Both projects were included this week among mitigation measures proposed by the Army Corps of Engineers to accompany a $400 million to $500 million effort to deepen the shipping channel from 42 feet to as much as 48 feet.
The 72-year-old New Savannah Bluff dam near Augusta Regional Airport was earmarked for demolition after a 1999 corps study concluded it was no longer needed to support commercial shipping - for which it was built in 1937.
The dam also blocks upstream migration of the endangered shortnose sturgeon, American shad and other species, including striped bass.
Efforts by local governments to save the dam - and its 13-mile pool of water tapped by industries and cities - yielded a congressional decree that it be repaired and turned over to local municipalities to maintain. So far, however, Congress has not provided the $22 million needed to renovate the dam and add fish passage.
The Savannah Harbor mitigation package, however, would finance all of the $7 million needed for the fish structure - a horseshoe-shaped, 75-foot-wide ramp with 9-inch ledges that would allow fish to bypass the dam and move upstream. The bypass would reopen more than 20 miles of river habitat to fish spawning - including the oxygen rich shoals upstream from Augusta.
Jason O'Kane, the corps' Savannah Harbor project manager, said the proposed mitigation funds would pay for only fish passage - not the entire rehabilitation.
"It would be independent of any rehab," he said, adding that such a structure could also be built without doing the other renovations simultaneously.
The timetable for the project will depend on the pace of the harbor deepening, he said. "We're looking at making that recommendation to Congress around January of 2011."
The mitigation package also proposes annual payments to Georgia's Wildlife Resources Division to help fund its striped bass restocking program in the Savannah River.
Bill Bailey, the corps' Savannah Planning Unit chief, said the amount of the payments will depend on how many feet the harbor is deepened. "The amount will depend on the depth, but it varies between $30,000 and $140,000 per year."
That decision, he added, will be made public early next year, when an Environmental Impact Statement and other related documents are opened for public comment and review.
Although it would be years before a fish passage structure could be built, its completion would trigger requirements for similar fish passage systems at two other dams above the city - the Augusta Diversion Dam at the canal headgates; and the Stevens Creek hydroelectric dam, owned by S.C. Electric & Gas Co.
Both upstream dams are under pressure from the Federal Energy Regulatory Commission to provide fish passage, but both projects were allowed to place such projects on hold until such time as fish can move past New Savannah Bluff, which currently blocks most upstream migration.
Successful fish passage at all three dams would open up the river to fish migration and spawning all the way to the base of Thurmond Dam.
Reach Rob Pavey at (706) 868-1222, ext. 119, or firstname.lastname@example.org.