Water Resource Disputes Escalate

News & Events

October 22, 2020


Water Rights,  Water Resources,
Hydrogeology, Watershed Hydrology


Water Resource Disputes Escalate

More than half of the US was experiencing abnormally dry conditions or more severe forms of drought as the Supreme Court of the United States (SCOTUS) recently began oral arguments in the interstate water resource dispute between Texas and New Mexico. At issue is whether water deliveries from New Mexico to Texas were correctly credited when New Mexico incurred evaporation losses from water stored for Texas during a period of flooding. Climate change is expected to exacerbate the frequency and severity of such conflicts, even in areas where water disputes have been less common, such as in the northeastern US. Three additional high-stakes legal battles are expected to reach SCOTUS in the next year and these cases may have wide-ranging implications for future water rights conflicts:

  • Mississippi v. Tennessee will be the first case in which SCOTUS will be asked to determine whether groundwater is considered an interstate resource. Technical considerations include the definition and delineation of the hydrogeology, groundwater-surface water interconnectedness, and pre-development flow patterns.
  • Florida v. Georgia is a decades-long dispute over the allocation of freshwater flows in the Apalachicola-Chattahoochee-Flint River Basin, especially during droughts. Technical considerations include agricultural water use, the hydraulic connection between groundwater and surface water, climate effects on long-term river flows, and potential harms to downstream biota.
  • Texas v. New Mexico and Colorado addresses whether specific groundwater withdrawals are interfering with surface water flows that are subject to an interstate compact. Technical considerations include the strength of the hydraulic connection and quantifying water budgets.

Water resources cases are often highly technical, requiring both hydrologic expertise and interpretation and communication of complex scientific concepts for legal and regulatory audiences. Cases frequently hinge on:

  • Quantifying water moving through different parts of the hydrologic cycle (Fig. 1), e.g., groundwater, surface water, overland flow, and evaporation modeling;
  • Distinguishing between natural flow patterns and anthropogenic influences, or determining historical flow patterns;
  • Determining the degree of interconnectedness between different parts of the hydrologic cycle and different anthropogenic forces; and
  • Understanding consumptive water uses, including agricultural use, plant uptake, and reservoir operations.

Evaluating these issues frequently requires extensive data evaluation and use of complex hydrologic and climate models. These scientific factors are likely to continue being the subject of significant debate in litigation. With decades of experience working on water resources and chemical fate and transport issues, Gradient is well-positioned to help parties evaluate complex water conflicts. Specific areas of Gradient’s expertise relevant to water resource issues include:

  • Numerical and probabilistic groundwater, surface water, sediment, air, and contaminant fate and transport modeling
  • Hydrogeology, watershed hydrology, water quality, water age, and geochemistry evaluations;
  • Monitoring program and pumping test design, data assessment, evaluation of pre-development conditions, and statistical modeling; and
  • Effective science and engineering communication.

If you have any questions about the future of water resource issues or Gradient’s capabilities, please visit our website or contact:


Figure 1 Select Components of the Hydrologic Cycle



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