Why Mitigation is Required

The New Savannah Bluff Lock and Dam has blocked endangered fish species, Atlantic and shortnose sturgeon, from their historical spawning grounds since its completion in 1937. Since cessation of commercial navigation in the 1970s, the structure has degraded due to Congress curtailing maintenance funding. Because the pool it holds is still important for the Augusta area, the lack of upkeep has gradually led to conditions that could lead to failure of the structure over time and eventually loss of pool. But since the Savannah Harbor Expansion Project (SHEP) also adversely impacts sturgeon and happens to be a fully funded project, SHEP is able to step in as the bill-payer to solve the problem of eventual lock and dam failure. To compensate for impacts to sturgeon from both SHEP and the lock and dam, SHEP includes construction funding (or partial funding) for an eventual solution. The eventual solution would need to function as a fish passageway to enable fish to gain access upstream of the current lock and dam.

The WIIN Act of 2016

The act specifies that one of two types of modifications are to occur:

(1) Section 1319 (c)(1)(A)(i) - repair of the lock wall of the NSBLD and modification of the structure to maintain the pool for navigation, water supply, and recreational activities as existed on the date of enactment of the WIIN Act and to allow safe passage over the structure to historic spawning grounds of shortnose sturgeon, Atlantic sturgeon, and other migratory species, or

(2) Section 1319 (c)(1)(A)(ii) - construction at an appropriate location across the Savannah River of a structure that is able to maintain the pool for water supply and recreational activities that existed on the date of enactment of the WIIN Act and remove the NSBLD once construction of the structure is completed.

The National Environmental Policy Act

Promotes Better Environmental Planning and Decision Making to Protect the Human Environment

1. Identify the problems and opportunities
   Section 1.4.1 to Section 1.4.6
2. Inventory, forecast, and analysis of conditions within the planning area relevant to the identified problems and opportunities
   Section 2.0 to Section 2
3. Formulation of alternative plans
   Section 3.0 to Section 3.5
4. Evaluation of the effects of the alternative plans
   Section 3.6
5. Comparison of alternative plans
   Section 3.7
6. Selection of a recommended plan based upon the comparison of alternative plans
   Section 4.0

Management measures are features or activities that can be implemented at a specific geographic location to address one or more planning objectives and avoid constraints.  Based on the two types of project modifications in the 2016 WIIN Act and the objectives of the study, the following management measures were created:

(1) Repair lock wall

(2) Repair dam gates and piers

(3) Remove lock wall

(4) Remove dam gates and piers

(5) Remove dam to foundation

(6) Construct an in-channel fish passage

(7) Construct a floodplain bench

(8) Construct a high-flow, flood gate and bypass channel