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HomeMy WebLinkAboutC_LUA17-000855HuynhSP_DEComments_180220 DEPARTMENT OF COMMUNITY AND ECONOMIC DEVELOPMENT M E M O R A N D U M DATE: February 19, 2018 TO: Alex Morganroth, Planner FROM: Ann Fowler, Civil Plan Reviewer SUBJECT: Utility and Transportation Comments for Huynh Short Plat 2007 Union Avenue NE LUA 17-000855 I have reviewed the application for the Huynh Short Plat at 2007 Union Avenue NE (APN(‘s) 0423059076) and have the following comments: EXISTING CONDITIONS The site is approximately 0.74 acres in size and is rectangular in shape. The eastern end of the site is currently occupied with an existing single family residence and is mostly cleared with some trees onsite. Water Water service is provided by the City of Renton. The site is in the Highlands service area in the 565 hydraulic pressure zone. There is an existing 12-inch City water main located on the east side of Union Avenue NE (see Water plan no. W-1944) that can deliver a maximum total flow capacity of 4,800 gallons per minute (gpm). The approximate static water pressure is 52 psi at the elevation of 442 feet. There is an existing 36-inch Seattle Public Utility water main on the west side of Union Avenue NE. The site is located within Zone 2 of an Aquifer Protection Area. There is an existing ¾ -inch water meter serving the existing residence. Sewer Wastewater service is provided by the City of Renton. There is an existing 8-inch concrete gravity wastewater main located in Union Avenue NE (see City plan no. S-0134). Storm Runoff from the existing site includes one single family residence where no stormwater infrastructure currently exists on-site. Runoff from the eastern portion of the site generally flows southeast onto the neighboring property to the south and into Union Avenue NE where a stormwater conveyance system begins with a Catch Basin located on the west side of Union Avenue NE. Runoff from the western portion of the site sheet flows west and northwest onto neighboring properties where stormwater is collected and routed into the existing stormwater facility located on the east side of the neighboring property. The overflow for the existing facility discharges to NE 21st Street. Huynh Short Plat – LUA17-000855 Page 2 of 5 Streets The proposed development fronts Union Avenue NE to the east, which classified as a Minor Arterial Street with an existing right of way (ROW) width of 60 as measured using the King County Assessor’s Map. There are no existing frontage improvements along the street frontage of Union Avenue NE however street improvements were constructed on the property immediately south of the proposed project. These improvements are 22-feet of pavement between the roadway centerline and the existing curb and gutter, 0.5 foot curb and gutter, 8 foot planter strip, 8-foot sidewalk, and a 1-foot clearance between the back of the sidewalk the right of way. CODE REQUIREMENTS WATER 1. According to Renton Fire Department review comments, 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. In order to provide adequate fire protection and to conform to City of Renton Code and Development Standards, the following water main improvements will be required (see enclosed illustration of water main improvements described below): a. Installation of approximately 180 feet of 10-inch water main within the new private access road and connecting to the existing 12-inch water main in Union Ave NE and extending westward to the west property line of proposed lot 1. A 1.5-foot vertical separation will be required between the new 10-inch water main and the existing 36- inch Seattle Public Utility water main. b. Installation of approximately 180 feet of 4-inch water main from the end of the above 10-inch water main and extending westward to the east line of proposed lot 3. c. Installation of a fire hydrant along the west side of Union Ave NE in front of proposed lot 1. d. Installation of a second fire hydrant near the west property line of proposed lot 1 connecting to the above new 10-inch water main. e. Installation of 1-inch minimum domestic water service and meter to each lot. If the new houses are to have fire sprinkler systems, the sprinkler designer will determine the service size. f. Abandonment of the existing ¾-inch water service line and capping the service line at the 12-inch water main in Union Ave NE. g. Each lot shall have a separate 1-inch water service line and meter, for a total of three (3) new domestic water service lines and meters. h. A public access/utility easement shall be placed over the proposed private access tract. 2. Civil plans for the water main improvements will be required and must be prepared by a registered professional engineer in the State of Washington. 3. Please refer to City of Renton General Design and Construction Standards for Water Main Extensions as shown in Appendix J of the City’s 2012 Water System Plan. 4. The development is subject to applicable water system development charges and meter installation fees based on the size of the water meters. a. Water system development charges for each proposed 1-inch domestic water service is $3,727.00 per meter. This is payable at construction permit issuance. Huynh Short Plat – LUA17-000855 Page 3 of 5 b. Water service installation charges for each proposed 1-inch water service is $2,850.00 per meter. This is payable at construction permit issuance. c. Drop-in meter fee is $460.00 per meter. This is payable at issuance of the building permit. d. A redevelopment credit of the water system development charges in the amount of $3,727.00 will be applied to the existing ¾-inch meter. SEWER 1. The proposed sewer main improvements as shown on the composite utility civil plan submitted with the Land Use Application provides the required extension of the new 8-inch sewer main within the proposed private access tract. The following sewer main improvements are required: a. Sewer main to be shifted south to provide 10 feet of separation between the water main and sewer main. b. A 1.5-foot vertical separation will be required between the new 8-inch sewer main and the existing 36-inch Seattle Public Utility water main. c. A public access/utility easement shall be placed over the proposed private access tract. 2. The existing side sewer will be required to be cut and capped during demolition of the properties. New side sewers shall be installed to serve each individual property. 3. All new side sewers shall be 6-inches and flow by gravity to the main at a minimum slope of 2%. Each lot shall have its own side sewer. Sewer cleanouts should not be located in the new driveways. 4. The development is subject to applicable wastewater system development charges based on the size of the new domestic water to serve the project. a. Wastewater system development charges for each proposed 1-inch domestic meter is $2,837.00 per meter. This is payable at construction permit issuance. b. A redevelopment credit of the wastewater system development charges in the amount of $2,837.00 will be applied to the existing ¾-inch meter. 5. The Honey Creek Sewer Interceptor Unit (Residential) Special Assessment District fee (SAD) fee will be applicable on the project. The SAD fee rate is $250.00 per lot. This is payable at construction permit issuance. SURFACE WATER 1. A geotechnical report, dated July 14, 2017 and revised September 28, 2017, completed by Migizi Group, Inc. for the site has been provided. The submitted report describes the site is a Low Erosion Hazard area. Erosion control measures will need to be in place prior to starting grading activities on the site. The report needs to discuss the soil and groundwater characteristics of the site including infiltration potential and provide recommendations for project design and construction. Geotechnical recommendations presented need to be address within the project plans. 2. A Preliminary Drainage Plan and Technical Information Report (TIR), dated December 17, 2017, was submitted by Encompass Engineering and Surveying with the Land Use Application. Based on the City of Renton’s flow control map, the site falls within the Flow Control Duration Standard area matching Forested Site Conditions and is within the Honey Creek Drainage Basin. The development is subject to Full Drainage Review in accordance with the 2017 Renton Surface Water Design Manual (RSWDM). All core requirements and five of the six special requirements have been discussed in the TIR. The following stormwater improvements are required and shall be discussed within the final TIR: Huynh Short Plat – LUA17-000855 Page 4 of 5 a. The final TIR shall discuss how Core Requirement #9 On-Site BMPs, are being addressed for all effective impervious area including impervious area within the private access tract. More specifically, the TIR shall discuss the permeable pavement within the access tract and how this relates to Core Requirement #9. b. Applicant shall include discussion of Special Requirement #6 in the final drainage report. SR #6 relates to the aquifer protection area, which is applicable to this site and should be noted as such in the report. c. The TIR submitted with the Land Use Application assumes that the soils beneath the permeable pavement will meet the requirement identified in RSWDM Section C.2.7 exempting permeable pavement from water quality. The Final TIR shall provide soils tests confirming this assumption or provide a water quality system that meets Basic Water Quality treatment. d. The proposed 7.5’ storm drainage easement running east to west, south of Lot 3 should be 10’ in width, as is the proposed 10’ storm drainage easement running north to south, east of Lot 3. 3. A Construction Stormwater General Permit from Department of Ecology will be required if grading and clearing of the site exceeds one acre. A Stormwater Pollution Prevention Plan (SWPPP) is required for this site. 4. A public access/utility easement shall be placed over the proposed private access tract. 5. The development is subject to applicable stormwater system development charges based on new single family residence. a. Stormwater system development charges for each new single family residence is $1,718.00. This is payable at construction permit issuance. b. A redevelopment credit of the stormwater system development charges in the amount of $1,718.00 will be applied to the existing home proposed to be demolished. TRANSPORTATION 1. Union Avenue NE is a Minor Arterial with existing right of way width of 60 feet. The Applicant submitted a street modification request. City Staff, Public Works Transportation Division and Community and Economic Development Department, reviewed the modification request and recommends its approval. The modification requests the following: a. The existing curb to curb width of 44 feet on Union Ave NE frontage remains as it is sufficient for this roadway. b. A new 0.5 foot wide curb, 8 feet wide landscaped planter, 8 feet wide sidewalk, and 1 foot wide clear space behind the sidewalk be constructed along the project frontage. c. A right of way dedication of 10 feet of right of way (subject to final survey). 2. Access to each of the lots may be granted via the proposed private access tract provided the tract meets requirements for emergency services access and must provide a turnaround in compliance with City code 4-6-060I. As noted by the Renton Fire Authority, fire department apparatus access roadways are required to be a minimum 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. Dead end streets that exceed 150-feet in length require an approved hammerhead type turnaround. If applicant desires to install only a 16-feet wide roadway, they must apply for a variance and approval would be conditioned that the new homes on Lots 2 and 3 would be equipped with an approved residential fire sprinkler system. Hammerhead type turnaround shown does not meet minimum dimensions per code and shall be widened prior to approval. Huynh Short Plat – LUA17-000855 Page 5 of 5 3. Refer to City code 4-4-080 regarding driveway regulations. a. Driveways shall be designed in accordance with City standard plans 104.1 and 104.2. b. Maximum driveway slope is 15%. Driveways which exceed 8% shall provide slotted drains at the lower end with positive drainage discharge to restrict runoff from entering the garage. c. The maximum width of a single loaded garage driveway is 9-feet and the maximum width of a double loaded garage driveway is 16-feet. If a garage is not present, the maximum driveway width is 16-feet. d. Driveways shall not be closer than 5-feet to any property line. 4. Per RMC 4-6-060, street lighting is not required since the project is less than four residential units. 5. The project does not require a Traffic Impact Analysis as the project produces less than 20 vehicles per hour in both the AM and PM peak periods. 6. Paving and trench restoration shall comply with the City’s Trench Restoration and Overlay Requirements. 7. The development is subject to applicable transportation impact fees based on new single family residence. a. Transportation Impact Fees for each new single family residence is $5,430.85. The transportation impact fee that is current at the time of building permit application will be levied. b. A redevelopment credit of the transportation impact fee in the amount of $5,430.85 will be applied to the existing home proposed to be demolished. GENERAL COMMENTS 1. Adequate separation between utilities as well as other features shall be provided in accordance with code requirements. a. 7-ft minimum horizontal and 1-ft vertical separation between storm and other utilities is required with the exception of water lines which require 10-ft horizontal and 1.5-ft vertical. b. The stormwater line should be minimum 5 feet away from any other structure or wall or building. c. Trench of any utility should not be in the zone of influence of the retaining wall or of the building. 2. 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. 3. All Civil Construction Plan 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 landscaping plan shall be included with the Construction Permit Application. 5. All utility lines (i.e. electrical, phone, and cable services, etc.) serving the proposed development must be underground. The construction of these franchise utilities must be inspected and approved by a City of Renton inspector. 6. Fees quoted in this document reflect the fees applicable in the year 2018 only and will be assessed based on the fee that is current at the time of the permit application or issuance, as applicable to the permit type. Please visit www.rentonwa.gov for the current development fee schedule.