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HomeMy WebLinkAboutL_StormDrainageCovenant_250323_v3 Return Address: City Clerk’s Office City of Renton 1055 S Grady Way Renton, WA 98057 DECLARATION OF COVENANT FOR INSPECTION AND MAINTENANCE OF DRAINAGE FACILITIES AND ON-SITE BMPS Grantor: Achhara Singh, Parminder Kaur, Simrit S. Dhillon, Gurvinder K. Dhillon, Jaswant S. Dhaliwal, and Sarabjit K. Dhaliwal Grantee: City of Renton, a Washington municipal corporation Legal Description: Lot 6 of City of Renton Short Plat No. LUA_______________. Recorded under King County Recording NO. ____________________ in King County, WA. Assessor's Tax Parcel ID#: IN CONSIDERATION of the approved City of Renton (check one of the following) Residential Building Permit Commercial Building Permit Clearing and Grading Permit Civil Construction or Utility Permit for Permit(s) B24005785 (Construction/Building/Utility Permit #) relating to the real property ("Property") described above, the Grantor(s), the owner(s) in fee of that Property, hereby covenants (covenant) with the City of Renton (“City of Renton” or “City”), a municipal corporation of the state of Washington, that he/she (they) will observe, consent to, and abide by the conditions and obligations set forth and described in Paragraphs 1 through 9 below with regard to the Property, and hereby grants (grant) an easement as described in Paragraphs 2 and 3. Grantor(s) hereby grants (grant), covenants (covenant), and agrees (agree) as follows: 1. The Grantor(s) or his/her (their) successors in interest and assigns ("Owners ") shall at their own cost, operate, maintain, and keep in good repair, the Property's drainage facilities constructed as required in the approved construction plans and specifications C19005282 (Project Plan #) on file with the City of Renton and submitted to the City of Renton for the review and approval of permit(s) B24005785 (Construction/Building/Utility Permit #). The Property's drainage facilities are shown and/or listed on Exhibit A – Site Plan. The Property’s drainage facilities shall be maintained in compliance with the operation and maintenance schedule included and attached herein as Exhibit B – Operations and Maintenance. Drainage ✔ Page 1 of 4 facili&es include pipes, channels, flow control facili&es, water quality facili&es, on-site best management prac&ces (BMPs) and other engineered structures designed to manage and/or treat stormwater on the Property. On-site BMPs include dispersion and infiltra&on devices, bioreten&on, permeable pavements, rainwater harves&ng systems, tree reten&on credit, reduced impervious surface footprint, vegetated roofs and other measures designed to mimic pre-developed hydrology and minimize stormwater runoff on the Property. 2. City of Renton shall have the right to ingress and egress over those por&ons of the Property necessary to perform inspec&ons of the stormwater facili&es and BMPs and conduct maintenance ac&vi&es specified in this Declara&on of Covenant and in accordance with the Renton Municipal Code. City of Renton shall provide at least thirty (30) days’ wriNen no&ce to the Owners that entry on the Property is planned for the inspec&on of drainage facili&es. APer the thirty (30) days, the Owners shall allow the City of Renton to enter for the sole purpose of inspec&ng drainage facili&es. In lieu of inspec&on by the City, the Owners may elect to engage a licensed civil engineer registered in the state of Washington who has exper&se in drainage to inspect the drainage facili&es and provide a wriNen report describing their condi&on. If the engineer op&on is chosen, the Owners shall provide wriNen no&ce to the City of Renton within fiPeen (15) days of receiving the City’s no&ce of inspec&on. Within thirty (30) days of giving this no&ce, the Owners, or engineer on behalf of the Owners, shall provide the engineer’s report to the City of Renton. If the report is not provided in a &mely manner as specified above, the City of Renton may inspect the drainage facili&es without further no&ce. 3. If City of Renton determines from its inspec&on, or from an engineer’s report provided in accordance with Paragraph 2, that maintenance, repair, restora&on, and/or mi&ga&on work is required to be done to any of the drainage facili&es, City of Renton shall no&fy the Owners of the specific maintenance, repair, restora&on, and/or mi&ga&on work (“Work”) required pursuant to the Renton Municipal Code. The City shall also set a reasonable deadline for the Owners to complete the Work, or to provide an engineer’s report that verifies comple&on of the Work. APer the deadline has passed, the Owners shall allow the City access to re-inspect the drainage facili&es unless an engineer’s report has been provided verifying comple&on of the Work. If the Work is not completed within the &me frame set by the City, the City may ini&ate an enforcement ac&on and/or perform the Work and hereby is given access to the Property for such purposes. WriNen no&ce will be sent to the Owners sta&ng the City’s inten&on to perform such Work. This Work will not commence un&l at least seven (7) days aPer such no&ce is mailed. If, within the sole discre&on of the City, there exists an imminent or present danger, the seven (7) day no&ce period will be waived and Work will begin immediately. 4. The Owners shall assume all responsibility for the cost of any Work, or any measures taken by the City to address condi&ons as described in Paragraph 3. Such responsibility shall include reimbursement to the City within thirty (30) days of the receipt of the invoice for any such Work performed. Overdue payments will require payment of interest at the maximum legal rate allowed by RCW 19.52.020 (currently twelve percent (12%)). If the City ini&ates legal ac&on to enforce this agreement, the prevailing party in such ac&on is en&tled to recover reasonable li&ga&on costs and aNorney’s fees. 5. The Owners are required to obtain wriNen approval from City of Renton prior to filling, piping, cu_ng, or removing vegeta&on (except in rou&ne landscape maintenance) in open vegetated stormwater facili&es (such as swales, channels, ditches, ponds, etc.), or performing any altera&ons or modifica&ons to the drainage facili&es referenced in this Declara&on of Covenant. Page 2 of 4 • • 198TH ST SE EXHIBIT A-SITE PLAN Exhibit B-Operations and Maintenance C.2.4.1 MINIMUM DESIGN REQUIREMENTS FOR BASIC DISPERSION All of the following requirements must be met in order for basic dispersion to be applicable to a target impervious or pervious surface: 1. Runoff from the target impervious or pervious surface must be discharged using one of the following dispersion devices in accordance with the design specificaƟons and maximum area of developed surface for each device as set forth in SecƟons Č.2.4.2 through C.2.4.5: • Splash blocks (see SecƟon C.2.4.2) • Rock pads (see SecƟon C.2.4.3) • Gravel filled trenches (see SecƟon C.2.4.4) • Sheet flow (see SecƟon C.2.4.5) 2. Each device must discharge runoff such that it flows over a minimum distance of vegetated area called the "vegetated flowpath segment." The minimum distance, or length of the flowpath segment, is specified in the design specificaƟons for each device. The "vegetated flowpath segment" itself must meet all of the following criteria: a) The flowpath segment must be over well-established lawn or pasture, landscaping with well- established groundcover, or naƟve vegetaƟon with natural groundcover. The groundcover must be dense enough to help disperse and infiltrate flows and to prevent erosion. b) The flowpath segment must be onsite or in an offsite tract or easement area reserved for such dispersion. c) The slope of the flowpath segment must be no steeper than 15% for any 20-foot reach of the flowpath segment. d) The flowpath segment must be located between the dispersion device and any downstream impervious surface or drainage feature such as a pipe, ditch, stream, river, pond, lake, or wetland. All or a porƟon of the flowpath segment may be located within a criƟcal area buffer. 3. For sites with sepƟc systems, the discharge of runoff from dispersion devices must be located down slope of the primary and reserve drainfield areas. CED review staff may waive this requirement if site topography clearly prohibits discharged flows from intersecƟng the drainfield. 4. Dispersion devices are not allowed in criƟcal area buffers or on slopes steeper than 20%. 5. Dispersion devices are not allowed within 50 feet of a steep slope hazard area, erosion hazard area, or landslide hazard. 6. Dispersion devices proposed on slopes steeper than 15% must be approved by a geotechnical engineer or engineering geologist unless otherwise approved by the CED. The geotechnical analysis must consider cumulaƟve impacts from the project and surrounding areas under full built-out condiƟons. 7. Dispersion devices proposed near slopes steeper than 15% must be approved by a geotechnical engineer or engineering geologist if the facility is located within a setback from the top of slope equal to the total verƟcal height of the slope area that is steeper than 15% unless otherwise approved by the CED. The geotechnical analysis must consider cumulaƟve impacts from the project and surrounding areas under full built-out condiƟons. 8. Dispersion devices that direct runoff toward a slope steeper than 15% may require evaluaƟon and approval of the proposal by a geotechnical engineer or engineering geologist as determined by CED. The geotechnical analysis must consider cumulaƟve impacts from the project and surrounding areas under full built-out condiƟons. 9. Dispersion devices proposed within 200 feet of a steep slope hazard area, erosion hazard area, or landslide hazard must be approved by a geotechnical engineer or engineering geologist unless otherwise approved by the CED. The geotechnical analysis must consider cumulaƟve impacts from the project and surrounding areas under full built-out condiƟons. 10. The dispersion of runoff must not create flooding or erosion impacts as determined by the CED. If runoff is discharged toward a landslide hazard, erosion hazard area, or steep slope hazard area, CED may require evaluaƟon and approval of the proposal by a geotechnical engineer or engineering geologist. The geotechnical analysis must consider cumulaƟve impacts from the project and surrounding areas under full built-out condiƟons. Exhibit B-Operations and Maintenance MAINTENANCE INSTRUCTIONS FOR BASIC DISPERSION If the basic dispersion on-site BMP is proposed for a project, maintenance and operaƟon instrucƟons must be recorded as an aƩachment to the required declaraƟon of covenant and grant of easement per Requirement 3 of SecƟon C.1.3.4. The intent of these instrucƟons is to explain to future property owners, the purpose of the BMP and how it must be maintained and operated. These instrucƟons are intended to be a minimum; CED may require addiƟonal instrucƟons based on site-specific condiƟons. Future updates to the instrucƟons will be posted on City of Renton's Surface Water Design Manual website. A reproducible copy of the instrucƟons, prepared for inclusion with the declaraƟon of covenant, is located in Reference SecƟon 8-M. C.2.11 PERFORATED PIPE CONNECTION Perforated pipe connecƟons are intended to convey concentrated runoff from impervious surfaces (usually roof runoff) directly to a local drainage system while providing some infiltraƟon of that runoff in the process. They are required for any pipe connecƟon of roof downspouts to the local drainage system regardless of the extent to which on-site BMPs are required or being used onsite. Perforated pipe connecƟons are intended to provide for some infiltraƟon during drier periods (late spring through early fall), which may help dampen the flashiness of stream flows in developed areas and provide some groundwater recharge. During the wet winter months, however, this BMP likely provides liƩle or no flow control benefits. Therefore, it is not credited with miƟgaƟng target impervious surface. Applicable Surfaces Subject to the minimum design requirements below, the perforated pipe connecƟon may be applied to concentrated runoff from any impervious surface or nonnaƟve pervious surface. OperaƟon and Maintenance See SecƟon C.2.11.2. C.2.11.1 MINIMUM DESIGN REQUIREMENTS Figure C.2.11.A illustrates a perforated pipe connecƟon for a typical single family residence. Impervious areas larger than 10,000 square feet and nonnaƟve pervious areas larger than 35,000 square feet may require larger pipe to adequately convey flows and should be designed by a civil engineer. Perforated pipe connecƟons must be installed according to the following requirements: 1. Where possible, the perforated pipe connecƟon must be placed in naƟve soil to maximize infiltraƟon of water, and must not be located under impervious surfaces, except as a last resort. 2. The gravel filled trench must be at least 10-feet in length for every 5,000 square feet of impervious surface or 35,000 square feet of nonnaƟve pervious surface from which runoff is conveyed. 3. The perforated porƟon of the system may not be placed in a criƟcal area buffer or on slopes steeper than 25%. Any proposed placement of the perforated porƟon on slopes steeper than 15% or within 50 feet of a steep slope hazard area or landslide hazard must be approved by a geotechnical engineer or engineering geologist unless otherwise approved by CED. 4. For sites with sepƟc systems, the perforated porƟon of the system must be down slope of the drainfield primary and reserve areas. CED review staff can waive this requirement if site topography clearly prohibits subsurface flows from intersecƟng the drainfield. 5. The perforated pipe connecƟon must not create flooding or erosion impacts as determined by CED. If the system discharges toward or is near a landslide hazard, erosion hazard area, steep slope hazard area, or a slope steeper than 15%, CED may require evaluaƟon and approval of the proposal by a geotechnical engineer or engineering geologist. 6. A minimum of a 5 foot setback is required between any part of the perforated pipe trench and any property line. Exhibit B-Operations and Maintenance C.2.11.2 MAINTENANCE INSTRUCTIONS FOR PERFORATED PIPE CONNECTION If the perforated pipe connecƟon on-site BMP is required for a project, maintenance and operaƟon instrucƟons must be recorded as an aƩachment to the required declaraƟon of covenant and grant of easement per Requirement 3 of SecƟon C.1.3.4. The intent of these instrucƟons is to explain to future property owners, the purpose of the BMP and how it must be maintained and operated. These instrucƟons are intended to be a minimum; CED may require addiƟonal instrucƟons based on site-specific condiƟons. Future updates to the instrucƟons will be posted on City of Renton's Surface Water Design Manual website. A reproducible copy of the instrucƟons, prepared for inclusion with the declaraƟon of covenant, is located in Reference SecƟon 8-M. C.2.13 SOIL AMENDMENT Naturally occurring (undisturbed) soil and vegetaƟon provide important stormwater funcƟons including: water infiltraƟon; nutrient, sediment, and pollutant adsorpƟon; sediment and pollutant biofiltraƟon; water interflow storage and transmission; and pollutant decomposiƟon. These funcƟons are largely lost when development strips away naƟve soil and vegetaƟon and replaces it with minimal topsoil and sod. Not only are these important stormwater funcƟons lost, but such landscapes themselves become polluƟon generaƟng pervious surfaces due to increased use of pesƟcides, ferƟlizers and other landscaping and household/industrial chemicals, the concentraƟon of pet wastes, and pollutants that accompany roadside liƩer. Establishing soil quality and depth regains greater stormwater funcƟons in the post development landscape, provides increased treatment of pollutants and sediments that result from development and habitaƟon, and minimizes the need for some landscaping chemicals, thus reducing polluƟon through prevenƟon. Applicable Surfaces Establishing a minimum soil quality and depth through soil amendment is not the same as preservaƟon of naturally occurring soil and vegetaƟon. However, establishing a minimum soil quality and depth will provide improved on-site management of stormwater flow and water quality. Soil organic maƩer can be aƩained through numerous materials such as compost, composted woody material, biosolids, and forest product residuals. It is important that the materials used to meet the soil quality and depth BMP be appropriate and beneficial to the plant cover to be established. Likewise, it is important that imported topsoils improve soil condiƟons and do not have an excessive percent of clay fines. Infeasibility Criteria Soil amendment can be considered infeasible on Ɵll soil slopes greater than 33 percent. C.2.13.1 MINIMUM DESIGN REQUIREMENTS • Soil retenƟon. Retain, in an undisturbed state, the duff layer and naƟve topsoil to the maximum extent pracƟcable. In any areas requiring grading remove and stockpile the duff layer and topsoil on site in a designated, controlled area, not adjacent to public resources and criƟcal areas, to be reapplied to other porƟons of the site where feasible. • Soil quality. All areas subject to clearing and grading that have not been covered by impervious surface, incorporated into a drainage facility or engineered as structural fill or slope shall, at project compleƟon, demonstrate the following: 1. A topsoil layer with a minimum organic maƩer content of 10% dry weight in beds, and 5% organic maƩer content in turf areas, and a pH from 6.0 to 8.0 or matching the pH of the undisturbed soil. The topsoil layer shall have a minimum depth of eight inches except where tree roots limit the depth of incorporaƟon of amendments needed to meet the criteria. Subsoils below the topsoil layer should be scarified at least 4 inches with some incorporaƟon of the upper material to avoid straƟfied layers, where feasible. 2. Mulch planƟng beds with 2 inches of organic material Exhibit B-Operations and Maintenance 3. Use compost and other materials that meet these organic content requirements: a. The organic content for "pre-approved" amendment rates can be met only using compost meeƟng the compost specificaƟon for BioretenƟon (Refer to SecƟon C.2.6) with the excepƟon that the compost may have up to 35% biosolids or manure. The compost must also have an organic maƩer content of 40% to 65%, and a carbon to nitrogen raƟo below 25:1. The carbon to nitrogen raƟo may be as high as 35:1 for planƟngs composed enƟrely of plants naƟve to the Puget Sound Lowlands region. b. Calculated amendment rates may be met through use of composted material meeƟng "a)" above; or other organic materials amended to meet the carbon to nitrogen raƟo requirements. and not exceeding the limits idenƟfied in Table 220-B, TesƟng Parameters, in WAC 173-350-220. 4. The resulƟng soil should be conducive to the type of vegetaƟon to be established.  ImplementaƟon OpƟons: The soil quality design guidelines listed above can be met by using one of the methods listed below: 1. Leave undisturbed naƟve vegetaƟon and soil, and protect from compacƟon during construcƟon. 2. Amend exisƟng site topsoil or subsoil either at default "pre-approved" rates, or at custom calculated rates based on tests of the soil and amendment. 3. Stockpile exisƟng topsoil during grading, and replace it prior to planƟng. 4. Stockpiled topsoil must also be amended if needed to meet the organic maƩer or depth requirements, either at a default “pre-approved" rate or at a custom calculated rate. 5. Import topsoil mix of sufficient organic content and depth to meet the requirements. More than one method may be used on different porƟons of the same site. Soil that already meets the depth and organic maƩer quality standards, and is not compacted does not need to be amended. Runoff Model RepresentaƟon • Areas meeƟng the design guidelines shall be entered into approved runoff models as "Pasture" rather than "Lawn." • Flow reducƟon credits shall be taken in runoff modeling when Soil Amendment BMP is used as part of a dispersion design under the condiƟons described in: o Limited InfiltraƟon o Full Dispersion (for public road projects) o Basic Dispersion C.2.13.4 MAINTENANCE INSTRUCTIONS FOR SOIL AMENDMENT If the soil amendment on-site BMP is proposed for a project, maintenance and operaƟon instrucƟons must be recorded as an aƩachment to the required declaraƟon of covenant and grant of easement per Requirement 3 of SecƟon C.1.3.4. The intent of these instrucƟons is to explain to future property owners, the purpose of the BMP and how it must be maintained and operated. These instrucƟons are intended to be a minimum; CED may require addiƟonal instrucƟons based on site-specific condiƟons. Future updates to the instrucƟons will be posted on City of Renton's Surface Water Design Manual website. A reproducible copy of the instrucƟons, prepared for inclusion with the declaraƟon of covenant, is located in Reference SecƟon 8-M. EXHIBIT B-OPERATIONS AND MAINTENANCE