Quincy Groundwater

Science Center Objects

The Issue: Since 1952, water diverted from the Columbia River for irrigation in parts of the Quincy Subarea in eastern Washington has resulted in rising groundwater levels and increased groundwater flows and storage. Managers of groundwater in the area need a better understanding of the flow system before and after the start of irrigation.

How the USGS will help: In a joint effort with Washington State Department of Ecology and the Bureau of Reclamation, the USGS will define the hydrogeology of the study area, determine flow patterns of the groundwater system and quantities of movement, and create a computer model to simulate the effects of management scenarios on groundwater availability.

Problem: Since 1952 water diverted from the Columbia River has been used to irrigate parts of the Quincy Subarea in eastern Washington. As a result of the surface-water irrigation, groundwater levels generally have risen in the area. The increases in groundwater fluxes and groundwater in storage have created a need to better understand the flow system before and after the start of irrigation to assist in the management of the groundwater resources.

Objectives: The objectives for the groundwater study have been defined by a joint effort of the Washington State Department of Ecology and the U.S. Bureau of Reclamation. These objectives are to: (1) define the hydrogeology of the study area, (2) determine flow patterns of the groundwater system and quantities of movement so that the effect of stresses on the system in terms of artificial recharge and groundwater withdrawals can be documented, and (3) simulate the effects of management scenarios on groundwater availability.

Relevance and Benefits: The study contributes to the goals of the U.S. Geological Survey (USGS) strategic science direction " Quantifying, Forecasting, and Securing Freshwater for America's Future," as identified and described in the Strategic Science Plan of the USGS. The study addresses groundwater availability and sustainability, and surface-water and groundwater interactions as related to water-resource management, which are priority issues for both the USGS Water Mission Area and the USGS Washington Water Science Center. This study will provide resource managers information to assist in the development of a long-term management plan to meet the needs of future water demands within the Quincy Groundwater Subarea, while also working to protect and improve its natural resources. Also, the public will gain an improved understanding of the source of their water supply.

Approach: Data collection, hydrogeologic framework characterization, and assessment of the water resources of the Quincy Subarea will be conducted on a basin-wide scale and all major components of the water budget will be examined. Existing hydrologic and hydrogeologic data will be compiled and entered into the appropriate databases and those data will be analyzed to determine seasonal and long-term trends in water levels and baseflows. New framework data focusing on the unconsolidated sediments and elements of the existing USGS Columbia Plateau groundwater-flow model (Ely and others, 2014) will be combined in a model to simulate changes in basin-fill groundwater storage due to existing anthropogenic stresses and potential management scenarios. A USGS Scientific Investigations Report will be published to describe the conceptual model of the flow system and present comprehensive water budgets.