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HomeMy WebLinkAboutL_Declaration of Covenant_190402_v3B18006356 R-3934 U16006676 Records of King County, Washington, Recording No. 8 Subdivision REVISION Received: 04/15/2019 / aalexander BUILDING DIVISION PR16000315 B18006356 V3 8 78 EXHIBIT B Maintenance Details DRYWELLS FOR LIMITED INFILTRATION (C.2.3.4) Drywells for Limited Infiltration Your property contains a stormwater management flow control BMP (best management practice) called “limited infiltration,” which was installed to mitigate the stormwater quantity and quality impacts of some or all of the impervious surfaces on your property. Limited infiltration is a method of soaking runoff from impervious area (such as paved areas and roofs) into the ground. Infiltration devices, such as gravel filled trenches, drywells, and ground surface depressions, facilitate this process by putting runoff in direct contact with the soil and holding the runoff long enough to soak most of it into the ground. To be successful, the soil condition around the infiltration devise must be able to soak water into the ground for a reasonable number of years. The infiltration devices used on your property include the following as indicated on the flow control BMP site plan: gravel filled trenches, drywells. The size, placement, and composition of these devices as depicted by the flow control BMP site plan and design details must be maintained and may not be changed without written approval either from the City of Renton or through a future development permit from the City of Renton. Infiltration devices must be inspected annually and after major storm events to identify and repair any physical defects. Maintenance and operation of the system should focus on ensuring the system’s viability by preventing sediment-laden flows from entering the device. Excessive sedimentation will result in a plugged or non-functioning facility. If the infiltration device has a catch basin, sediment accumulation must be removed on a yearly basis or more frequently if necessary. Prolonged ponding around or atop a device may indicate a plugged facility. If the device becomes plugged, it must be replaced. Keeping the areas that drain to infiltration devices well swept and clean will enhance the longevity of these devices. For roofs, frequent cleaning of gutters will reduce sediment loads to these devices. PERFORATED PIPE CONNECTION (C.2.11) Your property contains a stormwater management flow control BMP (best management practice) called a "perforated pipe connection," which was installed to reduce the stormwater runoff impacts of some or all of the impervious surface on your property. A perforated pipe connection is a length of drainage conveyance pipe with holes in the bottom, designed to "leak" runoff, conveyed by the pipe, into a gravel filled trench where it can be soaked into the surrounding soil. The connection is intended to provide opportunity for infiltration of any runoff that is being conveyed from an impervious surface (usually a roof) to a local drainage system such as a ditch or roadway pipe system. 1. The size and composition of the perforated pipe connection as depicted by the flow control BMP site plan, Exhibit B, must be maintained and may not be changed without written approval either from the City of Renton or through a future development permit from the City of Renton. 2. The soil overtop of the perforated portion of the system must not be compacted or covered with impervious materials. PLAN VIEW OF PARCEL TO STORM DRAINSYSTEMRIGHT- OF-WAYGENERAL NOTES:1.INFILTRATION TRENCHES LIMITED TO ROOF RUNOFF FROM SINGLE-FAMILY OR DUPLEX HOMES OR TO CONTROL BASEMENT FLOODING. CONSULT WA DEPARTMENT OF ECOLOGY REGULATIONS FOR UNDERGROUND INJECTION CONTROL PROGRAM (UIC) FOR OTHER TYPES OF RUNOFF MANAGEMENT.2.IMPERVIOUS AREAS LARGER THAN 10,000 SF AND NON-NATIVE PERVIOUS AREAS LARGER THAN 35,000 SF MAY REQUIRE LARGER PIPE AND SHOULD BE DESIGNED BY A CIVIL ENGINEER.3.THE PERFORATED PIPE MAY NOT BE PLACED IN A CRITICAL AREA BUFFER OR ON SLOPES STEEPER THAN 25%.4.SEE CONSTRUCTION PLANS FOR SPECIFIC PROJECT REQUIREMENTS.24" MIN.18" MIN.MIN. 1' ABOVE SEASONAL HIGH GROUNDWATER TABLE 6" MIN.1 1/2" - 3/4" WASHED DRAIN ROCK NON-WOVEN GEOTEXTILE FOR SEPARATION ON TOP AND SIDES OF TRENCH PER WSDOT SPECIFICATIONS SECTION 9-33.2(1) TABLE 3 COMPACTED TOPSOIL OR OTHER CLEAN FILL 6" MIN. PVC PERFORATED PIPE PER ASTM D1785 10' MIN. LEVEL TRENCH WITH PERFORATED PIPE, SEE NOTE 1 DOWNSPOUT WITH CLEANOUT FILTER, SEE DETAIL ASECTION A NOTES:1.TRENCH LENGTH TO BE 10 FEET IN LENGTH FOR EVERY 5,000 SF OF CONTRIBUTING IMPERVIOUS SURFACE, OR 35,000 SF OF NON-NATIVE PERVIOUS SURFACE, OR PORTION THEREOF. 5' MIN. 5' MIN.TO STORM DRAIN SYSTEM 5' MIN. 5' MIN. A DOWNSPOUT WITH CLEANOUT FILTER, SEE DETAIL 10' MIN. LEVEL TRENCH WITH PERFORATED PIPE, SEE NOTE 1 CONFIGURATION ON FLAT GROUND CONFIGURATION ON SLOPING GROUND UNDISTURBED NATIVE SOIL CLEANOUT PER STD. PLAN 226. 00 CLEANOUT PER STD. PLAN 226. 00 FILTER SCREEN 2'-5' TO GROUND SOLIDS/ LEAVES TYPICAL DOWNSPOUT FILTER DETAIL FOOTING DRAIN BYPASS CLEANOUT PER STD. PLAN 226. 00 PERFORATED STUB- OUT CONNECTION PUBLIC WORKS DEPARTMENT APPROVED:DATEGregg Zimmerman Public Works Administrator UNLESS OTHERWISE NOTED, DRAWING IS NOT TO SCALE ( NTS)STD. PLAN - 263. 40 DocuSign Envelope ID: 6EECF5B6-602A-4E4A-B436- A317AA638878 9/28/2018 | 9:45 AM