Frequently asked questions

Colorado River Watch Network

​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 the Colorado River Watch Network 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 are also sent to the Texas Stream Team statewide volunteer monitoring program on a quarterly basis. Texas Stream Team places the data on its Web site periodically, and communicates any areas of concern to the Texas Commission on Environmental Quality (TCEQ).

The results provide supplemental information to LCRA professional monitors, and are used in the monthly LCRA Water Quality Index. The water quality index report provides a measurement of water quality that is distributed to news media in 14 riverside communities in the lower Colorado River basin. Volunteer monitors also provide cumulative baseline data from sites that may otherwise be unassessed.

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 water body'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 learn more about water quality and other volunteer monitoring programs?

Where can I find basic information on water quality in my area?
If you live on or near the lower Colorado River, see State of the River. This is where LCRA publishes its monthly water quality index with data from 14 key locations along the Colorado River and tributaries.

If you live along the upper portions of the Colorado, see the Texas Clean Rivers Program's water quality data for the Upper Colorado or the Concho River basin at You can also get data on most all Texas water bodies at TCEQ's water quality viewer​.

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, the Texas Commission on Environmental Quality (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. See the latest ​draft of the 303(d) List found on TCEQ's site.