Background
Water Availability by River Basin
Background
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)
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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.
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 consider recommended environmental flow needs.
Environmental flow needs include instream flows and freshwater
inflows to bays and estuaries.
The water availability models provide information that assists
TCEQ staff in determining whether to recommend the granting or
denial of an application.
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Water Availability by River Basin
What are general water availability maps?
These maps are generated from WAM output for both of the
permitting runs (Full Authorization and Current Conditions) for each basin. The maps
generally indicate the percentage of months during the period of
record that unappropriated water is available at various locations
in each basin.
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How are general water availability maps used?
The water availability maps can be used as a general indicator
to see if water would be available with sufficient frequency to
consider submitting a new application or an amendment to an
existing water right. The availability of storage, the total amount
requested, the type of use, environmental flow needs and other
factors could affect the availability of unappropriated water for a
particular project.
In using these maps, please keep these points in mind:
- The maps do not show how much water is present at any given
point. If the river is always full but every drop is appropriated,
the map will be red, showing that no water is available.
- The maps do not show how much water is available. They show
only how often some water is available.
- Each map is valid as of the date shown on the map. New water
rights or amendments to existing water rights may have been
approved since the maps were created.
- The State Wide Availability Maps
provides a very general look at water availability for the entire
state. To look at water availability in a specific basin, use the
main specific maps.
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General Water Availability Maps by River Basin
Of the twenty three river basins in Texas, maps are available
for the following:
Other maps will be posted here as they become available.
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Canadian River Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
Back to List of Maps
Red River Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
Back to List of Maps
Sulphur River Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
Back to List of Maps
Cypress River Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
Back to List of Maps
Sabine River Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
Back to List of Maps
Neches River Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
Back to List of Maps
Neches-Trinity Coastal Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
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Trinity River Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
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Trinity-San Jacinto Coastal Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
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San Jacinto River Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
San Jacinto-Brazos Coastal Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
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Brazos River Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Full Authorization |
Current Conditions |
Current Conditions |
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Colorado River Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
Colorado-Lavaca Coastal Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
Lavaca River Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
Lavaca-Guadalupe Coastal Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
Guadalupe River Basin
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
San Antonio River Basin
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
San Antonio-Nueces Coastal Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
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Nueces River Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
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Nueces-Rio Grande Coastal Basin Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
State Wide Availability Maps
Click on Images to see full-size maps
Full Authorization |
Current Conditions |
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WRAP: The Modeling Program
All river basin models are compatible with the March 2003
version of WRAP. The TX-WRAP, Tables, and WinWRAP files are
compressed in executable (.EXE) format (Help
with Downloading Files.)
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Input Files by River Basin
Data files necessary to run the water availability model for the
following river basins are available as compressed files in "ZIP"
format (Help
with Downloading Files.)
Data for the TCEQ permitting runs (Full Authorization and
Current Conditions) is available. In addition to the basin specific
files needed to run the models, a text file is included in the ZIP
file for each permitting run that details recent changes to the
input files.
If you need more information, please contact: The Water Rights
Permitting & Surface Water Availability Team at 512/239-4691 or
send an email to: wras@tceq.state.tx.us
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.
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Canadian River Basin
Back to List of River Basins
Red River Basin
Back to List of River Basins
Sulphur River Basin
Back to List of River Basins
Cypress River Basin
Back to List of River Basins
Sabine River Basin
Back to List of River Basins
Neches River Basin
Back to List of River Basins
Neches-Trinity Coastal Basin
Back to List of River Basins
Trinity River Basin
Back to List of River Basins
Trinity-San Jacinto Coastal Basin
Back to List of River Basins
San Jacinto River Basin
Back to List of River Basins
Brazos River Basin and San Jacinto-Brazos Coastal Basin
Back to List of River Basins
Colorado River Basin and Brazos-Colorado Coastal Basin
Back to List of River Basins
Colorado-Lavaca Coastal Basin
Back to List of River Basins
Lavaca River Basin
Back to List of River Basins
Lavaca-Guadalupe Coastal Basin
Back to List of River Basins
Guadalupe River Basin and San Antonio River Basin
Back to List of River Basins
San Antonio-Nueces Coastal Basin
Back to List of River Basins
Nueces River Basin
Back to List of River Basins
Nueces-Rio Grande Coastal Basin
- Input data for Full Authorization
-
- Input data for Current Authorization
-
Rio Grande Basin
Back to List of River Basins
