Sometimes, history repeats itself. Sometimes, that is not a good thing.
After the Obama WOTUS 
rule was promulgated in 2015, the challenges came fast and furious, and in multiple forums. The Supreme Court, as I put it, adopted the “give me a break” theory over the “just plain nuts” theory, and ruled that challenges to the rule had to be heard in district courts. The text of the statute made pretty clear that such challenges did belong in district courts, and the Supreme Court felt no need to address concerns that it was just plain nuts to have multiple courts reviewing this issue, leading to a patchwork of different rulings. That’s Congress’s problem!
As anyone who remembers those halcyon days can attest, chaos did indeed result, with roughly half the states ending up subject to the Obama rule and half subject to the prior rule and the post-Rapanos guidance.
Now comes the Trump WOTUS rule, which became effective yesterday. It looks like déjà vu all over again. On Friday, two courts weighed in, with a judge in California declining to enjoin the rule and suggesting very strongly that EPA would prevail with its argument that the rule is entitled to Chevron deference, while a judge in Colorado enjoined the new rule, concluding that five justices in Rapanos precluded the new rule’s interpretation of WOTUS, thus barring any reliance on Chevron.
Other than saying “I told you so,” I think that the biggest takeaway so far is that, to the extent that the California decision carries the day, it’s also good news for fans of EPA’s recently released rule on section 401 water quality certifications. It basically adopts lock, stock, and barrel EPA’s rationale for why it can ignore a seemingly contrary Supreme Court decision. The short version is that the Supreme Court Brand X decision holds that, where the Supreme Court upholds an agency interpretation of an ambiguous statutory provision, that does not preclude the same agency from later adopting a contrary interpretation, so long as the new interpretation is also permissible under Chevron.
Time will tell which position prevails, at least in the lower courts. This one does seem likely to make it back to SCOTUS. For better or worse – likely worse – we might finally get some clarity on the definition of the waters of the United States. Until then, I am confident that chaos will reign.