Update January 23, 2020: The EPA and the Department of the Army finalized the Navigable Waters Protection Rule to define "waters of the United States." This replacement rule, which will become effective 60 days after publication in the Federal Register, gives farmers and ranchers the clarity they need to comply with federal regulations while protecting the nation’s waterways. For the first time, the agencies are streamlining the definition so that it: includes four simple categories of jurisdictional waters, provides clear exclusions for many water features that traditionally have not been regulated, and defines terms in the regulatory text that have never been defined before.
August 2019: On August 21, 2019, a federal court sided with Kansas (and other participating states) and declared the 2015 Waters of the United States (WOTUS) rule exceeded federal authority and violated administrative procedures. The ruling by Judge Lisa Godbey Wood in the U.S. District Court for the Southern District of Georgia granted summary judgment to the 10 plaintiff states, including Kansas. Because the Trump administration already has begun the proper rulemaking process to repeal the illegal 2015 WOTUS rule and replace it with a lawful rule, Judge Wood did not vacate the 2015 WOTUS rule but instead left in place the preliminary injunction she entered last year. That injunction will continue to prohibit the implementation of WOTUS in Kansas and the other plaintiff states while the repeal-and-replace rulemaking proceeds. To follow the EPA's and Department of the Army's joint rulemaking effort to provide clean water AND clear rules, you can visit their website here.
September 2018: There have been recent court decisions about the 2015 Clean Water Act Rule defining "Waters of U.S." Kansas is currently operating under the pre-2015 regulations and guidance (i.e. pre "WOTUS" rule), thanks to a preliminary injunction granted in a federal court in Georgia on June 8, 2018. States affected by a recent decision in the U.S. District Court for the District of South Carolina, however, are operating under the 2015 Clean Water Act Rule. For more information about the status of applicability of the 2015 Clean Water Act Rule, including a map showing the applicability of the rule in each state, you can view the EPA's webpage dedicated to this subject.