Sorry to see people with a very limited experience write comments on this forum. Yes there is plenty of water in Yunnan but mostly in rivers that just passes through. The higher places that are dependent on rainfall, and Kunming is part of that, lack water. Indeed some of it is due to bad planning and wastage but in general there has not been enough water for Kunming but especially for farmers that are dependent on it. When I travelled through the province just before the rain season I was shocked about how dry the countryside was and how low, even dry, the reservoirs are. Even natural lakes have much lower levels and wetlands are drying out. Not only that but the damage caused by wild fires has been enormous.
However; and I think that was the question, the water supply in Kunming is largely back to normal and even when it was restricted it was still manageable for house hold use by filling up some buckets during the supply period. Mind you, I was glad that I was not running a restaurant or something like that during the restricted period.
To put things in perspective. The Kunming water use is about 100 litres/person/day. The bare minimum is 5 litres/person/day (UNHCR Guidelines)
Anyway hardly anybody drinks the water (Also that is quite posible) and one commenly has 18 litres drinking water supplied for a few kuai at home nearly 24/7.