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HomeMy WebLinkAboutPN_Project_Narrative_180320_v1 2731 Wetmore Avenue, Suite 402, Everett, WA 98201  Phone (425) 493-5221 Fax (425) 374-5152 otak.com Project Narrative The City of Renton is proposing the May Creek and Ripley Lane Trestle Rehabilitation Project. The project intends to repair and retrofit two trestle bridges. The trestles are currently used as recreational pedestrian bridges and are planned to become part of the multi-use Eastside Rail Corridor Regional (ERC) Trail in Renton. The trestles are deteriorated and have defects and are in need of repairs to provide continuous use of the trail system. A bridge inspection revealed defects and deterioration in timber and steel members. Internal decay in timber stringers, piles and cap beams, and rusting of steel cap beams was observed. Repairs are recommended in order to utilize the bridges for the ERC Trail and to accommodate for the desired lifespan of the structure. In addition to repairs and rehabilitation of existing components of the trestle bridges, existing timber railroad ties and steel railroad tracks will be removed, and new decking and railing will be installed. The repair maintenance activities are exempt under RCW 80.50 for normal maintenance or repair of existing structures or developments. The project is located in the City of Renton, King County, Washington. The May Creek trestle is located approximately 300 feet north of N. 41st Street, west of Lake Washington Boulevard. The Ripley Lane trestle is located west adjacent to Ripley Lane N., west of Interstate 405. The project is located in Sections 32 and 29, Township 24 North, Range 05 East of the Public Land Survey System. The May Creek trestle is approximately 60 feet long and 13 feet wide, and the Ripley Lane trestle is approximately 406 feet long and 14 feet wide. The project is anticipated to occur in March 2018 and to be completed in late 2018 and will occur during the WDFW-approved in-water work window. A Land Use Permit and Right of Way Permit from the City of Renton will be needed for this proposal. An HPA from WDFW may be needed for work within 200 feet of regulated waters of the state. Wetlands and streams are located within the vicinity of the project site. One wetland (WR11) is located below the deck of the Ripley Lane trestle. WR11 spans from the center of the trestle to the southern end of the bridge. WR11 is classified as a depressional and riverine wetland with a palustrine forested (PFO) Cowardin habitat class. Wetland hydrology is driven by a flow-through stream (Stream SR6) and shallow groundwater. Three streams (SR6 , SR7, and May Creek) are located in the project vicinity. SR6 is an intermittent stream and is not typed per Washington State Department of Natural Resources (DNR) or the City of Renton (City). SR 6 flows parallel to the Ripley Lane trestle and flows into SR7. SR7 is a perennial stream that emanates from a culvert on the east side of Ripley Lane N, and flows west below the trestle. SR7 is a tributary to Lake Washington and is Type F (Fish) stream per DNR and Type NP (non-fish perennial) per the City. May Creek is located below the May Creek trestle. The stream is a perennial tributary to Lake Washington and is Type S (Shoreline of the State) per DNR and the City. The Natural Resources Conservation Service (NRCS) mapped soils include Norma sandy loam in the May Creek trestle project area and Alderwood gravelly sandy loam in the Ripley Lane trestle project area. Under existing conditions, stormwater runoff from the bridge decks of both trestles flows to the streams and uplands below. There will be no change in drainage patterns with respect to stormwater entering nearby waterbodies. Page 2 of 2 The total estimated construction cost and fair market value of the project is approximately $947,026.50. There will be no excavation or fill material for the proposed project. The proposed project includes repairs to existing components of the bridge, and new decking and railing will be installed in the same footprint of the existing features. No views will be obstructed as construction will occur within the same footprint of the existing bridge. Components to be removed will be disposed of at an approved location. No trees or woody shrubs will be removed for this project and adjacent trees and woody shrubs will be protected with high visibility fencing during construction. The May Creek trestle is located approximately 840 feet from the shoreline of Lake Washington, and the Ripley Lane trestle is located approximately 220 feet from the shoreline. The shoreline designation for the May Creek trestle is Urban Conservancy and the shoreline designation for the Ripley Lane trestle is Shoreline Residential. Shoreline in the vicinity of the project area is bordered by single and milt-family residences, private docks, and bulkheads.