In the late 1980s and early 1990s, Barr and the U.S. Army Corps of Engineers implemented a $40-million stormwater management plan for the BCWMC and the City of Minneapolis as the local sponsor. The plan included replacing the two-mile conduit to the Mississippi River with a combination of a double-box culvert and bedrock tunnel. This tunnel system provides conveyance and flood control for Bassett Creek and drainage for portions of Interstate Highways 394 and 94. This was in addition to implementation of several flood control project features along Basset Creek, including control structures, crossings, channel improvements, a fish barrier dam, and culverts.
Since construction, Barr has provided periodic inspections and designed repairs of the flood control project features and tunnel system for the BCWMC and the City of Minneapolis. The tunnel inspections consist of evaluating the tunnel for cracking, settlement, seepage, infiltration, concrete deficiencies, exposed rebar, and foundation issues. For example, Barr inspected the 6,100-foot bedrock tunnel in 2020 and the entire 5,600-foot double-box culvert section (cut and cover tunnel) most recently in 2019. Next, Barr will assist the BCWMC with implementing recommended repairs.