The dams in california were built years ago for a smaller population and since then they've only removed them.

If we simply built like the people who first came to california did we would never have water shortages again.

Any water shortage is a 1:1 failure of the state to do the clear and obvious task needed.

Water policy isn't as simple as you might think. Dams aren't a magical fix, they cause a lot of issues (like crashing the salmon populations, etc.). They're expensive to build and maintain, and the water you store in a big reservoir doesn't magically stay in place - you lose a lot to evaporation and you lose a lot that ends up going into the groundwater system. A much bigger part of the problem is western water law, where water rights are assigned based on prior appropriation and are lost if they aren't exercised. That leads to a lot of bullshit, like people growing very water hungry crops (alfalfa, rice) in the middle of the desert.

The reason we don't build like the people who first came to California did isn't because we're stupid, it's because we've learned a lot of lessons the hard way. If you're interested in some of the history I'd recommend Cadillac Desert, which is about western water in general, but which focuses a lot on California (including the machinations that the movie China Town was based on).

Can I ask why you see this as a clearcut issue? Dams have environmental costs, upfront monetary costs, maintenance costs, and can't prevent drought if conditions persist for multiple years. Why are dams the best way to address drought?

All the best sites were built on long ago. Dams require favorable geography. More can be built to squeeze out a bit more storage, but there are diminishing returns.

https://www.ppic.org/publication/dams-in-california/

At best dams let you draw down water based on average rainfall. They cost water via evaporation if you don’t have excess rainfall to store.

Thus removing dams was actually useful amid a 25 year drought.

dams have trade offs that they stop sediment outflows which can cause faster erosion. this is a big reason many california beaches have gone from mostly sandy to mostly rocky

If you look into the actual design capacity of our municipal water systems, many of them were designed for far larger populations. The EBMUD, for example, intentionally secured 325 million gallons per day in upstream capacity because that was 10x the needs of the service area in 1929. Implicitly they assumed that the service area would grow to 4 million people, but it never did, primarily because of zoning. Today EBMUD delivers only about 120 MGD. We could more than double the service area population without water issues.

The new Sites Reservoir and capacity increase of the existing San Luis Reservoir are both expected to start construction this year. Several other recent proposals like the Pacheos Reservoir have been cancelled due to cost but it is not the case that California is doing nothing re: new water infrastructure.