Texas Water Development Board

Link to: Texas Water Development Board Groundwater Information

NGWMN Contact:

Rebecca Storms

512-475-3302

rebecca.storms@twdb.texas.gov

The Texas Water Development Board (TWDB) is a water-level and water-quality data provider to the National Groundwater Monitoring Network (NGWMN). TWDB collects data to determine current water-level depths, trends over time and to aid in the development and calibration of groundwater availability models. The data are essential to local groundwater management and regional planning efforts in Texas. TWDB maintains an extensive network of approximately 2,250 wells and currently serves data from 1,322 sites to the NGWMN Portal. In 2009, TWDB participated in the NGWMN Pilot Program and has been a part of the Network ever since.

TWDB provides water-level and water-quality data from the Coastal lowlands aquifer system, the Texas Coastal uplands aquifer system, the Edwards-Trinity aquifer system, the Seymour aquifer, the Pecos River Basin alluvial aquifer, the Rio Grande aquifer system, and the High Plains aquifer system.

NGWMN Products:

NGWMN Texas Pilot Report

NGWMN Projects:

2015: 10/1/2015 to 9/30/2016

Initial project to become a NGWMN data provider. Completes work started on pilot project.

2016 Round 1: 6/1/2016 to 9/30/2017

Project is to support maintenance of connections to the NGWMN Portal and to keep site information up to date in agency databases and in the NGWMN Well Registry.

2017: 7/31/2017 to 7/30/2018

This is a one-year project for providing persistent data services and site information gap filling. Lithology data for 900 wells will be entered into their new database from paper files as part of the site information gap filling work.

2018: 9/1/2018 to 8/31/2021

This is a two-year project to provide persistent data services. Their web services will be updated as part of this work.

2019: 9/1/2019 to 8/31/2021

Project to add wells to the NGWMN and perform well maintenance activities at 8 wells with floating oil-phase produce that impact water-level measurements.

2020: 9/1/2020 to 8/31/2022

Project is to provide persistent data services for two years to ensure that data continues to flow to the NGWMN Data Portal, and that sites and site information are up to date.

2021: 11/1/2021 to 10/31/2022

This project is to replace continuous water-level monitoring equipment at 13 wells.

NGWMN Presentations:

December 2016 presentation to SOGW

Site Selection and Classification

Site Selection

In their baseline review, TWDB first queried the specific number of observation wells from the total of just over 7,100 available water-level observation wells and nearly 3,000 water-quality sites in each of the seven principal/nine major aquifers to identify wells with water-level records of at least 5 years. Using the Tip Sheets and Appendix 5 in the NGWMN Framework Document as guidance, TWDB eliminated sites not meeting field standards and minimum data requirements (with the exception of lithology logs in some wells with long records), and 5,947 wells with water levels (including 2,423 in the High Plains) and 1,005 sites with water quality data (including 364 in the High Plains) remained as possible NGWMN sites. We selected wells for the NGWMN from these two sets.

Maps and descriptions of wells selected in each of the Texas aquifers is included in the project report at: Final report from initial NGWMN project, October 2015 to September 2016

Site Classification

TWDB further classified these wells following descriptions in the Subnetwork Tip Sheet. Wells in the observation network, more than half of which are measured only once a year, were classified as surveillance. The 193 wells with measurements available to the NGWMN six times a month (or daily as provisional data through direct linking to the TWDB site were classified as trend. All water-quality sites, due to their typical monitoring frequency of once every four years, were identified as surveillance.

In reviewing data status, hydrographs were assessed to determine background, suspected, and documented changes in the water-level subnetwork wells. "Documented Changes" typified water-level fluctuations in a majority of the wells in all aquifers, unsurprisingly as these wells with long periods of record have been in areas in which the TWDB and its predecessors and/or cooperators have been interested in the effects of pumping. Because the TWDB's ambient water-quality program has not included analysis of anthropogenic constituents that easily indicate documented changes through their presence or non-detection and because few studies have been conducted with data from these wells that offer conclusive evidence of changes in the natural water quality, all of the surveillance water-quality sites were classified as background.

Principal Aquifer	Water level wells	Trend Wells	Surveillance Wells	Background Wells	Suspected Changes Wells	Documented Changes Wells
NGWMN water-level well summary
Coastal Lowlands	93	15	78	26	6	61
Texas Coastal Highlands	98	14	84	37	13	48
Edwards-Trinity	194	61	133	21	37	136
Seymour	37	2	35	1	2	34
High Plains	363	20	343	0	0	363
Pecos River Basins	30	4	26	0	2	28
Rio Grande	5	1	4	0	0	5


NGWMN water-quality well summary
Principal Aquifer	Surveillance Wells
Coastal Lowlands	103
Texas Coastal Highlands	106
Edwards-Trinity	190
Seymour	25
High Plains	126
Pecos River Basins	19
Rio Grande	5

Data Collection Techniques

TWDB and its cooperators collect groundwater levels and samples in accordance with standardized field procedures consistent with the standards outlined in Appendix 5 of the NGWMN Framework Document. Water-level monitoring field procedures, revised during 2016 to adhere more closely to standards in the Framework Document are available in the Field Manual for Groundwater-level Monitoring at the Texas Water Development Board. Water-quality sampling protocols are outlined in A Field Manual for Groundwater Sampling.

Data Management

Data management procedures used by TWDB and its cooperators for groundwater-level monitoring and water-quality sampling are included in the field manuals maintained by TWDB.