Managing turbidity for Delta smelt
From Maven’s Notebook:
“At the February 24th meeting of Metropolitan Water District’s Special Committee on the Bay-Delta, David Fullerton, Principal Resource Manager, and Paul Hutton, Senior Engineer, briefed the directors on the efforts to manage turbidity to reduce entrainment of Delta smelt at the export pumps in the south Delta.
David Fullerton began with an overview using a map of the Bay Delta system. He noted that the state and federal pumps are located toward the bottom of the map in the south Delta. “The Delta smelt basically live more or less in an arc from Cache Slough down into Suisun Bay and down to the bottom of Suisun Marsh; this is where they are most of the time,” he said. “However, during the winter, when we have storms, we can get a lot of turbidity coming into the system, particularly from the Sacramento River. If we get a lot of turbidity coming down the Sacramento River off these unregulated creeks that are pouring into that river after that big storms, it will pour into the Delta, and if simultaneously the exports are running at full blast, they are just sucking that turbidity south. The pumps are pulling the turbidity in and the Delta smelt are coming with that turbidity, and you can get a lot of salvage.”
There were a couple of years in the early 2000s where a lot of Delta smelt ended up at the pumps because of that scenario, he said. “Unfortunately, we don’t get a lot of water from the San Joaquin in some of these drier years, so when we pump water, it’s got to come from somewhere, and it’s coming from up the north; it brings turbidity and the turbidity brings fish,” he said. … “