Austin, TX collects assessment data to monitor its natural creeks, aquifers and lakes. All data are made available by the city through data.austintexas.gov. This site scrapes data off its Water Quality Sampling Dataset for the current year, and displays them on Google maps, if appropriate.
A Few Parameters in the Water Quality Sampling Dataset
There is a total of 3088 parameters under 96 parameter types monitored in Austin creeks, aquifers, and lakes, according to the dataset. Some of the parameters have been discontinued. A few of those that might be interesting to see are: