[bobthepanda]

California has strong local governments captured by NIMBYs which makes intra-jurisdictional projects hard and inter-jurisdictional ones nigh impossible.

As an example, the LA River is a giant concrete channel that rushes water into the Pacific. There is some support for restoring it into a more absorbent wetland state but it will take decades and doesn’t cover the whole river.

As a more farcical example, the recent storms have downed a tree across the Caltrain commuter rail line. They are slow on removing it because the jurisdiction the tree fell in consider it a historic tree despite the fact that it is eucalyptus, a species invasive to California.