Lake Dunlap Dam Failure Footage Video

Last Tuesday (May 14, 2019), one of Lake Dunlap spillway gate dams collapsed. The 38 seconds video went viral on Facebook and other social media.

The video went also viral on conservationist social media, because pro-dam business used to claim that spillway based dams, also known as run-of-the-river hydroelectric systems, never collapse. However, this event shows that spillways do collapse, and reminds us the importance of dam failure analysis.

Where is Lake Dunlap located?

Lake Dunlap is a reservoir on the Guadalupe River near the town of New Braunfels in Guadalupe County, Central Texas. It is about 45 km NW San Antonio Texas.

The reservoir was formed in 1931 by the construction of a dam to provide hydroelectric power to the area. Management of the dam and lake was assumed by the Guadalupe-Blanco River Authority on May 1, 1963.

Why did Lake Dunlap spillway collapse?

There is no official explanation yet. However, initial thoughts suggest aging structural steel to have caused the collapse.

The Guadalupe-Blanco River Authority said it’s committed to finding a way to replace spill gates at all its aging dams but noted that this depends on its ability to secure funds for the improvements, which will cost millions of dollars.

There were previous spillway collapse cases

A similar spill gate collapse occurred in 2016 at Lake Wood, 4 miles west of Gonzales, after structural steel inside that gate failed.

After the Lake Wood incident, the river authority consulted engineers on how to best repair or replace spill gates in the hydroelectric system. It ultimately decided to replace all aging spill gates with a more modern gate system.