Headwater streams are the small swales, creeks and streams that are the origin of most rivers. These small streams join together to form larger streams and rivers or run directly into larger streams and lakes. Streams may be home to small fish, amphibians and invertebrates.

Streams can be ephemeral, intermittent or perennial. Ephemeral streams are those that contain flowing water only after major rain events or for very short times during the year. Intermittent streams flow only during the wetter periods of the year. Perennial streams contain water year-round. The collective health and functioning of the stream network have profound influences on the quality and value of larger streams, rivers and lakes.

Compensatory stream mitigation may be required for impacts to streams and should be designed to restore, enhance, and maintain stream uses that are adversely impacted by authorized activities.

• Streamflow Duration Assessment Method: The Streamflow Duration Assessment Method (SDAM) for the Pacific Northwest is a scientific, rapid-assessment field tool developed to help determine whether a stream is perennial, intermittent or ephemeral.  
  • Streamflow Duration Assessment Method for the Pacific Northwest, 2015
  • SDAM Data Form, 2015
  • Macroinvertebrate Field Guide, 2012
• A stream mitigation plan must include the elements of a mitigation as required by the Federal Mitigation Rule as excerpted in this document entitled Components of a Mitigation Plan per the Final Rule. In particular, please note item 7.
• To ensure impacts are minimized and appropriate techniques are implemented, please utilize the Integrated Streambank Protection Guidelines published by the Washington State Department of Fish and Wildlife.

If you are performing work in tidal waters in Washington State, you must identify the limits of the Corps jurisdiction. Under Section 10 of the Rivers and Harbors Act, the limits of the Corps' jurisdiction is the line of Mean High Water.  Under Section 404 of the Clean Water Act, the limits of the Corps' jurisdiction is the High Tide Line (HTL) and adjacent wetlands. 

Per 33 CFR 328.3, the term high tide line means the line of intersection of the land with the water's surface at the maximum height reached by a rising tide. The high tide line may be determined, in the absence of actual data, by a line of oil or scum along shore objects, a more or less continuous deposit of fine shell or debris on the foreshore or berm, other physical markings or characteristics, vegetation lines, tidal gages, or other suitable means that delineate the general height reached by a rising tide. The line encompasses spring high tides and other high tides that occur with periodic frequency but does not include storm surges in which there is a departure from the normal or predicted reach of the tide due to the piling up of water against a coast by strong winds such as those accompanying a hurricane or other intense storm.

Please utilize this list to help you identify which waterways of Washington State are considered to be navigable waters of the U.S.
 

Some waterways are considered to be "traditional" navigable waters even if they are not on the Navigable Waterway List described above. This list describes some of these types of waters of the U.S.

The National Wild and Scenic Rivers System was created by Congress in 1968 to preserve certain rivers with outstanding natural, cultural, and recreational values in a free-flowing condition for the enjoyment of present and future generations. The Act is notable for safeguarding the special character of these rivers, while also recognizing the potential for their appropriate use and development. Please visit this website for more information on which waterways are designated Wild and Scenic Rivers.