WCHC26_ADVERTISE_PLANS.pdf

This is a set of technical drawings and specifications for the West Coast Hopper Maintenance Dredging 2026 project under Solicitation No. W9127N26BA003, issued by the US Army Corps of Engineers, Portland District.

The project encompasses maintenance dredging operations at multiple locations along the West Coast, including the Mouth of the Columbia River (RM 3+00-105+20), Lower Columbia River, East Sand Island, and various locations in California and Oregon. The drawings provide detailed hydrographic surveys, bathymetric data, and placement site layouts for dredged material. Key project sites include the Lower Columbia River with example acceptance areas and upstream/downstream limits clearly marked, East Sand Island with placement grid cells, and deeper water placement sites (DWS-05 and DWS-14) with specific depth and grid specifications. The documentation includes baseline and breakline alignments with cross-sectional profiles at multiple stations (54+00 through 78+00), showing pre-dredge conditions and design elevations. Acceptance areas are defined with specific depth parameters, and the drawings indicate both nearshore and offshore dredging/placement zones with clearly marked example acceptance boundaries. Cross-sections detail required dredging depths measured from established baselines, with reference to December 2025 survey data. The project includes specifications for construction beach fill stations, material placement procedures, and environmental compliance measures including avoidance areas. Coordinates are provided in the Horizontal Datum of NAD 1983 and reference NOAA statistical data.