Water Shortage

We have hot days like a real summer these days here. I have never seen any rain drops in a week. I think it seems like the rainy season has finished here in Matsue, Shimane Prefecture, but the Met Office have not declared that the rainy season has gone.
Recently, the authorities would announce it a few days after it was over. If the rainy season was be over now, I would be worried about the water shortage here. Our city, Matsue, often has a crisis because we do not have big rivers or dams in our city. Of course, we have a large lake called Lake Shinji, which is the seventh largest lake in Japan, but it can't be used for drinking because the water of the lake is brackish.
I hope someone will invent some equipment to make real water from salty water or brackish water and if it could be done any water crisis in the world would be solved.