Coastal Services Center

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The American Public Trust Doctrine (2 of 4)

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Geographical Scope

As discussed in Module 1, given the absence of navigable freshwater rivers in England, navigable waters were understood to mean tidewaters under the English common law. The American Public Trust Doctrine’s scope was expanded gradually to include U.S. freshwaters.

The expansion resulted in two classes of navigable waters:

• Tidewaters
  These waters are considered “navigable in law”: that is, they are defined as navigable regardless of whether they can actually be navigated.
• Freshwaters
  These waters are considered to be navigable only if they are navigable-in-fact.

One advantage of the earlier limitation of the Public Trust Doctrine to tidewaters was that the public nature of a water body, or lack thereof, was easier to establish. It can be difficult to determine whether a freshwater body is navigable-in-fact. (This problem is further discussed in Module 3).