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KITTITAS COUNTY <br />DEPARTMENT OF PUBLIC WORKS <br />PUBLIC WORKS — BOARD OF COUNTY COMMISSIONERS <br />STUDY SESSION STAFF REPORT <br />STUDY SESSION DATE: November 12, 2019 <br />TOPIC: Liberty Bridge at Swank Creek <br />ACTION REQUESTED: Direct Staff Pursue Temporary Access Options <br />LEAD STAFF: <br />Mark R. Cook <br />RECOl MffiNDATION: <br />Direct that staff evaluate options allowing Forest Service (FS) timber sale vehicle access <br />over the load limited bridge in Liberty at Swauk Creek. <br />BRIEFING SUMMARY: <br />• The existing bride in Liberty at Swauk Creek is load limited. <br />• The FS desires conducting a timber sale in Liberty in the near future. <br />• FS and County staff are having conversations regarding potential options <br />supporting access to the desired timber sale. <br />BACKGROUND: <br />Abutments at Liberty Road-Swauk Creek Bridge have been deteriorating for some time. <br />In December 2017, Public Works requested an Administrative Load Rating be <br />established for the bridge. KPFF (PW structural engineering consultant) developed the <br />requested load rating stipulating that "Overload trucks shall not be permitted to use <br />bridge". The load rating is problematic for supporting the proposed FS timber sale. <br />DISCUSSION: <br />Public Works maintains an inventory of temporary bridges that provide load rating up to <br />93,000 pounds. These bridges can be configured to meet the load demands of the FS's <br />desired timber sale. Conversations with FS staff confirm timber We duration's can <br />extend to five years or more. The reality of the sale duration provides additional <br />challenges to supporting heavy loads over a temporary bridge. <br />PW is seeking Board of County Commission approval to expense County resources <br />defining potential options supporting access to the proposed timber sale. PW proposes: <br />site investigation, project coordination with FS staff, consultation with PW structural <br />engineers KPFF, preliminary engineering and cost analysis along with the preparation of <br />a preliminary feasibility report. This proposed work program will define viability of <br />temporary bridge deployment and the financial resources necessary supporting access to <br />Page 1 of 3 <br />PUBLIC WORKS BOARD OF COUNTY COMIVIISSIONERS WORK SESSION STAFF REPORT <br />