Despite local objections, a 55-foot-tall bridge connecting Mount Pleasant and Berkeley County will be built over the Wando River on S.C. Highway 41.

After a thorough review, the Coast Guard has determined that the tall bridge, rather than a shorter span, best meets the "reasonable needs of navigation" for the waterway, the state Department of Transportation said Thursday.

DOT has directed its contractor, PCL Civil Constructors, to proceed with design and construction of the $30 million bridge scheduled for completion in the fall of 2016.

U.S. Rep. Mark Sanford said there is no practical reason for a 55-foot-high bridge because there is nothing upriver that would necessitate it.

"It just doesn't pass the common sense test. I just find it wildly frustrating," he said.

The river above the bridge becomes shallow quickly as it flows from the Francis Marion National Forest. Properties in that area have deed restrictions that prohibit larger vessels with toilets, he said.

Sanford said the decision by the DOT, based on an opinion from the Coast Guard, is not the "final nail." The DOT still has to receive a permit from the Coast Guard for the project, he said.

Mount Pleasant Town Council was unanimous in its support for a bridge not to exceed 35 feet, said Councilman Paul Gawrych.

"We had the support of the city of Charleston, Charleston County and Berkeley County," Gawrych said.

"I, like many people, am disappointed in the outcome as we fought a good fight for all the right reasons," Gawrych said in an email.

On the positive side, a hiker/biker lane for the bridge has been secured, and there is an effort to work with DOT to get as much land as possible on both sides of the river for public access, he said.

Traffic will be maintained on the existing bridge while the new bridge is under construction, said DOT.

The low-slung swing span bridge, built in 1939, is opened manually for boat traffic. It is classed as "structurally deficient" and "functionally obsolete," terms used to mean that it is nearing the end of its useful life.

The project has been 10 years in the making. The Federal Highway Administration has been involved in the decision-making process, and the DOT sent out more than 650 questionnaires to property/dock owners, marine facilities and to those who attended a public meeting held in December of 2012. The results of the survey were provided to the Coast Guard for their review, the DOT said.

Opponents of the tall bridge worry that it will open the upper reaches of the Wando River to development.

"This is an ecologically valuable and pristine area," said Natalie Olson, program manager with the South Carolina Coastal Conservation League. The league advocated for a 35-foot-tall bridge.

"The large height just isn't consistent with that area," she said.

In May 2010, two alternatives were presented: a 55-foot fixed span and a low-level bascule bridge, similar to the existing bridge. The bascule bridge was approved, but support faltered because of an added $10 million cost to build and maintain it, officials said.

The DOT and the FHA decided in 2012 to pursue a 35-foot bridge to satisfy the community's desires and because it would save the state about $3 million. The DOT even offered to buy retractable masts for two residents upstream who said they would be bound in because their sailboats wouldn't fit under a lower bridge.

About 3,400 vehicles cross the bridge daily. The river above the span runs for about five miles.

Three firms bid for the project, which includes replacing the bridge, realigning Highway 41 and relocating its intersection with Clements Ferry Road.

Reach Prentiss Findlay at 937-5711.