It's a wet job, but somebody's gotta do it
U.S. Army Corps of Engineers monitors dam, lake
By Richard Zowie
Times Guardian Staff Writer
From its hilltop office overlooking the aquatic vastness of Canyon Lake, the Army Corps of Engineers works toward four goals: monitoring the dam and lake levels, the operation of parks near the lake, recreational programs and boundary line issues on the lake.
Of those four goals, said COE lake manager Tim Horn, the Corps' main mission is flood control and water supply and conservation.
"When it was built, Canyon Lake had two primary purposes: water supply and flood control," he said. "We work to keep the dam in good shape and keep it monitored."
Each day, the COE releases figures regarding the current level of the lake (909 feet above mean sea level is optimal), how much water is flowing into the lake from the Guadalupe River and how much water is flowing out of the lake into the river. Each month they measure seepage and four times a year they check the interior of the dam using a piezometer, which the Merriam-Webster dictionary defines as "an instrument for measuring pressure or compressibility; especially: one for measuring the change of pressure of a material subjected to hydrostatic pressure."
"[The piezometer] tells us if there is any problem inside the earthen part of the dam," said Horn. "If the water level suddenly started rising, it would tell us something's going on."
Horn said the lake elevation level is also measured by a device inside the structure, and another the device transmits the information to various offices.
The COE has a reservoir control office in its district office that decides how much water can be released from the lake and when.
"A lot of times when the lake level goes up in particular when we're not releasing it, we get a lot of calls and questions from people wondering why we're not letting the flood water out," Horn explained. "And the reason is, the number one purpose of Canyon Lake is flood control. That means flood protection, especially for downstream areas. If downstream conditions if they've had a lot of rain there and the conditions aren't at a certain level, then we have to hold the water until those conditions clear out since they would flood if we released the water.
"Canyon Lake is a very special lake due to how it fills up so quickly and the downstream businesses people loving to go tubing," Horn added. "We know there's a lot of economic impact driven by the lake."
Canyon Lake ultimately is managed from the Fort Worth district office of the COE, one of the 41 COE district offices in the nation. The Fort Worth office oversees 25 other Texas lakes in its district.
Of the things that have changed about the lake, Horn said technology has improved along with recreation significantly changing. The COE has built better facilities over the years to accommodate the changes in the recreational industry.
"The industry makes huge RVs now, and we needed to build facilities to accommodate them," he said. "Sites from the 1960s would have a hard time accommodating them. And besides that, what people want in recreational experience has changed."
COE has on staff two full-time park rangers, is about to
hire a third and has four seasonal rangers and two who are temporary and
still in school. The Rangers spent a lot of time going around and educating
the public on safety education. They've been to expositions in Texas, boat
shows and schools to educate the public on ways to prevent drownings and
promote water safety.
Details to be worked out in Canyon Dam gorge
The U.S. Corps of Engineers met June 18 with members of Comal County's Water-Oriented Recreation District and the Guadalupe-Blanco River Authority to discuss plans to develop a gorge under Canyon Dam for recreational and educational purposes.
Canyon Lake COE lame manager Tim Horn described the meeting as "very productive" and said everybody left the meeting with details to get sorted out. They will meet again next month, and Horn said the issue might not be resolved until the fall.