According to the 2015 definition, what percentage of water in the US is covered as "waters of the United States"?

The correct percentage indicating the coverage of "waters of the United States" according to the 2015 definition is 60%. This classification includes various bodies of water such as rivers, lakes, streams, wetlands, and other navigable waters that substantially affect interstate or foreign commerce, as well as tributaries and adjacent waters. This comprehensive definition aims to provide federal jurisdiction over a wide array of water bodies to safeguard the integrity of water quality in the U.S.

This comprehensive determination underscores the importance of protecting not only the main navigable waters but also those smaller streams and wetlands that contribute to the overall health of larger water systems. The 60% figure reflects a significant portion of the U.S. land area that plays a crucial role in various ecological functions, such as habitat provision and water filtration, thus highlighting the critical nature of these waterways in sustaining the environment and supporting human activities.