There's less space but you can always build up. But none of the Cali cities allow this. That's why despite California's huge population you don't see any cities with skyscrapers and traffic is so bad.
Building upwards also solves the transportation issues.
Look at places like Tokyo and Singapore in comparison to Cali coasts. They're are all space constrained but these places managed to fit 20X the people in the same space and they still don't have Cali level traffic problems
As an aside, I came across a Tokyo density map overlaid on a map of CA (Greater Tokyo Area, not just the city of Tokyo) and it would be like taking the entire population of CA and condensing it into the city of Los Angeles.
Water usage in my small, coastal, mountain constrained town has decreased even as population has increased and number of connections to the water system have increased.
Check out page two of this PDF for the statewide picture; our use statewide urban water usage is going down, from a peak in 1995, even as our population increases:
https://cwc.ca.gov/-/media/CWC-Website/Files/Documents/2019/...
I first became aware of this when lots of people were complaining about water use for a new apartment complex that included below-marker-rate units, as it seemed preposterous that <100 new apartments could have any significant impact, especially when the alternative is for the same people to live further out in bigger places that need more watering of lawns.
Turns out that our city's urban water use had decreased quite a bit, despite a slowly growing population, as shown on page 25 of this PDF:
https://www.documentcloud.org/documents/20484267-2020-annual...
There's a lot of really bad and environmentally counterproductive thought from the 1970s that needs to be fact checked. People don't require a fixed amount of resources, they require a fixed amount of services, and we have gotten better and better at providing those same services with far less resources.
This is the same as the hard energy versus soft energy debate from around the same time period. We don't care about total energy available to a person, we care about the services that the energy provides. So things like greater efficiency through insulating homes, switching to more efficient lights, etc, doesn't actually result in more energy usage.
The same surprising (to some) result applies for water, apparently! Swapping out all those old, bad water fixtures, and being better about lawn watering, makes a huge impact.