sentences:  Further, upon a condemnation, the increased value inuring from proximity to a waterway would no longer be paid.These developments in the law led the Supreme Court to acknowledge in 1979 that Congress's power to regulate the nation's waterways is best understood when viewed in terms of more traditional Commerce Clause analysis than by reference to whether the stream in fact is capable of supporting navigation or may be characterized as navigable water of the United States.Under the most recent Commerce Clause decisions, the test for determining whether Congress has the power to regulate an activity is whether the activity "substantially affects" interstate commerce.