Project Goals/Objectives: This project is designed to assess continuing reductions in agricultural nonpoint source (NPS) pollution associated with Implementation Plan (I-Plan) activities for two total maximum daily loads (TMDLs) for the North Bosque River (NBR). Segments 1226 (North Bosque River) and 1255 (Upper North Bosque River) in the Brazos River Basin were included in the 1998 303(d) List as impaired under narrative water quality criteria related to nutrients and excessive growth of aquatic vegetation. Through the TMDL, phosphorus was identified as the nutrient most often limiting aquatic plant growth, and dairy operations and municipal wastewater treatment facility (WWTF) effluents were considered the major controllable sources of phosphorus to the river. The TCEQ adopted Two TMDLs for phosphorus in the NBR for Segments 1226 and 1255 in February 2001. These TMDLs were approved by the USEPA in December 2001. An I-Plan for Soluble Reactive Phosphorus in the NBR Watershed for Segments 1226 and 1255 was approved by the TCEQ in December 2002 and by the TSSWCB in January 2003.
As part of the I-Plan, a microwatershed approach to monitoring was included to provide finer geographic resolution for managing implementation activities (identified as “Tributary Monitoring” in the I-Plan). Monitoring at the microwatershed or subwatershed level also allows the impact of agricultural NPS implementation activities to be assessed separately from urban runoff and WWTF contributions. Monitoring at several microwatersheds was initiated in 2001 through TSSWCB projects 01-13 and 01-14 Technical and Financial Assistance to Dairy Producers and Landowners of the NBR Watershed within the Cross-Timbers and Upper Leon SWCDs. This monitoring has continued under a series of related projects: TSSWCB project 01-17 Extending TMDL Efforts in the NBR Watershed and TSSWCB project 04-12 Assessment of Springtime Contributions of Nutrients and Bacteria to the NBR Watershed and now this project 08-09. Data collected from these microwatersheds has been used to help the TSSWCB direct technical and financial assistance to property owners and to better characterize the effects of implemented management activities.
Project Location: North Bosque River Watershed within Erath, Hamilton, Bosque, Somervell, McLennan and Coryell Counties
Project Costs: Federal ($107,824); Non-Federal Match ($100,000); Total Project ($207,824)
Project Participant(s): TSSWCB, Texas Institute for Applied Environmental Research, US EPA, Brazos River Authority, and Texas Commission on Environmental Quality
Project Workplan: 08-09
Project QAPP: 08-09
Final Report: 08-09