Creating the Mid-Bay Bridge Connector
Those tasked with leading a vital transportation project at Eglin AFB discover their biggest challenge swimming in the water.
By Mike Spaits
With a host of benefactors that include military readiness, tourism, local travelers and the Okaloosa darter, everyone is winning thanks to a partnership between Eglin Air Force Base, Fla., and the Mid-Bay Bridge Authority (MBBA), and their combined efforts to open a new connector road between a major highway and the Mid-Bay Bridge in Northwest Florida.
The Mid-Bay Bridge Connector is a limited access highway that will connect the north end of the Mid-Bay Bridge with State Route 85 north of Niceville in northwest Florida. The bridge is a two-lane, 3.6-mi long toll road that has continually exceeded traffic volume projections since it was built in 1993 and which is slated for expansion after the connector is completed. The new connector will greatly reduce travel time from Interstate 10 to Niceville and other communities in the coastal area, improving traffic congestion as well as hurricane evacuation routes. The new highway also will address the expanded military mission of Eglin AFB, where there is a projected increase of 12,000 base personnel and families.
MBBA is a regional toll authority created by the Florida legislature to plan and build local transportation projects that would not otherwise be funded through the Florida Department of Transportation (DOT). The agency was faced with a choice when determining where to build the new highway: Cut through established neighborhoods in Niceville or use neighboring property owned by Eglin AFB. MBBA worked closely with the base, the Florida DOT and Okaloosa County to develop the optimum solution to ongoing congestion problems, and engaged architecture, engineering and consulting firm HDR to formulate the project development and environment study. The connector was planned in three phases. Phase One, which runs from Mid-Bay Bridge to County Road, Range Road within Eglin AFB, opened on May 12, 2011.
Department of Defense guidance requires that the Air Force receive fair market value for all grants of land use to outside agencies. As a result, Eglin will realize more than $20 million in payment in-kind from MBBA in exchange for the use of Eglin property in the new connector being constructed. The base is able to retain this value locally and will be using the proceeds to accomplish maintenance and repair at the installation.
THE OKALOOSA DARTER
One of the project’s largest challenges went well beyond the nuts and bolts of bridges and into the delicate world of wildlife preservation. How would construction of the Mid-Bay Bridge Connector impact the Okaloosa darter, a small perch-like fish, which has been listed as an endangered species since 1973? By 1994, no more than 1,500 Okaloosa darters were thought to exist and time had not magically made the number grow. Turns out a mix of teamwork and old fashioned sweat equity would play the deciding role.
“The partnerships formed for this venture were crucial in restoring the darter’s vital habitat,” said since retired Air Force Col. Sal Nodjomian, then the 96th Air Base Wing Commander. “From the Jackson Guard, to the Civil Engineer Dirt Boys, to the hundreds of base volunteers who planted trees and vegetation to control erosion on these sites as well as the Mid-Bay Bridge Authority, who funded several restoration projects off Eglin.”
U.S. Air Force photo by Jerron Barnett
More stressing, the 11-mi of roadway for the project crossed five of only six streams known to provide habitat for the darter. As a result, this project, with more than 98 percent of its range within Eglin AFB boundaries, was a major concern of the U.S. Fish and Wildlife Service. Erosion at road crossings, railroad beds and sand/clay pits at Eglin had impacted habitat for the Okaloosa darter and other aquatic species. Fill, culverts and impoundments also resulted in lost stream habitat.
Both traditional and nontraditional partnerships were needed to achieve recovery of this fragile species. Conservation partnerships forged over a nearly 20-year period has included Eglin AFB Natural Resources, the U.S. Fish and Wildlife Service, U.S. Geological Survey, Florida Department of Environmental Protection, the U.S. Army Corps of Engineers, Loyola University, University of Florida, University of West Florida, Three Rivers RC&D Council and The Nature Conservancy.
MBBA, though a new addition to the partnership, helped address difficult challenges in transportation and conservation planning in particular. Taking the approach of tackling problems head on, MBBA and HDR worked closely with Eglin staff and the U.S. Fish and Wildlife Service to both avoid and minimize impacts to the darter. Commitments were made early in the planning process to address darter research needs and undertake multiple stream restoration projects on and off the base. Approximately $3.8 million in restoration projects are underway in support of efforts to downlist, and ultimately delist, the Okaloosa darter.
MBBA will also use funding for environmental restoration projects around the reservation and local community. This work is helping restore degraded habitat for the federally listed endangered Okaloosa darter and would not have been possible were it not for the combined efforts of the partnership. “It’s not often that a project is satisfying on so many levels,” said Jim Vest, MBBA’s Executive Director. “Everyone involved really pulled together to make this a success.”
DESIGN & CONSTRUCTION
A number of design and construction features were critical to reducing impacts to the Okaloosa darter and helped make sure its conservation needs were met:
- Bridging all Okaloosa darter stream crossings.
- Designing bridges to span stream bankfull width plus 10 percent.
- Designing bridges to span riparian areas and adjacent wetlands.
- Using environmentally sensitive bridge construction techniques.
- Funding an Okaloosa darter population genetics study.
- Removing railroad crossing impoundments and three pipe culverts, and recreating a 196-ft-long stream channel at Swift Creek. New floodplain and wetlands were created and planted with native vegetation including sweet bay, Atlantic white cedar, cypress and long-leaf pine.
- Removing 100,000-yd³ of fill from an old railroad crossing, removing a 10-ft culvert, restoring 226-ft of stream channel and creating just over half an acre of wetlands/floodplain at Tom’s Creek.
- Restoring the Anderson Branch by rebuilding the impoundment, restoring the stream channel and reconnecting to Turkey Creek. The earthen dam at Anderson Pond was redesigned to create an off-line pond for recreation, which includes new boardwalks to improved access for recreational fishing. Nearly 3,000-ft of stream channel and a riparian floodplain were recreated to assure stable in-stream flow and sediment dynamics throughout the stream system.
- Replacing eight culverts with bottomless culverts or bridges.
- Replacing the Rocky Bayou Drive culvert with a bridge off of Eglin AFB in partnership with the U.S. Fish and Wildlife Service and Okaloosa County.
The comprehensive design and mitigation efforts of the team resulted in less than 5-acres of wetland impacts out of 11-mi of highway construction. Better still, on April 1, 2011, the U.S. Fish and Wildlife Service reclassified the Okaloosa darter from endangered to threatened, saying the small fish is making major strides in its fight for recovery. Population estimates now exceed 300,000 Okaloosa darters. Only one other fish species east of the Mississippi River—the snail darter—has been downlisted from endangered to threatened. While no fish, to date, has been removed from the Endangered Species List, that remains a goal of the team’s recovery efforts.
According to Rowan Gould, Director of the U.S. Fish and Wildlife Service, the darter’s improvement would not have been possible without the strong partnerships who came together to complete a significant number of recovery efforts.
It may take a village to save a fish, but it takes a whole lot more to save a species.