For more than three decades, Georgia, Alabama, and Florida have disputed the use of two shared river basins—the Apalachicola-Chattahoochee-Flint (ACF) and the Alabama-Coosa-Tallapoosa (ACT). These river systems are used to meet multiple needs, including drinking water, power generation, agriculture, aquaculture, navigation and recreation.
Surface waters from the ACF and ACT River Basins are critical for meeting metro Atlanta’s water supply needs because our access to groundwater is limited due to the granite geology underlying our region. While rainfall in metro Atlanta is generally abundant, river flows are not always sufficient to meet the area’s water supply needs. Therefore, we depend on our ability to store water in two reservoirs operated by the U.S. Army Corps of Engineers (Corps) to provide safe and clean water supplies for our residents and businesses: Lake Lanier in the ACF Basin and Allatoona Lake in the ACT Basin. Collectively, the Chattahoochee River and these two reservoirs accounts for approximately 80% of the metro region’s water supply.
The “Tri-State Water Wars” litigation began in 1990 when Alabama sued the Corps to prevent it from providing additional water to metro Atlanta from Lake Lanier and Allatoona Lake. Although the dispute has evolved and changed over time, it has focused on legal challenges to the Corps’ plans for managing the ACF and ACT Basins and a direct challenge in the United States Supreme Court by Florida regarding Georgia’s water use in the ACF Basin.
Find more detailed information on the background and history of the Water Wars litigation.
In 2021, there were a number of rulings in this longstanding dispute. Significant developments are summarized below:
ACF Supreme Court Litigation
In 2014, the State of Florida sued the State of Georgia in the U.S. Supreme Court. Florida asked the Supreme Court for an “equitable apportionment” of the waters of the ACF Basin that would restrict Georgia’s water use to 1992 levels. Florida claimed this substantial reduction in Georgia’s water use was justified because Georgia’s water use harmed the environment downstream and caused the collapse of the Apalachicola Bay oyster fishery. Georgia denied that its water use harmed Florida, explaining that its current and projected future water use will have only “a minor impact on the flow in the Apalachicola River at the state line,” and that the collapse of the Apalachicola Bay oyster fishery was the result of environmental factors and mismanagement by Florida.
In April 2021, the Supreme Court unanimously denied Florida’s request and dismissed its Complaint. The Supreme Court found that Florida had failed to prove that Georgia’s water use had caused the decline in the Apalachicola Bay oyster fishery or harmed riverine and plant species in the Florida.
While the Supreme Court observed that “the precise causes of the Bay’s oyster collapse remain a subject of ongoing scientific debate,” the Court rejected Florida’s argument “that Georgia’s overconsumption—and the consequent increased salinity and predation—was the sole cause of the collapse, or at least a substantial factor contributing to it.” The Supreme Court observed that “Florida’s own documents and witnesses reveal that Florida allowed unprecedented levels of oyster harvesting in the years before the collapse” and “that Florida failed to adequately reshell its oyster bars.”
The Supreme Court also observed that modeling by Florida’s expert “showed that reducing Georgia’s consumption by an amount ‘similar to the relief that Florida is requesting’ in this case would have increased oyster biomass by less than 1.5% in 2012,” explaining that “the data and modeling of [Florida’s] own experts” shows “that Georgia’s consumption had little to no impact on the Bay’s oyster population.” Given this, the Court ruled that Florida failed prove “that Georgia’s alleged overconsumption played more than a trivial role in the collapse of Florida’s oyster fisheries.”
The Supreme Court also ruled that Florida had not proved that Georgia’s water use “harmed river wildlife and plant life by disconnecting tributaries, swamps, and sloughs from the Apalachicola River, thereby drying out important habitats for river species.” The Supreme Court agreed with the Special Master appointed to oversee the case that there was “ ‘a complete lack of evidence’ that any river species suffered serious injury from Georgia’s alleged overconsumption.” Thus, the Supreme Court ruled: “Without stronger evidence of actual past or threatened harm to species in the Apalachicola River, we cannot find it ‘highly probable’ that these species have suffered serious injury, let alone as a result of any overconsumption by Georgia.”
The case also marked a turning point for Metro Atlanta’s water use. Consistent with its public claims over many years, Florida asserted in its complaint that Municipal and Industrial (M&I) water use in Metro Atlanta was unreasonable and harmed the environment downstream. Based on the evidence presented at trial, however, the Special Master found that Atlanta’s M&I “consumption has been reasonable,” noting the “concrete steps” taken “to increase efficiency and conserve in this area,” the “effectiveness” of those conservation programs, and the large benefits generated by its water use for millions of people in Metro Atlanta who depend on the Chattahoochee River for their water supply. Florida declined to challenge these findings in the Supreme Court and expressly abandoned any challenge to water use in Metro Atlanta.
ACT Water Control Manual, Allatoona Lake Reallocation Study, and Related Litigation
Since the 1980s, Metro Atlanta water providers have been seeking additional water supplies from Allatoona Lake in the ACT Basin. However, Alabama sued the Corps in 1990 to block action on these requests, precipitating the “Water Wars,” and the Corps declined to act on these water supply requests for many years.
In 2015, the Corps updated its Water Control Manuals for the ACT Basin but declined to take any action to address Metro Atlanta’s water supply needs. ARC, the State of Georgia, and the Cobb County-Marietta Water Authority (CCMWA) filed suit, seeking a court order compelling the Corps to act. The court found the Corps’ failure to address Metro Atlanta’s water supply needs was unlawful and ordered the Corps to make a final decision regarding water supply needs from Allatoona Lake by August 2021.
Following a three-year “Reallocation Study” and the preparation of a detailed Environmental Impact Statement, the Corps signed a Record of Decision on August 30, 2021 granting Metro Atlanta’s water supply requests from Allatoona Lake. The decision confirms that Metro Atlanta’s projected 2050 water supply needs from Allatoona Lake of 94 million gallons per day will be met, explaining that “exhaustive analysis” by the Corps demonstrates that meeting these needs will have “no significant adverse impacts to federal purposes” and no “appreciable effects on flows at the Alabama-Georgia state line, drought triggers, or water quality.”
The decision reallocates additional storage space in the reservoir to meet the City of Cartersville’s projected water needs through 2050.
Additionally, and perhaps more significantly, the decision recognizes CCMWA’s right to impound and withdraw “made inflows” to Allatoona Lake. Made inflows consist of reclaimed water returned to a reservoir for reuse and releases of water stored in other water supply reservoirs. Made inflows are a critical component of Metro Atlanta’s long-term water supply plan because they increase the amount of water flowing into a reservoir, thus allowing water providers to meet growing needs and improve water supply reliability by engineering projects to put more water back into existing reservoirs.
The decision to recognize CCMWA’s rights to made inflows marks a sea-change in Corps water policy. It will strongly incentivize additional water reuse in Metro Atlanta, enhance the resiliency of the region’s water supply, and maximize the use of existing reservoir storage space, thus avoiding economic and environmental impacts from the construction of additional and unnecessary water supply infrastructure.
Separately, the State of Alabama, Alabama Power Co. and others have also filed suit against the Corps to challenge aspects of the 2015 Manual and the Corps’ management of Allatoona Lake. In February 2022, Alabama requested to supplement its complaint to also challenge the Corps’ 2021 water supply reallocation and decision on return flows. This request to supplement was granted by the court in November 2022.
In November 2023, the court issued a decision rejecting all challenges by Alabama and Alabama Power to the 2015 Water Control Manual and Final EIS (case originally filed in May 2015). The remainder of this case remains pending in Washington, D.C.
More information on the ACT Water Control Manual and the ongoing litigation in the ACT Basin.
ACF Water Control Manual and Related Litigation
On March 30, 2017, the Corps adopted a final Master Water Control Manual and Environmental Impact Statement for the ACF Basin. The updated Master Manual explains how the Corps will operate the ACF Basin reservoirs, including how much water it will provide from Lake Lanier to metro Atlanta. It responds to a key decision by the Eleventh Circuit Court of Appeals in 2011, which dismissed challenges by Alabama, Florida and others to the Corps’ water supply operations and ruled that Congress intended Lake Lanier to be used as a water supply source for metro Atlanta.
The updated Master Manual confirms that the Corps will accommodate Metro Atlanta’s 2050 water supply needs from Lake Lanier and the Chattahoochee River below Buford Dam. The decision adopting the Manual explains that the plan is “technically feasible, in accordance with environmental and other applicable statutes, and the alternative that best serves the overall public interest.” It also explains that Metro Atlanta’s future water supply withdrawals and other changes to the Corps’ reservoir operations would have at most “negligible effects overall on flow conditions in the Apalachicola River, or water quality, salinity, and fish and aquatic resources in the River or Bay.”
In April 2017, shortly after the Corps adopted the updated manual, Alabama and several environmental organizations filed a lawsuit against the Corps to challenge it. In August 2021, the U.S. District Court for the Northern District of Georgia ruled in favor of the Corps, affirming its decision to meet Metro Atlanta’s water supply needs and rejecting all remaining claims by Alabama and the environmental groups. Summarizing, the court explained:
The ACF Basin Master Water Control Manual Update assures a dependable supply of water from Lake Lanier and the Chattahoochee River to the Atlanta Metropolitan region through the year 2050. It does so without significant sacrifices to environmental standards, and recognizes the need to maintain other uses of the ACF system such as flood control, hydropower generation, fish and wildlife conservation, navigation and recreation. The effect upon the Apalachicola River and Bay will be negligible. The decision was not arbitrary or capricious. The Plaintiffs have not met their burden of showing that this delicate balance should be upset. In the absence of an agreement among Georgia, Florida and Alabama, there is no better alternative. Decades of deferral and delay due to litigation should end.
Alabama and the environmental group have appealed the court’s decision to the U.S. Court of Appeals for the Eleventh Circuit. This appeal is pending.
More information on the Corps’ work on the ACF Water Control Manual.
Page last updated November 14, 2023.