> If you share an aquafer with others, rights are granted based on historic seniority and frozen historic usage.

That's at odds with that I understand was the norm. As I understand it, prior to 2014, if you had access to an aquifer, you could access as much of it as you wanted. No agency tracked or limited you in any way. The water board notes[1] that while the british unregulated system was deemed inappropriate in 1903, but that in most areas of the state landowners can use it as they want, and in a few southern California basins, it's controlled by court decrees. Notably, it doesn't seem like the appropriative or riparian rights systems that are used in water above ground is used in ground water rights.

If you have references to where some water use amount is specific and based on historic usage, and also not specific to subsets of California, then I'd be happy to review them.

> Alternatively If you were the only user of an aquafer, you had the right to drain it dry. Like oil, gold, or other natural resources, you literally bought the rights to all of it with the land.

If you mine, you own the rights to the area immediately under your property. You can't buy a mine entrance and mine the whole mountain behind it. Aquifers provide an unique challenge when considering them like mineral rights. Unlike an aquifur, if you mine the mineral resource in one area the relevant resource does not get pulled from subsequent areas you do not have the rights for to replenish it.

It makes no sense that a single plot of land can drain an entire aquifer as much as they want that may be many square miles, while the plot may be much smaller. People that live above the aquifer also have rights to that water, but their resource is being stolen.

> this is where things get crazy. Instead of unwinding of usage based on priority of assigned groundwater rights per the law

I'm still under the impression that for many, many areas, there are no specific groundwater rights between parties that specify use to unwind. If you're referring to the specific scheme in a particular county, as a state level regulation, I'm not surprised that it may barrel through those, but I also think trying to appease every individual county's system would be untenable.

> The commissions don't have the legal power to take away the water rights

They don't need to, if the state water board is to be trusted (but they are incentivized to not believe that, so if you have an alternative set of information I would be happy to read it). As the state water board presents it[1], "In the 1903 case Katz v. Walkinshaw, the California Supreme Court decided that the “reasonable use” provision governing other types of water rights also applies to groundwater." If that's the case, even though CA hasn't been regulating groundwater use much and in most places, doesn't mean they can't, and that's what they're doing now.

> However, most small to moderate farms don't have funds for a decade of legal battle against the state (as intended).

That's why there are special interest groups that I'm sure are behind a few cases to provide some muscle to try to get case law decided or some laws/regulation deemed unconstitutional. Every individual small farmer is not in an active case, they're waiting on bigger cases to come back with decisions they can use. I'm sure we both know how this works.

> The implementation is not to structured to curtail "overuse". "Fines" are a flat rate/gallon and set above 10x the possible revenue/gallon in some areas.

That seems like a good way to get farmers to stop growing water intensive crops and focus on crops that use much less water.

> This would keep them from losing their lives work and recoup costs, but this unacceptable.

Sounds a lot like people trying to get around the current regulations and changes in the hope it will all be reversed or changed in a year or two, in my opinion.

> The farmers gambled that the rule of law would protect them and respect their groundwater rights

I would say they gambled that the complete lack of state level regulation that they'd enjoyed to date would continue.

> They knew it was coming but had no possible exit strategy. Nut trees are profitable but have long lead times to return investment, especially smaller farms with lower profit margins.

And we've known for a long time that water was a problem, and the laws on the books are 6-7 years old at this time. Anyone that was planting nut trees a decade ago was taking a gamble they lost out on.

1: https://www.waterboards.ca.gov/about_us/water_boards_structu...