The District’s fees are intended to operate as an economic disincentive to producing groundwater as one of the available regulatory tools. The Regulatory Plan provides a permit fee structure that includes a Base Fee and a Disincentive Fee.
Base Fee – This fee is applied to all of a permittee’s authorized groundwater withdrawals. Funds obtained from the collection of base fees are used to cover the costs of issuing permits and performing other regulatory functions of the District.
Disincentive Fee – In addition to the base fee, a disincentive fee will be applied to groundwater withdrawals that exceed a permit limit. The purpose of the disincentive fee is to create an economic incentive for permittees to take steps to ultimately reduce groundwater use. The disincentive fee is applied in each permit year that groundwater reduction requirements are not met. The District periodically reviews the disincentive fee rate to ensure the rate encourages compliance with this Regulatory Plan and makes adjustments as needed.
HGSD’s Regulatory Plan provides several solutions to avoid disincentive fees, including Groundwater Credits, Groundwater Reduction Plans, and Groundwater Conservation Plans. Discover more information about these solutions in the District’s Rules.
The revenue collected from the disincentive fee is strictly dedicated to funding the District’s Science & Research program.
To view HGSD’s current fee schedule, please click here!
HGSD was created by the Texas Legislature in 1975 to prevent further subsidence. HGSD applies a science-based Regulatory Plan that establishes guidelines for groundwater withdrawals through a well-permitting process to reduce reliance on groundwater. The Regulatory Plan is an adaptive management strategy that is regularly reviewed using the best available data to ensure it is effective in preventing further subsidence. The most recent review was completed in 2025.
The goal is to shift our region’s primary water supply from groundwater to sustainable alternative water supplies that do not cause further land subsidence. However, the transition from groundwater to alternative water supplies (surface water, reclaimed water, etc.) is complex and requires regional water planning, which is why the Texas Legislature created Regional Water Authorities to provide local control for these water infrastructure projects. Regional Water Authorities are responsible for facilitating the conversion from groundwater to alternative water supplies to meet HGSD’s Regulatory Plan requirements.
In the 1990s, Regulatory Areas 1 and 2 were converted to surface water to meet the requirements laid out in HGSD’s Regulatory Plan, and they now have significantly improved subsidence rates. Conversion to alternative supplies is an ongoing process in Regulatory Area 3, with full conversion required by 2035.
Considerable supplies of surface water are available through the development of Lake Livingston on the Trinity River, Lake Houston and Lake Conroe on the San Jacinto River, and the Brazos River. The HGSD reviews the availability of freshwater resources as part of the science and research program. An alternative water supply assessment was completed as part of the Joint Regulatory Plan Review, which included an assessment of aquifer storage and recovery, brackish groundwater, and seawater desalination as alternative water supply options.
HGSD applies a science-based Regulatory Plan that establishes guidelines for groundwater withdrawals through a well-permitting process to reduce reliance on groundwater. The Regulatory Plan is an adaptive management strategy that is regularly reviewed using the best available data to ensure it is effective in preventing further subsidence.
The District also provides water conservation tools and resources to further reduce reliance on groundwater.
The traditional method used to measure changes in land surface elevation (also called “geodetic differential leveling,”) consisted of the establishment of permanent benchmarks that include precise elevations and coordinates (i.e., latitude and longitude) for each point. Benchmarks, according to the NGS, are a specific type of survey mark that has a known elevation above or below an adopted surface or datum.
As the land surface began to subside in the early 1900s due to groundwater and hydrocarbon withdrawals, the need to relevel benchmarks became necessary. Over the years, new benchmarks were added (for a total of more than 2,500) and “relevelings” were conducted by the HGSD in cooperation with the NGS in 1978, 1987 and 2000. Although the geodetic differential leveling method provided excellent spatial subsidence data, the cost and time of the releveling procedure for a specific period in time (an epoch) limits the accessibility of current data at a rate necessary to effectively monitor the effects of subsidence.
In the 1980s, new technologies emerged that provided the same accuracy as the geodetic differential leveling and while also allowing for constant monitoring in a cost-effective way. In 1987, in conjunction with the conventional releveling, an experimental Global Positioning Systems (GPS) releveling was initiated throughout the HGSD. The class-A benchmarks established for the GPS releveling have proven to be valuable benchmarks in the Houston area. Since 2000, all land surface elevation data is obtained through GPS measurements throughout the HGSD and surrounding counties.
Due to the extensive subsidence in the greater Houston area, stable benchmarks were needed to provide a reference frame. Therefore, stable borehole extensometers were equipped with GPS antennas mounted to the inner pipe to measure subsidence and act as a stable benchmark. The GPS equipment used at extensometers are permanent stations and are known as continuously operating reference stations (CORS). In the mid-1990s, the HGSD and NGS began developing the use of GPS Port-A-Measure (PAMs) to provide subsidence measurements.
One of the most important advantages to GPS is the ability to have continuous data. Using dual-frequency, full-wavelength GPS instruments (with geodetic antennas), data is collected at 30-second intervals and averaged over 24 hours. This method of data collection allows specific sites to be monitored and assessed daily. And just as important, the measurements are more reliable and handled at a fraction of the cost of conventional surveying.
The use of GPS to monitor subsidence has continued to evolve. In the mid-1990s, the HGSD, in cooperation with the NGS, developed the use of GPS PAMs to measure land-surface elevation or subsidence. Originally, seven portable trailers were constructed to store and secure GPS receivers, geodetic antennas, and associated equipment such as batteries, solar panels, and recording equipment. The trailers were moved weekly to different locations to record a week’s worth of GPS data for each PAM each month.
Portable trailer stores the receiver (the yellow box) and the configuration of the geodetic antenna (the circular disk on top of the tripod) used to collect GPS data. Source: HGSD
The HGSD first started the installation of permanent GPS monitoring stations in 2000. As of 2019, the HGSD has installed 85 GPS stations and also collects GPS data from over 220 GPS stations across the region.
During the monitoring period, GPS data are collected every 30 seconds, then processed and converted to a stable reference frame to eliminate tectonic plate motion. The GPS data include a three-component displacement time series involving the horizontal (East-West), vertical (North-South), and the ellipsoidal height (i.e., elevation above or below the reference ellipsoid) components. The ellipsoidal height is used to estimate land surface elevation and is how the HGSD measures subsidence.
Most GPS stations operated by the HGSD collect data periodically, while some collect it continuously. The periodic monitoring stations collect GPS data for approximately seven days every two months. The continuous monitoring stations, also known as Continuously Operating Reference Stations (CORS), collect GPS data 24 hours a day, every day of the year. The HGSD primarily uses periodic monitoring of GPS stations because the equipment is rotated among multiple stations, requiring less equipment and making it less expensive than operating a CORS site.
Periodic monitoring GPS stations are designed as a 2.5-in pipe drilled approximately 35 feet below ground surface with an 8-foot extension pipe above the ground. The extension pipe is mounted with a geodetic antenna. A separate pipe, which holds an enclosure box to store a battery and GPS receiver, as well as a mount for a solar panel, is installed within a few feet from the antenna pipe. Both pipes are surrounded by four bollards to provide additional protection, and all pipes are secured in a 5’ x 5’ concrete pad.
Example of a permanent GPS station, P023 located in Bayou Vista, that collects GPS data periodically. Source: HGSD
CORS are designed in two ways: 1) the same manner as the permanent GPS stations previously described or 2) mounted on pre-existing structures. As of 2020, the HGSD operates seven CORS that are constructed in the same manner as the periodic monitoring stations. The pre-existing structures include buildings and extensometers. For the building type, GPS equipment is usually mounted to the roof or high along an exterior wall. Additionally, buildings are selected with deep foundations as well as clear sky views to limit interference. The building mount CORS design is used by the UH who operate 71 permanent CORS as of 2020. For the extensometer type, the District operates five CORS (ADKS, LKHU, NETP, TXEX, and P096) installed on top of extensometers as of 2020.
Prior to 2001, the District issued Series A credits, which could be used for 100% of a permittee’s total water demand and expired 40 years from the date of issue. After an evaluation of the credits potential impact on the District’s mission to prevent future subsidence in 2001, the District discontinued issuing Series A groundwater credits and replaced them with the Series B groundwater credits.
Permittees can sponsor the HGSD Water Conservation School Program in exchange for Series B Credits, which can be applied during the permit renewal process to increase groundwater use without increasing the permit rate.
Sponsorships are priced at $40 per student each school year.
Each sponsorship will earn the permittee 84,000 gallons in Series B Credits that may be applied for an additional 30% groundwater use in the permit term.
Series B Credits are valid for 20 years from the date of issuance.
Municipal Utility Districts and water providers may sponsor the school program through interlocal agreements. Learn more here!
If a well serves anything other than one house, a permit is required. However, a permit may be required for a well that serves a house, depending on the following:
- What diameter is the well
- Where it is located
- When was it drilled
There are other exceptions spelled out in the District’s Rules. Regardless of whether a well needs a permit, it must be registered with the District before it can be drilled.
Most water wells in Harris and Galveston counties have been required to be permitted since 1976. After the 1993 legislative session, changes were adopted regarding which wells must be permitted by the District, resulting in an increase in the number of wells subject to permitting. In an effort to notify well owners of the changes in the permitting requirements, the District published notices in the newspaper, posted notices at the county courthouses, and held a public hearing to receive public comment. Despite these public outreach efforts, unpermitted wells are still periodically discovered by District staff during routine inspections throughout the District.
The District is required to consider many different factors when establishing the groundwater allocation for each permittee. Some considerations include the following:
- The amount of groundwater requested by applicant
- Location of the groundwater well
- Availability of alternative water supply
- Participation in a groundwater reduction plan
- Use of groundwater credits to offset groundwater pumpage
Each situation is unique. Please contact the District permitting staff if you have further questions.
Approximately four months prior to the expiration of your permit, the District will mail you a permit renewal application form. This form must be completed and returned to the District along with the renewal application fee. Renewal applications can also be completed online, but the application will not be processed until the application fee is received.
The renewal application form will require you to enter the amount of groundwater you pumped from your well during the previous 12-month period and the amount of water you purchased from other sources. If you have access to alternative sources of water, you will be required to submit copies of water bills to verify the amount of water purchased from other sources.
Our area has experienced the following consequences of subsidence:
- Permanent elevation loss
- Increased flooding
- Damage to infrastructure like roads, bridges, homes, pipelines, and more
- Faulting
One of the most significant instances of subsidence occurred in the Brownwood Subdivision in Baytown, Texas. The Brownwood subdivision originally had over 400 homes built in the 1940s. As a result of large volumes of groundwater withdrawal, the area experienced up to 10 feet of subsidence, leading to some homes being inundated and others experiencing frequent flooding. Brownwood is now mostly underwater and has been turned into the Baytown Nature Center – a habitat for native plants and animals. The Houston History Magazine wrote an article in March 2019 that includes links to original video footage of the site and interviews with the residents of Brownwood.
Brownwood Subdivision in 1944 to 2002. Slide the arrows to see the impact of subsidence.
In the simplest of terms, land subsidence is the gradual sinking of the Earth’s surface due to subsurface movement. In the greater Houston area, groundwater withdrawals have caused subsidence, or land sinking.
Although the process is slower than that of other natural hazards, subsidence has serious consequences. Once subsidence has occurred in our area, it is irreversible. Given our region’s proximity to the coast, any loss of land surface elevation poses significant threats from weather-related events like storm surges and flooding.
To prevent further subsidence, the Harris-Galveston Subsidence District works diligently to reduce reliance on groundwater through groundwater regulation and water conservation.
Illustration of subsidence in a Gulf Coast aquifer as a result of groundwater withdrawals producing a decrease in the potentiometric surface (the groundwater level). Source: Kasmarek, M.C., Ramage, J.K., and Johnson, M.R., 2016, Water-level altitudes 2016 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973–2015 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas: U.S. Geological Survey Scientific Investigations Map 3365, pamphlet, 16 sheets, scale 1:100,000, http://dx.doi.org/10.3133/sim3365.
Access the Portal on our website by clicking here.
- Current permit holders must use the email address associated with their well number to create an account.
- If you are not the current permittee or well owner, we will require permission (in the form of a letter or email) from the existing permittee or owner before you can be added to the account.
Over-Conversion Credits (OCCs) are offered to permittees with an approved Groundwater Reduction Plan (GRP) upon submission of proof that the permittee used more alternative water than required by the regulatory plan during the permit term.
OCCs may be earned by permittees whose total over conversion exceeds 10MG and GRP administrators. OCCs for Regional Water Suppliers are earned through the permit reconciliation process described in the District Rules. OCCs may be earned through any combination of alternative water use, including treated surface water, reclaimed water, or other District-approved alternative water management strategy.
Specific requirements and conditions for the transfer of OCCs are set forth in the District Rules and Regulatory Plan.
Although the District no longer issues Series A groundwater credits, there are entities that are willing to sell their Series A groundwater credits. Please contact the District if you would like information on those entities that have notified the District that they are willing to sell their Series A credits.
After May 17, 2021, well registration and all well permit applications will need to be submitted through the Portal.
All permit, rebate, and groundwater credits forms are now available in the Portal.
Mailed applications or applications submitted in person will still be accepted.
It is possible to purchase credits on the open market. The District maintains a list of organizations/individuals who have notified the District of their willingness to sell their credits to a third party. The District does not participate in the resale of credits. Please contact the District at 281-486-1105 or info@subsidence.org if you would like more information on credit transfer and purchase.
Yes, as long as the groundwater credits are valid and have not expired, they can be combined.
Your application must be verified by a staff member before the correct fee is applied to your account. Staff will review your application within 2-5 business days and then the appropriate fee will appear in the Pay Fees section.
If you’ve already started your renewal application, you do not need to submit your application again through the new permitting portal. However, if you would like to view the status of your application and next steps, create an account using the email address associated with your application.
In a simplified sense, borehole extensometers are used to measure vertical displacements in the ground. More specifically, they are deeply anchored wells that are used to measure compaction of the interval between the bottom of the extensometer and land-surface. An extensometer is the only mechanical method available to measure the compaction of the aquifer material.
Within the Houston-Galveston region, 14 borehole extensometers are operated and maintained by the USGS. These extensometers were constructed as wells drilled to various depths (650 to 3,300 feet below ground surface) and anchored in stable strata with a cement plug in order to measure compaction within different aquifers (Kasmarek, et al., 2015). The outer casing is equipped with slip-joints to maintain well integrity by preventing damage from subsidence and the inner pipe is attached to a cement plug at the bottom of the borehole. An interval approximately 10- to 20-ft above the cement plug is screened to allow water to flow into the cased well. The extensometers use analog (chart) recorders, which are connected to the inner pipe, to continuously measure the change between a reference point on the inner pipe and the land-surface elevation. This measurement is the compaction of specific aquifers at depth.
GPS stations have been installed at extensometers, including placement on the inner pipe to monitor movement of the cement plug and also on the surface to monitor land-surface movement around the extensometer.
It has been documented since the 1980s that aquifer compaction results in subsidence and therefore the compaction data provided by the extensometers is critical to understand groundwater withdrawal, depressurization of the aquifer, and associated subsidence. Although the accuracy and importance of this measurement method is impressive, the installation of an extensometer is rather expensive compared to a GPS PAM or CORS site. These data sets have been invaluable in understanding the causal relations between aquifer depressurization and aquifer compaction.
Over time, as technologies have evolved, the HGSD has moved toward more cost-efficient and equally accurate forms of measurement such as GPS technologies and remote sensing to measure land subsidence. Although the HGSD has determined that the cost effectiveness of GPS stations is better than a broad network of extensometers, the HGSD has recently worked with local and county agencies to install extensometers to learn more about the compaction of frontier and recently developed aquifer units such as the Jasper aquifer.
Cross-sectional view of a borehole extensometer. Source: Kasmarek, M.C., Ramage, J.K., and Johnson, M.R., 2016, Water-level altitudes 2016 and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction 1973–2015 in the Chicot and Evangeline aquifers, Houston-Galveston region, Texas: U.S. Geological Survey Scientific Investigations Map 3365, pamphlet, 16 sheets, scale 1:100,000, http://dx.doi.org/10.3133/sim3365