Disputes over Indian water rights are long-standing, expensive to resolve, and hinder the management of water resources at the local, State and National levels. The settlement of Indian Water Rights is a process by which the water claims of major water rights holders are settled providing certainty that improves water resource management. The Federal trust responsibility to American Indians and policy promoting self-determination and economic self-sufficiency is a major role for many Federal agencies with water responsibilities. Although the USGS is not directly involved with Indian Water Rights negotiations and settlements, the USGS Water Resources Mission Area and Water Science Centers provide decision makers with technical information needed to support water rights settlement work. USGS scientists work closely with tribal leaders around the country to address water availability issues related to the quantity and quality of water on tribal lands. In 2017 thru 2019, the GWSIP received dedicated cooperative matching funds (CMF) to continue working closely with tribal leaders in conducting water resource investigations to address Indian Water Rights negotiations, implementations, and settlements. The following are some of the activities supported by these CMF:
- Provide data used to quantify current groundwater and surface-water resources.
- Determine the current conditions in water quality and aquatic ecology, where appropriate.
- Provide technical expertise and studies to address specific technical questions that arise during water rights settlements and implementations, such as the collection and evaluation of needed data, modeling or analytical studies, or evaluation of scenarios of water use.
- Provide general technical support in the areas of geology, hydrology, and water resources.
In Fiscal Year 2019, the USGS provided CMF to the following projects:
- Arizona, Navajo Nation – First year of two-year project on the development of hydrogeologic framework and characterization of the Alluvial and Regional Aquifers near Leupp, Arizona. Matched with Tribal Funds. Project activities will include geological, borehole, water-level data, and geophysical methods. Refinements to a portion of an existing groundwater model will also be completed.
- California, Cahuilla Band of Indians and the Ramona Band of Cahuilla – The USGS is collecting hydrologic data, increasing the understanding of the water balance and aquifer properties, along with hydrologic characteristics of the Anza Basin. Specific activities include collecting of groundwater-level data, evaluating surface water/groundwater interactions and fluxes, and analyzing evapotranspiration and groundwater outflow from the basin. High-resolution time-lapse gravity measurements have been added in 2019.
- New Mexico, Pueblos of Acoma and Laguna – The final year in the assessment of current water resources to inform negotiations for the water-rights settlement. The USGS is characterizing and quantifying current surface-water and groundwater resources, how these resources are interconnected, and how these resources might be affected by changing stresses to inform negotiations for the water-rights settlement.
- Montana, Blackfeet – First year of the evaluation of water resources of the Blackfeet Reservation after a recent Water Rights Settlement and Water Compact. The goal is the development of an overall water management plan, planning and development of water settlement projects and tribal administration of water resources. Initial data collection efforts may begin this year.
- Utah, Navajo Nation - First year of two-year project to assess the feasibility of managed aquifer recharge by completing a pilot-scale test of a trench infiltration system. The effort includes groundwater modeling to predict larger impacts based on the pilot-scale test.