District details plans for lake

By Bob Buckel | Published Saturday, May 18, 2013

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If your home, your weekends, your life or your livelihood center around Lake Bridgeport, it’s easy to see how you might get a little paranoid.

All the reservoirs in the chain of lakes managed by the Tarrant Regional Water District are low – after all, North Texas is in the third year of a historic drought.

PARCHED LAKE BOTTOM - Cracked, dry ground and stressed plants are visible in an area that used to be underwater near Wise County Park at the north end of Lake Bridgeport. Messenger photo by Joe Duty

PARCHED LAKE BOTTOM – Cracked, dry ground and stressed plants are visible in an area that used to be underwater near Wise County Park at the north end of Lake Bridgeport. Messenger photo by Joe Duty

But the lake levels tell a story:

  • Richland-Chambers, in Navarro County, is just under 6 feet low;
  • Cedar Creek, in Kaufman and Henderson counties, is 3-1/2 feet low;
  • Lake Arlington is just a few inches below its normal conservation level;
  • Benbrook Lake and Lake Worth are both about 2-1/2 feet low;
  • Eagle Mountain Lake, just down the chain from Bridgeport, is almost 5 feet low.

Lake Bridgeport? It’s nearly 17 feet low.

Richard Ellis, Bridgeport Lake superintendent, said all but two public boat ramps have already been closed due to low lake levels.

“It’s Wise County Park and Runaway Bay, and that’s it,” he said. “We’ve closed the public ramp at the dam, and that was a very popular ramp.

“You go out to Wise County Park, and it’s just incredible. Vinchner Creek is just dry.”

The problem is “no appreciable rainfall in four or five years,” he said. But for those inclined to conspiracy theories, Bridgeport’s low level provides plenty of material.

“We hear all the rumors, every day,” Ellis said. He said the major ones are:

  • “We’re just going to close the lake.”
  • “We’re going to drain the lake to kill zebra mussels (which we don’t have).”
  • “We’re going to drain the lake to work on a pump (which we also don’t have).”
  • “We’re going to drain the lake to work on the dam (which we’re not).”
  • “We’re going to drain the lake to allow Devon to get out to work on Rattlesnake Island.”

In fact, the level of all the lakes is carefully managed in an effort to balance a host of water demands in the most efficient way possible. Among the factors weighed are rainfall, soil porosity, evaporation and the legally binding contracts TRWD has with a host of entities who use water.

“It’s a complicated shell game,” district spokesman Chad Lorance said. “The key is, they’re water supply lakes. People use them for recreation, but that’s not the priority.”

TRWD hydrologist Laura Blaylock said a few decisions have been made on how the lake will be managed this year.

“With the lake already 14 to 15 feet low, we’re going to release less, and we’re going to release it earlier,” she said.

TRWD is permitted to take 78,000 acre-feet of water from Lake Bridgeport each year, but this year they only plan to release about 20,000 acre-feet. That started around May 1 and will come to an end around the first of July.

In 2011 and 2012, the district took its entire allotment from Lake Bridgeport. Blaylock said there have also been years when they’ve taken none.

It’s hard to remember, but at the start of 2011 all the lakes were virtually full.

“2011 was the worst single drought year we’ve ever had, all the way back to the 30s,” Blaylock said. “We went from chock-full to lower than ever – even in the 50s – in one year. 2012 was not as dry, but it was still exceptionally dry.”

Despite a few scattered rain showers over the past few days, “the drought has not gone away,” she said.

“We got about an inch in the lake, but not enough to provide any runoff,” she said. “The soil composition is such that water just soaks right in. We would need 9 inches of rain to really fill up the soil and start pushing water through the creeks into the reservoir.”

Bridgeport pays a price for being the westernmost lake in the chain. The rocky, sandy soil is less prone to runoff than the clay soils of East Texas. In fact, the Upper Trinity watershed that feeds Lake Bridgeport is in the heart of a recharge zone for an underground aquifer.

Blaylock said when they release water from Lake Bridgeport, almost a third of it soaks into the ground before it gets to Eagle Mountain Lake.

And of course, the farther west you go, the less rainfall you see.

“It’s been really dry in the upper watershed,” Blaylock said. “That’s why we get water from the east. I-35 is really the dry line.”

TRWD gets more than 80 percent of its water from its two easternmost lakes – Richland-Chambers and Cedar Creek. Just a few years ago, they completed a pipeline and pumping system to move water from those lakes through Lake Benbrook, south of Fort Worth, into Eagle Mountain Lake.

The idea is not to make it a constant-level lake or enhance recreation. The idea is to take pressure off the dry western watershed.

“Eagle Mountain is 5 feet down, and we’ve been pumping water from East Texas since last October,” Blaylock said. “The pipeline into Eagle Mountain benefits Bridgeport because we don’t have to draw as much from Bridgeport.”

Everything a pipeline can do is literally a drop in the bucket compared to what Mother Nature could do with a nice rain.

“We’re pumping 100 million gallons a day into Eagle Mountain, and all we’re doing is slowing the fall,” she said. “We’re not filling it up.”

And in addition to the welcome, if spotty, rains last week, another trend was spotted for the first time as the temperature topped 90 degrees.

Evaporation takes a toll on the lakes far beyond drinking, drilling or any other water use.

“In the summer, 125 million gallons evaporates on an average day,” Lorance said. “At peak demand, our customers take maybe 20 million gallons per day.”

Lake Bridgeport supplies water for the cities of Bridgeport and Decatur, Walnut Creek Water Supply District and a couple of power plants. There are also three sizeable mining operations in western Wise County that have permits to draw specific amounts of water from the lake for their operations, but Ellis said they seldom tap the lake because they have sizeable reservoirs of their own.

The problem is simply a lack of rain in the 1,100 square miles of watershed that should be feeding Lake Bridgeport and Eagle Mountain Lake.

“Bridgeport and Eagle Mountain were built as a system, designed to work together to get the best yield out of the whole watershed,” Blaylock said. “We’ve done analyses in the 30s, the 50s, the 70s – and that continues to the present day. There were some awful droughts in those years.

“That’s when you analyze, during the critical periods. You want to know how it’s going to look at the periods of most stress.”

All the historical data confirm that this is one of those periods. That long-term perspective indicates that things will indeed get better within a few years – but that’s little comfort to a dad with a jet-ski, looking for a place to launch.

TRWD cannot control the weather, but one thing that has helped, and will continue to help, is restraining water usage.

When the system is down to 75 percent of storage capacity, it automatically triggers a set of watering restrictions by the cities and other entities in the district, Blaylock said.

“One thing we really have to stress is our very successful conservation program,” she said. “We have reduced demand up to 22 percent. It’s astounding how successful the conservation program is, and we plan to continue with that.”

The restrictions limit the days and hours when people can water. A disparity between what those on the lakefront were doing and those across the street, farther back in the housing development were doing prompted the district to close a loophole last year. Now, everyone will be under the same restrictions.

“It’s a drop in the bucket, but it was creating problems among neighbors,” Ellis said.

“And the reality is, when you water in the middle of the day you’re losing up to 70 percent of your water to evaporation,” Blaylock added.

No one knows if Lake Bridgeport will get enough rain and runoff to recover from 17 feet low anytime soon. That rests with an authority higher than TRWD. But at least after July 1, they won’t be letting any more water out.

“Her plan is going to stop the bleeding for me,” Ellis said. “We’ll still have evaporation, drought and local usage, but it won’t be running down to Eagle Mountain.”

TRWD is one of the largest raw water suppliers in Texas, providing water to more than 1.7 million people.


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