NCDOT hopes the work can be completed well before the spring-summer tourist season, which is the mainstay of Hatteras Island's economy.

"The work may also be expanded to address another nearby bent, where additional, though less severe, scour is occurring, so the final scope of the work to be done is still being refined," says Jerry Jennings, NCDOT division engineer.

The agency also plans to augment its scour-monitoring efforts with an automated scanning system, with bridge sensors providing real-time monitoring and alerts of any abnormal movement.

The relatively brief closure of the Bonner Bridge reopened the long-standing debate over constructing a replacement structure, a multi-decade process that has been repeatedly thwarted amid concerns over impacts to Hatteras Island's fragile ecosystem and the fact that the island is gradually migrating toward the mainland at a rate of 5 ft to 22 ft per year.

Shortly after NCDOT awarded a $215.8-million design-build contract in 2011 to PCL Civil Constructors Inc.- HDR Engineering Inc. to construct a new structure parallel to the Bonner Bridge, the non-profit Southern Environmental Law Center (SELC) filed suit in federal district court on behalf of the National Wildlife Refuge Association and Defenders of Wildlife blocking the project, contending the plan violated a federal mandate to address frequent washout and erosion problems on an adjoining 12-mile stretch of state Route 12 within the Pea Island National Wildlife Refuge.

The SELC also filed a companion petition with the state's Dept. of Environment and Natural Resources, asking that state-level environmental permits for the Oregon Inlet project be denied.

The group also argues that the bridge and road problems might be better addressed by a 17-mile structure that would bypass the refuge and unstable inlet but cost five to 10 times more to build.

NCDOT counters that two decades of study justify construction of the shorter bridge, with a long-term, multi-faceted monitoring and maintenance strategy to address the Pea Island erosion problems. The district court agreed and rejected the SELC's suit in mid-September. The organization has since filed an appeal with the 4th U.S. Circuit Court of Appeals, again delaying the replacement project.

Gov. Pat McCrory (R) and Tata called on the SELC to drop its suit, blaming the organization for endangering the safety and livelihood of Hatteras Island's residents and adding the costs of repairing the latest scour damage to the $56 million NCDOT already has spent on repairs to the Bonner Bridge since 1990.

In a statement issued two days after the closure, however, the SELC blamed NCDOT for a delayed replacement, due to the agency's "inability to secure all the necessary permits for its faulty plan to build a new bridge in the same unstable location." The SELC also said the agency has been aware of the risks of attempting an Oregon Inlet replacement since 2003.