From the thesis of architect and designer Gabriel Guerriero comes this beautiful Sankey diagram. Labels show quantitites but I have no information on the unit of measurement.
“[This Sankey diagram] illustrates the measures of capacity and exchange of water in the Sacramento/American river confluence. Sankey diagrams are an essential constructive framework to analyze the breaching processes and estimate the manipulated water flows. The work is supported with calculations derived from California Department of Water Resources measurements as a means to describe where flows become broken, crosswired, appropriated, or out of tolerance. While the Sankey should hold a useful matrix to describe a section of a closed system, the Sacramento/American River measurements describe a broken system of flows in which the input of 100% on the top end results in disrupted quantities of output.”
A similar diagram for the Colorado river catchement can be seen here.