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HomeMy WebLinkAboutPN_Project_Narrative_R2B_SSDP_171128_v1 (2) ATTACHMENT 1 - PROJECT NARRATIVE 1 Project Narrative Project Name: I-405, Renton to Bellevue Project, Stage 1 Size and Location of Site: May Creek Bridge: The site is located on I-405 over May Creek at MP 7.18. The existing bridge span is approximately 160 feet long. Latitude: 47°31'42.25"N Longitude: 122°11'52.20"W Section Township Range: S32 T24N R5E Lake Washington Trail: The section of trail to be relocated is within 100 feet of the southbound lanes of I-405 parallel to Ripley Lane and Seahawks Way; trail MP 7.35 to MP 10.25. Latitude: 47°32'13.79"N Longitude: 122°11'42.80"W Section Township Range: S32 T24N R5E Land Use Permits Required for Proposed Project: Master Land Use Permit Zoning Designation of the Site and Adjacent Properties: East and west of I-405 – Resource Conservation (May Creek Bridge) West of I-405 – Residential 8, Commercial Office Residential (Lake Washington Trail) The May Creek project area is within the following Critical Areas in the City of Renton: Flood, Regulated Slopes 15-<=90%, and Seismic Hazard. The Eastside Rail Corridor is within an area of Regulated Slopes 15-<=90%. Note that WSDOT has authority to design and construct state highways within WSDOT ROW. WSDOT design manuals address steep slopes and seismic hazards, and WSDOT’s design will comply with the substantive requirements of the City of Renton’s critical areas ordinance; however, permits are not required within ROW. Current use of the site and any existing improvements: Much of the property in the May Creek project area is currently within WSDOT ROW. Improvements support the roadway and associated roadway facilities necessary to provide a safe and efficient transportation corridor. To every extent possible, roadway designers will maximize the use of existing WSDOT ROW, but additional ROW may need to be purchased if deemed necessary. The proposed work area is occupied by I-405 and completely surrounded by open land with deciduous forest dominated by 2 red alder. East of I-405 is vacant land owned by the City of Renton; west of I-405 Renton owns the north bank of May Creek while the south bank is in private ownership. Within the Eastside Rail Corridor project area, land use is primarily residential along the Lake Washington shoreline west of the rail corridor, with some commercial and industrial development to the east interspersed with undeveloped areas of native vegetation. This section of the Eastside Rail Corridor is owned by King County. Special site features (i.e., wetlands, water bodies, steep slopes): The I-405 bridge crosses May Creek, an anadromous fish-bearing stream approximately 0.5 miles upstream of its outlet into Lake Washington. Most or all work at the May Creek Bridge is within Renton flood, regulated slopes (15-<=90%), and seismic hazard critical area designations. Statement addressing soil type and drainage conditions: Natural Resource Conservation Service (NRCS) soil maps show the vicinity of the May Creek Bridge to be predominately Norma sandy loam, which is associated with floodplains and poorly-drained with frequent ponding. Refer to Attachment 9 - Geology and Soils Technical Report The shoreline area of Lake Washington is characterized by Seattle Muck consisting of mucky peat and very poorly drained, while the area of the current bike path is within a unit of Alderwood gravelly sandy loam, a moderately well-drained soil. Proposed use of the property and scope of the proposed development: May Creek Bridge (MP 7.18): The Project will replace the northbound and southbound I-405 bridge structures over May Creek and provide habitat improvements along the creek by removing angular rock fill material from the floodplain, improving fish habitat along the stream channel, and providing buffer enhancement. This activity is within the 100-year floodplain. Pier saw cutting and removal will occur adjacent to the stream and quarry spall removal will occur within the ordinary high-water elevation of the stream. Installation and removal of the piles will occur during the times authorized by the Hydraulic Project Approval and the Federal Services Biological Opinion. The following outline describes a potential construction sequence; however, since the project will use the design-build project delivery method, construction sequencing and methods may vary. NB Bridge Replacement Staging (SB Bridge Replacement Similar):  Construct construction access to bridge. For the south approach, construction access will be constructed from west side of I-405. For the north approach, construction access can be constructed from either side of I-405.  Install a debris catch system to the existing bridge girders from an Under Bridge Inspection Truck (UBIT) or boom lift. o Build a portion of the new northbound bridge east of the existing northbound bridge. o Demolish the existing northbound bridge superstructure. o Remove the existing ACP overlay, concrete barriers and utilities from the bridge deck. 3 o Remove the existing bridge deck. o Add temporary bridge girder bracing and remove the existing bridge diaphragms. o Remove the debris catch system.  Demolish the existing northbound bridge substructure (columns/abutments) o Remove the existing northbound bridge columns. The WSDOT Design Build contractor will perform a scour analysis to determine whether removal of existing columns to a depth of 2’ is sufficient to prevent exposure. An access route to the piers will be graded in on the upslope side of the existing columns outside of the ordinary high-water level (OHWL). The existing columns will be removed either by saw- cutting sections of the columns and/or by jack- hammer and backfilled with previously excavated material. o Remove the construction access and regrade impacted areas back to the pre- constructed conditions. o Remove existing abutments. o Build the remaining portion of northbound bridge. The proposed bridge is a one span structure, so no piers will be located within the limits of May Creek. Equipment used on site may include, but is not limited to, back hoes, excavators, loaders, graders, rollers, dump trucks, concrete trucks, vactors, mobile and stationary cranes, drilling machines, pile drivers, and hand tools. There may be concrete pours associated with bridge abutment and bridge deck construction. May Creek Trail: An extension of the City’s May Creek Trail will be constructed on the north side of May Creek parallel to the channel and above the 100-year floodplain. The trail will be eight feet wide and will extend from the end of the existing May Creek Trail (which currently ends approximately 40 feet east of the eastern boundary of the WSDOT right-of-way) to Jones Road. However, only the portion of the trail within WSDOT right-of-way is being permitted as part of this application. The portions of the trail outside of WSDOT right-of-way will be permitted separately and are not part of this application. Lake Washington Trail: The Project proposes to construct a bike and pedestrian trail within the Eastside Rail Corridor from Ripley Lane in Renton to Coal Creek Parkway in Bellevue. Since King County bought the Eastside Rail Corridor, this portion has been open to the public as a trail even with the rails intact. At this time, King County is in the process of removing the existing rails and creating a gravel path on the existing railroad ballast between Ripley Lane and Lake Washington Blvd where it turns towards Newcastle Beach Park. For plats, indicate the proposed number, net density, and range of sizes (net lot area) of the new lots: Not applicable to this project Access: 4 May Creek Bridge (MP 7.18) From I-405, take the Northeast 44th Street exit. Turn west and continue onto Lake Washington Blvd. approximately 1,600 feet beyond the interchange. Park on the west side of the road adjacent to the rail road tracks. The bridge may be accessed via the signed May Creek Trail on the east side of the road. Lake Washington Trail From I-405, take the Northeast 44th Street exit. Turn west onto NE 44th Street and then right onto Seahawks Way and proceed north to where the road changes to Ripley Lane. The existing trail is to the right (east); the Eastside Rail Corridor is to the west. Proposed off-site improvements (i.e., installation of sidewalks, fire hydrants, sewer main, etc.: Minor off-site improvements may include pavement markings, drainage improvements, permanent signing, illumination, and barriers. Total estimated construction cost and estimated fair market value of the proposed project: Connecting Washington funded the Renton to Bellevue Stage 1 project as part of a larger set of improvements. The total funding for the full set of improvements, including project engineering and ROW, is $890M. Estimated quantities and type of materials involved if any fill or excavation is proposed: Since this is a design-build project, the exact excavation and fill quantities are not yet known. Attachment 4 - Conceptual Site Plans shows the location of anticipated grading within shoreline and critical areas designation. Number, type, and size of any trees to be removed: A board-certified landscape architect will prepare a roadside restoration plan and inventory of trees for removal. Maps showing the location of proposed tree planting areas, and a list of replacement species has been included in Attachment 5 – Tree Impacts and Restoration Plan. Explanation of any land to be dedicated to the City: Not applicable to this project. Any proposed job shacks, sales trailers, and/or model homes: Construction offices and staging areas will be within WSDOT ROW. Any proposed modifications being requested (include written justification): Not applicable to this project. Distance in feet from the wetland or stream to the nearest area of work: Lake Washington: Approximately 100 feet from the developed shoreline. May Creek: Adjacent to and above the wetted perimeter of the channel. Distance from closest area of work to the ordinary high-water mark: 5 May Creek: The bridge work area will include piers within approximately 50 feet from the Ordinary High-Water Mark (OHWM). The overhead bridge structure will be directly over the entire stream and directly adjacent to the OHWM. Lake Washington: The new trail alignment will be approximately 100 feet from the developed shoreline of the lake at its closest point. Description of the nature of the existing shoreline: May Creek: Vegetation and habitat conditions on most of the WSDOT roadway property are limited because the roadway currently supports a six- to 10-lane urban freeway and associated roadway facilities. River banks up and downstream support a mixture of Douglas fir, big-leaf maple, red alder, black cottonwood, and blackberry. Beneath the bridge, there is little vegetation and the banks are armored with riprap. For additional detail, refer to Attachment 6 - Wetland and Stream Assessment Report. Lake Washington: The Lake Washington shoreline at this location is entirely developed into residential and commercial properties, including a professional football practice field. Most of the properties have docks and/or bank stabilization such as cement bulkheads. Lawns and ornamental vegetation comprise most of the vegetation. Landward (east) of the homes is a buffer of trees and shrubs, then the rail corridor running parallel to I-405, and parallel to that, Ripley Lane, a two-lane paved road. The Lake Washington bike trail is between Ripley Lane and I-405. Total distance between the Eastside Rail Corridor and the bike lane averages approximately 100 feet.