cyr P6 0.20 1.00 30.00 0.0050 0.0120 0.10 3.28 0.13 12.85 1.64 3.85 cb6-Cyr Network Reach R5 ' REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P7 0.77 1.00 38.08 0.0486 0.0120 0.42 4.58 0.15 15.09 5.63 11.99 cb7-Cyr P8 0.79 1.00 31.62 0.0632 0.0120 0.43 4.12 0.14 14.33 6.23 13.68 cb8-Cyr ' Network Reach R6 - REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) ' P9 0.07 0.67 30.00 0.0332 0.0120 0.05 2.07 0.07 10.30 2.81 7.57 cb10-Cyr ' Network Reach R7 REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C_Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P10 0.88 1.00 125.00 0.0372 0.0120 0.50 6.17 0.17 17.45 5.39 10.49 cb9-Cyr Network Reach R8 REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C_Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P11 0.08 0.67 30.00 0.0050 0.0120 0.05 5.13 0.11 15.94 1.43 2.94 cb12-Cyr 11/22/99 11 :23 : 10 am RCA - Seattle page 7 First Builders - Renton Preliminary Drainage Report REACH SUMMARY Network Reach R9 REACH <-AREA> <-DIA> LENGTH SLOPE < n > DSGN Q % PIPE Ndepth %Depth Vact Vfull C_Area ID (Ac) (ft) (ft) ft/ft ------ (cfs) ------ (ft) ------ (fps) (fps) P12 1.11 1.00 29.41 0.0050 0.0120 0.62 20.95 0.32 32.27 2.81 3.85 cbll-Cyr 1 Appendix 3 SECTION 1 1.1 DESCRIPTION StormFilter is a passive, flow-through stormwater filtration system. It consists of vaults that house rechargeable cartridges filled with a variety of filter media. The filter systems are installed in-line with storm drains. The StormFilter works by passing stormwater through media-filled cartridges, which trap particulates and adsorb materials such as dissolved metals and hydrocarbons. After being filtered through the media, the treated stormwater flows into a collection pipe or discharges into an open channel drainage way. StormFilter is offered in three different configurations: cast-in-place, precast and linear. The precast and linear models utilize pre-manufactured vaults. The cast-in-place units are customized for larger flows and may be either covered or uncovered underground units. 1.2 OPERATION 1.2.1 Purpose The StormFilter is a passive stormwater filtration system designed to improve the quality of stormwater runoff from the urban environment before it enters receiving waterways. It is intended to function as a BMP (Best Management Practice) to meet local, state, and federal requirements, which have been, developed to comply with the Clean Water Act. Through independent third party studies, it has been demonstrated that the StormFilter is highly effective for treatment of first flush flows and flow-paced flows during the latter part of a storm. In general, StormFilter's efficiency is highest when pollutant concentrations are highest. The primary target pollutants for removal are: sediments (TSS), soluble metals, soluble phosphorus, nitrates, and oil and grease. 1.2.2 Sizing The StormFilter is sized to treat the peak flow of a water quality design storm as it passes through the filter. The peak flow is determined by calculations based on the contributing watershed hydrology and using a design storm magnitude. The design storm is usually based on the regulatory requirements set by the local stormwater management agency. The particular size of a StormFilter is determined by the number of filter cartridges (see Figure 4) required to treat the peak stormwater flow. Each cartridge is designed to treat a peak flow of 15 gpm. For example: a peak design stormwater flow rate of 150 gpm would require that 10 cartridges be used in the treatment vault. Because of the highly porous nature of the granular filter media, the flow through a newly installed cartridge is restricted to 15 gpm, using a restrictor disc, to ensure adequate pollutant-media contact time. 1.2.3 Basic Function The StormFilter is designed to siphon stormwater runoff through a filter cartridge containing media. The variety of media available can be designed to act as a mechanical filter to remove sediments, as an ion exchanger to remove dissolved heavy metals, and as an adsorber to remove oils and greases. ' 0 Stormwater Management updated 4/99 AIR vswr AIR nEusr VALVE SCREW' CAP, -Z FLOAT GRANULAR MEDIA I,-- HOOD OUTER SCREEN CENTER DRAINAGE TUBE opnowAL PLEATED FABRIC INSERT - BALL VALVE FLOOR FLOW Figure 4' Filter Cartridge 1.2.4 Priming System Function The treated otorrnvvater no||oota in the center tuba of the cartridge, which is equipped with a self- priming siphon system. Figure 4 illustrates this system. The key component of the system is the roto'mo|dgd float. The float consists of a ball located at the base leading up to larger portion, which provides increased buoyancy. Initially the bo|| rests in a seat effectively closing off the port to the drainage manifold. As a result, the filter fills the center drainage tube until the water level has risen high enough to purge the air fnonTthe filter cartridges and displaces the float. At a water depth of 22 inches the float pulls loose the ball and aUovva the filtered water to drain out through the manifold. This effectively "primes" aaiphon within the drainage tube and greatly increases the potential across the filter. The priming system increases GtormFi|ter'a ability tobe loaded with sediment. A related feature io the cartridge ^hood" This hood maintains the siphon effect by preventing air frombeing drawn into the cartridge until the external water level drops below the bottom of the hood. Cartridges are connected to the manifold with a plastic connector. Since some media used is potentially buoyant, othneaded connector affixed to the manifold with compression bolts is necessary to ensure the cartridge isn't lifted out ofplace. For the heavier leaf media, a slip connector ioused. StormFi|tgr is also equipped with flow spreaders that trap floating debris and surface fi|nno, even during overflow conditions. Depending on individual site chanactaristioa, some systems are equipped with high and/or low flow bypasses. High flow bypasses are installed when the calculated peak storm event generates a flow that overcomes the overflow capacity of the ovatenn. This is especially important for precast oyotarna. Low flow bypasses are sorno1inn8a installed to bypass continuous 0StormvvaterManagement updatod4/9S inflows caused by ground water seepage, which usually do not require treatment. All StormFilter units are designed with an overflow. The overflow operates when the inflow rate is greater than the infiltration capacity of the filter media. 1.2.4 Maintenance Overview The primary purpose of the StormFilter is to filter out and prevent pollutants from entering our waterways. Like any effective filtration system, periodically these pollutants must be removed to restore the StormFilter to its full efficiency and effectiveness. Maintenance requirements and frequency are dependent on the pollutant load characteristics of each site. To assist the owner with maintenance issues, Stormwater Management Inc. provides detailed Operation & Maintenance Guidelines with each unit. Maintenance services can be provided completely, or in part, by Stormwater Management Inc. Available services include tracking of installed systems, advising the system's owner of maintenance needs, and notification of the regulatory agency once the system has been maintained. Maintenance is usually performed late in the dry season to rejuvenate the filter media and prepare the system for the next rainy season. Maintenance activities can also be required in the event of a chemical spill or excessive sediment loading due to site erosion or extreme storms. It is good practice to inspect the system after severe storm events. END OF SECTION 1 ' ©Stormwater Management updated 4/99 Table 5: MAINTENANCE EQUIPMENT REQUIREMENTS Maintenance Equipment Required Minor Maintenance Pre-Major Maintenance Major Maintenance Cartridge Replacement Inspection Safety Equipment': first Safety Equipment': first Safety Equipment': first aid, cones, barricades, aid, cones, barricades, aid, cones, barricades, flagging, flares, tape, vests, hard hats. flagging, flares, tape, flagging, flares, tape, vests, hard hats. vests, hard hats. Work Clothes: rubber Work Clothes: rubber Work Clothes: rubber boots, coveralls, and boots, coveralls, and boots, coveralls, and gloves, loves. gloves. Door Bolt, Wrench, Door Bolt, Wrench, Door Bolt, Wrench, Pentasocket And Pentasocket And Pentasocket And Miscellaneous Tools. Miscellaneous Tools. Miscellaneous Tools. Tape Measure Tape Measure Tape Measure Flashlight Flashlight Flashlight Grapple or Net Pole Grapple or Net Pole Grapple or Net Pole Record Keeping Forms Record Keeping Forms Record Keeping Forms Trash/Debris Container Trash/Debris Container Vacuum Truck Replacement Cartridges Cartrid a Hauling Truck Crane, Tripod and Hoist, or Other Lifting Device 300 Ib. orgreater capacity) Shovels Extra 2 Inch PVC Caps Trash/Debris Container Vault Inlet Pipe Plug Doll PVC Pipe Cutter Ladder Cartridge Installation And Removal Sling Confined space equipment may be required for vault entry.This equipment must be used by personnel with the appropriate OSHA training. This equipment typically includes: atmospheric testing devices,atmospheric purging and ventilating devices, and entry,exit,and rescue assisting devices. 2.6 MATERIAL DISPOSAL The accumulated sediment found in stormwater treatment and conveyance systems must be handled and disposed of in a manner that will not allow the material to affect surface or ground water. It is possible for sediments to contain measurable concentrations of heavy metals and organic chemicals (such as pesticides and petroleum products). Areas with the greatest potential for high pollutant loading include industrial areas and heavily traveled roads. Sediments and water must be disposed of in accordance with all applicable waste disposal regulations. It is not appropriate to discharge these materials back to the stormwater drainage system. Part of arranging for maintenance to occur should include coordination of disposal of solids (landfill coordination) and liquids (municipal vacuum truck decant facility, local wastewater treatment plant, on-site treatment and discharge). Owners should contact the local public works department and inquire about how the department disposes of their street waste residuals. Disposal methods or reuse of the media contained in the cartridges will be determined by Stormwater Management Inc. If the material has been contaminated with any unusual substance, the cost of special handling and disposal will be the responsibility of the owner. ©Stormwater Management updated 4/99 S1 StormFilter -m Design Considerations The following are five primary factors that relate to StormFilter design: • Establishing the treatment flow or volume from site hydrological characteristics. • Assessing water quality and selecting a media. • Establishing the need for pretreatment. • Sizing, siting, system hydraulics and structural considerations. • Incorporating the StormFilter into the site stormwater management plan. Site Hydrological Characteristics Most water quality facilities are designed around a design storm, usually established by the local regulatory agency. Based on historical data, the agency determines the return period of the storm and specifies a modeling methodology to calculate either the peak water quality flow or the runoff volume associated with the design storm. The StormFilter is a flow-based system, and therefore, is sized by calculating the peak flow associated with the design storm. Another consideration related to the site hydrology is the calculated peak design flow used for sizing the conveyance system. The storm return period is usually set by the regulatory agency and varies from the 10-year to the 100-year storm. This peak flow is important for the evaluation of the hydraulic conveyance of the StormFilter in the case of severe storm events and to determine the need for high flow bypassing. The designer also needs to consider the presence of base flows as well. If groundwater releases a persistent flow to the StormFilter, a base flow bypass may be needed. In many urban areas where development has increased peak flows and caused local flooding, many agencies require detention of runoff to reduce the peak flows from the site to pre-developed conditions. In this case, detention becomes a factor in how to configure the StormFilter into the storm system. Watershed Characteristics Though difficult to quantify, the designer needs to consider other hydrologic factors such as watershed size relative to the peak flow. Larger watersheds with a lower C or CN Value can produce the same peak flow as a smaller more impervious site, but the total volume of flow from a given storm is greater. Hence, upsizing the facility is necessary. The recommended methodology is to execute a model of the pervious basin using the water quality storm to determine the peak water quality flow and runoff volume. Then take the peak water quality flow and use it as a basis to calculate the area required of an 85% impervious surface (i.e. execute a model of an 85% impervious site that has the same peak flow as the pervious site). This may require a few iterative models by guessing the area. 0 STORMWATER MANAGEMENT updated 4/99 S2 rOnce this is complete. Then compare the total runoff volume of the impervious site to the volume of the pervious site. The StormFilter is then sized by: Number of Cartridges = (1 - Pretreat)(Qwq 449/15)(Volume Pervious)/(Volume Impervious) Where Pretreat is a credit for pretreatment in terms of the percent removal of TSS. For example if a pretreatment facility was projected to remove 30% (0.30) of the TSS then the system would be downsized by 30%. Detention The StormFilter is usually placed downstream of detention systems, which allows downsizing of the facility, and if designed properly, provides excellent pretreatment. However, the detention system prolongs the flow into the StormFilter and increases the total volume of water treated. For example, the StormFilter may need to treat the entire volume of runoff resulting from a 10-year storm. The suggested methodology is to size the StormFilter using the water quality flow and then allow a credit for pretreatment. Typically the pretreatment credit is calculated by using the VbNr ratio and applying that ratio to the FHWA sediment removal efficiency prediction removal curves (FHWA, 1989). Assessing Water Quality and Selecting a Media Assessing the quality of stormwater directed to water quality facilities is difficult. Ultimately, each site develops its own water quality characteristics and even these will ' vary with time, seasons and random events such as spills or erosion. There are many factors that influence water quality. Land use, storm dynamics, source control and maintenance practices are some major factors. Paved surfaces, such as parking lots, tend to generate sediments, oil and grease and some heavy metals. The specific land use should be evaluated for elevated levels of these pollutants and other pollutants that are characteristic to the land use. A good example is grease associated with fast food restaurants or oil and grease from vehicle maintenance facilities. Selection of a media needs to be done with an understanding of the pollutants generated form the site and the sensitivity of the receiving waters. Table 1 below can act as a basic guideline or me is selection, however you should check with Stormwater Management to verify the application. Table 1 Media Selection Guide ' Pollutant CSF Leaf Perlite Zeolite SMZ Media Sediments Good Excellent Oil and Grease Excellent Excellent Soluble Metals Excellent None Excellent j Good Organics Varies Varies Total P Good Good Total N Good Good Phosphate Elevates Good ©STORMWATER MANAGEMENT updated 4/99 S5 Vehicle and equipment maintenance • Garbage storage, e.g. leaking dumpsters • Principal business activities, e.g. fast food restaurants washing greasy mats in the parking lot • Business sanitation practices e.g. sweeping metal filings to the outside rather than picking them up Site Sweeping It is useful to know the frequency of sweeping and vacuuming of the paved drainage surfaces as this will have direct impact on sediments, floatables, and BOD. Many commercial parking lots are swept weekly. Though sweeping is principally focused on large sized particles and trash, analysis of street sweeping debris has shown elevated levels of Total Petroleum Hydrocarbons (TPH) and heavy metals. Catch Basin Operation and Maintenance The catch basins are the first opportunity to pre-treat runoff upon entry into the storm system. Stormwater Management recommends the use of sumped catch basins with an inverted elbow to trap some oil and floatables. The sump should be at least 18" from the invert of the outlet preferably 24". IStormwater Management recommends that all of the catch basins be inspected every 6 months for sediments and oil accumulation. They should also be inspected to insure all piping is intact and bypasses are closed. They need to be cleaned when the sediment accumulation is greater than 1/2 of the sump depth, or annually when the StormFilter is maintained, whichever comes first. Pretreatment BMPs There are two types of pretreatment used in conjunction with the StormFilter. First is removal of oils and greases when heavy loads are expected. Second, and most commonly used, is pre-settling of sediments to reduce loading to the filter cartridges. Oils and Greases Parking lots and roadways tend to generate sustained loadings of oil and grease at levels of 10 mg/I or less. From paved surfaces, peak oil and grease (O&G) concentrations can easily hit 30 ppm. The O&G content is usually composed of a _ combination of free oils, creating a sheen and a sediment fraction to which O&G has adhered. Under these circumstances, the StormFilter does not need O&G pretreatment. In some applications, such as vehicle maintenance facilities, O&G loading may exceed the capacity of the StormFilter. Sustained amounts in excess of 25 mg/1 may trigger the need for a pretreatment facility. Our base recommendation is the addition of an API separator that has the ability to be retrofitted as a coalescing plate separator. These systems need to be sized and maintained in accordance with the manufacturer's recommendations. 0 STORMWATER MANAGEMENT updated 4/99 S9 Smaller diameter particles will be trapped by the filter cartridges. The filtering efficiency of the cartridges will increase as the system matures, however, there is an associated decrease in the hydraulic efficiency of the system. 4. Desired Frequency of Maintenance Maintenance frequency is highly dependent on the site characteristics storm dynamics, and various random events that occur on the site throughout the course of the year. As with any stormwater treatment system, maintenance needs vary from site to site and year to year. Maintenance is usually performed annually. Typically, maintenance is driven by sediment loading. Hence, the more effective the pretreatment, the less frequent the maintenance requirements. This manual has a copy of the O&M Guidelines for the StormFilter. 5. Filter Cartridge Performance As a StormFilter cartridge captures suspended solids from stormwater, it accumulates se Iments on the surface. This progressive loadingo sediments will reduce the cartridge permeability and cause a decline in the system's hydraulic efficiency. Studies of the StormFilter indicate that a loading of 11 Ibs of dry weight sediment per cylinder incident to filter chamber will decrease the permeability to 60% of design value. The following is the result of sediment loading studies by Stormwater Management. It shows how system permeability is affected by sediments after entering the cartridge chamber. 1 Flow Rate vs Ibs. of Sediment (CSF/70um/36um) 16 15r 14 12 Flow Rate Decrease by CL 10 6.7% _a 8 r 1°M 76 0 5 kr \, Flow Rate Decrease by LL 4 50 3 ' 2 1 0 0 5 10 15 20 25 30 35 40 CSF Flow Rate(gpm) Ibs.of Sediment/Cartridge -- -70 um Row Rate(gpm) 36 um Row Rate(gpm) ©STORMWATER MANAGEMENT updated 4/99 D1 Precast StormFiltet" Introduction Figure 1 shows a typical Precast Storm Filter, which consists of one or more precast concrete vaults ranging from 6'x8' to 8'x18' in size. These units treat peak water quality design flows ranging from 0.17 cfs to 0.8 cfs. Precast units can be placed in series or parallel to treat higher flows if needed. Design Considerations Typically, a precast StormFilter is installed in-line with the storm system. They can be installed with traffic-bearing lids for parking lot applications, and for all practical purposes, take up no land area. • Water Quality Flow Range from 0.17 to 0.80 cfs (higher for multiple precast units) • 2.3 feet of drop from the inlet invert to the outlet invert • Access for Maintenance • Pretreatment considerations • Buoyancy Measures • High Flow Bypass for flows >2.2 cfs Applications • Parking lots • Roadways • Residential developments • Retail/commercial developments • Business/industrial sites • Maintenance facilities The Design Process The following design documentation has been constructed as a step-by-step process to allow for easy and efficient incorporation into the civil construction documents by the civil engineer. We recommend that you review the design criteria and call Stormwater Management if you have any questions. Our technical staff has a broad experience base and can assist you with your stormwater problems. 0 STORMWATER MANAGEMENT updated 4/99 jD2 _.............. _...._.._..._..........._..........._............................................... s 1 %:.FOw F F . . ......... I . ."-�j -FLO14J StormFilterym — SECTION VIEW StormRlterTm C.S.PATENT N. N .OR42 E MR D78ER U.S. A.N D N P&TENTS CEND[NG . w STORMWATER" StormFiiterTm A G F �t Precast -- —— - � aa Figure 1 1 ©STORMWATER MANAGEMENT updated 4/99 D3 Precast StormRiter Design NOTE: Periodically check our web site at www.stormwatermgt.com to see if there are design changes. Updated files can be downloaded. ���ro•re� �y Step 1- Verify with Local Agency Verify with local agency if the StormFilter is an approved BMP Technology." If approved, proceed to Step 2. If not yet accepted, call Stormwater Management for assistance in gaining quick approval. Step 2 - Calculate Flows Calculate water quality flow (Qtreat) and peak conveyance flow (Qpeak) using approved hydrologic models that are usually established by the regulatory agency. If there are no agency guidelines we recommend the Santa Barbara Urban Hydrograph method for the water quality flows. Evaluate the need to adjust flow based on land use and C factor, using methodology outlined in the System Design section. Step 3 - Pretreatment and Bypassing Establish need for pretreatment and bypassing needs as outlined in the Pretreatment and Bypassing sections of the System Design section. • 6' x 8' vaults will require a pretreatment manhole. If Qpeak is greater than 2.2 cfs, the facility should have a high flow bypass. O. t cf5 Step 4 - Size the StormFilter • Determine the number of cartridges required, and then size the StormFilter based on Table 1 below. The number of cartridges is determined by: 449 gP�fs Number of Cartridges = Qtreat x 15 gP Cartridge • There may be cases where more cartridges are added as more of the site is developed. If this is the case, the unit should be sized to the ultimate build out conditions. i 0 STORMWATER MANAGEMENT updated 4/99 i 1 Table 1 Determination of Precast StormFilter Dimensions StormFilter Flow Typical Number Nominal Exterior Model Rate of Cartridges Footprint Number cfs Available Width Len th 6x8 Up to 0.20 4 to 6 7 9 6x12 0.18 to 0.37 6 to 12 7 13 8x12 0.40 to 0.46 12 to 14 10 14 8x16 0.50 to 0.80 15 to 24 10 18 8x18 0.54 to 1.00 17 to 30 10 20 8xl6/8x16 0.81 to 1.83 25 to 55 10 40 8x18/8x16 0.81 to 1.96 25 to 59 10 42 8x18/8x18 0.81 to 2.03 25 to 61 10 44 Note: Availability of vault dimensions may vary with region. For Example: Qtreat = 0.45 cfs. Therefore, the number of cartridges = 0.45 ' 449 / 15 = 13.5 cartridges. Round up to 14 and then use Table 1 to set the vault size at 8x14. Step 5 - Determine Inlet and Outlet Geometry • Diagram how the StormFilter fits into your storm system. • Determine rim and pipe invert elevations for the StormFilter. Remember that a difference of 2.3 feet must be maintained between the inlet and outlet invert elevations. Note: Use of standard riser sections will help reduce the overall cost of a unit. • The StormFilter requires a minimum depth of 5.25 feet from the top of the lid to the invert of the outlet. ' Show all o penetrations pipe p n the site plan. Pipes can enter the StormFilter from the end or the side within the confines of the inlet bay. The inlet pipe is preferably 0.1 feet above the invert of the flow spreader, which is 2.2 feet from the invert of the outlet pipe. The inlet invert may be greater than 0.1 feet but additional energy dissipation features may be required inside the vault. The typical vault is about 7 feet deep from the top of lid to the invert of the outlet pipe. Pipes may enter at an angle, however as the angle increases, the penetration becomes elliptical and begins to impact the strength of the vault's side. The hole cast into the vault is typically 2" greater in diameter than the outside diameter of the pipe. Angles greater than 101 from perpendicular to the face of the vault should be specified by the engineer on the plans. • Any type of pipe material can be used. Smooth pipes such as PVC pipes should have sanded fittings to ensure a good non-slip seal with the vault. Stormwater C STORMWATER MANAGEMENT updated 4/99 SECTION 2 RECOMMENDED MAINTENANCE AND EXPECTED PERFORMANCE 2.1 TYPES OF MAINTENANCE Presently, procedures have been developed for two levels of maintenance: Inspection/minor maintenance and major maintenance. Inspection/minor maintenance activities are combined since the minor maintenance does not require special equipment and typically little or no materials are in need of disposal. Inspection/minor maintenance typically involves opening the flow restricting valves (to pre-set levels) and cleanup of vegetation and debris. Major maintenance typically includes cartridge recharging. Major maintenance may involve disposal of materials that require consideration of regulatory guidelines. Depending on the particular unit configuration and equipment used, major maintenance may require an understanding of OSHA rules. Table 1 summarizes the primary activities associated with StormFilter maintenance. Table 1: StormFilter Facility Component Maintenance When Maintenance Activity Expected Facility Performance Requiring Maintenance Activity Is Required After Maintaining StormFilter Cartridges Trash and Debris Removal Floatable objects or other Permanent removal from storm and Containment trash is present in the filter. Remove system. Structure to avoid hindrance of filtration and eliminate unsightly debris and trash. Cartridge Replacement 1.Media has been contaminated by 1. New media is able to effectively and Sediment Removal high levels of pollutants,such as treat stormwater. after a spill. Drainage System Piping Flushing With Water Drainage system is obstructed by Outflow is not restricted. debris or sediment. 2.2 MAINTENANCE ACTIVITIES 2.2.1 Maintenance Activity Timing Two scheduled inspections/maintenance activities should take place during the year. During the minor maintenance activities (routine inspection, debris removal), the type of major maintenance required is determined and, if required for disposal, samples of the sediments and media are obtained. The next scheduled date is to perform major maintenance activities (replacement of the filter cartridges and associated sediment removal). In addition to the scheduled activities, it is important to check the condition of the filter after major storms to check for damage caused by high flows and to check for high sediment accumulation which may be caused by localized erosion in the drainage area. It may be necessary to adjust maintenance activity scheduling depending on the actual operating conditions encountered by the system. In general, minor maintenance activities will occur late in the rain season, and major maintenance Y J will occur in late summer to early fall, when flows into the system are not likely to be present. The months indicated in Table 2 show the best recommended times of year for maintenance activities to occur in the Pacific Northwest. ' ©Stormwater Management updated 4/99 f f Table 2: WORK CALENDAR FOR TYPICAL WET/DRY SEASON WET WET DRY WET JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC X X X XX XX XX X = Schedule minor maintenance inspection and media sampling during one of these months. XX= Schedule major maintenance during one of these months. 2.2.2 Maintenance Activity Frequency The primary factor controlling timing of maintenance for the StormFilter is sedimentation. A properly functioning system will remove solids from water by trapping these particulates within the porous structure of the media. The flow through the system will naturally decrease as more and more solids are trapped. Eventually the flow through a system will be low enough to require replacement of the ' cartridges. Sediment should be removed from upstream trapping devices on an as needed basis to prevent material from being re-suspended and discharged to the system. Site conditions greatly influence maintenance requirements. StormFilter units located in areas with erosion or active construction should be inspected and maintained more often than those in fully stabilized areas. The maintenance frequency may be adjusted as additional monitoring information becomes available during the inspection program. Areas that develop known problems should be inspected more frequently than areas that demonstrate no problems, particularly, after large storms. Ultimately, inspection and maintenance activities should be scheduled based on the historic records ' and characteristics of an individual filter. It is recommended that the maintenance agency develop a database to properly manage StormFilter maintenance programs. Prior to the development of the maintenance database, maintenance frequencies shown in Table 3 should be followed. Frequencies should be updated as required. The recommended initial frequency for inspection/minor maintenance is two times per year for the precast unit. StormFilter units should be inspected after all major storms. Sediment removal on an annual basis is recommended until further knowledge is gained about a particular system. Table 3: FREQUENCY OF MAINTENANCE ACTIVITY INSPECTION/MINOR MAJOR MAINTENANCE MAINTENANCE TIMES/YEAR) TIMES/YEAR StormFilter 1 (and after major storms) 1 (except in case of a spill_ © Stormwater Management updated 4/99 2.3 MAINTENANCE CREW REQUIREMENTS Table 4 lists the anticipated crew requirements for maintenance operations. Removal of water and sediments during major maintenance activities can be accomplished using either a pump and water truck or a vacuum truck. All applicable safety (OSHA) and disposal regulations should be followed. A general description of the maintenance activities follows. Table 4: ANTICIPATED CREW REQUIREMENTS Inspection/Minor Major Maintenance: Major Maintenance: M Maintenance Sediment Removal Cartridge Replacement Laborer Utility Worker 1 1 1 Senior Sewer Operator Vacuum/Water Truck Operator 1 1 Hauling Truck Operator 1 Total 1* 2* 3* Special Requirements Knowledge of Knowledge of Knowledge of Proper StormFilter Disposal Cartridge Removal Function Requirements and Installation Procedures * May require OSHA trained person if vault entry occurs. ' 2.4 MAINTENANCE METHODS 2.4.1 Minor Maintenance/Inspection (Once A Year) I Minor maintenance typically will involve the steps below, however if it appears that a spill of some type has occurred, the local hazard control agency and Stormwater Management Inc. should be notified immediately. In the case of a spill, the worker should abort maintenance activities until the proper guidance has been obtained. Steps for Minor Maintenance 1 . Maintenance to be performed by a utility worker familiar with StormFilter units. 2. If applicable, set up safety equipment up to protect pedestrians from fall hazards presented by open doors. Also set up appropriate safety equipment for work near roadways. 3. Inspect the external condition of the unit and take notes concerning defects/problems. 4. Open the doors to the vault and allow the system to air out for 5-10 minutes. 5. Without entering the vault, inspect the inside of the unit, including components. 6. Take notes about the external and internal condition. ' © Stormwater Management updated 4/99 ■ 7. Give particular attention to recording the level of sediment build-up on the floor of the vault in the forebay, and on top of the internal components. If flow is occurring, note the level of water and estimate the flow rate per drainage pipe. Record all observations. 8. Remove large. loose debris and trash using a pole with a grapple or net on the end. 9. Close and fasten the door, and remove safety equipment. 10. Finally, make notes about the local drainage area relative to ongoing construction, erosion problems, or high loadings of other materials to the system. 2.4.2 Major Maintenance Inspection (Once A Year) The primary goal of the major maintenance inspection is to assess the condition of the cartridges relative to the level of sediment loading. It may be desirable to conduct this inspection during a storm to observe the relative flow through the filter cartridges. If the submerged cartridges are severely plugged, large amounts of sediments should be present and very little flow will be discharging from the drainage pipes. It is likely that the cartridges need to be replaced. Major maintenance inspection will typically involve the steps below. However, if it appears that a spill of some type has occurred, the local hazard control agency and Stormwater Management Inc. should be notified immediately. In the case of a spill, the worker should abort maintenance activities until the proper guidance has been obtained. Steps For Pre-Major Maintenance Inspection 1. Maintenance to be performed by a utility worker familiar with Storm Filter units. 2. If applicable, set up safety equipment to protect pedestrians from fall hazards presented by open doors. Also, set up appropriate safety equipment for work near roadways. 3. Inspect the external condition of the unit and take notes concerning defects/problems. 4. Open the doors to the vault and allow the vault to air out for 5-10 minutes. 5. Without enteringthe vault iv he in, give t side of the unit, including components, a general condition inspection. 6. Take notes about the external and internal condition. 7. Give particular attention to recording the level of sediment build-up on the floor of the vault, in the forebay, and on top of the internal components. B. Remove large loose debris and trash using a pole with a grapple or net on the end. 9. If the visit is during a storm, make the flow observations discussed above. j� 10. Close and fasten the door, and remove safety equipment. ' 11. Make notes about the local drainage area relative to ongoing construction, erosion problems, or high loading of other materials to the system. ©Stormwater Management updated 4/99 12. Review the condition reports from the previous minor and major maintenance visits and schedule for cartridge replacement if needed. 2.4.3 Major Maintenance/Cartridge Replacement Major maintenance/filter cartridge replacement typically involves the steps below. However, if it appears that a spill of some type has occurred, the local hazard control agency and Stormwater Management Inc. should be notified immediately. In the case of a spill, the worker should abort maintenance activities until the proper guidance has been obtained. Depending on the configuration of the particular system, a worker may be required to enter the vault to perform some tasks. If vault entry is required, OSHA rules for general confined space entry must be followed. Filter cartridge replacement should occur during dry weather and it may be necessary to plug the filter inlet pipe if base flows exist. Standing water present in the vault should be regarded as polluted and contained during this operation by temporarily capping the manifold connectors. Steps For Cartridge Replacement Maintenance 1. Depending on the particular unit, one or two utility workers and a hauling truck operator will deliver the replacement cartridges to the site. Information concerning how to obtain the replacement cartridges is available from Stormwater Management Inc. 2. If applicable, set up safety equipment to protect pedestrians from fall hazards presented by open doors. Also, set up appropriate safety equipment for work near roadways. >� 3. Inspect the external condition of the unit and take notes concerning defects/problems. 4. Open the doors to the vault and allow the system to air out for 5-10 minutes. 5. Without entering the vault, give the inside of the unit, including components, a general condition inspection. 6. Make notes about the external and internal condition. 7. Give particular attention to`recording the level of sediment build-up on the floor of the vault, in the forebay, and on top of the internal components. 8. Remove large loose debris and trash using a pole with a grapple or net on the end. 9. Using a boom, crane, or other device (dolly and ramp), off load the replacement cartridges (150 lbs. each) and set aside. 10. Using an appropriate sling, (cartridges must be supported from the base) attach the cable from ' the boom, crane, or tripod to the cartridge being removed. The threads that the cap attaches to are not a safe lifting point. For more information contact Stormwater Management Inc. This activity may require that workers enter the vault to remove the cartridges from the drainage system and place them under the vault opening for lifting. Note that cartridges containing media other than the leaf media require unscrewing from their threaded connectors. Take care not to damage the manifold connectors. This connector should remain installed in the manifold and capped if necessary. (See figure 4). 0 Stormwater Management updated 4/99 11. Remove the cartridge (250 lbs. each) from the vault. Care must be used to avoid damaging the cartridges during removal and installation. The cost of repairing components damaged during maintenance will be the responsibility of the owner unless maintenance activities are being performed by Stormwater Management and damage is not related to discharges to the system. 12. Set the used cartridge aside or load onto the hauling truck. 13. Continue steps 10 through 12 until all cartridges have been removed. 14. Remove deposited sediment from the floor of the vault and, if large amounts are present, from the forebay. This can usually be accomplished by shoveling the sediment into containers which, once full, are lifted mechanically from the vault and placed onto the hauling truck. In some cases of extreme sediment loading, especially if the sediment is saturated, a vactor truck may be required. 15. Once the sediments are removed, it is necessary to assess the condition of the vault, particularly the manifold and the connectors. These are short sections of 2-inch schedule 40 PVC, or threaded schedule 80 PVC that should protrude above the floor of the vault. If required, apply a light coating of FDA approved silicon grease to the outside of the exposed portion of the connectors. This ensures a watertight connection between the cartridge and the drainage pipe. Replace any damaged connectors. 16. Using the boom, crane, or tripod, lower and install the new cartridges. Once again, take care not to damage connections. 17. Close and fasten the door, and remove safety equipment 18. Make notes about the local drainage area relative to ongoing construction, erosion problems, or high loadings of other materials to the system. 19. Finally, dispose of the residual materials in accordance with applicable regulations. Make arrangements to return the used cartridges to Stormwater Management Inc. 2.4.4 Related Maintenance Activities (Performed on an as-needed basis) StormFi lter units are often dust one of many components in a more comprehensive stormwater drainage and treatment system. The entire system may include catch basins, detention vaults, 1 sedimentation vaults and manholes, detention/retention ponds, swales, artificial wetlands, and other miscellaneous components. In order for maintenance of the StormFilter to be successful, it is imperative that all other components be properly maintained. The maintenance/repair of upstream facilities should be carried out prior to StormFilter maintenance activities. In addition to considering upstream facilities, it is also important to correct any problems identified in the drainage area. Drainage area concerns may include: erosion problems, heavy oil & grease loading, and discharges of inappropriate materials. 2.5 TYPICAL EQUIPMENT REQUIRED FOR MAINTENANCE ACTIVITIES ' Typical equipment required for conducting maintenance is shown in Table 5. Some of the materials listed are suggestions rather than requirements. It should be noted that there is more than one way to accomplish some tasks. Owners with available labor and equipment resources may desire to use alternative methods. However, it is advisable that guidance from Stormwater Management Inc. be obtained prior to using alternative techniques. 1 0 Stormwater Management updated 4/99 Sample StormFilter"w Minor Maintenance and Inspection Data Sheet Date: Location: System Size: TYPE: Cast-In-Place Precast Linear Personnel: System Observations Media Months in Service: Oil and Grease in Forebay: Sediment Depth in Forebay: Sediment Depth on Vault Floor: Structural Damage: Estimated Flow from Drainage Pipes (if available): Cartridges Submerged (Yes No ) How Deep: StormFilter Minor Maintenance Activities (check off if done and give description) Remove Trash and Debris: Minor Structural Repairs: Drainage Area Report Excessive Oil and Grease Loading (Yes No ) Source: Sediment Accumulation on Pavement (Yes No ) Source: iErosion of Landscaped Areas (Yes No ) Source: Items Needing Further Work: Comments: ' ©Stormwater Management updated 4/99 GENERAL NOTES: The STOR"ATER VANAGEI¢NT St JIMMter' 1.) STORMFILTER BY STORMWATER MANAGEMENT, PORTLAND, OREGON (503-240-3393). U.S. PATENT No. 6,522,62Y, No. 5.WA.576, AND OTHER US 2.) ALL STORMFILTERS REQUIRE REGULAR MAINTENANCE. REFER TO OPERATION AND MAINTENANCE MANUAL FOR AND FOREIGN PATENS PZKDING DETAILS. 3.) PRECAST CONCRETE VAULT CONSTRUCTED IN ACCORDANCE WITH ASTM C858. 4.) EXTERNAL PIPING AND COUPLINGS PROVIDED BY OTHERS. 5.) FLEXIBLE COUPLINGS TO BE SET 18" OUTSIDE FACE OF WALL FERNCO OR ENGINEER APPROVED. 6.) SEE PRECAST STORMFILTER DATA SHEET FOR VAULT DIMENSIONS, ELEVATIONS AND NUMBER OF CARTRIDGES. 7.) ANTI—FLOATATION BALLAST TO BE SET ALONG ENTIRE LENGTH OF BOTH SIDES OF FILTER AS SHOWN. SEE PRECAST FILTER DATA BLOCK FOR BALLAST WIDTH AND HEIGHT DIMENSIONS. /ANTI—FLOATATION BALLAST ALTERNATE PIPE IF FIVE OR LESS CARTRIDGES (BY OTHERS) PRE—CAST ALTERNATE CONCRETE VAULT a,,. _ �, e. ENERGY DISSIPATER ,q .{_1' A OUTLET 1 BAY 2' 1' X 2' SUMP TV INLET PIPE (BY OTHERS) 6 7 y OUTLET PIPE LADDER (TYP) \ � (BY OTHERS) FLEXIBLE COUPLING (BY OTHERS) 2 ENERGY DISSIPATER (TYP) 4 I_ V V. PIPE MANIFOLD (TYP) RADIAL FLOW CARTRIDGE (TYP) 6'x8' PRECAST STORMFILTER'- PLAN VIEW 1 SCALE: N.T.S 2 — 3'x3' DIAMOND PLATE DOORS (TYP) TRAFFIC BEARING LID (TYP) JOINT OVERFLOW SEALANT (TYP) FLOW SPREADER ROUTES LADDER (TYP) RADIAL FLO ARTRIDGE (TYP) f� ' FLOW RESTRICTOR •v 4.5' DISC (TYP) MINIMUM NOTE: I.E. IN — I.E. OUT = 2.3' MIN. Z_ 74 Q O PIPE MANIFOLD (TYP) INTEWALL 6'x8' PRECAST STORMFILTER" - SECTION A-A A-A SCALE: N.T.S ST 6'x8' PRECAST STORMFILTER" PLAN AND SECTION VIEW ' STANDARD DETAIL 1 SCx PRWEC'NO. DMwiHC ikE roof: A5 SnOwrr 1998 bpg.p Kies County Department of Development and Environmental Services SITE IMPROVEMENT 3600 136th Placc So thuat Bcllcv ,Washington 98006-14M BOND QUANTITY WORKSHEET Project Name: Fr2ST -j�J I LP EZ-S— >l 7-0>` SIERRA Project No.: Date: _1 164 17, )fj °J 9 Location: Q E ft TO lq Sierra Activity No. FOR ENTIRE PROJECT Unit Price Unit Quantity Price FERI /SEDIMENT CONTROL lt $ 1.30 LY Hydrossading .40 SY Juts Mesh 1.00 SY Mulch,by hand,strew,2'deep .35 SY Mulch,by machine,strew,1'deep .40 SY Rock Constr Entrance,50'x 15'x 1' 1,030.00 Each D3 Rock Constr Entrance,100'x 15'x 1' 1,800.00 Each Seeding,by hand .35 SY ESC SUBTOTAL EXISTING FUTURE PUBLIC PRIVATE RID FACILITIES AND BOND REDUCTIONS RIGHT-OF-WAY ROAD IMPROVEMENTS CONVEYANCE IMPROVEMENTS' SYSTEMS 1 2 3 Unit ,Quantity thy Quantity Price Unit tlwndry. Price Quantity Price Quantity Price Quantity Price Complete Price Complete Price Complete He* GENERAL ITEMS ClserlRennove Brush,by hand .24 SY SUBTOTAL FOR PAGE cn��Miser7isroa Pane 1 EXISTING FUTURE PUBLIC PRIVATE RA)FACILITIES AND BOND REDUCTIONS RIGHT-OF-WAY ROAD IMPROVEMENTS CONVEYANCE IMPROVEMENTS SYSTEMS 1 2 -3 . Unit' Quantty.. Quantity Quantity Price Unit Quantity Price Quantity Price Quantity Price Quantity Price Complete Price Complete Prloe: Complete Price GENERAL ITEMS(Con't.) Ciearin /Grubbin /Remove) trees 6,150.00 Acre 3 Excavation-bulk 1.10 CY Excavation-trench 3.00 CY Backfill&Compaction-embankment 3.60 CY Backfill&Compaction-trench 5.70 CY Fill&Compact-common barrow 1 1.10 CY RII&Compact-gravel base 15.60 CY Fill&Compact-screened topsoil 15.40 CY Grading,fine, with grader .70 SY Grading,fine,by hand 1.30 SY Fencing,ceder,6'high 25.00 LF Fencing,chain link,6'high 9.20 LF,. Fencing,chain link gate,20' 880.00 Each Fencing,temporary(NGPE) 1.10 LF Sod 4.82 SY Monuments 3'long 84.0.0 Each Surveying,lot IocationAines 630.00 Acre Surveying,line&grada 510.00 Da Trail 4'crushed cinder 6.50 SY Trail 4'top course 6.00 SY Gabion,3'thick no earthwork 97.00 SY Well retaining,rockary w/earthwork 21.00 SF 10,�s SUBTOTAL FOR PAGE Cr944:M13e-1 znn4 Page 2 r� rr r rr rr �r r rr rr rr rr r� rr r r r r rr r■� Sierra Project No. EXISTING FUTURE PUBLIC PRIVATE RID FACILITIES AND BOND REDUCTIONS RIGHT-OF-WAY (ROAD - .IMPROVEMENTS CONVEYANCE (IMPROVEMENTS- SYSTEMS 1 2 3 Unit,, Quantity Quendty Quendty Price]':',:,, Unit Qwntky Price Quantity Price Quantity Price Qu�ntky Price Complete Price Corn Price Complete Price ROADIMPROVEMENTS AC Grinding,4'machine 7.00 SY AC Removal/Dis osal/Re air 80.00 SY Barricade,type III 30.00 LF Barricade type 1 20.00 LF Curb,extruded asphalt 1.80 LF Curb,extruded concrete 1.80 LF Curb&Gutter,rolled 9.30 LF Curb&Gutter,vertical 6.80 LF �r U Demolition/Disposal,curb&gutter 10.30 LF Demolition/Disposal,sidewalk 22.50 SY Sawcut,asphalt,3'depth 1.30 LF zZ� Sewcut concrete,per 1'depth 1.10 LF Sealant .70 LF Shoulder AC see AC Road SY Shoulder,gravel 6,40 SY Sidewalk,4'thick,vertical curb 20.80 SY Sidewalk,5'thick,rolled curb 23.80 SY Striping,4'reflectorized line .20 LF Striping, er parking stall 2.90 Each Thickened Ede 4.70 LF r ROAD SURFACING (4'rock - 2.5 base& 1.5'top course) L/ AC Overle 1.5'AC 5.40 SY AC Ovede ,2'AC 6.50 SY SUBTOTAL FOR PAGE CA44:W3e•1znrv4 Page 3 rr rr rr wr rr ■r rr rr r rr rr rr rr �r rr r Sr;act f EXISTING FUTURE PUBLIC PRIVATE RID FACILITIES AND BOND REDUCTIONS RIGHT-OF-WAY ROAD IMPROVEMENTS CONVEYANCE IMPROVEMENTS SYSTEMS 1 2 J Unit Quantity Quantity Quantity Price Unit Quantity Price Quantity Price Quantity Price Quantity Price Complete Prloo Complete Prloe Complete Prioe ROAD SURFACING(Con't.) AC Road 2' 4'rock First 2500 SY 13.70 SY 2 �,/5(� AC Road,2' 4'rock Cry.over 2500 SY 9.10 SY /�0 AC Road 3' 4'rock First 2500 SY 16.50 SY AC Road,3',4'rock,Cry.over 2500 SY 11.00 SY AC Road,5' First 2500 SY 16.30 SY AC Road,5',Qty.over 2500 SY 10.80 SY AC Rood 6' First 2500 SY 19.10 SY AC Road,6',Qty.ovc. 2500 SY 12.70 SY Asphalt Treated Base(ATB)(Assume 2.05 ton/c ) 30.00 Ton Gravel Road,4'rock,First 2500 SY 7.20 SY Gravel Road 4'rock City.over 2500 SY 4,70 SY PCC Road,5',no base 14.30 SY PCC Road,6',no base 16.60 SY DRAINAGE (CPP - Corrugated Plastic Pipe,N-12 ore uivnlant) Access Road,R/D 9.30 SY Bollards-fixed 290.00 Each Bollards-removable 475.00 Each (CB9 include frame and lid) CB Typo 1 850.00 Each 13 CB Type IL 1,000.00 Each CB Type II 48'diameter 1,300.00 4'deep for additional depth over 4' +320.00 +1'depth SUBTOTAL FOR PAGE CH4.4:M13e-12/N4 Page 4 rr rr rr rr rr r� rr �r rr r r rr rr �r it rr err .r rr Sierra Project No, EXISTING FUTURE PUBLIC PRNATE R/D FACILITIES AND BOND REDUCTIONS RIGHT-OF-WAY ROAD IMPROVEMENTS CONVEYANCE IMPROVEMENTS SYSTEMS 2 3 Unit Quantfy Quantity Quantity Price Unit Quenthy Price Quantity Price Quendty price Quantity Price Complete Price Complete Price Complete Price DRAINAGE(Con't.) CB Type II 54'diemeter 1,450.00 4'dee Z. for additional depth over 4' +370.00 +1'depth 1 2-- CB Type II 60'diameter 1,600.00 4'deep for additional depth over 4' +410.00 +V depth CB Type 11 72'diameter 2,200.00 4'depth for additional depth over 4' +520.00 +1'depth Through-curb Inlet Framework(Add) 225.00 Each Cleenout PVC 4' 86.00 Each Cleenout PVC 8' 115.00 Each Cleenout PVC 8' 142.00 Each Culvert PVC 4' 4.50 LF Culvert CPP 8' 9.30 LF Culvert PVC 8' 6.40 LF Culvert,CMP 8' 9.50 LF Culvert,concrete 8' 12.90 LF Culvert,CPP 8" 10.00 LF ,SQ Culvert PVC 8' 8.00 LF Culvert CMP 12' 14.60 LF Culvert concrete 12' ` 17.90 LF Culvert CPP 12' 16.50 LF Culvert CMP 15' 18.70 LF Culvert concrete 15' 22.50 LF Culvert CPP 15' 18.50 LF Culvert,CMP, 18' 21.90 LF SUBTOTAL FOR PAGE Cn4.4:Mna-12nrv4 Pape 5 r r� w r r� �■r rr r r r r r r r r r S��ect EXISTING FUTURE PUBLIC PRIVATE - RID FACILITIES AND BOND REDUCTIONS RIGHT-OF-WAY ROAD IMPROVEMENTS CONVEYANCE IMPROVEMENTS. SYSTEMS 1 - 2 -:.3_. Unit Quantity Quantity Quantity Price Unit Quantity Price Quantity Price Quantity Price Quantity Price Complete Price Complete Price Complete Prig DRAINAGE(Con't.) Culvert,concrete 18' 27.60 LF Culvert,CPP 18' 22.00 LF Culvert,CMP, 24' 30.30 LF Culvert,concrete,24' 39.80 LF Culvert,CPP,24' 29.00 LF Culvert,CMP,30' 38.60 LF Culvert,concrete,30' 64.70 LF Culvert,CMP,36' 62.80 LF Culvert,concrete,36' 83.20 LF Culvert,CPP,36' 39.00 LF I d Culvert concrete,42' 101.80 LF Culvert,CMP,48' 80.60 LF Culvert,concrete,48' 113.00 LF Culvert,CMP 60' 112,00 LF Culvert,concrete,60' 164.00 LF Ditching,bare,roadside 5.40 CY.. Flow Dispersal Trench 1,100 base + 15.00 LF I O French Drain 12.30 LF Mid-tank Access Riser,36' 700.00 Each Pond Overflow Spillway 4.70 SY Restrictor/Oil Separator, 12' 785.00 Each Restrictor/Oil Separator, 15' 885.001 Each Restrictor/Oil Separator, 18' 1.035.00 Each SUBTOTAL FOR PAGE "44 M134-12/9/4 Page 6 r Sierra Project No. EXISTING FUTURE PUBLIC PRIVATE ': RID FACILITIES AND BOND REDUCTIONG RIGHT-OF-WAY ROAD IMPROVEMENTS'. " sCONVEYANCE IMPROVEMENTS :SYSTEMS 1 2 3 Unit Quantity Quantity Quantity Prim Unit Quantity Prim Quantity Price :Quantity Prior Quanthy 'Price Complete Pr1ce 'Complete- PrimComplata Price DRAINAGE(Con't.) Riprap,placed 28.00 CY Tank End Reducer 400.00 Each Trash Rack 12' 160.00 Each Trash Rack,15' 185.00 Each Trash Rack,18' 210.00 Each Trash Rack,21' 240.00 Each PARKING LOT SURFACING 2'A.C. 2'top course rock&4'select borrow 8.10 SY 1.5'top course rock&2.5'base course 4.70 SY 4'select borrow 1.75 SV WRITE-IN ITEMS SUBTOTAL(SUM ALL PAGES): 30%CONTINGENCY&MOBILIZATION: TOTAL: (A) (B) (C) Page 7 M M M M M = M M M M Sleet Ouantities above were completed by: Signature: Date: , PE Registration Number: Telephone Number: 206 3Z7— Sid Firm Name: V-r--'4 / WV I-'T- 20L-LA 95 Address: 81 y EA-�,T Pi!KF- - 7, sEA-rrt �, wA gS►zz This section to be completed by King County BOND COMPUTATIONS: PERFORMANCE BOND AMOUNTS MAINTENANCE BOND AMOUNT DEFECT BOND AMOUNT Stabilization/Erosion Sediment Control (ESC) (D) Existing Right-of-Way Improvements (E) Future Public Road Improvements (F) (E+F) x 0.25 = Private Improvements R/D Facilities and Conveyance Systems _ - - - _ - - - _ - - - _ - - x 0.15 = TOTAL (T) PERFORMANCE BOND AMOUNT RIGHT-OF-WAY &SITE RESTORATION BOND (D+E) (First $7,500 of bond shall be cash.) X1 PERFORMANCE BOND TOTAL AFTER BOND REDUCTIONS (T-A,B OR C) p2 p3 NOTE: The word 'bond' is used to represent Original bond computations Signature of Person Preparing Bond Reduction any financial guarantee acceptable to prepared by: Date: King County. X1 Date #2 Date 03 Date NOTE: Total bond amounts remaining after reduction shaff not be less than 30%of the original amount or the sum of the maintenance and defect amounts shown above, whichever is greater. rsrw..w.au M z""' Page 8 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL RETENTION/DETENTION SUMMARY SHEET Development ErV-sT 3QI CD 57S - Date _Q oV 1-�, 19 9 9 Location 12�� ' �',4 a" ENGINEER DEVELOPER Name C-t/ Name Firm 12C,4 /4400 '4�-collars Firm Address gi `l �- ��'�{ Address �ea t+l.�, W � q �►Z Z Phone 2_0& 32-q- ssoo Phone • Developed Site y 3s acres Number of Lots 2-9 • Number of Detention Facilities On Site • Detention provided in regional facility Regional Facility location • No detention required 71 Acceptable receiving waters • Downstream Drainage Basins Immediate Major Basin Basin A So 0T4 Basin B Li\_l Basin C Basin D TOTAL INDIVIDUAL BASIN Drainage Basin(s) A B C D Onsite Area z'3 �' n� /' 0 Off.site Area Type of Storage Facility V4 L)L- 1 Live Storage Volume C P Predeveloped Runoff Rate, ct5 2 year 0, 01 10 year D, o Postdeveloped Runoff Rate 46 100 year 0. 05O 06 o D 2 year o Z6 10 year o Z/ Developed O 100 year o,6 J Type of Restriction oQ I F►C C-- Size of Orifice/Restriction Orifice/Restriction No.1 31811 No.2 7 8� No.3 1 No.4 No.5 Project FI9zs'I ELP-KS -ZE t'T`( H TT Job No. S, o l Client ZOLLARS By G T Date Task ING°RP0RATE° Chkd _ Date Sheet of Nl7�T� (JI7 4,AD l92of NF Z�ITr S� 1. N;o� w A 9 go 5b z�?` „ Ce 00 30-$ O j "g�'3 OD qs P i+R�T ROAD o / i toC �B"Io cB 9 OD N GS��Z 30- Lg it i C.5. c, S. -��ATMeTIT � 4i FI}�I L I rY L_E�E�— rAfter recording return to: DECLARATION OF COVENANT IN CONSIDERATION OF the approved King County permit for application No. relating to real property legally described as follows: The undersigned as Grantor(s) , declares that the above described property is hereby subject an easement for a natural or constructed conveyance system and hereby dedicates, covenants and agrees as follows: 1 . King County shall have the right to ingress and egress over those portions not contained in Exhibit "A" to access such easement area for inspec- tion of and to reasonably monitor the system for performance, operational flows, or defects in accordance with and [as presented in King County Code Section 9.04. 120) . 2. If King County determines that maintenance or repair work is required to be done to the system, the Manager of the Surface Water Management Division of the Department of Public Works shall give notice of the specific maintenance and/or repair required pursuant to K.C.C. 9.04.030. The Manager shall also set a reasonable time in which such work is to be completed by the Grantor(s) , its heirs, successors or assigns. If the above required D8:M116 - 1 - otherwise provided for by the provisions of this Agreement shall be effective upon personal delivery, or three (3) days after mailing by Certified Mail , return receipt requested. 6. This Agreement constitutes the entire agreement between the parties, and supersedes all prior discussions, negotiations, and all agreements whatso- ever whether oral or written. This covenant is intended to protect the value of desirability of the real property described above, and shall insure to the benefit all the citi- zens of King County, and shall be binding on all heirs, successors and assigns. OWNER OWNER STATE OF WASHINGTON ) COUNTY OF KING ) ss. On this date personally appeared before me: , to me known to be the indiv-idual (s) described in and who executed the within and foregoing instru- ment and acknowledged that they signed the same as their free and voluntary act and deed, for the uses and purposes therein stated. Given under my hand and official seal this day of 199 NOTARY PUBLIC in and for the State of Washington, residing at My Commission Expires: D8:MI16 - 3 - KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 3 - CLOSED DETENTION SYSTEMS (PIPES/TANKS) Maintenance Conditions When Maintenance Results Expected Component Defect is Needed When Maintenance Is Performed Storage Area Plugged Air Vents One-half of the cross section of a vent is Vents free of debris and sediment. blocked at any point with debris and sediment. Debris and Accumulated sediment depth exceeds All sediment and debris removed from Sediment 10%of the diameter of the storage area storage area. for 1/2 length of storage vault or any point depth exceeds 15%of diameter. Example: 72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than 1/2 length of tank. Joints Between Any crack allowing material to be All joints between tank/pipe sections are Tank/Pipe Section transported into facility. sealed. Tank/Pipe Bent Any part of tank/pipe is bent out of shape Tank/pipe repaired or replaced to design. Out of Shape more than 10%of its design shape. Manhole Cover not in Place Cover is missing or only partially in place. Manhole is closed. Any open manhole requires maintenance. Locking Mechanism cannot be opened by one Mechanism opens with proper tools. Mechanism Not maintenance person with proper tools. Working Bolts into frame have less than 1/2 inch of thread (may not apply to self-locking lids). Cover Difficult to One maintenance person cannot remove Cover can be removed and reinstalled by Remove lid after applying 80 pounds of lift. Intent one maintenance person. is to keep cover from sealing off access to maintenance. Ladder Rungs King County Safety Office and/or Ladder meets design standards and Unsafe maintenance person judges that ladder is allows maintenance persons safe access. unsafe due to missing rungs, misalignment, rust, or cracks. Catch Basins See "Catch Basins" Standard No. 5 See "Catch Basins" Standard No. 5 - A-3 I/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 4 - CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance Is Performed General Trash and Debris Distance between debris build-up and All trash and debris removed. (Includes bottom of orifice plate is less than 1-1/2 Sediment) feet. Structural Damage Structure is not securely attached to Structure securely attached to wall and manhole wall and outlet pipe structure outlet pipe. should support at least 1,000 pounds of up or down pressure. Structure is not in upright position (allow Structure in correct position. up to 10%from plumb). Connections to outlet pipe are not Connections to outlet pipe are watertight; watertight and show signs of rust, structure repaired or replaced and works as designed. Any holes—other than designed holes— Structure has no holes other than in the structure. designed holes. Cleanout Gate Damaged or Cleanout gate is not watertight or is Gate is watertight and works as designed. Missing missing. Gate cannot be moved up and down by Gate moves up and down easily and is one maintenance person. watertight. Chain leading to gate is missing or Chain is in place and works as designed. damaged. Gate is rusted over 50%of its surface Gate is repaired or replaced to meet area. design standards. Orifice Plate Damaged or Control device is not working properly Plate is in place and works as designed. Missing due to missing,out of place,or bent orifice plate. Obstructions Any trash,debris,sediment, or vegetation Plate is free of all obstructions and works blocking the plate. as designed. Overflow Pipe Obstructions Any trash or debris blocking (or having Pipe is free of all obstructions and works the potential of blocking)the overflow as designed. pipe. Manhole See "Closed Detention Systems" Standard See "Closed Detention Systems" Standard No. 3. No. 3. Catch Basin See "Catch Basins" Standard No. 5. See "Catch Basins" Standard No. 5. A-4 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 5 - CATCH BASINS Maintenance Conditions When Maintenance Results Expected Component Defect is Needed When Maintenance is Performed General Trash & Debris Trash or debris of more than 1/2 cubic No trash or debris located immediately in (Includes foot which is located immediately in front front of catch basin opening. Sediment) of the catch basin opening or is blocking capacity of basin by more than 10%. Trash or debris (in the basin) that No trash or debris in the catch basin. exceeds 1/3 the depth from the bottom of basin to invert of the lowest pipe into or out of the basin. Trash or debris in any inlet or outlet pipe Inlet and outlet pipes free of trash or blocking more than 1/3 of its height. debris. Dead animals or vegetation that could No dead animals or vegetation present generate odors that would cause within the catch basin. complaints or dangerous gases (e.g., methane). Deposits of garbage exceeding 1 cubic No condition present which would attract foot in volume. or support the breeding of insects or rodents. Structural Damage Corner of frame extends more than 3/4 Frame is even with curb. to Frame and/or inch past curb face into the street (if Top Slab applicable). Top slab has holes larger than 2 square Top slab is free of holes and cracks. inches or cracks wider than 1/4 inch (intent is to make sure all material is running into the basin). Frame not sitting flush on top slab, i.e., Frame is sitting flush on top slab. separation of more than 3/4 inch of the frame from the top slab. Cracks in Basin Cracks wider than 1/2 inch and longer Basin replaced or repaired to design Walls/Bottom than 3 feet, any evidence of soil particles standards. entering catch basin through cracks, or maintenance person judges that structure is unsound. Cracks wider than 1/2 inch and longer No cracks more than 1/4 inch wide at the than 1 foot at the joint of any inlet/outlet joint of inlet/outlet pipe. pipe or any evidence of soil particles entering catch basin through cracks. - Settlement/ Basin has settled more than 1 inch or has Basin replaced or repaired to design Misalignment rotated more than 2 inches out of standards. alignment. Fire Hazard Presence of chemicals such as natural No flammable chemicals present. gas, oil, and gasoline. Vegetation Vegetation growing across and blocking No vegetation blocking opening to basin. more than 10%of the basin opening. Vegetation growing in inlet/outlet pipe No vegetation or root growth present. joints that is more than six inches tall and less than six inches apart. Pollution Nonflammable chemicals of more than No pollution present other than surface 1/2 cubic foot per three feet of basin film. length. A-5 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 5 - CATCH BASINS (Continued) Maintenance Conditions When Maintenance Results Expected Component Defect is Needed When Maintenance Is Performed Catch Basin Cover Cover Not in Place Cover is missing or only partially in place. Catch basin cover is closed. Any open catch basin requires maintenance. Locking Mechanism cannot be opened by one Mechanism opens with proper tools. Mechanism Not maintenance person with proper tools. Working Bolts into frame have less than 1/2 inch of thread. Cover Difficult to One maintenance person cannot remove Cover can be removed by one Remove lid after applying 80 lbs. of lift; intent is maintenance person. keep cover from sealing off access to maintenance. Ladder Ladder Rungs Ladder is unsafe due to missing rungs, Ladder meets design standards and Unsafe misalignment, rust,cracks, or sharp allows maintenance person safe access. edges. Metal Grates Grate with opening wider than 7/8 inch. Grate openings meet design standards. (if applicable) Trash and Debris Trash and debris that is blocking more Grate free of trash and debris. than 20%of grate surface. Damaged or Grate missing or broken member(s)of Grate is in place and meets design Missing the grate. standards. A-6 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 10 - CONVEYANCE SYSTEMS (Pipes & Ditches) Maintenance Conditions When Maintenance Resutts Expected Component Defect is Needed When Maintenance is Performed Pipes Sediment& Debris Accumulated sediment that exceeds 20% Pipe cleaned of all sediment and debris. of the diameter of the pipe. Vegetation Vegetation that reduces free movement of All vegetation removed so water flows water through pipes. freely through pipes. Damaged Protective coating is damaged; rust is Pipe repaired or replaced. causing more than 50%deterioration to any part of pipe. Any dent that decreases the cross section Pipe repaired or replaced. area of pipe by more than 20%. Open Ditches Trash &Debris Trash and debris exceeds 1 cubic foot Trash and debris cleared from ditches. per 1,000 square feet of ditch and slopes. Sediment Accumulated sediment that exceeds 20% Ditch cleaned/flushed of all sediment and of the design depth. debris so that it matches design. Vegetation Vegetation that reduces free movement of Water flows freely through ditches. water through ditches. Erosion Damage to See"Ponds" Standard No. 1 See"Ponds" Standard No. 1 Slopes Rock Lining Out of Maintenance person can see native soil Replace rocks to design standard. Place or Missing (If beneath the rock lining. Applicable) ' Catch Basins See "Catch Basins" Standard No. 5 See "Catch Basins" Standard No. 5 Debris Barriers See"Debris Barriers" Standard No. 6 See "Debris Barriers" Standard No.6 (e.g., Trash Rack) A-11 1/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 11 - GROUNDS (Landscaping) Maintenance Conditions When Maintenance Results Expected Component Defect Is Needed When Maintenance Is Performed General Weeds Weeds growing in more than 20%of the Weeds present in less than 5%of the (Nonpoisonous) landscaped area (trees and shrubs only). landscaped area. Safety Hazard Any presence of poison ivy or other No poisonous vegetation present in a poisonous vegetation. landscaped area. Trash or Litter Paper,can, bottles,totalling more than 1 Area clear of litter. cubic foot within a landscaped area (trees and shrubs only)of 1,000 square feet. Trees and Shrubs Damage Limbs or parts of trees or shrubs that are Trees and shrubs with less than 5%of the split or broken which affect more than total foliage with split or broken limbs. 25%of the total foliage of the tree or shrub. Trees or shrubs that have been blown Tree or shrub in place free of injury. down or knocked over. Trees or shrubs which are not adequately Tree or shrub in place and adequately supported or are leaning over,causing supported; remove any dead or diseased exposure of the roots. trees. ' A-12 I/90 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL NO. 12 - ACCESS ROADS/EASEMENTS Maintenance Conditions When Maintenance Results Expected Component Defect is Needed When Maintenance is Performed General Trash and Debris Trash and debris exceeds 1 cubic foot Trash and debris cleared from site. per 1,000 square feet, i.e.,trash and debris would fill up one standard size garbage can. Blocked Roadway Debris which could damage vehicle tires Roadway free of debris which could (glass or metal). damage tires. Any obstructions which reduce clearance Roadway overhead clear to 14 feet high. L above road surface to less than 14 feet. Any obstructions restricting the access to Obstruction removed to allow at least a a 10-to 12-foot width for a distance of 12-foot access. more than 12 feet or any point restricting access to less than a 10-foot width. Road Surface Settlement, When any surface defect exceeds 6 Road surface uniformly smooth with no Potholes, Mush inches in depth and 6 square feet in area. evidence of settlement, potholes, mush Spots, Ruts In general, any surface defect which spots,or ruts. hinders or prevents maintenance access. Vegetation in Road Weeds growing in the road surface that Road surface free of weeds taller than 2 Surface are more than 6 inches tall and less than inches. 6 inches apart within a 400-square-foot area. Shoulders and Erosion Damage Erosion within 1 foot of the roadway more Shoulder free of erosion and matching Ditches than 8 inches wide and 6 inches deep. the surrounding road. Weeds and Brush Weeds and brush exceed 18 inches in Weeds and brush cut to 2 inches in height or hinder maintenance access. height or cleared in such a way as to allow maintenance access. - A-13 I/90