Streamflow refers to the volume of water flowing through a stream or river at a particular location at any given time. It is the pulse of the productive landscape of Southeast Alaska. The annual discharge of freshwater entering the Gulf of Alaska exceeds that of the Mississippi River and is four times greater than the Yukon River. Across Southeast Alaska parks, streamflow is influenced by surface runoff from rain and snow, glacial meltwater, and groundwater input from wetlands and other aquifers. In turn, streamflow influences water quality, nutrient loads, stream-dwelling organisms, and coastal marine ecosystems.
The United States Geological Survey (USGS) independently operates a streamflow gage on the lower Alsek River, a large glacial river on the outer coastline of Glacier Bay National Park and Preserve. A second gage is operated by USGS along the Salmon River near the park boundary in the town of Gustavus, with support from the Alaska Department of Transportation. A funding partnership between the National Park Service (NPS), USGS, and the Municipality of Skagway enables operation of a streamflow gage by the USGS along the Taiya River, another glacial river that runs through Klondike Gold Rush National Historical Park. A similar partnership among the NPS, USGS, and City of Sitka sustains operation of a gage on the Indian River, just upstream of the boundary of Sitka National Historical Park.
The primary objective is to monitor current streamflow in all three Southeast Alaska parks and to quantify long-term trends in annual and seasonal streamflow patterns.