drifter with high-precision receiver to capture flow speeds

Keswick Reservoir, on the Sacramento River near Redding, receives both water and contaminants via outflow from an upstream dam. Information is needed on dilution rates and how these vary with hydrological/meteorological forcing and reservoir management. To better measure flow for a mixing study, scientists from he California Water Science Center built "drifters" mounted with high-precision receivers that capture flow speeds better than standard navigation-grade GPS receivers.