The U.S. Army Corps of Engineers this week issued a Regulatory Guidance Letter in response to the U.S. Supreme Court’s decision in Hawkes v. United States.

In that decision, the court said that a jurisdictional determination—in which the Corps decides whether a piece of land should be subject to federal oversight under the Clean Water Act—is something that a developer can take to court.

The guidance letter clarifies the differences between the two kinds of jurisdictional determinations and how builders and developers can obtain them.

Jurisdictional determinations are important because developers have no way of knowing whether a feature is jurisdictional simply by looking at it. However, once the Corps issues a jurisdictional determination, it carries significant legal and financial consequences on everything from lending practices to state rules and regulations.

The Supreme Court said in Hawkes that when the Corps determines the precise boundaries of jurisdictional waters on a landowner’s property, that landowner can dispute the determination in court.

The new guidance—the first of its kind issued by the Obama Administration—accepts the Supreme Court decision and provides guidance to the Corps’ staff (and public) explaining when it is appropriate to issue an approved jurisdictional determination or preliminary jurisdictional determinations or not make any determination at all.

The Corps guidance explains that approved jurisdictional determinations are official determinations that jurisdictional waters exist on one’s property, while preliminary jurisdictional determinations are not legally binding. Finally, the guidance provides the forms that property owners are to use when requesting that the Corps conduct an approved jurisdictional determination or preliminary jurisdictional determinations.