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HomeMy WebLinkAboutDiaz_Response_180828 August 28, 2018 Tricia and John Diaz 12915 SE 95th Way Renton, WA 989056 Email: teamdiaz4@gmail.com SUBJECT: Response to Project Comment Letter Forest Terrace Preliminary Plat / LUA18-000124 Dear Tricia and John Diaz, Thank you for your comment letter regarding the Forest Terrace Preliminary Plat application currently under review by the City of Renton. The project had been placed on-hold March 19, 2018 pending additional information and correction requested by staff. While on-hold, staff requested the applicant also provide a response to your comment letter, which is enclosed. The project was taken off-hold on August 23, 2018 and a revised notice of application was issued as the proposal now includes a critical areas variance and street modification with the master application. Documents related to the master application can be viewed on the City’s website with the following link: https://edocs.rentonwa.gov/Documents/1/fol/1120072/Row1.aspx. Responses to you comment letter are provided below and reflect the following items: street alignment; stormwater; pipeline easement; sensitive slope grading; hazard trees; and sewer connection. Street Alignment The location of Road B, the north/south residential access street, is intended to provide connections to the north when the abutting properties are developed in the future as required by the City’s subdivision regulations, see RMC 4-7-150. Both Road A and B are classified as a residential access streets that will contain a width of 53-feet. The streets cross sections will contain two 10-foot wide travel lanes, one 6-foot wide parking lane, two 6-inch wide curbs, two 8-foot wide planter strips, and two 5-foot wide sidewalks. Road B will stub at the northern property line of the site for future connectivity. Maintenance of the stormwater facility will occur within the portion of Tract A labeled Fire and Drainage Access along the northeastern portion of the subject property. This portion of Tract A will also provide temporary emergency vehicle access until such time a permanent secondary access point is provided via development of abutting properties. The location of Road B provides adequate separation from the Union Ave intersection and the Olympic Pipeline easement. The stub abuts multiple parcels under the same ownership (Dalpay properties) that extend to SE 95th Way with significant frontage along 132nd Ave SE. The preliminary grading plans identify this street can be constructed to meet the 15-percent grade limitation set forth in RMC 4-6-060F.2. The proposed stub provides connectivity to a future street grid to the north when those underdeveloped properties subdivide. The proposed connection does not fail to meet street standard citations identified in your letter as the residential street classification provides a complete street section to accommodate a range of users and the stub is not a permanent dead end street as it is intended to be connected to a future street grid to the underdeveloped parcels to the north. The location of the stub does not negatively impact the future growth of parcel 334510-0450 as connections could be made to a future street grid on the Dalpay properties by connecting via an east/west direction. Stormwater The applicant is required to ensure that all stormwater shall discharge at its natural drainage location. The current proposal is to route existing sheet flow from the south of the subject property and convey it into a 50 foot long dispersion trench thereby discharging flows into the same drainage location as the predeveloped conditions. All of the surface water runoff from this project will eventually discharge into May Creek located to the north and there is no indication that the amount of flows will change due to the development of the subject property. At this time the City does not see a justification to require a Level 2 downstream analysis. Pipeline Easement The City and applicant are aware of the Olympic pipeline and Puget Sound Energy transmission line easements that bisect the western portion of the property. The preliminary plat application requires preliminary grading plans to accommodate a general design for the street, infrastructure, and lot layout. Following preliminary plat approval, the applicant will be required to refine their grading plans for the construction permit that is required to be issued prior to any ground disturbance. The applicant will be required to have their construction plans reviewed by the easement grantors to ensure compliance with their standards prior to receiving approval from the City. Sensitive Slope Impacts to Abutting Properties It appears the geotechnical engineer has reviewed the preliminary grading plan and found no offsite impacts caused by the proposed grading. Due to the topography and amount of grading on the site, it will be likely that SEPA mitigation measures will be recommended to the City’s Environmental Review Committee to require the applicant to have the geotechnical engineer review the construction permit plans to ensure that all recommendations of the initial report are followed. Hazard Trees The applicant’s arborist report did provide an inventory of the site’s trees and indicated those that were in poor health condition and nonviable. Most of the trees proposed to be retained are along the southern portion of the property abutting Sierra Heights Elementary School. There are several trees proposed to be retained along the northern boundary in Tract B. Trees to be retained are considered protected trees and must be fenced around the dripline, mulched, watered, and left undisturbed throughout construction. As shown on the tree retention plan (Sheet 9 of 9), those trees abutting your property (parcel 334510-0450) would be removed. Sewer Connection Your parcel is outside of the City’s sewer service area. Please contact the Coal Creek Utility District for sewer availability information. Closing Please feel free to contact me at 425.430.6593 or mherrera@rentonwa.gov should you have any questions regarding this letter. Sincerely, Matt Herrera, AICP Senior Planner enc: Barghausen Letter dated June 25, 2018 1.0 CIVIL ENGINEERING, LAND PLANNING, SURVEYING 18215 72ND AVENUE SOUTH KENT, WA 98032 (425) 251-6222 (425) 251-8782 FAX BRANCH OFFICES TUMWATER, WA KLAMATH FALLS, OR LONG BEACH, CA ROSEVILLE, CA SAN DIEGO, CA www.barghausen.com June 25, 2018 ELECTRONIC DELIVERY Matt Herrera, AICP Senior Planner City of Renton Community and Economic Development Department 1055 South Grady Way Renton, WA 98057 RE: Responses to Comments Forest Terrace Subdivision and Lot Line Adjustment City of Renton File Nos. LUA18-000124 and 125 Our Job No. 18396 Dear Matt: We have revised the plans and technical documents for the above-referenced project in accordance with the City of Renton "On Hold" Notice letter dated March 19, 2018 and the Diaz comment letter dated May 2, 2018. Enclosed are the following documents for your review and approval: 1. Revised Project Narrative prepared by Barghausen Consulting Engineers, Inc. dated June 22, 2018, including: a. Modification Request – Retaining Wall Height exceeding 72 inches b. Modification Request for Modified Minor Arterial Street Design c. Variance Request - Slope Impact 2. Revised SEPA Checklist prepared by Barghausen Consulting Engineers, Inc. dated June 2018 3. Protected Slope Analysis prepared by Terra Associates, Inc. dated June 18, 2018 4. Revised Preliminary Plat Plan Set prepared by Barghausen Consulting Engineers, Inc. dated June 18, 2018, including: a. Cover Sheet b. Preliminary Site Plan c. Preliminary Utility Plan d. Preliminary Drainage Plan e. Preliminary Grading Plan f. Preliminary Road Profile Plan g. Preliminary Tree Retention Plan h. Preliminary Tree Replacement and Landscape Plans 5. Revised Technical Information Report prepared by Barghausen Consulting Engineers, Inc. dated June 18, 2018. Matt Herrera, AICP Senior Planner City of Renton Community and Economic Development Department - 2 - June 25, 2018 The following outline provides each of the comments in italics exactly as written, along with a narrative response describing how each comment was addressed: The following four items will need to be submitted before June 18, 2018 so that we may continue the review of the above subject application: 1. As shown on the preliminary grading plan sheet 5 of 9, portions of the site contain finished grades that would result in Protected Slopes. Pursuant to RMC 4-4-060M.2 and N.6, slopes created from cuts and fills shall not result in the creation of permanent slopes 40-percent or greater which are 15-feet in height, i.e. protected slopes. A revised grading plan that complies with these grading regulations will be required. Response: The grading plan for the proposed project has been revised to incorporate additional retaining walls/rockeries into the design. In general, proposed slopes of 2H:1V will not exceed 14 feet in height without an additional wall breaking up the overall slope. 2. The grading plan and site sections sheet 6 of 9 identify the stormwater vault containing an exposed face of up to 8-feet in height. The applicant will need to reduce above-grade vault exposure to 6-feet and lower. Additionally, aesthetic treatment of the exposed face and ground level landscaping will be required. Response: As requested, the fill above the detention vault has been reduced so that the exposed face on the northwest corner of the vault does not exceed 6 feet in height. A note regarding aesthetic treatment and approval of landscaping has been added to Sheet 6 of 9. 3. The modified minor arterial street section along Union Ave NE will require a modification application. The modified minor arterial standard would require a right of way width of 81'. The paved roadway width required would be 44' consisting of 2 — 11' travel lanes, 1 12' travel lane, and 2 - 5' bike lanes. A 0.5' curb, 8' planter; 8' sidewalk, and 2' clear at the back of sidewalk are required along each side of the roadway. A right of way dedication of approximately 10.5' along the Union Avenue NE frontage will be required to provide a half street right of way width of 40.5'. The application form can be found on the City's CED Forms page by searching for City Documents" in the search bar on the City of Renton website. The modification fee is 262.50. Response: A modification for the modified minor arterial standard is included as part of the Project Narrative, as requested. 4. The minimum Horizontal separation between the water line and the 2 storm lines shall be 10 feet. Please relocate the storm lines to provide the 10-foot separation. The City will accept a minimum of 7.5 feet of horizontal separation between the water line and the storm line (outside wall to outside wall) if a city approved restrained joint pipe system and fittings are provided for the water line in addition to concrete blocking at the fittings. Response: The plans have been revised so that the second storm line has been eliminated. The following two items below are advisory and will need attention during the construction permitting stage of the proposal: Matt Herrera, AICP Senior Planner City of Renton Community and Economic Development Department - 3 - June 25, 2018 1. The street and water/sewer mains need to be extended to the west edge of the property line. A blow-off assembly shall be required at the end cap for the water main and manhole for the sewer main will need to be located within a paved surface. Response: The water and sewer mains have been extended to the west property line. A note regarding a blow-off has been added to Sheet 3. A paved access will be provided to the sewer manhole. Actual details of the extension will be provided during final engineering. 2. There is an existing 12" ductile iron dead end water main east of the site in Union Avenue NE that can deliver a maximum flowrate of 1,240 gallons per minute (gpm). Reference Project File WTR2702847 in COR Maps for record drawings. The flow restriction is due to a 300' section of 8" water main in Union Avenue NE from NE 25th Street to the north property line of Sierra Heights Elementary School. If this 300' section of 8" pipe is replaced with a new 12" pipe, the flowrate of the existing 12" main in Union Avenue NE from of the development will increase to approximately 3,000 gpm. The maximum flow rate of the internal water main will be limited to 1,240 gpm unless the 300' section of 8" pipe in Union Avenue NE is replaced with a 12" main as indicated above. Residential buildings that have over 3,600 square feet of gross building areas may have fire flow demand of 1,500 gpm or more. Please verify with the Renton Regional Fire Authority to determine the preliminary fire flow demand and size the water main(s) accordingly to provide adequate flow to the new hydrants. Response: Comment noted. These offsite improvements will be evaluated during final engineering once house sizes are determined. The applicant acknowledges that if the improvements are not constructed that automatic fire sprinklers will likely be required. Public Comment Letter from Tricia and John Diaz dated May 2, 2018 Zoning. The proposed subdivision and adjoining properties are included in the King County Proposed Annexation Area (PAA). While not required as part of the Hearing Examiner determination, we formally request that City of Renton's Planning Division consider the opportunity to plan, coordinate and synchronize the PAA area. Spacing and typical transportation classification for motorized and pedestrian use will define future opportunities. While the City of Renton cannot dictate future development, with proper planning and forethought community infrastructure and utilities can promote "good planning" and facilitate healthy, safe growth. To be specific, the spacing of the north south access road will constrain or restrain future growth. A north south residential road shown in red in the imagery below) too close to Union Avenue causes vehicular safety, access, and neighborhood circulation issues – a primary reason why most municipal codes have strict guidelines on neighborhood residential roads. Response: The project is designed per City of Renton standards for connectivity and R-4 zoning requirements. The north-south Road B was provided in the location shown as required by the City of Renton to provide for future connectivity to potentially developable property to the north. The proposed subdivision the ability for future connections as shown on the preliminary plans. The east west future connection makes perfect logic; however, a south connection is problematic due to steep slopes. The natural connection in order to provide fire safety, access and circulation is to the north; however, there are multiple existing single family residences that limit access points along SE 95th Way. As outlined in PAA and Land Use objectives for both King County and the City of Renton, there is a “long term” need for complete streets and safe residential roads. The north south alignments shown in green below illustrate safe, access points. Matt Herrera, AICP Senior Planner City of Renton Community and Economic Development Department - 4 - June 25, 2018 Response: Road B was provided in the location shown as required by the City of Renton to provide for future connectivity to potentially developable property to the north. The east-west Road A will be an opportunity for future connectivity to properties west of the site as development occurs. Road B_1a) What is the purpose and classification of this roadway? It clearly illustrates operations and maintenance of Tract B's stormwater facility; however, it appears to serve as a future road connection north for future development. Response: Road B was provided in the location shown as required by the City of Renton to provide for future connectivity to developable property to the north. The classification of Road B is Residential Access. As an interim condition, until such time that future potential development to the north occurs, Road B will provide a connection to the Forest Terrace project's emergency secondary access as required by the City of Renton. Road B_2a) The current location of Roadway B fails to meet zoning code requirements (sections 4-6-060 STREET STANDARDS (G) and (H)). A future connection at this location negatively impacts future growth in parcels 334510-0450 and impedes infrastructure and utility connections. A "north-south" neighborhood connect is better provided 1500 feet west of Union Road. The proposed subdivision roadway is almost 1150 feet from centerline (Union Road) to center of cul- de-sac creating special conditions for fire safety and access, a secondary access route is needed. Response: Road B was provided in the location shown as required by the City of Renton to provide for future connectivity to developable property to the north (satisfying RMC 4-6-060-H). The design of Road B provides for a complete street section (satisfying RMC 4-6-060.G). The connection location could serve a group of parcels that are owned by the same family, which are more likely to be developed than smaller properties owned by separate parties (see below). Preliminary TIR notes upstream contributory areas, but does not review current situation. The topography currently breaks into two downstream paths. The currently omitted path absent from the TIR runs down the combined utility easement to the v-ditch then travels westward. The site topography clearly illustrate a draw between lots 12 and 13. This draw sheet flows onto our property eventually contributing to May Creek. The upstream surficial flows are important to our native plant vegetation. Diversion of this flow negatively impacts the native salmonberry, ferns and salil that receive surface water from the upstream slopes. While not a designated wildlife trail or area, the Matt Herrera, AICP Senior Planner City of Renton Community and Economic Development Department - 5 - June 25, 2018 area serves as a native species habitat and access way up to the park and school areas. Diverting surficial and sub surficial flows could and most likely will impact the native species currently on tax lot 334510-0450. Soil conditions in Test pits 8 and 9 depict shallows infiltration are feasible. Dispersion techniques are required to "mimic" current hydrology patterns and not damage downstream native growth. The engineer downstream analysis omits the current which receives offsite upstream flows (approximately 3.8 acres), then conveys them along the Olympic Pipeline/Puget Sound Energy Easement to a roadway ditch running parallel and on the south side of SE 95th Way. The Preliminary TIR downstream analysis omits the second flow path. Downslope storm water impacts. King County Parks and Stormwater Division worked collaboratively on fish and plant restoration of downstream May Valley Creek. The Level I downstream analysis does not reflect the upstream contributory and splits. Redirecting flows most likely will affect current stream flow rates and locations negatively affecting salmonid and biohabitat in May Valley Creek. Retention of native biodiversity is critical for environmental stewardship. King County May Creek Fish Habitat project impacts for degradation of the not just water quality, flow rates and nutrients are critical to salmonid habitat. Upstream flow rates, water quality and quantity require special modeling and studies. While the Preliminary TIR recommends that a Level II TIR is not required, we disagree due to the significance of downstream habitat, terrestrial and stream. Response: The offsite drainage analysis and preliminary drainage plans have been updated to show the collection of the upstream basin and discharge at its natural location. The upstream basin that flows onto the property on the southwest portion of the property and into the onsite draw will be collected and routed to the north boundary and discharged via a level spreader where the draw fades out at the property line. This basin will continue to flow in a northerly direction until it is intercepted by the roadside ditch along S.E. 95th Way. Based upon site visits and a review of known information, runoff within the ditch will flow easterly towards the intersection of Union Avenue N.E. All runoff generated onsite will be detained and treated for water quality. Upon discharging to a roadside ditch in Union Avenue N.E., stormwater will combine at the intersection of S.E. 95th Way with the previously mentioned upstream basin and continue to flow along the natural flow path, ultimately discharging into May Creek. For further detail, please refer to the Downstream Drainage Analysis in the updated TIR. Based on our analysis, it is our professional opinion that a Level 2 Downstream Analysis is not required for this development. Safety, environmental and engineering issues are omitted related to the Olympic natural gas pipeline both in plans, TIR, environmental checklist and studies. The easement clearly shows two types of utilities, Puget Power and Olympic Natural Gas. The geotechnical report does not evaluate cuts over sensitive slopes and utilities, specifically, the natural gas pipeline. The developer proposes final grading consisting of both cut and fill over the existing pipe. There is no discussion of temporary construction techniques for areas where heavy construction activity traverses over or creates overburden loads onto the pipe. The omission of the Olympic Natural Gas pipeline easement, assessment and special engineering recommendations to mitigate safety and environmental risks does not generate confidence in the developer’s due diligence, especially his professional staff. Response: The applicant is aware of the Olympic Natural Gas (ONG) pipeline and easement. The SEPA Checklist has been revised to include references to the existing natural gas pipeline. Matt Herrera, AICP Senior Planner City of Renton Community and Economic Development Department - 6 - June 25, 2018 During the final engineering process, the applicant will coordinate with both Puget Sound Energy and Olympic Natural Gas for permits and construction requirements/methods. Sensitive slope grading adjacent to properties. Our parcel has a terraced rockery. The geotechnical engineer should define grading or slope treatment such that development does not impact adjacent homeowner property. Response: A geotechnical report has been prepared and submitted along with the preliminary plat application. No impacts to adjacent properties were identified due to the proposed grading activities. Hazard trees need to be identified. Over 1,000 trees were inventoried, yet zero were identified as hazard" trees. The arborist must identify hazard trees and the developer must sequence the removal or harvest of trees such that they do not create a public safety hazard to adjacent homes. This is specifically the case for our parcel. Response: The project arborist identified trees that were in poor health and not to be counted as retained. During construction activities the project arborist will be retained to evaluate construction activities on trees that are to be saved. At that time trees deemed to be a hazard will be slated for removal. Sanitary sewer connection. Location of sanitary sewer to support homeowner connects north and south of proposed subdivision. We would like to transition our current septic system to Renton utilities for sewerage. Response: The Diaz property is located outside of the City limits and is within a different sewer basin than the proposed project. Due to significant elevation differences it is impossible to provide gravity sewer service to the Diaz property via the proposed onsite sewer. We believe that the above responses, together with the enclosed revised plans and technical documents, address all of the comments in the City of Renton "On Hold" Notice letter dated March 19, 2018 and the Diaz comment letter dated May 2, 2018. Please review and approve the enclosed at your earliest convenience. If you have questions or need additional information, please do not hesitate to contact me at this office. Thank you. Respectfully, Ivana Halvorsen Senior Planner IH/lb [18396c.004.docx] enc: As Noted cc: Kyle Lublin, Pulte Homes of Washington, Inc. (w/enc) Thomas A. Barghausen, Barghausen Consulting Engineers, Inc. Barry J. Talkington, Barghausen Consulting Engineers, Inc.