Hilton Head bridge project was expected to cost $272M. Why is it now $290M?
The estimated price tag for the sprawling U.S. 278 corridor project was roughly $272 million last summer.
But a year later, the S.C. Department of Transportation’s favored construction plan for the highway, or “preferred alternative,” is now expected to cost almost $290 million.
What happened?
Craig Winn, the state’s project manager, provided some clarification in a Wednesday phone call.
As part of the project, Winn said, the state initially planned to use $43.5 million in SCDOT bridge replacement funds to address U.S. 278’s deficient eastbound lanes over Mackay Creek.
The transportation agency, though, later amended its estimate and projected that $65.5 million in bridge replacement funds were actually needed for its proposal to demolish the existing Hilton Head Island bridges and replace them with a single, six-lane bridge, Winn said.
The bridge replacement funds, he said, are specifically set aside to address the eastbound lanes over Mackay Creek.
SCDOT increased its cost estimate because the state drilled holes into the earth below U.S. 278 to determine how deep the newly proposed bridge foundation would have to go to meet South Carolina’s current seismic design standards, among other things, Winn said.
“The depths have not been finalized as bridge design is in (a) conceptual stage,” Winn wrote in a follow-up text message.
But SCDOT does know that the foundation will have to be deeper than it is now, Winn said.
The state’s seismic design standards were first created in 2001 so SCDOT could better prepare bridges to weather earthquakes, Winn said.
The existing Hilton Head bridge system was built in 1982 when the James F. Byrnes swing bridge was replaced. That means the current bridges do not meet SCDOT’s seismic standards, Winn said. The proposed six-lane bridge would meet those standards, he said.
The addition of a 10-foot-wide pathway for runners and bicyclists along the proposed bridge also affected SCDOT’s estimated need for bridge replacement funds, Winn added.
What about the project’s other funding sources?
The project’s other funding sources have not changed over the past year, according to Beaufort County.
Jared Fralix, assistant county administrator, told The Island Packet that the entire project will be funded with:
Beaufort County’s one-cent sales tax: $80 million.
Beaufort County road impact fees: $12.3 million.
Beaufort County general obligation bonds for the Jenkins Island road project: $7 million. (The county had secured $7.18 million for the Jenkins Island project as of August 2019 and needed an additional $2.4 million in road impact fees to fund the project, The Island Packet reported at the time. The Jenkins Island project eventually was incorporated into the larger U.S. 278 plan.)
Town of Hilton Head Island right-of-way dedication: $3.35 million.
Federal Guideshare funds: $4.2 million.
SCDOT bridge replacement funds: $65.5 million.
State Infrastructure Bank grant: $120 million.
Roughly $292 million in funding has been secured for the project, Fralix said.
What’s next?
Residents are able to review SCDOT’s preferred alternative documents online, submit written suggestions or recommendations to agency officials, attend an in-person public hearing on Thursday to discuss the preferred alternative, and set up appointments at the Island Recreation Center between Aug. 18 and Aug. 21 to learn more about the state’s proposal.
The public hearing will be held from 2 to 7 p.m. Thursday at the rec center at 20 Wilborn Road. People can drop by to ask questions from 2 to 6 p.m. An hour-long meeting for residents to speak out about the plan will run from 6 to 7 p.m.
