RECHARGE ENHANCEMENT
From Rain to Recharge
Aquifer recharge enhancement (ARE), also known as Managed Aquifer Recharge (MAR) or Aquifer Storage and Recovery (ASR), is the intentional human process of adding water (like stormwater, treated wastewater, or surface water) to aquifers to replenish groundwater supplies, buffer against drought, and improve water security. Methods include infiltration basins, injection wells, and in-channel modifications, with benefits like reduced evaporation, water treatment as it percolates, and cost-effectiveness compared to surface reservoirs.
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The Trinity Aquifer recharges slowly from rainfall on its outcrop areas and seepage from streams, with water moving through its complex fractures and layers, unlike the faster Edwards Aquifer, with recharge rates varying greatly by region, often only 4-6% of rain, and is affected by urban development reducing natural infiltration, making artificial recharge efforts crucial for sustainability.
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Watch the general water cycle 3-D model simulation below to see how precipitation falls on the Earth's surface, collects in rivers and creeks running across the land and then recharges an aquifer, like the Trinity Aquifer, through fractures and sinkholes in the riverbed. The rainfall then makes it way through various fissures in the various rock formations that make up the aquifer. Healthy soil and vegetation improve the land’s ability to absorb water.
Trinity Aquifer Recharge Occurrence - How Recharge Occurs
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Precipitation & Streams: Rain falling directly on the aquifer's exposed (unconfined) areas, as well as water seeping from rivers and ponds where the ground slopes downward, replenishes it.
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Karst Features: Water travels through fractures, bedding planes, and solution cavities (karst) in the limestone, allowing for both rapid flow and localized storage.
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Inter-Aquifer Flow: Some water can also move from the overlying Edwards Aquifer down into the Trinity in certain areas, though this is less significant than direct recharge.
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Recharge rates are not uniform; some sections replenish quickly, while others take much longer, making management challenging.
​Common Recharge Enhancement Techniques
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Berms and Swales – To slow and sink water.
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Rock or Brush Structures – To slow and sink water.
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Grassed Waterways – Shaped Channels lined with vegetation that slow rainfall runoff and encourage infiltration.
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Check Dams – Small barriers placed in drainage ways that slow water, spread it out, and increase soak-in time.
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Rangeland Restoration – Improving soil health and perennial vegetation so the land absorbs more rainfall.
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Recharge Basins – Engineer shallow basins that temporarily hold stormwater, letting it soak in instead of running off.
The video below is a segment from a Trinity Glen Rose District sponsored Go Gardening Show. The video was shot at the Edwards Aquifer Field Research Park in Northern Bexar County along the Cibolo Creek. You'll get a great look at how berms, swales, small rock dams, enhanced vegetation and shallow recharge basins help move water from rain to recharge.
Cibolo Creek in Northern Bexar County
Cibolo Creek in Northern Bexar County
Cibolo Creek is a major Recharge feature to the Trinity Aquifer
Recharge for the Trinity Group of Aquifers occurs via local precipitation on its outcrop. The outcrop area takes in recharge flow from the Cibolo Creek and other overlying units where it is in the subsurface. When Cibolo Creek has water in the stretches along northern Bexar County, the movement of water from the creek into the groundwater 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.​​
Helpful Resources - From Rain to Recharge
Soil Erosion is a form of soil degradation in which the top layer of soil is carried away by wind and water. Rain and channelized water flow dislodge and wash exposed soil downhill. This cumulative loss of soil poses a major challenge to landowners and managers.
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The Hillside Stewardship guide highlights a series of erosion-control structures that Hill Country landowners and managers are using to slow and sink water into the land.
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Just click on the cover photo of the guide to the left to download it.
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If you'd prefer a video on the topic, you can watch the "Hill Country Groundwater Recharge With Bryan Hummel" by clicking the video link.