Dropping Lake Levels Mean Rising Water Quality Issues

As lake and river levels throughout the state drop due to the intense 13-month drought, concerns about the quality of water supplies in Texas cities are growing.

“One noticeable thing is that our water quality has gone down some,” said Matt Irvin, the utilities director for the city of Odessa, whose water supply contains a relatively high amount of dissolved solids. As water evaporates and little inflow replenishes the lakes, he said, "the salt content begins to concentrate a bit more."

Irvin said it wasn't a significant problem for Odessa yet. But in Robert Lee, a small town about two hours east of Odessa, a resident told Reuters that the tap water, which comes from an almost-dry lake near town, "tastes ugly and it stinks."

In Austin, Jason Hill, a spokesman for Austin Water Utility, said that water quality was not an issue. However, “we have seen some more persistent algae problems in Lake Austin water than we normally observe,” Hill said, speaking about Austin's water-supply lake (which is itself supplied by Lakes Travis and Buchanan, which combined are at 38 percent capacity).

Stagnant water — which the drought has helped cause through diminished inflows into the lakes — encourages algae growth, an issue Midland (which shares water sources with Odessa) has struggled with, too.

Hill said Austin Utility is adding a chemical called Powdered Activated Carbon to help with the algae issue, which adds cost to the water-treatment process. “Other than that, we are able to treat the water as we normally do, but that could change with further worsening of the drought situation,” he said.

Water quality is also a big worry for fish, many of which are turning up dead in Texas' lakes and streams.

A Baylor University study released this summer shows that drought conditions worsen the toxicity of chemicals in streams and could be harmful to aquatic life. Ryan King, a co-author of the study and an associate professor of biology at Baylor, says concentrations of some chemicals that are often released from wastewater treatment facilities are usually harmless to plants and animals at normal pH levels but can become toxic to these organisms at high pH levels.

“This is an important issue for Texas because the state is likely to see more frequent and more severe droughts in the next few decades,” King said. “This, coupled with a fast-growing human population that will need more water and produce more wastewater, suggests that drought-induced risk of toxicity will increase and will occur in more places in Texas in the near future.”

For now, amid the worst single-year drought in recorded state history, “our streams are very concentrated," said Andrew Sansom, executive director of the Texas State River Systems Institute. Half of all of the rivers in Texas are flowing at 10 percent or below normal flow, he said, and "the biggest threat is that there is so little water that there isn’t enough of it to dilute the stream."

For towns and cities, water quality worries will persist if the drought continues to worsen as projected.

A water quality study completed by the Brazos G Regional Water Planning Group as part of its 2011 water plan found that water quality in three reservoirs upstream of Possum Kingdom Reservoir — Fort Phantom Hill Reservoir, Lake Graham and Lake Stamford — would “considerably degrade” as reservoir levels dropped during the drought because of increased concentrations of “various constituents."

“The water quality during those times would be so degraded that advanced treatment measures, like reverse osmosis, would be required to produce clean supplies of sufficient quality,” said Samantha Heng, a Texas Water Development Board spokeswoman.

The worsening water quality could also become a concern for high-tech manufacturers in Central Texas, given their need for huge amounts of very pure water for memory chips. “Obviously, the higher the water quality, the better it is for us,” said Catherine Morse, a spokeswoman for Samsung Austin Semiconductor. “But even when the water quality is high, we treat it anyway."