Critics of the Corps's decision-making powers in this area say the ruling is only a start in clarifying the intent of the Act and the Corps' regulatory authority. "The National Multi Housing Council has long asserted that the current regulatory system is overly broad, unevenly applied and excessively burdensome with respect to the time and costs involved in the permitting process," says Eileen Lee, NMHC's vice president of environment. The council filed a "friend of the court" brief in support of this view.

The Supreme Court decision, however, did not provide a clear outline of the extent of the Corps' authority, noting that it can regulate wetlands that have a "significant nexus" with water quality in adjoining wetlands. This matter has been legislated for several years, reaching the Supreme Court once before in 2001. Then, in Solid Waste Agency of Northern Cook County v. US Army Corps of Engineers, the court ruled that the Corps does not have jurisdiction over isolated wetlands. Inconsistent rulings by lower courts since then have continued to muddy the waters. Most observers say decisions will continue to be made on a case-by-case basis until Congress steps in.

Although the ruling was a clear victory for property owners, Lee says, "the issue remains very contentious. Environmental activists are pushing Congress to expand the Clean Water Act and Congress sent a message of support for such action with a 222-198 vote in the US House of Representatives on the issue in May. The close court ruling combined with the close vote in the House means this will be a protracted battle."