Laserfiche WebLink
City of Tukwila My WebLink |HelpSearch Tips |About |Sign Out
format as the initial set of alternative figures and costs provided by Otak under a previous contract. The options <br />will consist of the following crossing structures: <br />(E) In -kind 9-Foot Dia. CMP <br />(F) Upgraded 10-Foot width box culvert <br />(F) Upgraded 15-foot width box culvert <br />Each alternative will include corresponding inlet and outlet structures (head, apron and wing walls) and the figures <br />will also demonstrate the channel section and streambed approaching the structures, and channel section and <br />streambed through the crossing structure. The intent is to establish an alternate in -kind replacement option, <br />comparable to the retrofit option, that the City would be responsible for, and two incremental upgrades to be <br />considered for cost sharing with other parties to improve fish and debris passage. <br />Otak will prepare a narrative description with the concept plan for each alternative documenting design criteria, <br />design considerations, constructability issues, and maintenance issues. <br />TASK 6.7 DELIVERABLES <br />• Concept plans and cost estimates for each of the Alt 3 optional culverts (draft and final, electronic pdf) <br />• Concept Design Narrative for each alternative for future Phase II Alternatives Analysis Report (draft and <br />final, electronic .docx format) <br />TASK 6.7 ASSUMPTIONS <br />• City will provide one list of consolidated comments on the draft concept plans, cost estimates, and narratives. <br />Comments will be addressed and incorporated into the final conceptual design plans, estimates, and <br />narratives. <br />6.8 Preferred Alternative - Plan, Estimate, and Construction Schedule <br />Otak will conduct review meetings with the City to compare the new Alt 3 options developed under Task 6.7. <br />Through the meetings and review comments from the City, a preferred alternative will be selected for <br />development of schematic plans, construction cost estimate, and construction schedule suitable for grant funding <br />applications. The schematic plans will show proposed confluence habitat improvements for the preferred <br />alternative and will incorporate the upstream habitat improvements being developed under a separate task. <br />Cross -sections will be developed to show the grading for habitat enhancement upstream and downstream of the <br />crossing structure. The schematic plans are anticipated to include the following sheet list developed in AutoCAD: <br />The schematic design plans are estimated to include the following sheets developed in AutoCAD: <br />o Overall Site Plan <br />o Culvert Plan and profile <br />o Site Cross -Section Details <br />o Culvert Inlet and Outlet Details (Headwalls and retaining wall structures) <br />o Habitat Landscaping and Large Woody Material Plan <br />o Channel Section Details <br />The cost estimate and construction schedule will be developed in the same format as the initial Alt 3 cost and <br />schedule developed by Otak under a previous contract. <br />TASK 6.8 DELIVERABLES <br />• Preferred Alternative 3 Option Schematic Design Plans (draft and final, electronic pdf) <br />• Preferred Alternative 3 Option Construction Cost Estimate (draft and final, electronic pdf) <br />Otak — Scope of Work <br />51 <br />