The package of bills passed by the Legislature Aug. 29 to regulate California groundwater usage were called the biggest change in water law in our lifetimes by Butte County’s top water official. And there’s not a bit of hyperbole in that.

What the state did is assume authority over the water beneath our feet. It assumed authority over the water beneath your property, if you’re a landowner.

It’s the first time that’s happened in California. The feds have always asserted control over surface water, but whatever was underground — oil, minerals, water — was solely the concern of the person who owned that bit of the Earth’s surface above.

Sure, Gov. Brown still has to sign the legislation, but there’s no one who thinks that won’t happen. There are likely to be a flurry of lawsuits over government taking a private resource without compensation, but California isn’t breaking new ground here. Groundwater regulation is the rule rather than the exception throughout the West, and it’s almost curious regulation-drunk California hasn’t gotten to it sooner. The law will be upheld.

And it’s really hard to argue that it isn’t necessary. It’s unfortunate, because it’s one of those laws that says, “don’t do something stupid that harms your neighbors.” Such laws are necessary because people get stupid (well, greedy) and do things that harm their neighbors.

The particular act of stupidity that prompted this legislation is overdrafting, which is sucking up more groundwater than the land can provide.

It’s stupid, because it drops the water table, forcing deeper and deeper wells. Aquifers don’t stop at property lines, so every moron who pumps too much impacts his neighbors’ wells too. And overdrafting can lead to compaction of the soil that makes it pretty much sterile to all but the hardiest weeds.

It’s not a huge problem up here, where the ag economy is based on family farms that have generations on the ground and an eye to the family’s heritage, as well as long-term cooperative relationships with their neighbors who see things in a similar way. Farmers here aren’t going to hurt their family’s future, or their neighbors and friends

There are plenty of farmers like that in the San Joaquin Valley too, but corporate farms are more common. There, concern for a family’s legacy is replaced by maximizing the profits of stockholders. Stupid things are done, like planting higher-value crops like almonds that require a reliable water supply, even though there is no reliable water supply.

Well, there is a reliable water supply, if you have deep enough pockets to drill ever deeper, and don’t care about your neighbors who can’t keep up in the race to reach the center of the earth, and ultimately will see their farms turn to dust.

That’s happening, and that’s why these bills were passed. And that’s why it’s hard to argue with the legislation. That doesn’t mean we shouldn’t be afraid of it.

The state of California, which doesn’t have a record for gentle or even reasonable enforcement of its regulatory authority, is taking charge of yet another resource, and the most crucial one of all. Once the water beneath the ground becomes the state’s water, it can limit private abuses, but it can also foster public abuses. If it can say someone is using too much, it can also say someone is hoarding too much and it needs to share.

We’d be the hoarders, folks.

It’s unclear what will happen, because the law is, unsurprisingly, incredibly vague. The law says the bureaucracy will figure it out over the next few years. No one has to submit a groundwater management plan until 2020 (we here get a couple of extra years), and no one knows what the plan must include to past state muster. They’ll let us know. Sometime. They’ll let us know when.

It’s hard to imagine how there could be a bigger change in water law in our lifetime. And it’s hard to imagine how there could be a scarier one.