Environmentalists are rightly fretting over the Supreme Court’s recent power plant emissions decision. In Michigan v. Environmental Protection Agency, the Court limited the government’s environmental regulatory power by insisting that affected businesses’ costs of compliance for new regulations must be factored into regulators’ decision-calculus.

While a majority of companies have already complied with the mercury-limitation rule that’s central to this case, the decision does set a dangerous precedent that will make it harder for the Environmental Protection Agency (EPA) to regulate all kinds of emissions in the future.

As if clean air wasn’t enough to worry about, there’s another threat to environmental protection in the works, this time to clean water. In May, President Obama announced a new water protections rule, called “Waters of the United States,” that would clarify the Clean Water Act and limit pollution in approximately 60 percent of the country’s bodies of water by restoring the ability of the federal government to regulate them.

Red Fish, Blue Fish

Democrats lauded this as bona fide executive leadership, happily assuming that it would help Obama continue to shape a strong environmental legacy that already includes land protection in Alaska, an anti-Keystone stance, improved automotive fuel standards, and an aggressive international stance on climate change.

But it isn’t just Democratic politicians and environmentalists who have applauded this decision: 80 percent of small business owners support Waters of the United States, and a group of craft breweries has also spoken out in favor, reminding lawmakers that even their favorite, craftiest beer is about 90 percent water.

Republicans, on the other hand, would still rather not have their beers with Obama. Displeased, the establishment on the right has called the administration’s move yet another example of executive overreach—Speaker John Boehner dismissed it as “a raw and tyrannical power grab that will crush jobs.” Farmers, developers, and industry groups have also joined together to protest the financial burden they claim the rule will inflict on them.

Chances are high that the nine justices of the Supreme Court will soon be assessing the merits of clean water—again. Two Bush-era SCOTUS cases, in 2001 and 2006, dealt with clean water protection, and their contradictory rulings are actually responsible for the current confusion over the exact lines of the federal government’s authority when it comes to H20. While the EPA says that the new rule clarifies that question, by giving the feds ultimate authority, Republicans disagree and have called foul.

Now, the opposition has united to bring a serious challenge. In the final days of June, sixteen states filed three lawsuits objecting to the new rule. All three suits insist the federal government has trod on states’ toes by assuming authority over these water resources. One suit calls the rule “an attempt by two agencies of the federal government to usurp the States’ primary responsibility for the management, protection, and care of intrastate waters and lands”; another claims it’s an “impermissible expansion of federal power over the states” that threatens “the very nature of the Constitution, and therefore liberty itself.” Meanwhile, on the legislative side, House Republicans have approved a law that would block the new regulations, although it is unlikely to make its way through the Senate.

Don’t Waste (Clean) Water

Clean water is not something to toy with. One-third of our country’s drinking water comes from sources that, without the new rule, aren’t sufficiently protected from pollution. In fact, the change is projected to bring higher-quality water for 117 million citizens. Beyond safe drinking, clean water supplies are crucial for wildlife protection, agriculture, and major businesses from tourism and recreation to manufacturing and food service.

Although most of the attention on Waters of the United States has focused on its local impact, the rule also will have an important benefits for coastal waters and oceans. (After all, all drains lead to the ocean, kid.) The new rule will protect against agricultural runoff, which currently composes 70 percent of a dead zone in the Gulf of Mexico, where low oxygen levels suffocate animal life. That zone is the size of Connecticut, and it’s still growing.

There’s also a strong case for federal oversight. Today, hundreds of different agencies across all levels of government share the responsibility for the United States’ water, bringing variations in quality and a lack of accountability. Water oversight is also expensive, and many states simply don’t have the resources to guarantee that anti-pollution standards are being met. Turning it over to the federal government both alleviates a financial burden on the states and ensures that water protection has the funding it deserves.

Where clean water protections have failed, disasters have often followed. Contamination last year in Lake Erie from algae toxins, which were likely the result of agricultural runoff, led to a municipal ban on drinking water in parts of Ohio and Michigan. Neurotoxins in the water sickened many residents, while others were left without water for days. The overall cost of the catastrophe was nearly $4 million. That Ohio, under Republican Governor John Kasich, is one of the states challenging the new rules demonstrates the absurdity and politicization of the situation.

This is one case where common-sense must prevail. The new rule does little more than close a loophole. Polluters have, in recent years, began dumping toxins into wetlands or upstream tributaries, areas that, unlike larger, navigable waterways, are generally not protected by federal authority. Because these areas are still connected to larger bodies of water, polluters have managed to continue their deleterious effects, while reducing their legal liability.

The cases challenging Waters of the United States still have a ways to go before reaching the halls of the Supreme Court  Although it may be an upstream battle, there is much that can be done in the meantime to protect the new rule. Supporters can continue to speak out in its favor and promote public education about its benefits. Those in Congress can work to defeat the House’s challenge, or even, ideally, to strengthen the Clean Water Act through further legislation.

We have already seen the consequences of poor water quality, and it is time to move forward in environmental protection. Water recycles itself; let’s not let history do the same.