A major source of Austin s non-point pollution problem results from storm water. When precipitation falls onto urban surfaces, it picks up loose debris, oils, grease, lead-based paints, fertilizers and herbicides, and transports them through storm water drains to the creek. These chemicals are extremely harmful and sometimes fatal to species that live within the creek's ecosystem. Furthermore, as fertilizers accumulate in the creek, unwanted plants may begin to grow and disrupt water flow. Austin residents contribute to non-point pollution problems by flushing household cleaners, grease and, oil, down the drain or washing them down the street.
Residents also have the tendency to over-water their lawns.
Over-watering increases chemical runoff to the creek. Moreover, paved surfaces transfer heat to water runoff, increasing the temperature of water within the receiving creek. The native species of fish and other aquatic life cannot survive in these warm waters, so we see little aquatic life if any in Shoal and Waller creeks. Here is an example on contamination in Shoal Creek.