The Corps is required to develop a “water control plan” for each of its reservoirs that explains how it will be operated to meet its various authorized purposes, such as water supply, flood control, and hydropower generation. Where there are multiple reservoirs in a system, as there are in the ACF and ACT Basins, the Corps must prepare a Master Water Control Manual that includes the individual water control plans for each reservoir and that describes how the system as a whole will be operated.
The master water control manual for the ACF Basin reservoirs was stalled for decades due to a combination of litigation, the ongoing interstate negotiations, and political maneuvering in Congress.
This began to change in 2011, when the 11th Circuit issued a key ruling recognizing that the Corps was authorized to use Lake Lanier to provide a safe and reliable water supply for Metro Atlanta. That decision also recognized, however, that the Corps needed to make a final decision about how Lake Lanier would be operated for water supply. To make sure that happened, the court gave the Corps one year to determine how much water it believed could be supplied.
This direction set the stage for the development of a new Master Water Control Manual for the ACF reservoirs, including Lake Lanier. Based on analyses prepared in response to the 11th Circuit’s order, the Corps found it has the legal authority to meet all of metro Atlanta’s long-term projected water supply needs. The Corps stated that it could not make a final decision about whether it would do so, however, until all required environmental studies were completed.
Over the next five years, from 2012 to 2017, the Corps prepared draft and final versions of an updated Master Water Control Manual for the ACF Basin. This included a decision about how much water it will provide to Metro Atlanta from Lake Lanier and the Chattahoochee River downstream of the reservoir. As is also required, the Corps prepared an Environmental Impact Statement (EIS) under the National Environmental Policy Act (NEPA), analyzing the environmental benefits and impacts that would result from its updated operating plan. Draft and final versions of the Water Control Manual and EIS, as well as comments submitted on the draft, are available here.
The Corps signed a Record of Decision (ROD) adopting the Final ACF Water Control Manual on March 30, 2017. The ROD states that the Corps will reallocate storage in Lake Lanier and release water into the Chattahoochee River to accommodate Metro Atlanta’s long-term (year 2050) projected water supply needs. Among other things, the Corps’ decision was based on its finding that meeting Metro Atlanta’s needs and adjusting its reservoir operations “would have no more than negligible effects overall on flow conditions in the Apalachicola River, or water quality, salinity, and fish and aquatic resources in the River or Bay.”
On April 5, 2017, Alabama filed suit to challenge the Updated Manual and Final Environmental Impact Statement. On April 27, 2017, three environmental groups (including the Apalachicola Riverkeeper) filed a related challenge the Corps’ Updated Manual. Both cases have been consolidated and are pending in federal district court in Atlanta. Further details on these challenges are provided below.
On January 20, 2021, the Corps executed a long-term water supply storage contract with the State of Georgia for Lake Lanier. This contract provides for permanent storage in Lake Lanier sufficient to meet the future water supply needs of metropolitan Atlanta communities that withdraw from the lake (Gwinnett County, the City of Buford, the City of Gainesville, the City of Cumming, and Forsyth County) as well as upstream communities. The 11th Circuit ruling and the updated ACF Water Control Manual already ensure that sufficient water will be available in the river below Lake Lanier to meet the long-term needs of the other metropolitan Atlanta communities.