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 some other minor exceptions that are spelled out in the Rules. Regardless of whether a well needs a permit, or not, the well is still required to be registered with the District before the well 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 filled out and returned to the District along with the $60.00 renewal application fee. Renewal applications can also be completed online, but the application will not be processed until the $60.00 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.
Flooding is a serious consequence of subsidence especially in the Houston-Galveston area as much of the land is either within coastal zones or has limited green space to absorb surficial water. Other impacts of subsidence include localized faulting and infrastructure damage.
A perfect example of the effects of subsidence in coastal areas is the Brownwood Subdivision located in the City of Baytown. The Brownwood subdivision originally had over 400 homes built in 1940s. As a result of large volumes of groundwater withdrawal, the area experienced as much as 10 ft of subsidence that resulted in some homes being inundated and others experiencing frequent flooding. Brownwood is now mostly underwater and has been turned into the Baytown Nature Center that provides 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.
Subsidence can be reduced, stopped in some cases, when the pumping of groundwater is reduced. However, the conversion from groundwater to alternative sources of water (surface water, reclaimed water, etc.) is not as simple. Many of the cities, industries, and others in Regulatory Areas 1 and 2 (the coastal areas) converted in the 1990s to surface water, at considerable costs. Conversion to alternative supplies is an ongoing process for Regulatory Area 3, with full conversion required to be completed 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 is currently underway as part of the Joint Regulatory Plan Review, and will include an assessment of aquifer storage and recovery, brackish groundwater and sea water desalination as alternative water supply options.
HGSD’s goal is to regulate groundwater use in volumes that will not deplete the aquifers in order to prevent subsidence and ensure future water availability. Since 1975, HGSD has regulated the use of groundwater and strongly encourages water users to shift from groundwater to other sources of water, such as treated surface water, through disincentive fees. Additional information on the HGSD’s regulatory program is provided in the Regulatory Plan, which works in conjunction with the District’s well permitting program. As a result of HGSD rules, groundwater use has reduced dramatically in the areas along the coast and Houston Ship Channel, and consequently subsidence in those areas is negligible.
In the simplest of terms, land subsidence is the sinking of the earth’s surface due to subsurface movement. Aquifer compaction from groundwater withdrawal, oil and gas extraction, underground mining, sinkholes, drainage of organic soils, and natural depositional compaction are the most common causes of subsidence in the United States. More specifically for the greater Houston-Galveston region, land subsidence is the decrease in land-surface elevation caused by aquifer compaction due to abundant, long-term groundwater withdrawals.
In the greater Houston-Galveston region, groundwater is pumped primarily from the Chicot and Evangeline aquifers as a source of freshwater. The geology of these aquifers includes discontinuous layers of gravel, sand, silt, and clay. The extraction of large volumes of groundwater causes clays to depressurize and compact. Aquifer compaction affects overlying stratigraphic units all the way to the land surface and is observed as subsidence.
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.
Yes, historically the District has issued Series A credits which could be used for 100% of a permittee 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.
No, currently each sponsorship (which includes one student in the school program and all of the other aspects of the program) issues 84,000 in Series B groundwater credit which can be used for up to 30% of the permittees total water demand and expires 20 years from issue date.
Although the District no longer issues Series A groundwater credits, there are entities that are willing to sell their 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 A credits.
Valid Series A groundwater credits may be used until expired.
Yes, as long as the groundwater credits are valid and have not expired, they can be combined.
If you are unable to meet the required conversion to alternative water, then you may be subject to a disincentive fee. See our schedule of fees for the current disincentive fee rate.
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.
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 broad extent of subsidence in the Houston-Galveston region, stable benchmarks were needed to provide a reference frame. Therefore, stable borehole extensometers (described subsequently) were equipped with GPS antennas mounted to the inner pipe to measure subsidence and act as 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 means that specific sites can be monitored and assessed on a daily basis. And just as important, the measurements are more reliable and handled at a fraction of the cost than conventional surveying. Improved GPS techniques and processing have reduced the cost of two centimeters. Now that’s progress!
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 provide land-surface elevation or subsidence measurements. 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 in order to record a week’s worth of GPS data on each PAM every 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 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 period of monitoring, GPS data are collected every 30 seconds, and then processed and converted to a stable reference frame to eliminate tectonic plate movements. 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.
The majority of GPS stations operated by the HGSD collect data periodically and some stations collect data continuously. The periodic monitoring stations collect GPS data for approximately seven days every two months. The continuous monitoring stations, also known as a Continuously Operating Reference Station (CORS), collect GPS data 24 hours a day every day of the year. The HGSD primarily uses periodic monitoring for the GPS stations because less equipment is needed since it is rotated to multiple GPS stations and therefore is 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.
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
The Subsidence District is switching to a new system that will make applying for and renewing a new permit seamless. With all forms consolidated in one place, permit holders can submit forms, make payments online and check the status of applications.
The permit process itself will not change. For an overview of the permitting process, click here.
All current and new permit holders will be able to create an account on May 17, 2021. Current permit holders will need to 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. That information can be provided during the process of renewing your permit.
After May 17, 2021, well registration and all well permits applications will need to be submitted through the Portal. The rest of the HGSD forms are still available on the Forms page and will be migrated to the new system later this summer.
All permit, rebate, and groundwater credits forms are now available in the Portal. While the new forms look different, no new information is required. Step-by-step user guides are provided at the bottom of the page for assistance navigating the forms.
Mailed applications or applications submitted in-person will still be accepted.
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.
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.