Bacterial Source Tracking

The Meadows Center conducted initial bacterial source tracking near downtown Wimberley, in partnership with the City of Wimberley and Texas A&M University. This effort provided additional information about the contributions of bacteria to Cypress Creek. For additional information, please email



Sampling Event 1

These are the initial results from our first round of bacterial source tracking, which uses DNA to identify sources of bacteria in water samples. Our first samples were collected in August, during rainy conditions both upstream and downstream from the downtown RR12 Bridge in Wimberley. It is important to note that no conclusions can be made from the results of a single sampling event. It is also very important to understand that bacteria concentrations tend to be greater and come from more diverse sources during a rain event. This is because bacteria and other pollution is picked up and carried by rainfall flowing across the watershed and into the creek.

2017 Cypress Creek Bacterial Source Tracking: Project Update #1

2017 Cypress Creek Bacterial Source Tracking- Sampling Event #1 Findings

Downstream RR12 Test Report

Bacterial Source Tracking Results Collected 08/07/2017

In addition to bacteria that might normally be in the creek, bacteria from the landscape is added to the water column. The next two sampling events will be collected during dry conditions and the three sets of results will be compared. The initial sampling results showed multiple contributors of bacteria at the upstream location, including livestock, domestic animals, non-avian wildlife and feral hogs. Sources of pollution at the downstream location include raw sewage from several sources including human, cattle and feral hogs. These results are not unusual – multiple sources of pollution were likely carried into the creek by rainfall runoff.

Human bacteria could be coming from saturated aerobic septic systems, leaking tanks (rainfall can leak into tanks) or tanks can collect and release water from saturated substrates, as often is the case during rain events. Another source could be septic leakage directly into the creek. Results from the next two sampling events should provide additional information and are expected in November and January.



Sampling Event 2 & sampling event 3

Sampling events were collected on September 12, 2017 and October 16, 2017 during dry conditions and the three sets of results were compared.

The following PDF details: 1) the composition and performance of the current Texas E. coli Bacterial Source Tracking library that was used to categorize the isolates and 2) a summary of the Bacterial Source Tracking results for the isolates.

Cypress Creek Bacterial Source Tracking Results for 09.12.2017 and 10.16.2017.




The following report provides a summary of the Cypress Creek Bacterial Source Tracking study and presents laboratory results from three sampling events conducted by The Meadows Center staff on the following dates:

  • Round 1 – Wet Weather Conditions – August 7, 2017

  • Round 2 – Dry Conditions – September 12, 2017

  • Round 3 – Dry Conditions – October 16, 2017

2017 Cypress Creek Bacterial Source Tracking Study: Cumulative Report.

Texas A&M AgriLife Research - Soil & Aquatic Microbiology Laboratory E. coli concentration and lab sheets for all events.