On November 5, 2018 the 10th Circuit Court of Appeals ruled in favor of the U.S. Army Corps of Engineers’ approval to store more water in Colorado’s Chatfield Reservoir. The Audubon Society had challenged the Corps’ decision under the National Environmental Policy Act and the Clean Water Act, arguing that the Corps decision was arbitrary and capricious.
The project proposes to raise the water level in Chatfield Reservoir to store an additional 20,600 acre-feet of water, thereby flooding hundreds of acres of the adjacent Chatfield State Park.
Of the 38 potential alternatives, the Corps conducted a detailed analysis of only four alternatives. They determined that most of the alternatives did not warrant further study. In addition to selecting the alternative of raising the water level in Chatfield by 12 feet, the Corps considered a no-action alternative in which water providers would use a combination of alternative storage facilities and groundwater to meet demand and an alternative that would raise the water level in Chatfield by only five feet.
The Audubon Society argued that the Corps should have analyzed a number of other alternatives that had been dismissed in initial stages. The court rejected these arguments, finding that the Corps had supplied sufficient reasons to reject these alternatives from the start.
The Audubon Society also argued that the Corps should have conducted a more searching Clean Water Act analysis related to the need to discharge dredged materials into regulated waters. Specifically, Audubon argued that under the Clean Water Act’s “404(b) guidelines” the Corps should have analyzed a wider range of alternatives to the contemplated discharge. The Court recognized that the scope of analysis under this part of the regulations implementing the Clean Water Act is ambiguous, and gave deference to the Corps’ interpretation of the regulation:
We conclude that the Corps complied with § 230.10(a) because it reasonably found that it could approve the Reallocation Project without allowing the discharge of dredge and fill, such that it was appropriate for the Corps to confine its CWA analysis to the recreation relocation and environmental mitigation plans. The Corps explained in the EIS that it was “feasible” to complete the recreation relocation and environmental mitigation plans without discharging dredge and fill. As part of its analysis, the Corps explained how the plans could be amended to avoid the discharge of dredge and fill. Potential changes included moving “recreational facilities . . . farther from the reservoir,” shortening culverts, and positioning “stilling basins . . . outside of wetlands”. Audubon disputes the Corps’ conclusion, but provides no reasoned basis to doubt the Corps’ explanation that dredge and fill could be avoided if the recreation facilities and mitigation activities were moved further from the wetlands.
This case is one of several recent cases involving the legality of water storage projects in Colorado (for example, litigation is currently pending with respect to the proposed expansion of Gross Reservoir), and sets an important precedent for the level of deference that the courts will give to the Army Corps in reviewing the legality of these projects under various environmental laws.