Comparison of Streamflow in Maine to Seasonal Aquatic Base Flow

This web application provides the latest streamflow values for U.S. Geological Survey (USGS) streamgages in Maine relative to seasonal aquatic base flows associated with the State of Maine In-stream Flows and Lake and Pond Water Levels rule (Maine Department of Environmental Protection, 2026a).

 

The State of Maine In-stream Flows and Pond Water Levels rule, Chapter 587 establishes river and stream flows and lake and pond water levels to protect natural aquatic life and other designated uses in Maine’s waters. The rule applies to direct or indirect withdrawal, removal, diversion or other activity or use that alters the natural flow or water levels of a non-tidal fresh surface water of the state. These waters include rivers, streams, brooks, lakes and ponds that are classified state waters (Maine Department of Environmental Protection, 2026b).

 

 

Maine Department of Environmental Protection, 2026a, Sustainable Water Use Program, Ch. 587 Q&A, Maine Department of Environmental Protection, accessed May 11, 2026, at https://www.maine.gov/dep/water/swup/587qa.html.

 

Maine Department of Environmental Protection, 2026b, Chapter 587: In-stream flows and lake and pond water levels, accessed May 11, 2026, at https://www.maine.gov/sos/sites/maine.gov.sos/files/content/assets/096c587.doc.