Sitka Airport Improvements

Sitka, Alaska

Hart Crowser conducted intertidal and subtidal studies and provided technical oversight and review of studies of marine resources at risk to extension of the runway safety zone at the Sitka Airport. The existing runway was surrounded by rock fill in a high energy marine environment that provides a rich marine habitat and supports a portion of the substantial Sitka Sound herring stock. Data were used to assess project alternatives and to help define reasonable mitigation for unavoidable resource impacts.

Hart Crowser prepared biological sections of a National Environmental Policy Act (NEPA) environmental impact statement (EIS) assessing the impacts of various airport expansion alternatives, and analysis of effects on Essential Fish Habitat. Hart Crowser also prepared a Biological Assessment (BA) of potential project impacts on Endangered Species Act-listed species and successfully completed ESA consultations with the federal USFWS and NMFS. We developed an innovative approach to quantifying project impacts and mitigation requirements of the Corps of Engineers Clean Water Act Sec. 404 permit, using an adaptation of the NOAA/NMFS habitat equivalency analysis (HEA). We led a series of meetings to cooperatively enhance the understanding and acceptance of the approach among resource and regulatory agencies.

Hart Crowser then prepared a Mitigation Plan that used the HEA approach to quantify project impacts, to evaluate mitigation options, and to define reasonable mitigation for unavoidable resource impacts. Hart Crowser worked with NMFS and the Southeast Alaska Land Trust (SEAL Trust) to evaluate and map habitat characteristics of a proposed property acquisition site in Sitka and used HEA to negotiate a mitigation package.

We are now completing 5-year post construction surveys, monitoring of the rate of colonization of the newly placed rock. The purpose of this monitoring program is to test assumptions made in the HEA regarding the rate of development of ecological functions on the new rock habitat.