Did you know that in some places, our groundwater aquifers are directly connected to surface water and influence groundwater resources and ecosystem health in these areas? This interconnected surface water is characterized by surface water bodies (e.g. streams, rivers, and lakes) interacting with aquifers in all types of landscapes, and the biological health of plants and animals in those places is dependent on this flow of water. The interaction takes place in three basic ways: surface-water bodies gain water from inflow of groundwater through their bed, they lose water to groundwater by outflow through the bed, or they do both, gaining in some areas and losing in other areas. Many variables contribute to these outcomes, including climate conditions, elevation, and directional flow of water and groundwater pumping.
This year, with funding from the state grant, the GSAs are working to better understand interconnected surface water in our basins via collaboration with a work group of experts including scientists from state and local agencies and organizations like the Laguna de Santa Rosa Foundation, Sonoma County RCD and Gold Ridge RCD, Sonoma Ecology Center and the California Department of Fish and Wildlife. The group will assess the location, quantity and timing of depletion of surface water, hoping to better determine if the depletion of surface water is causing a significant impact to groundwater levels, and determine the impact of groundwater pumping on habitats associated with interconnected surface water. Field work will commence in Summer 2025 with many data collection activities such as monitoring and measuring flow rates and water temperature, oxygen and moisture levels in streams and a survey of other environmental health and habitat conditions.
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Curious to know more about this topic, in depth? Read Depletions of Interconnected Surface Water, and Introduction from the California Dept. of Water Resources Sustainable Groundwater Management Office.