The Record Searchlight, Redding (Sept. 14, 2013). Jay Lund, director of the Center for Watershed Sciences, explains how Shasta Dam improved water quality in the Delta. Before the dam, he said, winter rains would fill the streams and rivers and flush out the delta. But in the summer, upstream creeks and rivers dried up and saltwater from the ocean would flow into the delta. The dam now provides a steady stream of water flowing into the delta during the summer keeping out the saltwater.