Sailing the Salt Line
… Today, Carquinez Strait is where the coast meets the valley, but the line of engagement between fresh and salt water is always moving, and it even varies vertically in the water column. Bigger freshwater outflows push the salt line westward; humans regulate these flows from January to June. X2, as scientists call the salt line’s daily (and vertical) average, is defined as a distance from the Golden Gate Bridge. Its location is a subject of intense political interest, because it is influenced by the amount of water we Californians use. That’s been true ever since we started damming the rivers and plowing the Delta.