Project header_Spillway Remediation

As part of a spillway remediation project in the Southeastern U.S., Barnard is enlarging an existing auxiliary spillway and constructing an innovative, non-mechanical means of controlling the spillway: a Fusegate® system composed of individual concrete gates designed to tip over at certain hydrological thresholds to further increase spillway capacity.

The spillway remediation project involves the modification of a high-hazard dam structure that, in its present configuration, is overtopped at approximately 40 percent of the Probable Maximum Flood (PMF). The remediation will enhance the safe discharge of inflows associated with the PMF. Barnard is expanding the auxiliary spillway through drilling, blasting, and rock excavation. The excavated material is either hauled away or loaded onto barges and deposited within the lake. As the drill and blast activities progress, Barnard is installing rock bolts, wire mesh, and rock anchors and overseeing foundation grouting. Once drill and blast activities are completed, the Fusegate® structure and concrete training walls will be constructed at the mouth of the auxiliary spillway. The final scope of work on the project will involve demolishing approximately 10 feet of the existing dam, which will be built back up with a concrete PMF wall.


Location: Southeastern United States

Owner and Engineer: Confidential

Contract Type: Fixed Lump Sum

Status: Currently under construction


  • 360 rock slope anchors and bolts
  • 68 foundation grouting holes drilled to 35 ft. deep
  • 156 tiedown anchors and dowels
  • 6,700 CY of concrete
  • 30,000 SF of wire mesh rockfall protection
  • 6 concrete Fusegates®
  • 600-ft. x 7-ft., 6-in. PMF wall
  • Limited laydown space
  • Remote location
  • On-water work

240,000 CY of rock excavation

3,100 barge loads of rock

86,000 LF of precision presplit

Project footer_Spillway Remediation