A local groundwater management agency in Ventura County, CA recently started a pilot program that established a groundwater market among farmers in the county.
Following the early 2010s drought in California, laws were enacted to cap and eventually reduce the amount of groundwater that can be extracted. Recent advancements in water usage tracking infrastructure, combined with the law has led to a natural environment to create a cap and trade system.
Interestingly, farmers view water usage as a trade secret, and so the pilot marketplace is using block-chain to provide an anonymous marketplace. Groundwater management in California (and I assume across the nation) is regulated by a patchwork of different local government agencies and laws, but there is an awesome opportunity to provide a unified software based marketplace to establish a groundwater commodity market.
A market also facilities conservation as farmers now have incentive to lower their water usage and sell excess water on the market. A big challenge however is transportation of water across vast distances.