I don't have an exact prediction for Lake Mead's water level, and of course such a prediction would be risky, given the uncertaity of El Nino's effects in the region. But prospects are good for decent, and maybe even quite heavy, rainfall during the coming 6 months in your region, which would help refill Lake Mead. Please see my reply to "Sunday" above, who has asked the same sort of question but for southern California rainfall. The answers are similar for Lake Mead to what they are for southern and central California.