Erath County’s flood-control lakes are doing what they were designed to do, controlling the deluge of water received over recent days.
Tony Huffman, district conservationist with the office of the USDA Natural Resources Conservation Service, said Erath County has 76 “conservation lakes” in four separate watersheds.
During the Special Meeting for Emergency Preparedness called by Erath County Judge Tab Thompson Wednesday afternoon, Huffman said the lakes can still flow in tremendous amounts of water at this point.
Each lake is designed for a “50-year-storm,” Huffman said. “The watershed plans are Paluxy, North East Tributaries into the Leon River, Greens Creek and the Upper North Bosque.”
What does that mean for Erath County residents?
A 50-year storm for the county would mean 8.2 inches of rainfall in a 24-hour-period, according to Huffman.
So far, this summer, that hasn’t happened.
More than 8.2 inches in twenty-four hours could mean water would start running around the dam with no control into the emergency spillway.
“It might rain more and not even get there,” Huffman said. “Because there is a safety factor built into each.”
Huffman said his employee looked at 8 or 10 lakes Tuesday and he personally inspected the one behind Hope, Inc. on Highway 377 and what could be seen from the road looked to be in good shape.
“We did not shoot them with an engineering level,” Huffman said. “We just did a visual. Where we could drive by, we could see them flowing water.”
Huffman said the lakes have anywhere from 6 to 12 feet before they reach capacity.
Some had expressed concern that a few dams on the lakes were nearing 50 years of age and could possibly breach should the county experience more downpours.
Huffman said he’s not too concerned over that possibility because all the lakes are functioning correctly. They are not built in a series. Even if one did break it would not cause a domino effect nor would it cause a wall of water “ like in a movie,” he said. “It would just be more water into the main tributary of the river. If one broke it would cause the crest of the river to be slightly higher than with the dam in place.”
The systems are designed to release water, Huffman said.
“Everyday that we don’t get big heavy rain - two inches in an hour - we’re in that much better shape,” Huffman said. “Just mist will still soak into the ground somewhat.”
Should a dam become compromised or an emergency spillway fail it would erode a “V” cut and flow water out which would cause a rise in water that would inundate things but not a wall of water, Huffman said. Huffman mentioned grass cover prevents a lot of erosion. And the emergency spillway is designed to protect the integrity of the dam.
During the meeting, Erath County Commissioner Randy Lowe, expressed concern over the Everett, Jack Berry and Copeland lakes. He felt over the years the spillways were filling in and when looking with binoculars he said, “It looks like water is starting to go the opposite way. I’ve got real concerns with it but my eyes may not tell the truth on it,”
Huffman said the lakes are inspected annually and none have significant problems. Most of the lakes hold water for approximately twenty days before they go back to the principal inlet level, Huffman said.
“They are emptying as we speak, which is a good thing,” Huffman said.