The Texas Commission on Environmental Quality (TCEQ) has designated Plum Creek for aquatic life, contact recreation, and fish consumption. Three permanent water quality monitoring stations (Plum Creek Road near Uhland, Caldwell County Road 135 near Luling, and one mile south of Caldwell County Road 202 near Lockhart) and several temporary monitoring sites are used to track water quality trends. The Guadalupe-Blanco River Authority has obtained grant funding from the TSSWCB and has been conducting the water quality sampling and the data can be accessed from their website at http://www.gbra.org/plumcreek/data.aspx .
Plum Creek historically was shallow and intermittent, running dry in times of drought but flowing after heavy rainfall. Before urban development, Plum Creek above Lockhart ran dry almost every summer, as that portion of the creek was driven by rainfall and runoff. Below Lockhart, small springs that remain today flow throughout the year and feed Plum Creek.
Due to increased discharge from wastewater treatment plants, Plum Creek now flows year-round over most of its length. USGS gages at U.S. Highway 183 near Lockhart and at Caldwell County Road 131/Biggs Road near Luling monitor Plum Creek streamflows.
Water Quality Assessment
Plum Creek has high nutrient (nitrogen and phosphorus) concentrations and is impaired by high E. coli bacteria levels. According to the Texas Water Quality Inventory and 303(d) List, Plum Creek does not support contact recreation. The TCEQ updates these data every two years.