To meet increasing demands and required safety enhancements, Juneau International Airport (JNU) needed to complete an environmental impact statement (EIS) for proposed facility improvements.
JNU is bounded to the west by the mercurial Mendenhall River, to the north by commercial development, and to the south and east by the tidal wetlands of the 4,000-acre Mendenhall Wetlands State Game Refuge.
ESA was part of a team in collaboration with the Federal Aviation Administration that prepared the EIS. We led the water resources analysis including river and tidal geomorphology and water quality. We prepared a Water Resources Technical Working Paper documenting the conditions of surrounding rivers and creeks, ponds, palustrine and estuarine wetlands, and groundwater. In support of three channel evolution scenarios for East Runway Slough, we evaluated the impacts of various alternatives for runway safety and navigational improvements. We led a technical memorandum on potential tidal channel impacts on East Runway Slough and lower floodplain impacts on the Mendenhall River. Our team met with resource agency staff to review methods, findings, and conclusions on impacts and to confirm appropriate mitigation for completing the Final EIS.
ESA helped ensure the two main goals of the airport and stakeholders throughout the environmental process: maintaining a safe operating environment at JNU, and protecting the quality and value of the resources around the airport.
Across Puget Sound, there are competing demands on floodplain areas: local jurisdictions need to manage flood risk, salmon recovery entities need to restore and reconnect habitat areas, and farmers need to ensure that their farms remain viable.