I am worried about water

This year is the first since I have been here that the lake did not spill over. As I learn the nuances of the vineyard, I find that with an irrigation regime that starts in April, I get a  healthier canopy,  better set, and fruit that matures sooner. In our current extreme drought conditions, the vines need more water, and I have less. My reservoir is nearly empty, and it is only mid-July.