Specifications include, but are not limited to: • Site Evaluation: Perform an in-depth site assessment to determine stream reach characteristics, channel composition, vegetation, bridge alignment, etc. for both projects. County will provide survey control data (horizontal/vertical datum) and existing right of way information. The Consultant shall provide all provide topographical survey required for both projects. • Concept Options: Consultant will conduct a hydrologic and geomorphic analysis using available LiDAR, topographic survey data, SSURGO soils mapping, as‐built drawings, previous upstream bank protection engineering reports (Senn Rd.), aerial photos, and findings from the field reconnaissance to identify processes contributing to existing scour conditions and estimating likelihood of future channel adjustments (i.e., long‐term degradation and lateral migration). Consultant will develop three scour mitigation countermeasure design alternatives (using methods from FHWA HEC 18/23, WDFW, and/or WSDOT) and provide probable costs estimates for construction at both project sites. • 100% PS&E: After preliminary plan options are reviewed by Lewis County (and WSDOT Local Programs), the Consultant shall advance the selected repair plans to 90% PS&E. -- to apply for all required environmental permits and identify construction easement areas/staging (right of way acquisition by Lewis County). Following Lewis County’s review/approval of 90% PS&E, provide 100% PS&E to advertise for contractor construction. Note, due to outside funding authorization there may be a significant time lag from 90% plan submittal by the Consultant until 100% PS&E is requested.
