Eckert Road Bridges 2147 and 2148– Boise River and Ridenbaugh Canal, Eckert Road and Boise Avenue Roundabout

Ada County Highway District (ACHD) is soliciting bids for demolition and reconstruction of Eckert Road Bridges 2147 and 2148 spanning the Boise River and Ridenbaugh Canal, with sealed bids due August 19, 2026, at 3:00 p.m. through the ACHD eProcurement Portal. All irrigation and bridge work must comply with the Nampa & Meridian Irrigation District (NMID) Approval Letter dated July 16, 2026.

The scope encompasses demolition of existing structures and construction of new prestressed concrete girder bridges (364 feet over the Boise River with three spans; 91 feet over Ridenbaugh Canal with one span), a single-lane roundabout at the Eckert Road and Boise Avenue intersection, reconstruction of roadway approaches, a multi-use pathway along the west side of Eckert Road, a Greenbelt underpass beneath Eckert Road, modifications to Barber Park driveway access, roadway excavation and embankment, pavement construction, curb and gutter work, sidewalks, retaining walls, drainage improvements, irrigation and utility adjustments, traffic control, permanent signing and pavement markings, illumination, landscaping, erosion and sediment control measures, and environmental protections. Bid quantities include 718 feet of prestressed WF girders for Bridge 2148, 2,148 feet of 74-inch-depth prestressed WF girders for Bridge 2147, and extensive concrete, reinforcement, and roadway components across five bid schedules.

The estimated contract value exceeds $25 million in total bonding requirements. The Notice to Proceed is anticipated October 1, 2026, with substantial completion required by June 21, 2028 (approximately 20 months). Liquidated damages of $12,000 per calendar day apply for failure to meet completion deadlines, with no extensions for weather, utility delays, material procurement, labor shortages, or contractor performance. The contractor is liable for damages from disruption of irrigation water delivery.

Bidders must be licensed Idaho Public Works Contractors (Type 1, 2, or 4) and submit unit-price proposals on substantially all work items. Bid security of 10 percent of total proposal amount is required as certified check, cashier's check, or bid bond. The successful bidder must furnish Performance and Labor/Material Payment Bonds equal to the full contract price, provide commercial general liability insurance of $2 million, automobile liability of $2 million, and statutory workers' compensation with employer's liability of $1 million. Contractors domiciled outside Idaho must bid at a percentage less than the lowest Idaho-domiciled bid per Idaho Code sections 67-2348 and 67-2349.

Geotechnical conditions include fill materials overlying medium to very dense gravels with cobbles, interbedded with sand and clay layers; groundwater at approximately 22 feet in some locations. Foundation design includes driven HP14x117 H-piles at bridge abutments and drilled shafts at piers (4-foot and 6-foot diameter). Environmental authorizations include a U.S. Army Corps of Engineers Nationwide Permit 14 (issued March 23, 2026, expiring March 15, 2031), Idaho Department of Environmental Quality 401 Water Quality Certification (December 16, 2025), and Idaho Department of Water Resources Stream Channel Alteration Permit (expires December 31, 2028) requiring low-flow construction timing, dewatering plan submission at least four weeks prior to construction, and site inspection within 14 business days of completion.

Nine utility companies require coordination, including Idaho Power, Lumen, Sparklight, Zayo, City of Boise, Intermountain Gas, Syringa Networks, Veolia, and the irrigation district. Utility relocations, adjustments, and installations may require approximately 160 working days from Notice to Proceed. Contractors must notify Digline at least three working days before excavation. All work must comply with AASHTO LRFD Bridge Design Specifications (10th Edition) and ITD standards, comprehensive stormwater management requirements, and historic preservation review procedures.

Questions are due August 14, 2026, at 12:00 p.m. Contract award is anticipated within 60 calendar days of bid opening. No federal aid funds finance the project; all applicable state and local sales and use taxes must be included in bid prices.