Although both projects had been discussed as options, they were formally included this week in the U.S. Army Corps of Engineers' draft Environmental Impact Statement as mitigation measures for the $520 million harbor project.
Work on the fish passage device could commence as early as 2013, said Alan Garrett, the corps' civil works project management chief.
The 72-year-old New Savannah Bluff dam near Augusta Regional Airport blocks upstream migration of the endangered shortnose sturgeon, American shad and other species, including striped bass.
It had been earmarked for demolition after a 1999 corps study concluded it was no longer needed for commercial shipping -- the purpose for which it was built.
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, Congress has not provided the $22 million needed to renovate the dam and add fish passage.
As a mitigation effort associated with the harbor project, the fish passage structure has a greater chance of completion and could be built independently of other needed work, Garrett said.
Local governments remain involved in efforts to get federal funding for the other renovations.
"We are still working very closely with Augusta and North Augusta," Garrett said.
The fish passage was designed as a horseshoe-shape, 75-foot-wide ramp with 9-inch ledges that would allow fish to bypass the dam and move upstream.
It would be built on the river's South Carolina side and -- on completion -- would reopen more than 20 miles of river habitat to fish spawning, including the oxygen rich shoals upstream from Augusta.
Garrett said it is likely that new studies would precede actual construction to insure that the design incorporates the newest technology for such devices.
If the fish passage structure is 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.
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. The amount of the payments will depend on how many feet the harbor is deepened.
The Savannah Harbor plan involves deepening it from its current depth of 42 feet up to a maximum depth of 48 feet. The public comment period on the proposals will open officially for 45 days beginning Nov. 26 and end on Jan. 10, 2011.