The saltwater barrier near Tivoli is about 10 miles upstream of the mouth of the Guadalupe River.
Current extreme, dry weather conditions in the lower Guadalupe River Basin have caused a gradual decline in the river’s level as recorded at the GBRA lower Guadalupe diversion dam.
Because a 2 to 4 foot drop in water level is possible from the upstream to the downstream side of the saltwater barrier when the bags are inflated, GBRA is issuing a boating caution for anyone who uses the lower Guadalupe River near Tivoli for water recreation or commercial fishing. Warning signs will be posted and lights illuminated for nighttime conditions.
Attempting to pass through the structure in a boat while the barrier is in operation could result in serious injury, or possible loss of life. Boaters on the upstream side should stay a safe distance away from the structure to avoid being carried downstream by strong currents.
Herb Wittliff, manager of GBRA’s Port Lavaca operations, explained, “The operation of the barrier would prevent the possible intrusion of salty water from the San Antonio Bay system into the fresh water supply, which might occur during low river flow conditions.
“When the fabridam bags are not in operation, the design of the barrier allows normal flows of the river to pass through without restriction, because the bags are completely deflated and lie flat on the river bottom.
“However, when the barrier is activated by inflating the bags, upstream water will ‘pool’ to the desired operating level of 4 feet msl, with most of the water flowing over the bags and downstream to San Antonio Bay.”
The lower Guadalupe diversion dam and saltwater barrier was built in 1965 by GBRA.
The barrier will remain in operation until river conditions improve. While GBRA is aware of the inconvenience to the boating public, operation of this structure is essential to safeguard water supplies for agricultural, industrial and municipal drinking water use.
For more information, contact GBRA’s Calhoun County office at Port Lavaca at (361) 552-9751.