Water Resources Collections and Archives

To evaluate possible effects of groundwater pumping on streamflow in tributaries draining the Rancho San Carlos development near Carmel, Monterey County, California site, I compared pre- and post-development rainfall to stream runoff. Despite higher annual precipitation, unusually low summer flows occurred in San Jose Creek after 2000, when Rancho San Carlos groundwater pumping began. These results suggest that pumping groundwater has affected flow in streams, potentially affecting recharge to the Carmel River, and flows to steelhead trout and water supply for the Monterey Peninsula.