Where Oldpunk and myself live, it's typically 20-30+ days a year well over 100F. 110-115 even for a few days. But...it'ds a dry heat, so the water is evaporated really fast.
Water supplies here are a two pronged issue. On the one hand, you have what is called raw water, and then there's drinking water. Drinking water supplies are different, they cost more due to treatment and the supplying is different also.
California has massive amounts of water available for residential and industrial use. We only use about 4% for residential and 3% for industrial use. This includes landscapes, parks and golf courses etc which is roughly 80-90% of this 7% total.
Where is the other water used? To irrigate 1 million acres of crop lands in a desert. That accounts for 47% of the water. So what about the 46%? Livestock. Yep, cattle, chickens, milk, eggs and other critters. A cow drinks 23 gallons per day compared to a human, 1 gallon.
So 93% is use for agriculture. They want CHEAP water. Cities will pay a premium for water, they can consider things like desalting the water, which is okay for drinking, but if the desalt plants break down, which is often the case, then there's a big issue. But this is simply impossible for large scale agriculture. Cost way too much and produces too little.
The other issue with increased temps: as global temps climb and local temps do also, the snow pack ........which supplies the water.............climbs ever higher in the mountains. Since mountains are only so high, this means less and less snow. So less and less water.
Damns will not fix this issue either. They also cost a lot to maintain and who pays for them? State tax payers, and Federal tax payers. Same with all the damns here and the irrigation canal aqueduct projects.
Source: Pacific institute, 2012 Water report.
Now what happens when aquatic weeds infest the canals? It reduces the flows by 90%, clogs pumps and intake screens, mosquito habitat, lowers water quality. So when water is a serious resource that's fought over, pest like aquatic weeds become a big issue.
All the stakeholder sides can get behind fixing those issues.
For many folks, when a drought starts, the water quality also goes to the dog house. KH rises, TDS rises etc. Then plant issues start in your tanks.
Water is a funny thing.