Trash In Creeks: A field survey of trash intensity and source types in Austin, Texas

Field Survey Extent and Proximity

More than a hundred miles of creeks were selected to represent the general spatial extent within the city limits (Left Photo) as well as to ensure representation of creeks within all ten city council districts (Right Photo). Sample areas included a mix of residential, multifamily, commercial, park, urban, suburban and undeveloped space within twenty watersheds. Sixteen creeks were sampled in their entirety from the headwater to their confluence with the receiving waterway, however, four creeks were only partially sampled because of their large size, access problems, and extent beyond the City of Austin jurisdiction. As part of the staff assigned to the project, I took part in field work as a team or solo with limited supervision traversing through miles of often running creeks.

Procedures and Results

A rubric, or matrix (Top Left), to visually characterize trash intensity for a one-time snapshot of trash in creeks was developed for the purpose of estimating aesthetic intensity, cumulative volume and time necessary to collect. Variability in rubric interpretation, or error, was limited by utilizing a small number of trained and calibrated staff scientist throughout the survey period. As the assistant project manager and one of the main scientist assigned to the project, I led one of these teams into the field, documenting any findings and reporting all field data.

While the study initially was conducted in response to rising motorized scooters and homelessness within the Austin, more sources were found to contribute to the trash being observed. While homelessness turned out to be a major contributor to the issue, many other occurrences played a role in the current litter problems as seen in the pie chart above on the right.

Assuming the non-surveyed creeks (117 miles of mainstem creeks) within the City of Austin full purpose jurisdiction (city limits) are generally similar to the surveyed creeks, then the total volume and clean-up time can be estimated for the city limits the and extra territorial jurisdiction, shown in on the excel chart I created above on the bottom right.

In the end, 19,467 total data points were collected every 30 feet for 110 miles of 20 creeks around the city.