Austin exploring new ways to look at water quality

A discussion at the most recent meeting of the Environmental Commission revealed that the city is in the process of creating a new way to explain and track how policy decisions impact water quality in Austin.

Since 1994, the Watershed Protection Department has used the environmental integrity index, or EII, which scores quality across 50 watersheds, accounting for 500 miles of creek mainstems. 

That sounds impressive, said conservation program supervisor Andrew Clamann, until you realize that there are about 5,500 total miles of creeks in Austin. The department is currently looking at a new system that more carefully tracks how “drivers” like stormwater controls and land use impact water quality and what solutions will fix water quality issues, even with an expectation that population and pollutants will continue to grow.

To that end, the now city is mining its existing data from the past 30 years of collection and is clustering them by similarities to “crunch the data” using a model that can explain the physical, chemical and biological parameters for 3,000 points in the city (as opposed to the previous 120 sites). The clusters, explained Clamann, will help craft solutions to water quality issues “on the fly” based on the results the data gives.

Presently, the city posts the results of its water quality monitoring online at atxwatersheds.com, making the results for overall quality and more specific categories like habitat quality and water chemistry available to everyone.

“Certainly, we aren’t (updating) it as frequently as we have in the past, because we are moving towards something much better and much more progressive,” he said, noting the generalized information they had been collecting and distributing up until this point was “good for communication, bad for science.” 

The city collects data on creeks annually and will continue doing so, even as the new models come online. Right now, the Watershed Protection Department is waiting for the models to have enough data to be properly calibrated. “Some aspects are ready right now, other aspects might take a year or two. Other aspects might take five or six years before we can get all that math. We’re in this for the long haul; we’ve got the in-house expertise and knowledge to do it,” said Clamann. “It’s going to take time because math.

“We are looking into a very, very big change, not a lot of change in actual data collection per se, but in how we use that data, how we communicate that data and what that data can do for us. It’s much more powerful,” he said. 

As the city works to bring the new model online, data collection for the citywide environmental index will continue, and the city will continue to monitor for a wide array of water quality issues (and potential issues). The monitoring takes into account things like water pH, temperature and conductivity, and the presence of things like nitrogen, phosphorus, arsenic, mercury, pesticides and herbicides. In addition, the city keeps an eye on biological indicators, looking at the ecological diversity, flora and fauna of local waterways.

“It kind of makes my head spin when I start to really get into the details on this,” said Clamann. “The topic of water quality is kind of like the topic of your health … (it’s) complicated.”

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