The intent of these projects is to assess water quantity and quality under current and projected management conditions using models and GIS. Results may indicate critical areas contributing to sedimentation and related nonpoint source water quality problems which can be addressed by conservation practices. Practices applied on private lands will provide benefits to the landowner as well as to the downstream watershed and/or reservoir manager. Some of the studies are more interested in water quantity. The model was used in these cases to simulate varying water yields as a result of changes in land use/land cover.
The majority of our project partners are using the SWAT (Soil and Water Assessment Tool) model developed by USDA-Agricultural Research Service (ARS). Scientists with Texas AgriLife have developed the interface between the Geographic Information System (GIS) databases and SWAT to provide required model inputs and to graphically display the output data.
Some of our projects call for very detailed studies at the farm level. APEX (Agricultural Policy/Environmental eXtender) is the model of choice in these cases. APEX has the advantage of allowing the user to customize inputs so that they are very site specific. There is less long term monitoring for calibration purposes at the farm scale.
Agricultural land uses are dominant in all the basins and without adequate treatment and management, soils are subject to accelerated erosion. Conservation practices for alleviating water quality problems are unique to each soil type, location and land use. Large amounts of sediment are being deposited in the water supply reservoirs, depleting water storage volume and increasing treatment costs.
Cooperative projects have been developed to date between Texas NRCS and partners listed above and shown below.