Image for Lake Dunlap Spillgate

GBRA Lake Dunlap

Guadalupe County, TX

Guadalupe-Blanco River Authority (GBRA)

May 2021 - December 2023

$35 million



The project will rebuild and replace all three 93-year-old spill gates on Lake Dunlap Dam. This dam is located on the Guadalupe River between Seguin and New Braunfels, TX in Guadalupe County. In May 2019, one gate collapsed due to aging steel supports. This failure drained the lake by 12 feet, halted power production, and plummeted local property values. To get the two-year project going, Zachry built a trestle in front of the existing dam, allowing crane access to install a temporary coffer dam and reconstruct the dam with new hydraulic gates.

Work will consist of a 15-foot widening of the existing dam structure to include new gates and a new overhead gantry crane for future dam maintenance. A new concrete 220-footwide emergency spillway will be added to the east side of the dam. New armoring consisting of both concrete and rock riprap will also be added along the existing 1,500-foot-long core wall extending on both sides of the dam.