Residential Watershed Protection

The mission of the Denton Watershed Protection program is to maintain the quality of each watershed, ultimately protecting our water sources and the ecosystems within our watersheds.

Areas of Concern for Watershed Protection

Non-point source pollution is water pollution that originates from surprisingly common sources such as our homes, yards, cars and even our pets. It is generated by a variety of everyday activities and is Denton's leading cause of water quality degradation. What may initially appear as harmless behaviors such as fertilizing, mowing, taking out the trash and walking the dog can clog or pollute a storm drain which drains to Lewisville Lake, a primary source of drinking water for much of the DFW Metroplex.

Importance of Watershed Protection

The Watershed Protection division administers programs to reduce the overall pollutants within the surface waters of Denton and to ensure compliance with the National Pollution Discharge Elimination System (NPDES) Storm Water Phase II rule. In Texas, the Texas Commission of Environmental Quality (TCEQ) administers the Texas Pollution Discharge Elimination System (TPDES). As a TPDES phase 2 City, Denton operates and maintains a 'municipal separate storm sewer system' or MS4 for residents and businesses within the City of Denton.

Watershed Protection Services

Detecting and eliminating illicit discharge

  • Construction stormwater inspections
  • Public education, outreach and involvement
  • Review of Stormwater Pollution Prevention Plans (SWPPPs) and erosion control plans
  • Ensuring regulatory compliance with TPDES
  • Environmentally Sensitive Area assessments
  • Coordination of volunteer citizen scientists
  • Industrial stormwater inspections
  • Municipal good housekeeping

Through routine monitoring, baseline conditions for the physical, chemical, and biological components of the city's surface water resources are established and monitored. Results from this monitoring program are used to support the requirements of the Phase II storm water program and assess water quality for the purposes of source water protection.

Main Denton Watersheds

Cooper Creek, Hickory Creek, Pecan Creek and Clear Creek are the four main watersheds that convey water through Denton. Using topographical information, approximately 85 sub-basins have been delineated within the city. Sampling stations were established within these sub-basins at locations that would likely represent the water quality of the sub-basins. Monitoring of these sub-basins during base-flow conditions was initiated in January 2001 and has continued on a monthly basis ever since. Parameters analyzed in the tributary samples include flow status, temperature, dissolved oxygen, pH, conductivity, turbidity, salinity, litter index, visual evaluation and odor. Bimonthly, ten sampling stations are randomly selected for more intense analysis which includes E coli bacteria, metals, phosphorus, nitrogen, ammonia, nitrate, chlorides, sulfates, alkalinity, hardness, total solids and total suspended solids.

Watershed Monitoring

Permanent monitoring stations are established near the downstream ends of the three major watersheds (Hickory, Pecan and Cooper Creeks) prior to the confluences with Lewisville Lake and an additional station is established in Lewisville Lake near the drinking water intake. Real time monitoring is conducted at these locations by datasondes, instruments with multiple sensors. These stations provide a more comprehensive assessment of the combined effects of sub-basin water quality just prior to entering the City's main drinking water source as well as near our primary drinking water intake on Lewisville Lake.

The data from the stream monitoring program are analyzed with the following objectives:

  • Characterize the general water quality condition of the stream
  • Identify illicit discharges
  • Identify long-term water quality trends

To learn more about the construction and industrial components of our program, visit the Business Watershed Protection page.