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HomeMy WebLinkAboutM_ERC_MitMeasAdvisNotes_180824.pdfDEPARTMENT OF COMMUNITY AND ECONOMIC DEVELOPMENT SIGNATURES: Gregg Zimmerman, Administrator Public Works Department Date Rick M. Marshall, Administrator Renton Regional Fire Authority Date Kelly Beymer, Administrator Community Services Department Date C.E. Vincent, Administrator Date Department Of Community & Economic Development ENVIRONMENTAL (SEPA) DETERMINATION OF NON-SIGNIFICANCE - MITIGATED (DNS-M) PROJECT NUMBER: LUA17-000189 APPLICANT: Jamie Waltier, Harbour Homes, LLC / jwaltier@harbourhomes.com / 1441 N 34th St, Ste 300, Seattle, WA 98103 PROJECT NAME: Cedars at the Highlands PROJECT DESCRIPTION: The applicant is requesting Preliminary Plat, SEPA Environmental Review, and a Tier II Temporary Use Permit for approval of a 14-lot subdivision. The 4.49 acre site is located at 14120 160th Ave SE (APN 1457500110) within the Residential-4 zoning district. The rectangular shaped parcel would be divided into 14 residential lots, a storm drainage tract, a tree retention tract, and a critical area tract. The 8,361 square feet (sf) drainage tract consists of a stormwater vault located at the southeast corner of the site. The applicant would dedicate 28,777 sf for public right- of-way to serve the new lots. The proposed lots would range in size from 9,002 sf to 16,100 sf with an average lot size of 10,224 sf. The plat would result in a net density of 3.66 du/ac. Access to the site would be gained by extending a residential access road (Road A) from 160th Ave SE through the center of the lot. The site contains a Type Ns Stream in the northeast corner of the site that requires a minimum 50 ft buffer as well as a 15 ft building setback. No areas meeting wetland criteria were found on the site. Soils consist of medium dense to dense silty sand with gravel and stiff silt (ML). The soil density was observed to increase with depth. The west side of the site is relatively flat. However, the east side of the site descends approximately ten feet towards the southeastern property line. The existing shop and barn are proposed to remain as part of the plat construction. There are 284 significant trees on the site and the applicant is proposing to retain 41 original trees. The applicant has submitted an Arborist Report, Critical Areas Study, Technical Information Report, Traffic Impact Analysis, and a Geotechnical Engineering Study with the application. PROJECT LOCATION: 14120 160th Ave SE, Renton WA 98059 LEAD AGENCY: City of Renton Environmental Review Committee Department of Community & Economic Development The City of Renton Environmental Review Committee has determined that it does not have a probable significant adverse impact on the environment. An Environmental Impact Statement (EIS) is not required under RCW 43.21C.030(2)(c). Conditions were imposed as mitigation measures by the Environmental Review Committee under their authority of Section 4-9-070D Renton Municipal Code. These conditions are necessary to mitigate environmental impacts identified during the environmental review process. Because other agencies of jurisdiction may be involved, the lead agency will not act on this proposal for fourteen (14) days. Appeals of the environmental determination must be filed in writing on or before 5:00 p.m. on September 7, 2018. Appeals must be filed in writing together with the required fee with: Hearing Examiner, City of Renton, 1055 South Grady Way, Renton, WA 98057. Appeals to the Examiner are governed by RMC 4-8-110 and more information may be obtained from the Renton City Clerk’s Office, (425) 430-6510. PUBLICATION DATE: August 24, 2018 DATE OF DECISION: August 20, 2018 DocuSign Envelope ID: DA5EE113-EBEA-486A-A176-507A6F80B5DC 8/21/2018 | 3:24 PM PDT 8/20/2018 | 2:13 PM PDT 8/20/2018 | 3:43 PM PDT 8/20/2018 | 3:47 PM PDT DETERMINATION OF NON-SIGNIFICANCE – MITIGATED (DNS-M) MITIGATION MEASURES AND ADVISORY NOTES PROJECT NUMBER: LUA17-000189, ECF, PP, TU APPLICANT: Jamie Waltier, Harbour Homes, LLC / 1441 N 34th St, Ste 300, Seattle, WA 98103 / jwaltier@harbourhomes.com / 206-315-8130 PROJECT NAME: Cedars at the Highlands PROJECT DESCRIPTION: The applicant is requesting Preliminary Plat approval and Environmental Threshold Determination (SEPA) for a proposed 13-lot subdivision. The project site is 195,531 square feet (4.49 acres) and is located at 14120 160th Ave SE. The project site is located in the Residential-4 (R-4) zoning designation. The proposed single-family residential lots range in size from 9,000 square feet to 17,565 square feet with an overall proposed density of 3.36 dwellings per acre. The applicant has requested a Temporary Use Permit to allow for two existing outbuildings to remain for a period of five years. The structures are located across proposed Lots 9 and 10. Additional proposed improvements include a 3,195 sq. ft. storm drainage tract (Tract A) in the southeast corner of the site along the unimproved 162nd Ave SE right-of-way (ROW) frontage, a 3,500 sq. ft. tree retention tract (Tract C) along the north property line adjacent to lots 11 and 12, and a 20,246 native growth protection tract (Tract B) in the north-east corner to encompass the proposed 75-foot reduced wetland buffer. The proposed lots would be served by a new public residential access street off of 160th Ave SE and a cul-de- sac would be provided near the eastern end of the property. Proposed lots would be served by sanitary sewer along the new street that would connect to an existing main within 160th Ave SE. Proposed lots would be served by a new water main extending from 160th Ave SE along the new street. Construction of the proposed subdivision infrastructure improvements would result in approximately 5,000 cubic yards of cut and 8,000 cubic yards of fill. A Type Ns stream and Category III wetlands are mapped on the site according to COR maps and a Wetlands Report submitted by the applicant . Slopes on the site generally fall to the southeast across the property at a range of 0-20%. Soils consist of Alderwood gravelly sandy loam (AgC). The applicant has proposed to retain approximately 35 of the 284 significant trees onsite. The applicant has submitted a Technical Information Report, Arborist Report, a Critical Areas Determination and a Geotechnical Engineering Study with the application. PROJECT LOCATION: 14120 160th Ave SE, Renton WA 98059 LEAD AGENCY: The City of Renton Department of Community & Economic Development Planning Division MITIGATION MEASURES: 1. Project construction shall comply with the recommendations found in the submitted geotechnical support prepared by Earthworks NW, dated February 23, 2017. ADIVISORY NOTES: The following notes are supplemental information provided in conjunction with the administrative land use action. Because these notes are provided as information only, they are not subject to the appeal process for the land use actions. DEPARTMENT OF COMMUNITY AND ECONOMIC DEVELOPMENT Page 1 of 6 LUA**-000*** ADVISORY NOTES TO APPLICANT The following notes are supplemental information provided in conjunction with the administrative land use action. Because these notes are provided as information only, they are not subject to the appeal process for the land use action. Planning: (Contact: Name, 425-430-7219, amorganroth@rentonwa.gov) 1. RMC section 4-4-030.C.2 limits haul hours between 8:30 am to 3:30 pm, Monday through Friday unless otherwise approved by the Development Services Division. 2. Commercial, multi-family, new single family and other nonresidential construction activities shall be restricted to the hours between seven o’clock (7:00) a.m. and eight o’clock (8:00) p.m., Monday through Friday. Work on Saturdays shall be restricted to the hours between nine o’clock (9:00) a.m. and eight o’clock (8:00) p.m. No work shall be permitted on Sundays. 3. Within thirty (30) days of completion of grading work, the applicant shall hydroseed or plant an appropriate ground cover over any portion of the site that is graded or cleared of vegetation and where no further construction work will occur within ninety (90) days. Alternative measures such as mulch, sodding, or plastic covering as specified in the current King County Surface Water Management Design Manual as adopted by the City of Renton may be proposed bet ween the dates of November 1st and March 31st of each year. The Development Services Division’s approval of this work is required prior to final inspection and approval of the permit. 4. A National Permit Discharge Elimination System (NPDES) permit is required when more than one acre is being cleared. 5. The applicant will be required to submit a Final Wetlands Mitigation Report and Maintenance and Monitoring proposal. In addition, the applicant will be required to comply with all the code requirements of RMC 4-3-050 Critical Areas. This includes, but is not limited to, placing the critical area within a Native Growth Protection Easement, providing fencing and signage, and providing the City with a site restoration surety device and, later, a maintenance and moni toring surety device. 6. The applicant may not fill, excavate, stack or store any equipment, dispose of any materials, supplies or fluids, operate any equipment, install impervious surfaces, or compact the earth in any way within the area defined by the drip line of any tree to be retained. 7. The applicant shall erect and maintain six foot (6') high chain link temporary construction fencing around the drip lines of all retained trees, or along the perimeter of a stand of retained trees. Placards shall be placed on fencing every fifty feet (50') indicating the words, “NO TRESPASSING – Protected Trees” or on each side of the fencing if less than fifty feet (50'). Site access to individually protected trees or groups of trees shall be fenced and signed. Individual trees shall be fenced on four (4) sides. In addition, the applicant shall provide supervision whenever equipment or trucks are moving near trees. 8. This permit is shall comply with the Bald and Golden Eagle Protection Act. The permitted is responsible for adhering to the U.S. Fish and Wildlife Service National Bald Eagle Management Guidelines (2007) and /or your U.S. Fish and Wildlife Service permit. Development Engineering: (Contact: Name, 425-430-7298, rnair@rentonwa.gov) 1. See Attached Development Engineering Memo dated August 17, 2017 ADVISORY NOTES TO APPLICANT Page 2 of 6 LUA**-000*** Fire Authority: (Contact: Corey Thomas, 425-430-7024, cthomas@rentonwa.gov) Environmental Impact Comments: 1. The fire impact fees are applicable at the rate of $718.56 per single family unit. This fee is paid at building permit issuance. Code Related Comments: 1. The fire flow requirement for a single family home is 1,000 gpm minimum for dwellings up to 3,600 square feet (including garage and basements). If the dwelling exceeds 3,600 square feet, a minimum of 1,500 gpm fire flow would be required. A minimum of one fire hydrant is required within 300 -feet of the proposed buildings and two hydrants if the fire flow goes up to 1,500 gpm. Ther e are no existing hydrants within 300-feet of the proposed homes. Existing 4-inch water main in 160th Ave SE will not provide the minimum required fire flow, new on-site and off-site water mains will be required. A water availability certificate is required from King County Water District 90. Fire sprinkler systems may be required if insufficient fire flow cannot be obtained. 2. Fire department apparatus access roadways are required to be a minim um of 20-feet wide fully paved, with 25-feet inside and 45-feet outside turning radius. Fire access roadways shall be constructed to support a 30-ton vehicle with 75-psi point loading. Access is required within 150-feet of all points on the buildings. An approved cul-de-sac type 90-foot diameter turnaround is required for all dead end streets exceeding 300-feet in length. Building: (Contact: Craig Burnell, 425-430-7290, cburnell@rentonwa.gov) 1. Recommendations of the geotechnical report must be followed as a condition of building permits. ADVISORY NOTES TO APPLICANT Page 3 of 6 LUA**-000*** DEPARTMENT OF COMMUNITY AND ECONOMIC DEVELOPMENT M E M O R A N D U M DATE: August 17, 2017 TO: Alex Morganroth, Associate Planner FROM: Rohini Nair, Civil Engineer III, Plan Review SUBJECT: Cedars at the Highlands Plat 14120 160th Ave SE LUA17-000189 I have reviewed the preliminary plat application for the above-referenced proposal located at parcel 1457500110 and have the following comments: EXISTING CONDITIONS The site is approximately 4.49 acres in size and is rectangular in shape. The existing site is developed with an existing workshop, one shed and gravel driveway. The site includes: Water Water service is provided by King County Water District 90 (425-255-9600 or www.kcwd90.com). The site is located outside of an Aquifer Protection Area. Sewer Wastewater service is provided by the City of Renton. There is an existing 10-inch wastewater main located in 160th Ave SE (see City plan no. S-3235). There is an existing 8-inch wastewater main located in 162nd Ave SE (see City plan no. S-3613). Storm There is an existing 12-inch stormwater main located in 160th Ave SE. There is an existing stormwater ditch located in 160th Ave SE fronting the subject property. Streets The proposed development fronts 160th Ave SE along the west property line(s). 160th Ave SE is classified as a Residential Access Road. Existing right-of-way (ROW) width is approximately 60 feet. The proposed development fronts 162nd Ave SE along the east property line(s). 162nd Ave SE is classified as a Residential Access Road, and is an unimproved right-of-way. Existing right-of-way (ROW) width is approximately 60 feet. CODE REQUIREMENTS WATER 1. A water availability certificate from King County Water District 90 was provided with the site plan submittal. The water availability certificate noted that a flow rate of 1,500 gallons per minute (gpm) can be provided to the site by an 8” water main extension to the site. 2. Review of the water plans will be conducted by King County Water District 90 and the Renton Regional Fire Authority. ADVISORY NOTES TO APPLICANT Page 4 of 6 LUA**-000*** 3. Plans approved by King County Water District 90 shall be routed to the City for final review prior to permit issuance. SEWER 1. The development is subject to a wastewater system development charge (SDC) fee. The 2018 SDC fee for sewer is based on the size of the new domestic water to serve the project. The current sewer fee for a 1 -inch meter install is $2,837.00 per meter. Each lot shall have a separate meter. The final fee amount is calculated and payable at the time of construction permit issuance. 2. The development is in the Central Plateau Interceptor Special Assessment Districts (SADs). a. The Area SAD fee for the Central Plateau Interceptor SAD is $351.95, plus interest of $0.05111 per day, for each lot. As of 8/7/2018, the total SAD fee is calculated as $519.78 per lot. The final fee amount is calculated and payable at the time of construction permit issuance. b. The Frontage SAD fee for the Central Plateau Interceptor SAD is $5,810.34, plus interest of $0.84369 per day, for each lot with frontage along 160th Ave SE. As of 8/7/2018, the total SAD fee is calculated as $8,581.03 for each lot that has frontage on 160th Ave SE. The final fee amount is calculated and payable at the time of construction permit issuance. 3. The existing sewer main along 160th Avenue SE along with the existing sewer service located on Lot 1 as shown on the composite utility civil plan submitted with the Land Use Application. 4. The proposed sewer main improvements as shown on the composite utility civil plan submitted with the Land Use Application provides the required 8-inch sewer main extension from the existing sewer main located in 162nd Avenue SE and extending west into Cedars at the Highlands for future extension by the City. The required extension of the new 8-inch sewer main from 162nd Avenue SE into the future public ROW is shown on the conceptual utilities plan and provides the required sanitary sewer service to lots accessing off of internal project street except Lot 1 which will utilize the existing sewer service on the lot. The lots accessing from 160th Avenue SE will obtain sanitary sewer service from the existing 8-inch sewer main within 160th Avenue SE. a. A 15-foot public sewer easement is shown A 15-foot public sewer easement shall be provided for the extension of the sewer main through the stormwater tract for any portion of the extension located outside of the public ROW. 5. All new side sewers shall be 6”. All side sewers shall flow by gravity to the main at a minimum slope of 2%. As shown on the preliminary utility plan, each lot shall have its own side sewer. SURFACE WATER 1. The development is subject to a storm water system development charge (SDC) fee. The 2018 SDC fee for storm water is $1,718.00 for each new lot. The final fee amount is calculated and payable at the time of construction permit issuance. 2. A Preliminary Drainage Plan and Technical Information Report (TIR) prepared by DR Strong dated June 29, 2018 were submitted to the City as part of the site plan submittal. The site is located in the City’s Flow Control Duration Standard (Forested Site Conditions). The site is located in the Lower Cedar River drainage basin. The TIR was completed in accordance with the standards found in the 2017 Renton Surface Water Design Manual (RSWDM). All nine core and six special requirements were addressed. A detention vault is proposed to meet the flow control facility requirement to satisfy Core Requirement #3. The detention vault has been sized to the City’s Flood Problem Flow Control Standard (King County Level 3) using WWHM to help mitigate potential downstream drainage issues. The project matches the pre-developed discharge rates from 50% of the 2-year peak flow up to the full 50-year peak flow and peak discharge rates for the 2 and 10- year return periods as required in the City’s Flow Control Duration Standard (Forested Site Conditions) area. In addition, the site matches the 100-year peak discharge rate to the pre-developed 100-year peak discharge rate to meet the City’s Flood Problem Flow Control Standard. The project is subject to Basic Water Quality treatment standards to satisfy Core Requirement #8. A stormwater quality vault following the detention vault will be utilized to address this requirement. ADVISORY NOTES TO APPLICANT Page 5 of 6 LUA**-000*** The project is subject to on-site BMP requirements found in Core Requirement #9. Full dispersion and full infiltration are not feasible on-site BMPs as the minimum design requirements cannot be met. Permeable pavement, bioretention, and rain gardens were deemed infeasible per the infiltration testing in the geotechnical report. Limited infiltration is deemed infeasible due to the till soils. Basic dispersion may be feasible. If feasible, basic dispersion should be implemented to the maximum extent feasible which may be more than 10% of the total lot area. Feasibility of on-site BMPs for each lot will be reviewed at the time of single family building permit. The restricted footprint BMP can still be used in addition to receive the 10% lot area modeling credit when sizing the detention vault. Final TIR should clearly explain how target surfaces from plat infrastructure (road and sidewalk) are mitigated by on-site BMPs or how BMPs are infeasible for these surfaces. 3. A geotechnical report evaluating site soil conditions was prepared by Earth Solutions NW LLC dated February 23, 2017 and a Geotechnical Infiltration Evaluation prepared by Earth Solutions NW LLC dated July 13, 2017. The report describes the site’s erosion hazard level as low. The soils on site were described as 4 to 10 inches of organics over medium dense silty sand with gravel and dense poorly graded sand were encountered extending to the maximum exploration depth of 11.5 feet below existing grade. There was approximately 1.0’ to 4.0’ of fill encountered in the northwest portion of the site. Earth Solutions NW LLC evaluated onsite soils for infiltration using the “Pilot Infiltration Testing” at four locations. The Pilot Infiltration Test is an approved infiltration testing procedure per Section C.1.3 of the RSWDM. No infiltration was observed in three out of the four locations. At the fourth location (TP-104, located in the southeast portion of the site) there was limited infiltration however advancing the test pit deeper than the infiltration test depth resulted in an observed confining layer of silt that limits the capacity of the underlying subgrade to infiltrate. It is the geotechnical engineer’s opinion that this confining soil layer can result in lateral migration of water which can create flooding rated issues on the neighboring properties to the south of the subject site since it is sited lower in the elevation than the subject property. 4. The report concludes that infiltration of stormwater and low impact development (LID) techniques at the site are infeasible. 5. There is an existing Unspecified Drainage Conveyance System flowing through the project site that appears to convey upstream tributary from 160th Avenue SE. The Applicant is proposing to capture and convey this upstream flow to the downstream conveyance system via a storm water piped system that will be routed through the future proposed right of way through the project site. The size of the bypass conveyance system shall be determine in accordance with the RSWDM and provided as part of the Civil Construction Permit Application. 6. A Construction Stormwater Permit from Department of Ecology is required if clearing and grading of the site exceeds one acre. TRANSPORTATION 1. Each new lot is subject to a transportation impact fee. The 2018 transportation impact fee is $5,430.85 per single family home. A credit for one lot will be issued due for the existing home. The transportation impact fee is due at the time of building permit issuance for each individual home. 2. The proposed development fronts 160th Ave SE along the west property line(s). 160th Ave SE is classified as a Residential Access Road. Existing right-of-way (ROW) width is approximately 60 feet, which satisfies the RMC 4-6- 060 required minimum required ROW width of 53 feet. No additional right-of-way fronting the site will be required. To provide consistency with the existing pavement width in the corridor adjacent to the project site, a half street paved width of 16 feet, gutter, 0.5 feet wide curb, 8 feet wide landscaped planter, 5 feet wide sidewalk, street trees, storm drainage improvements and undergrounding of any overhead utility lines along the frontage of the property are required on the project frontage. 3. The proposed development fronts 162nd Ave SE along the east property line(s). 162nd Ave SE is classified as a Residential Access Road, and is an unimproved right-of-way. Existing right-of-way (ROW) width is approximately 60 feet, which satisfies the RMC 4-6-060 required minimum required ROW width of 53 feet. Per RMC 4-6-060, a paved half street width of 13 feet, a 0.5-foot curb, an 8-foot planting strip, an 5-foot sidewalk, street trees, storm drainage improvements, and undergrounding of all utilities are required on the project frontage. However, the applicant has submitted a street modification request to allow the existing street and frontage section to remain. ADVISORY NOTES TO APPLICANT Page 6 of 6 LUA**-000*** The modification was requested due to the presence of the stream that runs through the ROW and altering the existing conditions of 162nd Ave SE would impact the stream and the adjacent critical area. Staff supports the requested modification. 4. A dead end public street with 53 feet ROW width and 26 feet wide pavement is proposed for the internal site access. 0.5 feet wide curb, 8 foot wide planters and 5 foot wide sidewalks are proposed on both sides of the internal street. The proposed widths meet the minimum required widths mentioned in RMC 4-6-060. Undergrounding of all utilities is required. 5. Current City of Renton standards require a cul-de-sac turnaround for dead-end streets greater than 300 feet and less than 500 feet. Reference RMC 4-6-060H. a. Cul-de-sacs shall have a minimum paved and landscaped radius of 45 feet with a right-of-way radius of 55 feet for the turnaround. b. The cul-de-sac turnaround shall have a design approved by the Administrator and Fire and Emergency Services. 6. Refer to City code 4-4-080 regarding driveway regulations. a. A minimum separation of 5 feet is required between driveway and the property line. b. Maximum driveway slopes shall not exceed 15%. Driveways exceeding 8% shall provide slotted drains. c. The maximum width of single loaded garage driveway shall not exceed nine feet (9') and double-loaded garage driveway shall not exceed sixteen feet (16'). 7. Street lighting is required from a development that includes more than 4 residential units. A photometric study and street lighting plan per City standard shall be submitted at the time of construction permit review. 8. All ramps and sidewalks shall be designed in accordance with ADA Regulations. 9. Paving and trench restoration within the City of Renton right of way shall comply with the City’s Restoration and Overlay requirements. GENERAL COMMENTS 1. The fees listed are for 2018. The fees that are current at the time of the respective permit issuance will be levied. Please see the City of Renton website for the current fee schedule. 2. Retaining walls that are 4’ or taller from bottom of footing and stormwater detention vaults will require a separate building permit. Structural calculations and plans prepared by a licensed engineer will be required as part of the building permit review. 3. All civil plans shall conform to the current City of Renton survey and drafting standards. Current drafting standards can be found on the City of Renton website. 4. A separate plan submittal will be required for a construction permit for utility work and street improvements. All plans shall be prepared by a licensed Civil Engineer in the State of Washington. 5. Please see the City of Renton Development Engineering website for the Construction Permit Application and Construction Permit Process and Submittal Requirements. Please contact the City to schedule a construction permit intake meeting. 6. All utilities serving the site are required to be undergrounded.