First, you are not the only ones that pay. Only 25% of the project costs are paid by OKC. Taxpayers subsidize the other 75% of the project operating fees.
Canton is like a plate, Hefner is like a bowl. When Canton is as low as it will be after this draw, Canton will be inactive. Hefner is 75 ft deep. 17 ft low at Hefner is not the same as 17 ft low at Canton. Yes, in the summer, Canton has a larger evaporation rate due to it's larger surface area, but it is not summer yet. No one asked OKC to never take the water, they only asked for you to wait, even for a month or two. It would have been worth the risk. We could have had rains between Canton and OKC that would have filled Hefner, making the draw unnecessary, saving Canton's water for a later need.
That's why I'm saying you should pray for rain. Until it rains above Canton Lake, there will be no more water from Canton. My understanding is when the water stops flowing, you are done until the Lake recharges enough to get released water to OKC.
I know what will happen to Canton and the small towns around it, and I think everyone who gets their water from Canton should know the real costs. I think people totally dependent on Hefner water should know their situation. What is plan B? I would think they have some plan B.