Colorado River Watch Network

Frequently Asked Questions

What do you do with the data?

Once the data is received from the monitors, professionals review it for areas of potential concern, then the data are entered into the CRWN database and are available on the CRWN water quality data site. The test results collected by CRWN are used as an early warning system for potential threats to water quality.

If an area of concern is identified, the information is communicated to LCRA water quality staff, who take appropriate follow-up action. The results also are sent to the Texas Stream Team, a statewide volunteer monitoring program, on a quarterly basis. Texas Stream Team places the data on its website periodically, and communicates any areas of concern to the Texas Commission on Environmental Quality (TCEQ).

What is a stream segment?

These are streams and water bodies that have been individually defined by TCEQ and assigned unique identification numbers. Because they have relatively similar chemical, physical and hydrological characteristics, segments provide a basic unit for assigning site-specific standards and for applying water quality management programs.

Is the historic information important, or just the most recent data?

It’s important to understand that water quality can vary simply because local conditions may change. In fact, the results of a single measurement of a waterbody’s properties are actually less important than looking at how the properties vary over time. Some CRWN sites only contain historic data while others are active and reporting currently. Some of the data may reflect different detection levels or methods of sampling procedures that have changed over the years.

Where can I find basic information on water quality in my area?

Visit for LCRA’s water quality data for the lower Colorado River basin and the Texas Clean Rivers Program’s water quality data for the Upper Colorado or the Concho River basin.

How can I tell if a water body is polluted?

The answer depends on many factors, including the intended use of the water, such as drinking, fishing or boating. For example, after a heavy rainfall, the water may be unsafe for close human contact. That’s because heavy rain will increase the amount of runoff, potentially causing a spike in bacteria and pollutants.

Under the federal Clean Water Act and the Texas Water Code, TCEQ has the authority to develop and enforce statewide surface water quality standards. For each water body, TCEQ defines how the water will be used and sets upper and lower limits for common water quality criteria. The definition is based on four categories: protection of aquatic life; fishing; contact recreation such as swimming; public water supply. (A water body may be assigned more than one of these uses.)

Bodies of water that don’t meet state water quality standards are found on the state’s 303(d) List, which refers to a section in the Clean Water Act.

How did CRWN begin?

In 1988, a handful of Austin citizens, teachers, and students began sampling water along a tributary of the Colorado River. Within two years, they had expanded to about 20 sites along the Colorado. The volunteers’ work turned up potentially problematic levels of phosphate, which at the time was commonly found in laundry detergents. Phosphates encourage algae to grow, and when in excess can rob the water of oxygen.

In 1991, the group presented their findings to the Austin City Council, which led to Austin passing the first ban in Texas of detergents containing more than 0.5 percent phosphate. By December of the same year, volunteer monitors in Smithville, La Grange and Wharton successfully lobbied their city councils for similar ordinances.

In 1992, LCRA began to manage the CRWN program, and helped expand monitoring sites throughout the lower Colorado River watershed from Brownwood to the Gulf of Mexico. The program has grown into a sophisticated system of more than 120 certified volunteers spread across the basin.