The Other Hydrogen Economy™ and 3D Precision Irrigation™ are competent means for supplying Renewable Water, Power, and Agriculture.™
The Other Hydrogen Economy™ uses renewable energy to extract hydrogen from seawater, or from other sources, via electrolysis and transforms it into electricity and potable water. This creates a micro-grid which may or may not connect to the regional grid. A portable version of this is explained at: https://theotherhydrogeneconomy.com/renewablewaterandpower.html
According to the BBC, there is a global race to produce hydrogen from the planet's oceans. https://www.bbc.com/news/business-55763356
3D Precision Irrigation™ is an autonomous, sensor-based, data-driven, irrigation system that automatically adjusts irrigation cycles to the changing needs of the plants and trees that it monitors (without AI). Details are available at: newhydrotech.com
Deployed together, these comprehensive technologies enable us to start agricultural communities in areas where it was previously thought to be impossible due to a lack of resources. These communities, if started soon enough, might help to prevent, or reduce, the vast displacement of people that are anticipated to some day be in search of inhabitable land.
In California, these technologies would enable us to populate our vast deserts, transform desert terrain into fertile soil, and in doing so, offset the water and agricultural losses in the San Joaquin valley that are inevitable (from rising sea levels) due to the threats to the Sacramento–San Joaquin River Delta.