Michael, on the subject of contributing nothing to the river, try this one on for size. Under the original agreement for sharing the water the United States is obligated to send a certain amount past the border into Mexico. Is the U.S. getting any water from snow melt that originates in Mexico? Uh, NO. Is the U.S. getting raw sewage and industrial waste flowing south to north from Mexico via the New River into the Salton Sea? Uh, YES. Seems fair to me!
But that topic is for another thread.