Water Availability Models
The WRAP Input files for River Basins.
The GIS files for all River Basins.
These GIS files include the Water Rights shapefile, the Control Points shapefile, shapefiles for use with the WRAP GUI, and the Flowline shapefile.
Updated version of the WRAP GUI
What is a water availability model?
A water availability model is a computer-based simulation predicting the amount of water that would be in a river or stream under a specified set of conditions.
The model of a specific river basin consists of two parts:
- the modeling program, called "WRAP", short for Water Rights Analysis Package
- a text file that contains basin-specific information for WRAP to process (these text files are called input files or WAM's)
How are these models used?
Water Availability Models are used to determine whether water would be available for a newly requested water right or amendment or whether a water right amendment can affect other water rights. The water availability models provide information that assists TCEQ staff in determining whether to recommend the granting or denial of an application.
TCEQ staff uses two models in evaluating applications:
- the Full Authorizaton simulation, in which all water rights utilize their maximum authorized amounts, is used to evaluate applications for perpetual water rights and amendments.
- the Current Conditions simulation, which includes return flows, is used to evaluate applications for term water rights and amendments.
If water is available, these models estimate how often the applicant could count on water under various conditions. For example, would water be available only one month out of the year, half the year, or all year? And would that water be available in a repeat of the drought of record?
In evaluating applications for a new appropriation of water and some applications for amendments to existing water rights, TCEQ staff must also consider recommended environmental flow needs. Environmental flow needs include instream flows and freshwater inflows to bays and estuaries.
WRAP: The Modeling Program
The Water Rights Analysis Package (WRAP) Modeling System includes computer programs for processing basin imput files for each river basin in Texas. These computer programs are maintained by Dr. Ralph Wurbs of Texas A&M University. Dr. Wurbs maintains model exectuables and manuals and these can be found at WRAP Model.
Which Input Files by River Basin do I need?
Input files are available as compressed files in "ZIP" format.
- For new permanent water rights or amendments, use the Full Authorization data set. This model shows the amount of water that would remain available for appropriation if all currently permitted perpetual water rights withdrew their full authorized amount of water.
- For new term water rights and amendments, use the Current Conditions data set. This model shows the amount of water that would remain available for appropriation if all currently permitted water rights, both perpetual and term, withdrew the amount of water they are currently using. The current conditions data set includes return flows.
What do I get with the downloaded files?
When you download and unzip the Full Authorization or Current Conditions data set files, you will get these items:
- Full Authorization files include RUN3 - *.dat, *.dis, *.eva, *.fad, *.flo, *.txt files and other files as applicable. Note: Not all basins include all of these files.
- Current Conditions files include RUN8 - *.dat, *.dis, *.eva, *.fad, *.flo, *.txt files and other files as applicable. Note: Not all basins include all of these files.
When you download and unzip the GIS files, you will get these items:
- Water Rights (WR) shapefile which is the legal representation of all features (reservoirs, diversion points, discharge points, etc.) authorized in the water right.
- Control Points (CP) shapefile which represents the water rights as modeled in the WAM. Not all water rights have CPs if they do not have the authorization to store or divert state water.
- WRAP GUI shapefile that is intended solely for the purpose of displaying WRAP output using the WRAP GUI executable and include CP_ID, RES_ID, WR_ID and IF_ID files.
- Flowline shapefile which is a representation of the watercourses in the basin.
WRAP GUI is a file compressed in ZIP format that includes the executable and it includes the WRAP GUI Users Manual.
It should be noted that the basin input files are dated and the information can change as new and amended water rights are added to the models.
WRAP Input files and GIS files by River Basin
What do I get help?
If you need more information, please contact: The Surface Water Availability Team at 512/239-4691 or send an email to: email@example.com
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