Northern portion of the Gulf Coast Aquifer SystemGroundwater Availability Model (GAM)This map shows the extent and location of the northern portion of the Edwards and Trinity Regional GAM.

In October 2019, the US Geological Survey in cooperation with the Harris-Galveston Subsidence District and the Fort Bend Subsidence District began updating the groundwater flow model for the northern portion of the Gulf Coast Aquifer System. The model, known as the GULF-2023 model, is expected to be completed at the end of 2021. The TWDB and the Harris-Galveston Subsidence District have signed a letter of agreement that once the model and other deliverables satisfy the technical standards and procedural requirements of the TWDB GAM Program, the model, report, and source data will replace the Houston Area Groundwater Model (HAGM) as the GAM for the area.

In 2013, the US Geological Survey in cooperation with the Harris-Galveston Coastal Subsidence District, the Fort Bend Subsidence District, and the Lone Star Groundwater Conservation District have updated the model for the northern portion of the Gulf Coast Aquifer System (HAGM).

GULF-2023 Model

Joint Regulatory Plan Review Meetings (JRPR)

ID Date Location
JRPR-1 05/20/2020 Online meeting; by clicking at left, you will be leaving the TWDB website

 

Northern portion of the Gulf Coast Aquifer System GAM

Model Files

Please see the GAM files download page for a copy of the model files.

Model Grid

Model grid cells are geographically assigned to counties, groundwater conservation districts, river basins, groundwater management areas, and regional water planning areas within the model study area using a centroid based approach. The model grid is available in ESRI® shapefile format and comma-delimited text file.

Download model grid.

Aquifer Data

Aquifer data is only available as a package for the entire model area and requires GIS software for processing. Please see the GAM files download page for aquifer data.

Stakeholder Advisory Forums (SAF)

Send us an email if you would like to receive SAF notifications.

ID Date Location
SAF 8 2/17/2004 Friendswood, Texas - Harris-Galveston Coastal Subsidence District (1660 West Bay Area Blvd)
SAF 7 7/24/2003 Friendswood, Texas - Harris-Galveston Coastal Subsidence District (1660 West Bay Area Blvd)
SAF 6 4/24/2003 Friendswood, Texas - Harris-Galveston Coastal Subsidence District (1660 West Bay Area Blvd)
SAF 5 1/29/2003 Friendswood, Texas - Harris-Galveston Coastal Subsidence District (1660 West Bay Area Blvd)
SAF 4 6/5/2002 Friendswood, Texas - Harris-Galveston Coastal Subsidence District (1660 West Bay Area Blvd)
SAF 3 11/15/2001 Friendswood, Texas - Harris-Galveston Coastal Subsidence District (1660 West Bay Area Blvd)
SAF 2 8/2/2001 Friendswood, Texas - Harris-Galveston Coastal Subsidence District (1660 West Bay Area Blvd)
SAF 1 5/2/2001 Friendswood, Texas - Harris-Galveston Coastal Subsidence District (1660 West Bay Area Blvd)

Other Resources

Please see the Gulf Coast Aquifer System and the Research Projects in Support of Groundwater Models pages for other reports and publications.

For model runs see the GMA 14 page.

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