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LCRA poised to begin massive

Monday, November 27, 2000 by

Environmental research project

Plan is to model entire Colorado River Basin

The Lower Colorado River Authority (LCRA) has started work on a plan to create a model of the entire Colorado River Basin. The model will be designed so the agency’s staff can better predict the impact of population growth, increased pollution and catastrophic spills anywhere in the basin.

LCRA General Manager Joe Beal told In Fact Daily, “With Central Texas changing as fast as it is, the Colorado Basin can’t afford to wait and see what will happen when environmental conditions change. We need to be smart enough to know how the river will respond to more people or more pollution, so that we can choose to take the right protective measures. That’s why the environmental model is a high priority for me.”

Environmental managers Ken Manning and Dennis Daniel have started the task by outlining the kinds of questions the LCRA wants to be able to answer quickly, without seeking outside expertise. Daniel said, “Right now, we know a lot about the lakes, a lot about the water quality, but what we don’t have is the predictive capabilities. And that’s what the modeling is intended to do, to give us the ability to look forward rather than just looking at how it is now.”

The LCRA especially wants answers to numerous questions regarding the impact of a spill from the Longhorn Pipeline into the Pedernales River.

The pipeline, running 700 miles from near Houston to El Paso, crosses a number of creeks, streams and rivers, as well as the Edwards Aquifer. It was built in 1950 and is being revamped to transport gasoline, diesel, and jet fuel to markets throughout the southwestern United States. In 1999, LCRA, the City of Austin, and the Barton Springs/Edwards Aquifer Conservation District joined a group of Kimble County ranchers in suing Longhorn to prevent the company from using the pipeline for gasoline without doing an environmental assessment first. (See In Fact Daily, Oct. 26, 1999, Sept. 7, 1999) Longhorn Partners agreed and hired Radian International Corp. to do the assessment. Radian found the pipeline would have “no significant impact” and federal officials have accepted that finding.

LCRA needs scientific model

When Longhorn announced plans to run gasoline through the pipeline, LCRA officials were worried. But lacking a scientific model, they didn’t know how worried they should be. They could only guess how gasoline would move from a spill site in the river through Lake Travis and Lake Austin into the Colorado. Manning explained, “What we want to be able to do is say, if you have 100,000 gallons spill into the Pedernales, then in that 20 miles from where (the pipeline) crosses the Pedernales to where it goes into Lake Travis, how much of it would have evaporated? How much would simply dissolve? And, then, once it got to Lake Travis, what would happen? What is the circulation pattern within Lake Travis itself? We know a lot about Lake Travis’ lake levels but we know almost nothing about how the water circulates within the lake.”

“Radian has done enough of the modeling to show that it would be really bad if there was a big spill,” Daniel said.

After the pipeline’s consultants modeled a spill, the LCRA hired an outside consultant to review their assumptions. “Decisions are being made that we are not equipped to be a part of,” Daniel said. “We believe that LCRA should develop better capabilities to do technical and scientific analysis of what’s going on in our basin, and what might go on with respect to water quality—to have some sound technical underpinnings” for the agency’s positions on various matters.

The LCRA could have used another model recently when one of the City of Austin’s wastewater treatment plants discharged wastewater into Walnut Creek. That discharge put “a significant amount of partially treated sewage into the river,” he said. If the project were complete, the LCRA would have been able to model the effects of that discharge on the river. “There would have been more certainty about the effect and what the fixes might have been,” Daniel concludes.

Manning said, “We released 55 million gallons of water to flush it downstream. The amount of water that we released was totally a judgment call. If we had the kind of tools that we envision, we might have been able to release only half that amount. We released water—which was absolutely what we needed to do. But how much should we have released?”

Manning and Daniel cited variables such as how fast the river was flowing, how much rain was falling, and where, as variables that would have been analyzed to give the LCRA more information about what needed to be done. The models consist of very complex equations written in Fortran. “The work is in taking those various lines of code in physics and applying them to the basins so that they have all the right parameters. And you’re talking about thousands of different parameters, like describing the shape of the lake or the shape of the stream and describing what type of sun might be on it,” Daniel said.

Discharge ban on Highland Lakes

The LCRA also needs more technical data on the effect of wastewater in the Highland Lakes. At present, there is a ban on discharge of wastewater into the lakes. “There is not a good functioning model,” Daniel said, “of the effects of such discharges into the lakes. There will be increasing pressure to look at that discharge ban and whether it is technically defensible from a scientific viewpoint. We believe that the LCRA should be positioned to answer and engage in those debates. This project is intended to help build that foundation.”

Manning said, “Right now they have to irrigate. If developers had their way, they would say, ‘Let us treat it to the highest reasonable standard and let us discharge into the lake. Don’t make us waste all this land irrigating with effluent.’”

“The regulatory landscape today is simply very different than it was 10 years ago. There is an appropriate expectation that regulations will have the kind of technical underpinning that demonstrates that they are needed and can be expected. For example, the Environmental Protection Agency is saying that by 2003 they want to have nutrient standards for both lakes and rivers,” he said. “Part of our goal is to become the acknowledged expert on water quality within the Colorado River, so whenever anything like this comes up, their first instinct would be to pick up the phone and call LCRA and say, ‘Tell us about this.’”

Manning remembered, “In the discussion of the water sale contract, one of the Council Members asked if we could assure that the water quality would be good for the 50- or 100-year time frame to meet the city’s needs. We said we could not provide that assurance. Part of the reason we couldn’t provide that assurance is we don’t have the tools to provide that predictive analysis. The kind of package of tools we’re talking about would have enabled us to respond to that question.”

Manning said, “If we had the kind of tools we’re talking about, we could have said, ‘Well, we assume that the growth in the watershed is going to be 2.5 percent per year. That will increase the loading of the nutrient in the lakes by 5 percent over 50 years. Under these sets of assumptions, here’s what we can expect the water quality to look like in 50 years. Certainly it would be predicated on a longer list of assumptions. That’s what we’re really after, that predictive ability to ask what if questions and come up with technically credible answers.”

Technical modeling could also have an impact on decisions such as building the water line to Dripping Springs. Manning said one of the models he envisions developing would be for runoff. “So whether you’re looking at the Barton Creek watershed, the Walnut Creek watershed, the Pedernales, or whatever, you’d say, okay, what’s the water quality in that creek going to look like if I have x amount of development and this land use? So, that’s model No.1, the watershed model. That feeds into model No. 2, which is the river or the creek. That would feed into model No.3: what happens when that river or creek feeds into a lake?”

Another model would show what happens when the water gets to Matagorda Bay. Manning said, “A number of different models need linkages. We will want to say what are the land use changes in the Pedernales River watershed going to translate into as far as the water quality in Lake Travis. But you’ve got to go through three or four models before you can answer that question. This is not one model. You have a different model for each step in the hydrologic process.”

Daniel added, “In areas like Barton Creek, you have a whole additional layer of complexity, which is the ground water. How does the surface water relate to the ground water and how does that ground water relate to the surface water? It really makes it more complex. Our modeling project should be invisible in how it works to most folks. But what it should do for managers, decision makers and folks who want to know what is going on is give them better knowledge about the system.”

Manning noted that “the gestation of this project has been fairly lengthy. This is a five-to-ten-year project.” It might take a year to produce the first model. Daniel said the next step in the project is securing funding for a detailed design, but he declined to name the pricetag. He said General Manager Joe Beal plans to ask the LCRA Board of Directors for that funding in December.

©2000 In Fact News, Inc. All rights reserved.

Water policy . . . The Policy Advisory Committee of the Barton Springs/Edwards Aquifer Conservation District will meet at the district office Wednesday at 7 p.m. Board President Craig Smith said the committee would discuss whether to ask for changes to the district’s enabling legislation, known as SB 988. The board is interested in building aquifer recharge facilities but cannot do so because any money the district borrows must be repaid within one year. The committee may also discuss changes to district rules regarding drought levels . . . More money in Dripping Springs . . . Dripping Springs received nearly $33,000 in sales tax revenues for the quarter, up more than 56 percent from a year ago, according to the Century-News. Hays County’s quarterly revenues also rose nearly 40 percent over 1999, bringing the county about $523,000 . . . Airport advisors . . . Airport Advisory Board Member Hannah Riddering says the group is supposed to have a special called meeting on the proposal to replace the current board with citizens from specifically-designated segments of the community, but no date has been set. The City Council postponed considering those changes when Riddering and another board member said they had not been consulted on the matter. She said, “Staff is in such a rush (to get the new ordinance) because the reappointments are in January ”. . . Worried about Dick Cheney and the 12th Amendment? . . . Lawsuits in federal courts in Texas and Florida claim that Vice-Presidential candidate Dick Cheney is an “inhabitant” of Texas, not Wyoming. If that is the case, the suits say, the 12th Amendment prevents him from serving along with Texan George W. Bush. Hoping to “debunk the claims of those suits,” the conservative Texas Review of Law & Politics offers ‘ Much Ado About Nothing: Dick Cheney and the Twelfth Amendment,’ available at

© 2000 In Fact News, Inc. All rights reserved.

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