Why Nueces County Has Less Groundwater Than Its Neighbors
Understanding the science and policy behind our regional water limits
Ever wondered why Modeled Available Groundwater (MAG) is lower in Nueces County than in neighboring counties such as San Patricio or Kleberg? The answer lies in a mix of geology, planning limits, and conservation priorities designed to safeguard our shared aquifer system.
1. Stricter Limits to Protect Local Aquifers
Regional water planners set long-term “desired future conditions” (DFCs) that define how much drawdown (lowering of water levels) is acceptable in each county’s portion of the aquifer by 2080.
For Nueces County, the approved drawdown limit is approximately 26 feet, one of the most conservative thresholds in the region. These limits are established by the Coastal Bend Regional Water Planning Group (Region N) to ensure groundwater levels remain sustainable.
As a result, Nueces County’s MAG — the modeled volume available for annual withdrawal while meeting those conditions — is roughly 7,600 acre-feet per year, compared to over 49,000 AFY in San Patricio County and more than 12,000 AFY in Kleberg County.
2. Coastal Geology and Salinity Risks
Unlike inland counties, much of Nueces County sits on the coastal edge of the Gulf Coast Aquifer, where freshwater zones become thinner and saltier closer to the bay.
Excessive pumping can draw saltwater upward or inland, threatening freshwater supplies. Because of this delicate balance, groundwater availability models for Nueces are intentionally more restrictive to prevent saltwater intrusion and preserve long-term water quality.
3. Comparing Groundwater and Municipal Planning Data
According to consulting hydrogeologists working with the City of Corpus Christi, the current sustainable groundwater production capacity from both planned well fields is estimated around 28 million gallons per day (MGD) — equivalent to 31,364 acre-feet per year.
That’s roughly five times higher than the MAG recommended by the regional planning group to maintain the adopted DFCs as of September 11, 2025.
It’s important to note that these modeled figures are planning tools, not pumping mandates — and do not account for future developments such as the South Texas Water Authority (STWA) and Seven Seas projects or other industrial growth in rural Nueces County.
📎 Source: Coastal Bend Regional Water Planning Group – Region N
4. Legal and Management Context
Texas Groundwater Law
Texas follows the Rule of Capture, allowing landowners to pump groundwater beneath their property for beneficial use. However, this rule is balanced by Groundwater Conservation Districts (GCDs), which can set limits to protect shared aquifers.
Currently, rural Nueces County has no active GCD — meaning groundwater use is guided primarily by state planning frameworks under Groundwater Management Area 16 (GMA-16) and its partner districts.
Surface–Groundwater Disconnect
Texas law treats surface water (like the Nueces River) and groundwater as separate legal entities, even though they’re physically connected. This distinction complicates efforts to manage springflow and river baseflow, which depend on groundwater discharge to sustain downstream ecosystems.
5. Environmental and Economic Considerations
Reduced Springflow & Baseflow: Declining aquifer levels can lessen freshwater seepage into the Nueces River, affecting river health and estuarine balance.
Salinity & Estuary Impacts: Lower river inflows raise salinity in Nueces Bay, impacting oyster reefs and coastal wetlands.
Recharge & Water Quality: Over-withdrawal or contamination can reduce natural recharge rates and introduce pollutants or saltwater into freshwater zones.
Shared Resource Dynamics: While individual landowners have pumping rights, heavy withdrawal across many wells can lower water tables and reduce available supply for neighboring users or shallow domestic wells.
6. Looking Ahead: Sustainable Management for Future Generations
Balancing groundwater access with environmental protection is one of South Texas’ most complex water challenges. In the absence of a local conservation district, continued coordination among landowners, municipalities, and regional planners remains essential to preserve both the quantity and quality of our aquifers for generations to come.
References:
Coastal Bend Regional Water Planning Group (Region N). (2025). Groundwater Availability and Desired Future Conditions for GMA-16.
City of Corpus Christi. (2025). Consulting Hydrogeologist Reports on Groundwater Availability.
Texas Water Development Board. (2024). Groundwater Management Area 16 Documentation.
Texas Supreme Court. Edwards Aquifer Authority v. Day, 369 S.W.3d 814 (Tex. 2012).
