waw-lpo-multi1_plans_IFB.pdf

This document is a comprehensive set of Plans for Proposed Project specifications and detailed construction drawings for the Little Pend Oreille National Wildlife Refuge Culvert Improvements project in Stevens County, Washington. The project, designated WA FWS LPO MULTI(1), involves culvert replacements, stream rehabilitation, and earthwork across multiple construction schedules totaling approximately 0.58 miles of roadway improvements.

The project encompasses eight construction sites with three primary schedules: Schedule A (0.15 miles), Schedule B (0.20 miles), and Schedule C (0.23 miles). Key construction activities include removal and replacement of existing corrugated metal pipe and pipe-arch culverts with precast reinforced concrete box culverts and structural plate pipe-arch structures; implementation of fish passage and stream habitat improvements; erosion and sediment control; drainage improvements; and permanent and temporary traffic control measures. Specific deliverables include precast concrete box culverts ranging from 11 to 20 feet span with 9-foot rise, structural plate pipe-arch culverts (14-foot span, 7-foot-3-inch rise), placed riprap (Method A, Class 3), streambed material conservation and realignment, fish passage boulders, rock weirs, log barriers and deflectors, rootwads, and mitigation plantings including willow pole cuttings and turf establishment. Construction includes temporary stream diversion, fiber roll erosion control, temporary and permanent traffic control signage systems, and coordination with the Coville National Forest and wildlife refuge boundaries. The design incorporates specifications for construction of roads and bridges on federal highway projects per FP-14 standards, with detailed hydraulic information for each culvert site including design discharges, water surface elevations, and fish species accommodation (Resident Bull Trout) within specified instream work windows (July 1 – September 30).