Take advantage of the Trinity Glen Rose District's conservation program incentives. RAINWATER HARVESTING Rainwater harvesting is the capture, diversion, and storage of rainwater for a number of different purposes including landscape irrigation, drinking and domestic use, aquifer recharge, and stormwater abatement. In a residential or small-scale application, rainwater harvesting can be as simple as channeling rain running off an unguttered roof to a planted landscape area via contoured landscape. To prevent erosion on sloped surfaces, a bermed concave holding area down slope can store water for direct use by turfgrass or plants. More complex systems include gutters, pipes, storage tanks or cisterns, filtering, pump(s), and water treatment for potable use. Rainwater Harvesting Q&A Just hover your cursor over the photo to see the answer for each question. What are the basic parts of a rainwater harvesting system? Catchment surface: the collection surface from which rainfall runs off, typically a roof on a home or building Gutters and downspouts: channel water from the roof to the tank Leaf screens, first-flush diverters, and roof washers: components which remove debris and dust from the captured rainwater before it goes to the tank One or more storage tanks, also called cisterns Delivery system: gravity-fed or pumped to the end use Treatment/purification: for potable systems, filters and other methods to make the water safe to drink What are the benefits a rainwater harvesting system? The water is free; the only cost is for collection and use. Rainwater provides a water source when groundwater is unavailable, or it can augment limited groundwater supplies. The zero hardness of rainwater helps prevent scale on appliances, extending their use. Rainwater is superior for landscape irrigation. Rainwater harvesting reduces flow to stormwater drains and also reduces non-point source pollution. Rainwater harvesting reduces consumers’ utility bills. How much water can I capture? The basic rule for sizing any harvesting system is that the volume of rainwater is that can be captured (the supply) must equal or exceed the volume of water used (the demand). In theory, approximately 0.62 gallons per square foot of collection surface per inch of rainfall can be collected. In practice, however, some rainwater is lost to first flush, evaporation, splash-out overshoot from the gutters in hard rains and small leaks. How do I get started with a rainwater harvesting system? Rainwater collection systems can be as simple as collecting rain in a barrel or as elaborate as harvesting rainwater into large cisterns to supply your entire household. Rainwater storage systems and equipment can be purchased at local home improvement stores, lawn and garden stores, and even ordered online! A great resource for you to use is the Texas Water Development Board's Rainwater Harvesting guide. Just click the link below to download a PDF of that guide. Plus, you might want to read the Tax Exemption information as well. The Trinity Glen Rose District put together a "how to" video for building your own rain barrels. Check it out below. Texas Water Development Board - Rain Water Harvesting - Download Manual HCA Rainwater Harvesting in Central Texas - A Practical Guide TAX EXEMPTION RESOURCES Application for Property Tax Exemption for Water Conservation Initiatives Sales Tax Exemption Form for Purchasing Rainwater Harvesting Equipment TGR Rain Barrel Construction Video Safety First! Safety is always a must when working with power tools. So, we strongly recommend you wear a pair of safety glasses or some sort of eye protection during this project. Where to find an empty barrel: Dave the Barrel Man (www.davethebarrelman.net ); 811 Roosevelt, San Antonio, Tx 78210; Phone: 210-534-5416 Tanks A Lot - 39332 IH 10 West, Boerne, TX 78006; Phone: 830-331-7330; http://www.tanksalottx.com/ Barrels by Joel - Phone: 210-717-6850 https://barrelsforsale.net/ Home Depot/Lowes - small barrels Many on-line resources - Watch out for shipping costs! Tools needed: drill - 3/8 to 1/2 hp Paddle (spade) bit, 15/16" and 2 3/8" hole saw Set of hole saws or a jigsaw to make a 6" hole in the top Materials needed: A ¾” brass faucet (hose bibb) 2” male PVC connectors & electrical Nut Tube of silicone (bathtub) Barrel Step 1 - Drill a hole in the top of the barrel for rainwater to flow into. Mark a spot in the top of the barrel. It doesn’t have to be the middle. Use a 6” hole saw to cut it out. Or using the bottom of a one-gallon plastic pot, mark a circle around the bottom of the pot. Drill a ¼” hole on one side of the circle and saw the circle out. Saw to the outside line you drew with the plastic pot. Step 2 - Drill the overflow hole. Using the pot as a depth gauge, mark and drill the overflow hole just beneath the depth of the pot. Use the 2 3/8” hole saw. Step 3 - Drill a hole for the hose bibb. About 3 inches up from the bottom of the barrel, drill a 15/16” hole for the 3/4” hose bibb. Step 4 - Install the hose bibb. Put a little silicone around the threads on the hose bibb, push down and screw it in. It will be sealed when you finish. Be sure to point the hose bibb to the side for better access. About 3 inches up from the bottom of the barrel, drill a 15/16” hole for the 3/4” hose bibb. Step 5 - Install the overflow. Insert the 2” adapter with the male threads through the hole. Thread the 2” electrical nut on adapter inside of the barrel. Step 6 - Screening out debris. Place mosquito screen in bottom of pot & add rocks (about 2-3 inches deep) and place it in the top of the barrel. This is the filter to keep out the large stuff off the roof. Step 7 - Connect your rain barrel to the downspout. Place your rain barrel in a location where it will capture rain running off of the roof. Or, you can attach a diversion to your existing downspout that will direct water into the barrel. Other Considerations Level your barrel!! Elevating barrels provides room for watering cans and increases gravity flow If linking barrels together, place an overflow pipe on last barrel Pond Pumps and transfer pumps can be used to increase flow Consider placement of faucet if you live in a windy area If you have children, strongly advised to anchor the barrel to your home Connecting two or more barrels together is easy! 1.If you want to hook two or more barrels together, use the overflow hole as the hookup between the barrels. 2.Use a piece of 2” PVC pipe with a male-threaded connector glued to the end and screw it into the female fitting on the inside of the first barrel. Do the same thing on the other end of the pipe and on the next barrel until all the barrels are hooked up. 3.If you do the same setup on the bottom of all the barrels, the water will empty out of all the barrels at the same time. PLUS, you only need one hose bibb in one barrel.

Here you will find the latest research by the Trinity Glen Rose District in our effort to learn about the Trinity Aquifer. Water Planning The TGRGCD was created to address groundwater issues or problems within the District overlaying Trinity group of aquifers. The District includes data from the TWDB’s Groundwater Availability Models (GAMs), input from the Groundwater Management Area 9 cooperative planning process, public input, and the most current and accurate site-specific data available in the development of its management plan to preserve, protect and conserve the Aquifer. The District also cooperates with adjacent groundwater districts, Groundwater Management Area 9, Regional Water Planning Groups, local water purveyors and stakeholders, and adjacent counties with similar aquifers and/or groundwater usage to ensure a collaborative means of protecting water supplies in this area of the state. Groundwater Management Area 9

Take advantage of the Trinity Glen Rose District's conservation program incentives. You know the saying "Everything's Bigger in Texas." Well, that truism couldn't be more important than when it applies to conserving water, especially when it's hot (which can be most of the year). Did you know outdoor watering can double your water use during the summer? And lots of that wet stuff can be wasted through evaporation, runoff and just plain overwatering. And indoor water is wasted through leaks and incorrect water use habits, like leaving the water running when you're not using it. So, you need to love our local aquifers like the Trinity Aquifer and the Edwards Aquifer like you mean it. And that's why we say Don't Waste the Wet Stuff, because wasting water is just not Texas-like. Here are some great ideas for how your family can save water inside and outside and protect our water resources as well. So how many gallons does it take to produce one hamburger? According to Water Footprint Calculator, it takes 660 gallons of water to produce all of the ingredients in one hamburger. Check it out at this link. www.watercalculator.org/footprint/what-is-the-water-footprint-of Don't Waste the Wet Stuff! 1. Fix Leaks! Always be on the lookout for leaking faucets, pipes, and toilets to prevent water loss, which is water waste. Even minor leaks can accumulate significant waste and expense over time. 2. Never Leave the Water Running! If you're not using the water, turn it off. For example, don't let the water run when you're brushing your teeth. 3. Install Low-Flow Showerheads! Modern shower heads can produce great water pressure while reducing the actual use of water. Heck, you might even get creative and shut of the off water while soaping up. 4. Take Short Showers! The math on this water-saving tip adds up quickly. Get in, soap up, rinse off, turn the water off. Save the singing for when you're drying off! 5. Only Wash When You Have a Full Load! Your clothes washer is near the top water device in your home when it comes to using water. So only use it when you have a full load to do. And, the next time you have to buy one, find a low-water-us appliance. 6. Wash Only Full Loads of Dishes! Did you know that your dishwasher is more efficient than washing dishes by hand? That's because people tend to leave the water running when washing dishes in the sink. Save some time, money and water by putting that dishwasher to use. Water only on your designated day and preferably in the early morning. Check your sprinkler system and controller to ensure it is running efficiently. Install rain sensors on sprinkler systems. Fix leaky faucets and hoses..they waste water and money. Water your grass…not the sidewalk and street. Native plants don't require much water, overwatering can kill them. Make plans to change out your high water use turf grass to low water use, colorful native plants and ground cover. You don't have to do it all at once. Pick a spot in your yard that needs little love and start there. The Trinity Glen Rose District co-sponsors a video series called Go Gardening which teaches homeowners how to convert their landscapes to native plants, hardscapes and other decorative landscape materials. Click here to watch Go Gardening. Mid-day sun doesn't play well with landscape sprinklers. Use a broom to clear away debris, instead of using the hose. Here's What Your Yard Can Look Like with Texas Native Plants

The Trinity Glen Rose District partners with many great entities to teach water conservation and pollution prevention. Pollution Prevention - See Park Slide Shows Below Practicing Pollution Prevention Each Day Over the next few months, the Trinity Glen Rose Groundwater Conservation District is going to be featuring some of the beautiful parks that are located within the District’s boundaries. The bottom line is that parks, water and pollution prevention go hand-in-hand. So, the more you know about how those three work together, the more likely you’ll be to help prevent pollution from getting into our local rivers and aquifers. So that’s why we’re calling this series “Learn and Live.” Each month, we will inform you about one of the must-see parks in Northern Bexar County. And with that learning, we hope you will not only want to visit that park, but you’ll also want live your life by developing the best pollution prevention habits that researchers have developed so far. Learning About Pollution Prevention Historically, cities have paved roadways, sidewalks, trails, parking lots, sports courts, alleys, driveways, and other surfaces to reduce the annoyance and cost of slippery mud and blowing dust. Unfortunately, having so many hard, water-repelling surfaces (along with a vast number of urban rooftops) can be environmentally harmful. After it rains, vast amounts of water, now called “stormwater,” will collect in these areas, pick up the grease, grime and other pollutants that are deposited on them each day, and then head for a water source like a creek, river or aquifer. Here are some of the ways dirty stormwater can pollute a water supply: most stormwater runoff escapes natural cleansing by plants, rocks and soil; without nature slowing down the stream of water after a rain, higher amounts of water are funneled to local streams; urban streams become prone to flash flooding from rapid runoff, resulting in severe scouring, erosion, and reduction of plant life; once stream beds are scoured, flooding becomes more common. The solution is to hold back the water where it hits, slow it down so that the destructiveness of erosion and contaminants is controlled, and that it is naturally cleaned it before it reaches a waterway or aquifer recharge feature. So, now that you’ve learned how unabated stormwater can create flooding and pollution issues for our aquifers and streams, you can also understand why maintaining and increasing large natural areas like parks is so important to our community. The important point to never forget is that the less runoff, and the slower the runoff we have, the less damage there is to rivers and aquifers and the overall environment. Living Pollution Prevention Here are the Top 6 Pollution Prevention Habits You Should Develop Practice water conservation in your home each day. The less water you use, the more water is left in the Trinity Aquifer for future use. Practice energy conservation in your home each day. Large amounts of water are needed to cool power plants that provide electricity to our city. Less energy production requires less water to be used. Use non-toxic cleaning chemicals in your home. Never dump oil or others types of solvents on the ground or in the street where they can run off into a stream or an aquifer. Use only environmentally-safe weed-killers and fertilizers on your landscapes. Always pick up your pet's waste and dispose of properly. Pet waste that runs off into a creek or stream only increases the bacteria levels in that body of water. Enjoy the parks and advocate for more green spaces in your communities. “Learn and Live” at Stone Oak Park 3V3A0300 IMG_6942 3 3V3A0119 3V3A0300 1/28 Numerous natural areas and community parks beautify Northern Bexar County where the Trinity Glen Rose Groundwater Conservation District (TGR) works to preserve and protect the Trinity Aquifer each day. In addition to these parks’ aesthetic value, they also play a major part in preventing pollution from entering the Trinity Aquifer and Edwards Aquifer which are both critical to the water supply in Bexar County. To highlight pollution prevention message, TGR is bringing its constituents an informative series about the six major parks and natural areas in the district. This month, we are highlighting Stone Oak Park located at 20395 Stone Oak Parkway. Stone Oak Park features a 3.2-mile loop trail located in the heart of the Stone Oak neighborhood. Despite its urban setting, park designers succeeded at creating a very rustic feel as the trails wind through some traditional South Texas hill country scenery. Currently, there are some beautiful wild flowers dotting the trails, and with the recent rains, the park is quite green. The park also contains some interesting sculpture art and some work out stations (push ups, site ups, pull ups) for those looking for an additional level of exercise. The trails are rated as moderate, and dogs are also welcome but owners must be keep them on leash. “Learn and Live” at Panther Springs Park Panther Springs Park Panther Springs Park Panther Springs Park Panther Springs Park 1/21 Panther Springs Loop is a 3.6-mile lightly trafficked loop trail located near San Antonio, Texas that features beautiful wild flowers in the spring, hill country type wooded areas and many beautiful open meadow-like vistas. The trails are paved and considered good for all skill levels of hikers, walkers and runners. The park, which opened in March of 2015, consists of 279 acres which were donated by Dan Parman and the San Antonio River Authority (SARA). The dog park which is located near the entrance of the park includes areas for larger dogs and one for smaller ones. Bird watchers have documented 46 different species in the park to include the Greater Roadrunner, two species of hawks and numerous other types of smaller, colorful birds. The San Antonio River Authority collaborated with the City of San Antonio in the development of Panther Springs. SARA’s portion of the project included design and construction work to improve the water and sediment conveyance in the existing natural channel. The agency continues to monitor the stream for changing conditions as the landscape slowly changes over time. Preserving the community’s natural areas goes a long way toward helping efforts to maintain excellent water quality in local aquifers and other waterways. That is why the Trinity Glen Rose District is urging you to learn about the parks and to live a little by visiting each one to experience the environmental beauty and ecological benefits they provide. “Learn and Live” at Friedrich Wilderness Park Windmill along Water Trail woods 1 bridge 1 Windmill along Water Trail 1/23 Numerous natural areas and community parks beautify Northern Bexar County where the Trinity Glen Rose Groundwater Conservation District (TGR) works to preserve and protect the Trinity Aquifer each day. In addition to these parks’ aesthetic value, they also play a major part in preventing pollution from entering the Trinity Aquifer and Edwards Aquifer which are both critical to the water supply in Bexar County. To highlight pollution prevention message, TGR is bringing its constituents an informative series about the six major parks and natural areas in the district. This month, we are highlighting Friedrich Park located north of Loop 1604 on Milsa Drive. Friedrich Wilderness Park offers approximately 10 miles of hiking trails with varying degrees of difficulty. It is home for rare birds, terrestrial orchids, steep hills and deep canyons. It is internationally known for bird watching. Perched on the edge of the Balcones Escarpment, Friedrich is a nesting site for the endangered Black-capped Vireo and the Golden-cheeked Warbler. In 1971, Norma Friedrich Ward bequeathed 180 acres of land on Heuermann Road near Leon Springs to the City of San Antonio for use as a public park. She also gave $100,000 to make improvements to the land. It was Mrs. Ward’s wish that the natural vegetation and native trees and shrubs be protected and that native birds and wildlife be protected and encouraged to use the park as a sanctuary. The following year, Wilbur Matthews and Glen Martin donated another 52 acres to enlarge the park according to the same guidelines specified by Mrs. Ward. The park was developed with a grant from the Texas Parks and Wildlife Department and was dedicated on August 31, 1978. Preserving the community’s natural areas goes a long way toward helping efforts to maintain excellent water quality in local aquifers and other waterways. That is why the Trinity Glen Rose District is urging you to learn about the parks and to live a little by visiting each one to experience the environmental beauty and ecological benefits they provide. For reservations and more information about the Friedrich Wilderness Park, you can visit the park’s website here . Come “Learn and Live” at Eisenhower Park Eisenhower old fence Eisenhower Park Sign Eisenhower Sunset 2 Eisenhower old fence 1/20 Numerous natural areas and community parks beautify Northern Bexar County where the Trinity Glen Rose Groundwater Conservation District (TGR) works to preserve and protect the Trinity Aquifer each day. In addition to these parks’ aesthetic value, they also play a major part in preventing pollution from entering the Trinity Aquifer and Edwards Aquifer which are both critical to the water supply in Bexar County. To highlight pollution prevention message, TGR is bringing its constituents an informative series about the six major parks and natural areas in the district. This month, we are highlighting Eisenhower Park located north of Loop 1604 on NW Military Highway. Dwight D. Eisenhower Park is a 320-acre park managed by the City of San Antonio containing excellent examples of Hill Country landscapes, including wooded dry creek beds and rocky canyons. The park features more than 6 miles of paved and unpaved trails. There are seven different trails in the park most of which are paved. The 2.5 mile Hillview Trail circles the perimeter of the park and leads to the observation tower located about midway through the hike. The one-mile Cedar Flats Trail runs through the heart of the park and contains a combination of paved and rugged terrain. All of the trails have plenty of signage posted and many of the plants and flowers you will see are marked as well. Eisenhower Park is pet friendly, but is a designated natural area park which means roller blades, skateboards and bikes are not allowed on the trails. There are several pavilions in the park for barbecues and picnics that are located near the entrance of the park. Various park amenities are available for rental and you can learn how to make a reservation at this link. The City of San Antonio also offers various types of classes in the parks and you can learn about them at this link. Preserving the community’s natural areas goes a long way toward helping efforts to maintain excellent water quality in local aquifers and other waterways. That is why the Trinity Glen Rose District is urging you to learn about the parks and to live a little by visiting each one to experience the environmental beauty and ecological benefits they provide. You can learn more about Eisenhower Park here. Government Canyon State Natural Area Government Canyon Cover 3V3A6961 3V3A7100 Government Canyon Cover 1/31 Government Canyon State Natural Area is part of the Texas State Parks system. It is designated a natural area rather than a state park because its primary focus is protection of the property's natural resources. Given that designation, access and recreational activities may be restricted if the Texas Parks & Wildlife Department (TPWD) deems such action necessary to protect the environment there. The reserve is located in northwestern Bexar County inside the Trinity Glen Rose Groundwater Conservation District’s boundaries. It protects a large, relatively pristine tract of Hill Country terrain that is home to numerous and diverse species of plants & wildlife and the upper Culebra Creek and Leon Creek watersheds. The approximately 12,000 acres of land Government Canyon State Natural Area occupies was originally purchased to protect the critical aquifer recharge zone which diverts rainfall into the Edwards Aquifer, the main source of drinking water for San Antonio. First opened to the public in October, 2005, Government Canyon State Natural Area offers more than 41 miles of trails. Visitors can camp, attend a program or guided hike, geocache, picnic, take nature photos and look for birds and other wildlife. For those looking for a place to go birding, Government Canyon is a good place to find the endangered Golden-cheeked warbler. One of the most visited features on the property are the dinosaur tracks which are located about 2.5 miles from the visitor’s center. Scientists believe the tracks were made about 110 million years ago. At that time, this location was actually near the shoreline of the Gulf of Mexico. The dinosaurs would walk along the moist, fine-grained mud and leave tracks which would then be exposed to the sun allowing them to dry and harden. Erosion over time have exposed the tracks for today’s people to discover, study and protect. The Witte Museum, University of Texas at San Antonio, Trinity University and Texas Parks and Wildlife are continuing to study and preserve these unique dinosaur tracks today. You can learn more about Government Canyon here. Crownridge Canyon Park Entrance Crownridge Canyon Map 3V3A6275 Entrance 1/15 Crownridge Canyon was the first City natural area developed as part of the Edwards Aquifer Protection ballot initiative. The 200-acre preserve features Level 1 ADA trails and Level 4 hiking trails through a variety of habitats. Features include a canopy level bridge overlook, beautiful forested canyon bottoms, hillside vistas, and restored grasslands. There are excellent opportunities to view the endangered Golden Cheeked Warbler during its nesting season. This park features interpretive elements highlighting local flora, fauna, geology and the aquifer recharge cycle, as well as the area’s early human inhabitants. The landscape at Crownridge feature native plants of northern Bexar county. Many are numbered and can be identified using the Natural Areas Plant Key. Crownridge Canyon Trails offer both gentle Level 1 trail surfaces and more natural and challenging Level 4 surfaces. Trail markers will soon be placed along the trails to identify native plants. Red Oak Trail: Red Oak is the lower trail loop leading to the bridge crossing Red Oak Canyon. It has a 1.3 mile stabilized base surface meeting ADA accessibility requirements. Level 1 . Bear Grass Trail: Bear Grass Trail is a natural surface, .6 mile loop in the upper part of the park. This trail is Level 4 and offers medium difficulty with few steep slopes and rocky ledges. Level 4. Pets, alcohol, bikes, and loud music are not allowed. Location: 7222 Luskey Blvd. 78256 Hours: Sunday-Saturday: 7:30 a.m. – sunset

Need help with a past TGR agenda, meeting minutes, or newsletter? We keep our documents archived here. TGR ARCHIVES

Looking for water data? You've come to the right place. You can find water well locations and data at this page. AQUIFER SCIENCE TGR Regional Pumping Impact Study Following notification of a proposed groundwater production project in Bexar county, TGR commenced with a regional impact study through WSP to assess potential impacts. The project would include the activation of production wells located in northeastern Bexar County. Click the link below to read the report. TGR Modeling Results Final Report TGR Research and Aquifer Studies USGS Spring Survey Results Dr. George Veni Presentation on Karst Aquifer Features of the Trinity Glen Rose Aquifer

Here you will find the latest research by the Trinity Glen Rose District in our effort to learn about the Trinity Aquifer. TGR District General Elections Next TGR District Officer General Elections will next be held on May 6, 2028 Election of Officer Information for May 2, 2026 General Elections ORDER OF ELECTION CANCELLATION (February 19, 2026) The May 2, 2026 director elections has been cancelled. NOTICE OF DEADLINE TO FILE APPLICATIONS FOR PLACE ON THE BALLOT ORDER OF ELECTION (English version ) Called January 15, 2026 ORDER OF ELECTION (Spanish version) Posted Order of Election Bexar County - Elections Office Notice Page Location of Election: BEXAR COUNTY EARLY VOTING LOCATIONS & HOURS Bexar County participates in the Countywide Polling Place Program under Section 43.007, as amended, Texas Election Code. Registered voters will be able to cast their Election Day ballots at Vote Center's identified on the County Elections website. Location to File: Location a person may file candidate applications is at 12274 Bandera Rd. #106, Helotes, TX 78023 Candidate Filing Requirements: Fill out all content legibly and completely on the " Application for a Place on the Ballot for a General Election " , click link to document provided. Once complete please file at the Location of Election, there is no filing fee. Filing dates are January 14, 2026 - February 13, 2026. Qualifications for Office: To be qualified to be elected as a director, a person must be a registered voter in the precinct that person represents, be at least 18 years old, a U.S. citizen, a resident of the State of Texas for 12 months, and a resident of the district for 6 months prior to the regular candidate filing deadline (78 days before election day), not totally or partially mentally incapacitated, and not a convicted felon, unless pardoned or otherwise released from the resulting disabilities. Details on Requirements and “Eligibility for Public Office” can be found here in the Election Code, Chapter 141.001 . Current Board of Directors and Terms Important Websites Secretary of State, Elections Division Bexar County Elections Department Comal County Elections Department Kendall County Elections Department 2024 Campaign Finance Reports 2026 Campaign Finance Reports Precinct Boundaries

Looking for water data? You've come to the right place. You can find water well locations and data at this page. Trinity Aquifer in Northern Bexar County The Trinity Aquifer is one of nine major aquifers defined by the state , stretching from the Texas Hill Country into Oklahoma, and it is the primary water source within the Trinity Glen Rose Groundwater Conservation District (TGR). Though often referred to as a single aquifer, the Trinity Aquifer is really a group of aquifers , experts say. It’s divided into three units — the Upper, Middle and Lower Trinity — and within those are more layers, or strata, made up of different formations, all of which allow water to move through in different ways and at different rates. TRINITY AQUIFER EDUCATION You can download a technical geologic and hydrologic report of the Trinity Aquifer by clicking this link. The Trinity system stretches across 61 counties from northeast of Dallas to southwest of San Antonio covering more than 10,000 square miles at the surface and more than 21,000 square miles below ground. It runs throughout much of the Hill Country, including all or portions of Kendall, Comal, Hays and Blanco counties, and is considered one of the “most extensive and highly used groundwater resources in Texas” by the Texas Water Development Board. The Trinity Aquifer is a low production aquifer which recharges slowly, with only an estimated 4–5% of rain recharging it. Despite its slow recharge rate, it stands as one of Texas’ most extensive and heavily used groundwater resources. Primarily utilized by municipalities, it also serves as a vital source for rural homes, irrigation, livestock, and other domestic uses. Trinity Aquifer Trinity Aquifer Subgroup (down dip) Trinity Aquifer in Northern Bexar County Trinity Aquifer water well depths vary from shallow, hand-dug wells to drilled wells that can be more than 1,200 feet deep based on TWDB records for Bexar County. Depths are highly variable and depend entirely on site-specific topography and geology, especially faulting. Well yields in the Trinity are typically dependent on the nature of fractures and dissolution features intersected by the well bore, which can be highly variable over short distances. Well yields are typically low (less than 20 gallons per minute (gpm) ) but may occasionally be significantly higher, with yields of 400-600 gpm being reported in some wells. Water quality within a specific aquifer can be defined or characterized in a general sense, but can vary significantly based on local geology, hydrology, and structure. The Trinity Glen Rose District is located in the southern portion of the Trinity Aquifer where it underlies the Texas Hill Country. The District includes the northern third of Bexar County as well as small parts of Comal and Kendall counties and is part of the Edwards Plateau. Although it is defined by the state as a major aquifer, the water quality and productivity of the Trinity Aquifer throughout the region, including the District, varies greatly. The District is located entirely within the San Antonio River basin and is divided by three sub-basins: the Cibolo Creek, Medina River, and Upper San Antonio River sub-basins. The Cibolo Creek, Leon Creek, Salado Creek, and the Upper San Antonio River watersheds provide for surface drainage generally from the northwest to the southeast within the District. Cibolo Creek is a tributary of the San Antonio River and drains from northwest to southeast across the Trinity Group of Aquifers, where it is a major recharge feature of these aquifers. Cibolo Creek is also the county boundary between portions of northern Bexar County and adjacent counties to the north and east. Salado and Leon Creeks flow from northwest to southeast through the middle of the District, eventually joining the San Antonio and Medina Rivers to the south. Trinity Aquifer Surface Geology & Fault Map - Click the Map to View Interactive Map Recharge to the Trinity Group of Aquifers occurs via local precipitation on its outcrop, infiltration of flows in Cibolo Creek, and through the overlying units where the Trinity is present in the subsurface. The quantification of recharge to the Trinity Aquifer in the Hill Country is difficult and estimates of recharge to the Trinity Aquifer vary significantly, from as low as 1.5 percent of precipitation to as much as 11 percent of precipitation (Muller and Prince, 1979; Kuniansky, 1989). Most estimates are between 4 and 7 percent of precipitation (Mace and others, 2000). However, the recharge dynamics in the District are quite different than the Trinity Aquifer throughout much of the Hill Country due to the rapid recharge that occurs through large recharge features, which are present in many areas of the District, but most prevalent in the Cibolo Creek area. When Cibolo Creek has water in the stretches along northern Bexar County, the losses of water from the creek are substantial and serve as a significant recharge source to the Trinity Aquifer in the District. Although this rapid recharge can occur in other isolated areas of the Trinity Aquifer in the Hill Country, it is a dominant recharge mechanism in the District. The substantial volume of recharge that periodically occurs during wet periods and flooding along Cibolo Creek creates relatively large variations in water levels in the Trinity Aquifer in the District. When water levels are high in the District, there is a natural hydraulic gradient that drives groundwater laterally to the southeast into the Edwards Aquifer. After groundwater is recharged to the aquifer, the karstic nature of many of the formations allow the rapid movement of groundwater through the aquifer. The result can be large fluctuations in water levels in wells as groundwater moves quickly through the aquifer. Dolomitic Limestone Fossiliferous Limestone Shale and Sandstone Discharge from the Trinity Aquifer - When water levels are high in the District, there is a greater driving force to move groundwater laterally to the southeast into the Edwards Aquifer. While the Edwards Aquifer does receive large volumes of water from the Trinity Aquifer, water wells are also a primary source of discharge from the Trinity in Bexar County. Historic pumping from the Trinity Aquifer within Bexar County has increased over time, from approximately 11,000 acre-feet in 2009 to greater than 23,000 acre-feet per year since 2016. Production from wells can vary significantly based on water levels in the Trinity. Water demand will continue to increase in the Hill Country, and this may add more pressure to increase groundwater production from the Trinity Aquifer in the District. Production from the Trinity Aquifer is primarily used for municipal purposes, with some production for domestic, irrigation, livestock and mining. More than 80 percent of the current groundwater production from the Trinity in the District is used for public water supply. Brackish Water in the Trinity Aquifer The Texas Water Development Board (TWDB) Brackish Resources Aquifer Characterization System (BRACS) Program was established in 2009 to map and characterize the brackish portions of Texas aquifers to provide useful information and data to regional water planning groups and other entities interested in using brackish groundwater as a water supply. Both Texas industry and public water supply planners are looking at brackish groundwater to supplement stressed freshwater resources. Brackish groundwater is a significant water supply component that can be used to meet future water demands. Groundwater desalination strategies in the 2022 State Water Plan represent additional new groundwater supply for nine of the regional planning groups. Desalination of brackish groundwater has been recommended as an additional supply volume of approximately 19,000 acre-feet per year in 2020, with an additional 157,000 acre-feet per year of brackish groundwater recommended to be in service by 2070. Trinity Aquifer in Northern Bexar County (dark green) Bexar County The Hill Country Trinity Aquifer is the southern portion of the larger Trinity Aquifer system, one of Texas’ nine major aquifers. It extends across roughly 15,500 square miles of Central Texas, spanning 24 counties from the Hill Country to the Gulf Coastal Plain. Composed of layered Cretaceous-age limestone, sandstone, and shale of the Trinity Group, the aquifer thickens southeastward and is heavily faulted by the Balcones and Luling Fault Zones, which influence groundwater flow and salinity. The aquifer includes six primary water-bearing units divided into 3 hydrologic units: the Upper Trinity, Middle Trinity, and Lower Trinity. The map above displays the study area boundary and the official TWDB Trinity Aquifer boundary. The outcrop (in dark green) is the area where the aquifer is exposed at the surface or is very close to the surface. The downdip or subcrop (in lighter green) is the portion of the aquifer that is below the surface, under other formations. The BRACS study boundary extends further downdip than the official aquifer footprint because brackish studies focus on deeper portions of the aquifer. VIEW THE BRACKISH WATER STORY MAP HERE

Here you will find the latest research by the Trinity Glen Rose District in our effort to learn about the Trinity Aquifer. TGR Board Adopts Changes to Precinct Boundaries Redistricting is part of the election process in the United States. And because the Trinity Glen Rose Groundwater Conservation District’s (TGR) board members are elected, the district recently reviewed its population changes over the past 10-year period and found it needed to adjust its boundaries due to population shifts in the precincts. The objective is to balance the per capita representation for each precinct in order to give all district constituents an equal say via their elected representatives regarding district policies and future directions. The TGR Board used the following criteria to make its final boundary adjustments: begin and end with identifiable boundaries maintain communities of interest & neighborhoods use whole voting precincts if possible base plan on existing districts adopt districts of relatively equal size draw districts that are compact and contiguous keep existing incumbents in their districts to preserve previous voter wishes tailor plan to comply with the Voting Rights Act The Board opened its planning documents up for public review and comment. At the Dec. 4 board meeting, the Board held a public hearing to receive any final comments before taking official actions to change the TGR precinct boundaries. After a thorough planning process and public comment period, the TGR Board officially changed its boundaries to reflect a more consistent population base in each precinct. Due to the change in boundaries, the district will be holding an election to fill all precinct seats in May, 2022. Click here for more information. Please see the charts below which show the population unbalance before the boundaries were changed and then the chart with showed precinct populations in balance after the official changes were made to the precinct boundaries. These new boundaries will remain in place until the next U.S. census reports are received. Resolution Approving the Redistricting of Director Precincts Effective December 9, 2021 Newly Adopted Precinct Boundaries The map above shows the current boundaries designated by the red lines. The colored areas which extend outside of the red lines demonstrate how the precinct boundaries were redrawn to bring the district into compliance with equal population representation guidelines. Click on this link to download a PDF of this map to review it in more detail. Click on this link to see the current TGR District Precinct map. See District Precincts Map Population and Demographic Adjustments The two charts below show where the population and demographics for each TGR precinct before the board changed the precinct boundaries and how they changed after redrawing boundaries occurred. The first chart shows the existing population. The second chart shows the population representation numbers with new boundaries.

Learn about the latest activities of the Trinity Glen Rose District board of directors. ABOUT THE TGR DISTRICT TGR Management Plan TGR District Brochure The Trinity Glen Rose Groundwater Conservation District (TGRGCD or District) was created for the purpose of conserving, preserving, recharging, protecting and preventing waste of groundwater from the Trinity Aquifer in Northern Bexar County. The District was also created in response to the Texas Natural Resources Conservation Commission designating a portion of the Trinity Aquifer within Bexar County as a Priority Groundwater Management Area (PGMA). The Trinity Glen Rose Groundwater Conservation District is the governing body of only that portion of the Trinity Aquifer that is located in northern Bexar County. This Aquifer is considered very important to the State of Texas and subject to the provisions in Chapter 35 of the Texas Water Code. The TNRCC designated this area a PGMA in January 2001 and created the TGRGCD in order that appropriate groundwater management techniques and strategies could be implemented at the local level to address groundwater issues or problems within the District. A PGMA designation is given to an area “that is experiencing, or is expected to experience critical groundwater problems.” One of the primary reasons that a PGMA was designated in this area is the explosive growth in North Bexar and surrounding counties. The duty of the TGR Board members will be to ensure that the water in the aquifer is managed in a reasoned and balanced manner to allow for growth in the area, while still preserving the ability of residents or their water suppliers to draw water for their families. The District will conduct administrative and technical activities and programs to achieve these purposes. The District will collect and archive water well and aquifer data, regulate water well drilling and production from non-exempt wells, promote the capping or plugging of abandoned wells, provide information and educational material to local property owners, interact with other governmental or organizational entities, and incorporate other groundwater-related activities that may help meet the purposes of the District. Enacting Legislation The Trinity Glen Rose Groundwater Conservation District was created by HB 2005 during the 77thTexas Legislature . HB 2005 was authored by State Representatives Frank Corte Jr. and John Shields and sponsored by Senator Jeff Wentworth. The bill was signed into law and took effect on September 1, 2001 and confirmed by voters in 2002. The District was created as a result of the Texas Commission on Environmental Quality (TCEQ) designating the Trinity group of aquifers lying within northern Bexar County as a Priority Groundwater Management Area (PGMA). In 2009, the 81st Texas Legislature passed HB1518 allowing an increase of production fees and allowing municipalities to request inclusion of annexed areas into the District as provided by Chapter 36 Texas Water Code. The mission of the District is to provide rules and regulations to manage, conserve, preserve, protect, maximize recharge and prevent waste of the water resources within the section of the Trinity Aquifer located in northern Bexar County.

This the TGR District Precincts Page with a map of the five precincts where representatives are elected. Helpful Website Links US Drought Monitor - Interactive map of the current U.S. drought status. U.S. Geological Survey State Texas Water Development Board (TWDB) TWDB Groundwater Resources Texas Alliance of Groundwater Districts (TAGD) Texas Department of Licensing and Regulation Texas Well Owners Network - Fact Sheets for Well Owners Texas Commission on Environmental Quality Texas Commission on Environmental Quality Approved Water Haulers Updated July 2026 South Central Texas Regional Water Planning Group Cibolo Center for Conservation Edwards Aquifer Authority Hill Country Alliance Greater Edwards Aquifer Alliance Local San Antonio Water System (SAWS) SAWS Garden Style San Antonio River Authority San Antonio Parks and Recreation - Parks Gardening Volunteers of South Texas Texas Agrilife Extension Landscaping

The Trinity Glen Rose District partners with many great entities to teach water conservation and pollution prevention. TGR EVENTS 2021 Watersaver Landscape Tour Videos The Trinity Glen Rose District cosponsored the 2021 Watersaver Landscape Tour. This event was held online and more than 350 people took time to watch. In case you missed it, you can watch the tour videos featuring some beautiful, water-saving landscapes from around San Antonio. We'd like for you to come away with a few ideas on how you can improve the look and feel of your yard while substituting native plants for grass and other nonnative plants that require lots of water to keep healthy. Many thanks are due to the homeowners who agreed to not only let us show their yards but also participate in the videos. They are quite informative. One last item...you can download the plant lists we put together for each yard, which should help you next time you visit a nursery to pick the right plants for your home's landscape. We hope you enjoy these videos as much as we did in putting them together. Download the plant list here. 2019 Watersaver Landscape Tour - Photos Trinity Joe 3V3A8317 Trinity 1/32 The Trinity Glen Rose District cosponsored the 2019 Watersaver Landscape Tour. This tour offered residents the opportunity to visit various landscapes in various parts of the city to see how they can improve the look of their yards while saving water. Click the arrows to view the photos.