Aquifer Recharge Enhancement
The concept of storing excess water underground for later use is typically referred to as aquifer recharge enhancement. Aquifer recharge enhancement can include recharge structures for infiltration enhancement or injection of water into aquifers. The use of artificial recharge to store surplus surface water underground can be expected to increase as growing populations demand more water, and as the number of good surface water reservoir sites still available for construction become fewer. There are several key advantages to aquifer recharge enhancement over surface water reservoirs.
•Minimal Evaporation
•Reduced Environmental Impacts
•Competitive Costs
•Flexible Implementation
•Broad Range of Applications
Texas Projects
There are numerous examples of existing aquifer recharge enhancement projects in Texas.
•Dell City – uses injection wells downstream of flood control dams to divert stormwater into the Diablo Plateau Aquifer system.
•El Paso – uses injection wells to store highly treated wastewaters in the Hueco Bolson Aquifer.
•Edwards Underground Water District – uses rainwater diversion structures to divert excess rainwater into caverns and sinkholes in the Edwards Aquifer.
•San Antonio Water System – uses injection wells to store excess Edwards Aquifer water in the Carrizo Aquifer.
•Kerrville – uses injection wells to store excess Guadalupe River water in the lower Trinity Aquifer.
GBRA Proposed Recharge Enhancement Project
The Texas Water Development Board has approved a loan from the Water Infrastructure Fund to the Guadalupe Blanco River Authority (GBRA) to finance development costs of the Mid-Basin Water Supply Project. GBRA will use these funds to perform a feasibility study for its Mid-Basin Water Supply Project to identify surface and groundwater supplies and transmission delivery options to meet the needs for entities in Hays, Caldwell, Comal, Guadalupe and Kendall counties. The study will include an evaluation of alternative water management strategies including aquifer recharge enhancement.
The aquifer recharge enhancement study will assess the recharge capabilities of the Carrizo Aquifer outcrop area through surface infiltration. Water infiltration tests will be conducted along various intermittent stream channels in the outcrop area to assess the infiltration rate of the aquifer sands.
If the feasibility study proves favorable for a surface water infiltration recharge project, GBRA proposes to use excess Guadalupe River water as the source water. The water would be collected in the vicinity of the spillway in the City of Gonzales and piped to the City of Luling treatment plant where solids would be settled out of the water. The water would then be transported through underground pipelines across the outcrop area of the Carrizo Aquifer in Caldwell County. Discharge pipes would rise to the surface at key infiltration areas determined by the feasibility study and the water would flow across the land surface and slowly infiltrate into the Carrizo sands.
For more information on aquifer recharge enhancement contact the Gonzales County Underground Water Conservation District at (830) 672-1047.