Portfolios and Case Studies

Duluth Sky Harbor Airport Runway Relocation

Written by Admin | August 29, 2022

Challenge

Duluth Sky Harbor Airport is a General Aviation airport whose unique location, facilities and services have contributed to its ability to support a unique mix of users. The airport opened in 1939, consisting of a single paved and lit runway, two sea lanes and a seaplane ramp and dock. The airport is also an International Port of Entry to the U.S.

Duluth Sky Harbor Airport is located on Minnesota Point, approximately 5 miles from downtown Duluth. Minnesota Point serves as a natural boundary between Lake Superior and Superior Bay. It’s one of the largest baymouth sandbars in the world, as well as being home to several State-listed, protected species and the federally protected piping plover.

In 2007, the Duluth Airport Authority (DAA) and Minnesota Department of Transportation (MnDOT) identified several obstructions to the runway’s approach surface – including a treasured old-growth pine forest growing into the approach and departure surfaces. SEH was selected to help find a solution to this challenge, leading all aspects of airport planning, environmental review and permitting, design and construction over the course of 13+ years.

Led by the DAA, project partners included the Minnesota Department of Natural Resources (DNR), MnDOT, the Federal Aviation Administration (FAA), Minnesota Department of Transportation Aeronautics, U.S. Army Corps of Engineers (USACE), U.S. Fish and Wildlife Service, as well as other local and environmental agencies.

After years of planning, environmental review, stakeholder engagement and other processes to carefully evaluate all options, the project team’s solution was a full runway relocation. Specifically, the team would rotate the runway by 5 degrees into Superior Bay and shorten it to 2,600 ft. – protecting more than 27 acres of old-growth forest.

Solution

Over 10 years of public engagement and community conversations combined with innovative engineering and construction solutions resulted in a win for aviation, the DAA, the Duluth community and the natural environment.

SEH facilitated a complex environmental review, permitting, mitigation, design and construction process for maintaining this airport within and adjacent to protected and regulated natural resources. The project created 7 acres of new land and involved constructing a rotated airport runway into Superior Bay.

Public participation, agency participation and transparency were key to the project's successful development, with each leading to minimal controversy as the project took shape and progressed. The project team used a Memorandum of Understanding (MOU) between the DAA, FAA, and USACE to merge the NEPA and Clean Water Act Section 404 review and permitting processes. As the project moved from NEPA into the permitting phase, the project team’s merged process resulted in an efficient permitting process. Because there is no prescriptive program for open water mitigation, the project ultimately included project-specific enhancements of rare terrestrial communities and aquatic habitat structures at mitigation elements.  

The new land was created over the course of three years and included fill, surcharge and surcharge removal. The SEH team minimized impacts to airport users through a unique phasing plan, which allowed the runway to remain open through nearly all of construction outside of just one 30-day runway closure at the end of the three-phase project. The project team avoided construction impacts to a 5-mile residential street, a historic lift bridge and Duluth’s tourist district by barging 210,000 tons (12,500 truckloads) of material to the site. Barging also saved approximately 50,000 gallons of fuel.

The new, stabilized shoreline provided the foundation to support operations, protect the environment and provide infrastructure that is resilient to rising lake levels. Construction required careful planning and innovation to protect and nurture the land and habitats around the project site – one unique example being the barging of nearly all materials to the site.

Strategic drone filming and video production
In addition to the complex environmental review, permitting, mitigation, construction and design that went into making the Duluth Sky Harbor Runway Relocation project a reality, the SEH Aviation team used drone filming to document construction and supplement stakeholder engagement. The project video above and photos below offer a glimpse of the footage captured throughout the project’s many phases and features.

Awards

  • 2021 Engineering News-Record Midwest Best Project Award
  • 2021 Engineering Excellence Grand Award | American Council of Engineering Companies, Minnesota Chapter (ACEC-MN)

Project
Duluth Sky Harbor Airport Runway Relocation

Location
City of Duluth, Minnesota

Client
Duluth Airport Authority

Project features

  • 13+ year effort
  • Airport layout plan
  • Environmental Assessment
  • Merged National Environmental Policy Act (NEPA) and Clean Water Act Section 404 Permitting processes
  • Legislative funding secured to cover nearly all local share of construction

Airport features

  • 2,600 ft. by 75 ft. runway
  • 25 ft. wide parallel taxiway
  • Light-emitting diode (LED) lighting along runway and taxiway
  • Precision approach path indicators (PAPIs)
  • 27 acres of old-growth forest protected (500+ trees)
  • Creation of 7 acres of new land in Superior Bay
  • Shoreline construction and stabilization
  • Seawall replacement
  • Barging 210,000 tons of material reduced construction impacts
  • Barging reduced fuel consumption, saving 50,000 gallons of fuel

Mitigation features

  • Invasive plant species removal from 10 acres of old-growth forest
  • Plants and seeds cultivated on-site and grown in local greenhouse during construction
  • 3,000 plants and 300 low shrubs installed at the airport
  • Further protection of three rare plant species growing on the airport
  • 250+ local ecotype aquatic plants installed along the airport shoreline
  • Installation of 20 in-water fish crib structures across 8 acres of Superior Bay

Services

  • Stakeholder engagement
  • Airport planning
  • Transportation planning
  • Environmental documentation and review
  • Environmental compliance and permitting
  • Airport engineering
  • Environmental engineering
  • Water resources engineering
  • Surveying
  • Marketing communications
  • Drone services