There's so much to say/write about on this issue.
As mentioned above, tap water is cheap, very cheap. That is going to change and quickly. If you buy your water from the City of San Diego, expect a big increase in your water bill over the next several years. Rates have to be increased because City has done an good job at building it's water resources and water independence by building additional storage and reuse treatment plants. San Diego County as a whole is doing a good job. We have the Carlsbad desal plant (delayed for years because of Surfrider, etc...), the Oceanside Pure Water plant, the Padre Dam PURE Water plant, the Sweetwater Authority desalting plant, etc....
There are several other regions in the State building advanced treatment plants as well but it won't be nearly enough and costs $$$$. So we will pay unless the State/Fed funds these improvements with grants. If the money is made available, expect 2-5 years to construct small to medium large plants and 5-7 years for large to big plants. In addition to potable reuse, brackish water desalting and PFAS treatment are a big help allowing us to tap into what were in the past unusable ground water resources. All of this takes $$$$ so our rates have to go up.
For ocean water desal to move forward, the Coastal Commission has to get on board. Based on the Huntington Beach vote, they are not. Ocean water desal is the most costly of the options but the source is unlimited which in my mind makes it very attractive.
Regarding reservoir level manipulation, the BoR has been doing that for years. Right now, they are focused on ensuring that there's enough head pressure behind each dam to keep the turbines turning. The BoR is on of those agencies that doesn't need to pull a shenanigan to get emergency money. The issue is, we are in a severe drought and there is no water flowing into the watershed that supplies the CO River. Couple this with the decades of ground water mismanagement, we're fvcked!