In the case of Bennett v. Spear (520 U.S. 154 (1997)), the Fish and Wildlife Service (FWS) was worried that the operation of the Klamath Irrigation Project would adversely impact two species of endangered fish.  Pursuant to the Endangered Species Act (ESA), they ordered several reservoirs to maintain minimum levels of water.  Some of the people downstream, who wanted the water for irrigation sued, claiming that FWS did not consider their decision's economic impact on the region. The Trial Court and the Appellate Court dismissed for lack of standing. However, the US Supreme Court unanimously reversed, and found that private parties who claim they suffered economic harm from the enforcement of the ESA had standing to sue in order to seek reversal of the decision.