… Last year, San Diegans paid almost $148 million to the Imperial Irrigation District for what amounts to just over 40 percent of San Diego’s water supply. That funds about half of the Imperial Irrigation District’s budget on the water side, an agency that operates almost debt free. (It also operates a public energy utility with an over $775 million budget.) And it was the San Diego deal that paid $5.7 million for this reservoir. … The water San Diego buys from Imperial Valley is some of its most expensive supply. A few San Diego political leaders have suggested the Water Authority sell off that water, arguing that the region doesn’t need all of it as rates continue to rise despite San Diegans using less.