Impacts on Surface Waters
Generalized ground-water-flow pattern in the Columbia Plateau aquifer system.
IMPACTS ON CRAB CREEK
Overpumping of the Odessa Aquifers is also causing surface water depletion. The upper basalt aquifer system in the Odessa Subarea feeds Upper Crab Creek, an intermittent stream deeply incised into the Columbia basalts.
According to the local watershed assessment, Crab Creek receives a substantial portion of its flow from the Wanapum basalt aquifers. It is unknown to what extent the groundwater pumping is contributing to low flows and de-watering of Crab Creek, however, the Odessa Aquifers do discharge to Crab Creek and other small streams in the area. The decline in basalt aquifer levels is likely having some effect on streamflow.
Scarce waters provide important habitat on the semi-arid Columbia Plateau. Even ephemeral and intermittent streams, potholes and springs provide for the seasonal cycles of plants and animals. But the state of Washington does not manage water resources in this region to ensure that habitat is protected.
IMPACTS ON THE COLUMBIA RIVER
Groundwater in the lower basalt aquifers beneath the Odessa Subarea flows and discharges to the Columbia River. Although state law requires the Department of Ecology to consider the “natural interrelationships between ground and surface waters,” the state has not assessed the impact of Odessa groundwater pumping on surface waters.
Diagram: Groundwater flow patterns beneath the Columbia Plateau. To enlarge diagram, click here. (Source: Whiteman, K. J., et al., The hydrogeologic framework and geochemistry of the Columbia Plateau Aquifer System, Washington, Oregon, and Idaho, U.S. Geological Survey Professional Paper No. 1413-B (1994))
“Full recognition shall be given in the administration of water allocation and use programs to the natural interrelationship of surface and ground waters.”
RCW 90.54.020(9), Washington Water Resources Act of 1971
“To the extent that any underground water is part of or tributary to the source of any surface stream or lake, or that the withdrawal of ground water may affect the flow of any spring, water course, lake, or other body of surface water, the right of an appropriator and owner of surface water shall be superior to any subsequent right in or to ground water.”
RCW 90.44.030, Washington Ground Water Code
Columbia Institute for Water Policy
Map: Upper Crab Creek, (source: WRIA 43 Upper Crab-Wilson, Washington Dept of Ecology)
Dry streambed of Upper Crab Creek in Odessa, WA. (photo: John Osborn)
Below: diagram of Coulee cross section, (WRIA 43 Technical Assessment of Crab Creek, Kennedy Jenks 2005); see also Dep’t of Ecology’s Crab Creek website