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
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
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.