[tamade]

The reason is California lacks infrastructure to collect rainwater. Rain hitting urban areas mostly heads out to the ocean or into the sewage network. The tech and engineering know-how to collect and recycle storm water at scale is available-- Singapore does a great job at this.

[hinkley]

California farmland lacks the technology to collect rainwater. If you catch the water high in the watershed you don’t have to deal with the deluge at the bottom. Also ground water can end up being aquifer water.

[WalterBright]

Terracing is an ancient technology that turned arid land into gardens.

[hinkley]

Indeed.

There’s a book out of copyright for a few decades called Farmers of Forty Centuries which tries to answer the question of “how is it the Chinese haven’t destroyed their fields in 400 years like we have?”

A lot of it is the slowing of the water, but also harvesting silt from the rivers and canals to build up material and keep the waterways from silting up.

A question I’ve had since reading that book is what has happened since the industrial revolution? Did manufacturing effluent break that process, and if so how extensively? Only in the deltas or how far upriver?