During the substantial flooding of the Missouri River in the summer of 2011, a support structure for one of Omaha Public Power District's large transmission lines became engulfed by the expanding river and experienced extensive scour and wash-out around its foundation. To solve this problem, Hawkins was retained to backfill the scour holes around the foundation with approximately 3,000 tons of sand and construct a sheet pile cofferdam around the entire foundation. The cofferdam was reinforced with large rip-rap around the outside and a gabion blanket on top to further protect the structure from any future flooding.
When flooding devastated Nebraska again in 2019, OPPD contracted with us to repair three transmission structure foundations, this time on the Platte River near Springfield, Gretna and Ashland. We completed road improvements on three miles of access roads in order to safely move our equipment to the structure repair sites. Like in 2011, we built sheet pile cofferdams with structural steel bracing. Granular backfill and partially grouted rip rap filled the cofferdams. A temporary trestle was constructed for crane access to install a cofferdam in the river.
Omaha Public Power District (OPPD)
Homer, NE & Sarpy County, NE
2011 & 2020
Diversified Infrastructure Construction & Repair