Columbia River Basalt groundwater flow

Representation of features within a typical single CRBG flow. Most groundwater flow occurs in the FLOW TOP ZONE and FLOW BOTTOM ZONE, which make up a relatively small proportion of the total flow thickness. The region labeled FLOW INTERIOR have very low permeability and is responsible for the slow rates of groundwater recharge described in this study. Figure 5 from Kahle and others, 2011.