2021-2 SWM Culvert Replacement and Drainage Improvement

This contract awards Snohomish County the design‑build replacement of existing storm‑water management (SWM) culverts and associated drainage improvements across the county. The scope includes site preparation, earthwork, installation of ductile‑iron culvert pipes (4‑in., 6‑in., 24‑in., 30‑in.), temporary stream diversions, road grading, gravel and ballast placement, stream‑bed restoration, erosion‑control measures, and temporary traffic‑control facilities. The winning vendor, Redtail LLC, submitted a unit‑price bid totaling $1,264,401.12, which is approximately 18 % below the engineer’s estimate of $1.42 M. • Replacement of culverts (various diameters) and associated drainage structures • Comprehensive earthwork, grading, and material placement (gravel, ballast, borrow) • Erosion control, temporary stream diversion, and traffic‑control installations required for safe project execution.