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HomeMy WebLinkAboutPN_9_COR Project Narrative ph3_230215_v1.4 crbCity of Renton Project No: 27-3708 Project Narrative City of Renton: Cedar River 205 Levee Recertification Phase 3 Page 1 of 4 Project Name: Cedar River 205 Levee Recertification Contract: CAG-15-224 City Project No: 27-3708 Department: Surface Water Utility Project Manager: Chester Bennett Date: 2/15/2023 Cedar River 205 Levee Recertification - Project Narrative Summary The project is currently in phase 3 which includes the following: • Consultant led design of improvements noted in phase 2. • Consultant led federal and agency permitting requirements with city oversight. • Consultant led updates to the Levee Certification Report from phase 2. • Local permitting requirements to be coordinated by the City of Renton’s project manager. The required structural improvements to be designed in this phase were identified by Tetra Tech during subsequent phases. These improvements are necessary to allow certification of the levee system. This phase of work was awarded to Tetra Tech to deliver Plans, Specification and Estimate (PS&E) along with permitting submittals and approval, required reports, technical analysis, and all other support documents. Design reviews consist of 30%, 75%, 90%, and 100% which require review by the City of Renton (the City) as well as other required federal agencies to obtain permits for the proposed improvements. Tetra Tech will also prepare and submit required reports and revisions as required by the United States Army Corps of Engineers (USACE) and Federal Emergency Management Agency (FEMA). Technical Project Details The use of the sites varies based on location and includes: • Public Recreation • Commercial • Airport activities • Residential housing Relevant City of Renton Codes: • 4-3-050 • 4-3-090 • 4-8-080.G Relevant Impacts: • The project sites are near the Cedar River Shoreline on the right and left banks. City of Renton Project No: 27-3708 Project Narrative City of Renton: Cedar River 205 Levee Recertification Phase 3 Page 2 of 4 • Due to dispersed project sites work will be within the following zones: o Public Right-of-Way o CD o R-10 o Undesignated which includes the river channel • 9 trees are proposed for removal and mitigation for such impacts are proposed. Types and details are noted on construction plans. • In total 43 CF of total fill will be added to various sites for the project. See breakdown per site below: Area Sheet Fill (CY) Excavation (CY) Net Fill (CY) Net Excavation (CY) Area 4 Boeing Bridge C-109 259 195 64 0 Area 5 Stadium C-110 143 110 33 0 Area 11 Sidewalk C-111 13 13 0 0 Area 6 Senior Center C-112 104 150 0 46 Area 7 Airport Weather Station C-101 70 85 0 15 Area 8 Airport Wall C-102 0 0 0 0 Area 8 Airport Wall C-103 67 75 0 8 Area 9 E Perimeter MSE C-105 238 245 0 7 Area 10 Sub Shop C-107 207 185 22 0 Totals 119 CY 76 CY Total Project = 43 CY of fill • No offsite improvements are proposed or required. All improvements related to the project are shown in the construction plans which include mitigation plantings. • No new lots or easements will be required or created with the proposed work. • No views will be obstructed due to proposed work and modifications to the levee system. • Site drainage conditions and patterns will be unaffected by the work and will maintain overland sheet flow dispersion and collection of low-lying areas with city compliant drainage and conveyance structures. • According to the geotechnical borings and report dated Nov 17, 2017 by Lyle J. Stone, PE of GeoEngineers the project contains “…a soil profile of interbedded alluvial sands, silts, clays and gravels. As expected in an alluvial soil profile, the layers of soils vary in thickness and composition along the length of the project area.” City of Renton Project No: 27-3708 Project Narrative City of Renton: Cedar River 205 Levee Recertification Phase 3 Page 3 of 4 Background The Cedar River levees were designed by the USACE in the mid-1990s, and their construction began in April 1999. In December 2000, the flood control was complete. The Cedar River levees are part of the Cedar River Section 205 Flood Damage Reduction project, constructed in cooperation with the USACE. The levees are located on the lower 1.25 miles of the Cedar River and extend from Williams Avenue N to the mouth of the Cedar River at Lake Washington. The Cedar River 205 project protects portions of downtown Renton, The Boeing Company’s 737 plant, and the Renton Municipal airport from the 100-year flood. At the time of completion of the levees in December of 2000 the obligations for operation and maintenance were transferred to the City of Renton. The USACE started certification of this levee system in 2004 which allows for adjacent areas (listed above) to be mapped as outside of the FEMA 100-year floodplain critical area. However, in July of 2012 the USACE informed the City that the certification previously issued by the USACE would expire in August 2013. If the levee is not certified, then the levee cannot be considered to offer sufficient protection to keep the areas in the lower 1.25 miles of the Cedar River outside of the 100-year floodplain. Thus, the City is responsible to manage necessary certification of the levee system to keep current FEMA floodplain mapping unchanged. Project Work – Completed RFP Advertisement and Award In August 2015, the City of Renton Surface Water Engineering advertised a request for proposal for engineering consulting services to evaluate and certify the Cedar River 205 right bank and left bank levees and floodwalls and seek reaccreditation by FEMA in accordance with FEMA requirements. Following the evaluation of the proposals received and the conduction of interviews, Tetra Tech was selected in October 2015 to perform the work and services required to achieve the recertification and reaccreditation of the levee. The Engineering Consultant Contract, CAG-15-224, with Tetra Tech was signed by the Mayor on December 7, 2015. Phase 1 – Preliminary Assessment Phase 1 began in December of 2015 and contained two amendments (No 1 and No 2) both issued in 2016. Phase 1 work consisted of data collection and preliminary hydraulic and geotechnical assessments. The final product in this phase was a report that defines the analyses needed for the certification analysis and defined the scope of work for Phase 2. Phase 2 – Analysis and Certification Findings Report Phase 2 began in June of 2018 and contained two amendments (No 3 and No 4) issued in 2018 and 2019 respectively. Phase 2 work included the technical engineering analysis required for certifying the levees and the compilation of the certification report. Phase 2 expanded upon the preliminary analyses that were conducted for Phase 1 in order to determine any necessary improvements that would be required in order for Tetra Tech to issue a certification of the levee system. The final product is the Levee Certification Report. City of Renton Project No: 27-3708 Project Narrative City of Renton: Cedar River 205 Levee Recertification Phase 3 Page 4 of 4 Project Work – Current and Ongoing Phase 3 – Design Plans Specs & Estimate and Permitting Phase 3 began in June 2019 with amendment No 5 issued June 2019 and is continuing via amendment No 6 issued April 2022. Phase 3 is a result of the technical analyses in phase 2 that identified structural improvements necessary to allow certification of the levee system by Tetra Tech. The project is currently working to finalize 90% design plans, review specifications, complete permits with the USACE and other federal agencies, and begin coordination of local permitting requirements for the City of Renton. The final deliverables for Phase 3 include: • Design drawings of levee improvements • All relevant permits and support documents, federal and local. • An updated Levee Certification Report and associated technical memorandum • Preparation of all required Conditional Letters of Mapping Revision (CLOMR) application documents The City will conduct submittal plan reviews for 30%, 75%, 90% and 100% (Final) designs to meet local standards and submittal requirements for capital improvement projects. Tetra Tech will prepare all materials necessary with oversight from the City for permitting submittals including but not limited to: • Review and approval of USACE Section 408 permit and associated reports along with Endangered Species Act compliance and National Environmental Policy Act (NEPA) review and determination. • Submittal of Conditional Letters of Mapping Revision (CLOMR) application for review and approval to FEMA and associated application documents. Once all federal and agency review processes and permits have been reviewed and approved comments from these reviews will be incorporated into the PS&E package. Project Work – Upcoming Currently construction is planned for a subsequent phase of work forecasted to begin May of 2024 and go through May of 2025. Tetra Tech’s services are forecasted for work in phase 4 of this project. Subsequent phases of work will be determined as needed. Phase 4 – Construction Support Once the 100% PS&E package is finalized and appropriate permits obtained the project will be posted for bid in April of 2023. During which time Tetra Tech will provide bidding support through May of 2023. Once a contractor is selected Tetra Tech will provide construction engineering support. Construction is forecasted to begin May 2023 and go through May of 2024.