Streamflow Models in Southeast Alaska

a stream flows through temperate rainforest
Duration: 
Aug 2018

Information need

Resource managers and city planners in Southeast Alaska need a way to predict peak and low freshwater streamflows at the watershed level.

End products

  • Predictive stream discharge models for Southeast Alaska watersheds and
  • A searchable online map with past, current, and predicted streamflow information

Why are we doing this?

  • Freshwater flow dynamics in Southeast Alaska are expected to dramatically shift over time with changes in precipitation and air temperature.
  • Understanding changes to streamflow is essential for infrastructure planning such as culvert replacement, bridge design, hydropower development, drinking water reservoir location identification, and floodplain restoration. Projections of peak flow are particularly important for culvert and bridge engineering, while seasonal variation and low flows may be more significant for hydropower and fish habitat restoration planning.
  • Resource managers need better models for small, ungaged watersheds, and future flow models for all watersheds for planning purposes. Typically, most long-term gages are placed on larger rivers, creating inaccurate predictions for smaller streams.
  • The resolution of most global climate models of future weather is too coarse to capture the spatial variety of the Southeast Alaska landscape.

Partners

Oregon State University, USFS Tongass National Forest, Alaska Department of Natural Resources, National Weather Service, Department of Transportation Facilities, Information, and Asset Management