A new agreement allows the San Diego County Water Authority to sell some of its Colorado River water rights to Arizona and Nevada, addressing critical water shortages in these states. The arrangement, established on Wednesday, is a response to increasing demand and dwindling water supplies affecting a vast region that serves 40 million residents and 5.5 million acres of farmland. Although water will not be physically moved, San Diego will reduce its own withdrawals from the river, creating a surplus thanks to its desalination plant that has been operational for a decade. This landmark deal marks the first large-scale water trade between states with claims on the Colorado River, which previously lacked a legal framework for such transactions. Scott Cameron, the acting director of the Bureau of Reclamation, highlighted the urgency of the situation, stating that the agreement could significantly enhance water security in the Southwest. However, details regarding the amount of water San Diego can provide and the costs for Arizona and Nevada remain to be negotiated, necessitating further legal and managerial discussions in the near future. Dan Denham, general manager of the San Diego utility, stressed the need for swift action given the ongoing water scarcity.