Two projects in different parts of the country are highlighting the potential conflict between the needs of the people and the needs of wildlife. Both illustrate, in different ways, the tricky juggling act agencies like the US Army Corps of Engineers must perform to balance diverse—sometimes incompatible—priorities as they manage the nation’s waterways.Are you subscribed to Erosion Control magazine? Click here for a free subscription!
In Los Angeles, officials are attempting to capture and use water that otherwise would flow into the Los Angeles River. For decades, the largely concrete-lined river has sped stormwater runoff directly to the ocean. Beginning in the 1930s, the Army Corps of Engineers confined and channelized the river to help reduce flooding in the rapidly growing city.
Now the city would like to claim some of that runoff, as well as dry-weather flow from treatment plants, landscape irrigation, and the like, to reduce its dependence on imported water. A plan calls for diverting about 30,000 acre-feet of treated wastewater to spreading grounds, where it will infiltrate and replenish the local aquifer. Various green infrastructure installations are expected to infiltrate another 130,000 to 170,000 acre-feet of water, which presumably can be pumped from the ground for later use. (Orange County has proposed a somewhat similar plan.)
The problem, environmental groups say, is that the combined diversions—green infrastructure, diverted wastewater, and the general reduction in landscape watering during the drought—will cause the river to dry up for several months during the year. That will harm the species that have come to depend on it, including birds that feed in the algae-lined concrete channel. As this Los Angeles Times article explains, researchers at UCLA are trying to help figure out a balance between infiltrating more water and maintaining habitat; part of the puzzle involves figuring out what a reasonable habitat might look like in a region whose waterways have been drastically altered and that has lost most of its natural wetlands.
No one seems to be talking about a lawsuit to stop the city’s plan to capture and infiltrate water, but thousands of miles away, a federal judge has just issued a ruling that might have some relevance for this and similar situations. The winners in this case, though, are the humans, not the wildlife, and the issue is too much water rather than too little. The Army Corps of Engineers has, over the last decade or so, changed the way it manages releases of water from dams along the Missouri River; whereas the emphasis used to be on flood control, the agency is now attempting to restore a more natural flow of water to improve habitat for a number of threatened species.
A group of 372 plaintiffs in six states has argued that the changes resulted in flooding to their properties, causing more than $300 million in damages. Their lawsuit maintains that the agency has placed protection of wildlife above the landowners’ economic interests. A federal judge has just ruled that the Corps of Engineers’ change of policy is indeed responsible for the flooding, although the court has not yet said whether the property owners are entitled to monetary compensation. This article examines the issue in more detail, noting that the Corps is required by federal law to “capture and release water by balancing flood control, navigation, water supply, irrigation, power, recreation, water quality, and wildlife preservation.” As one member of the Sierra Club (which was not involved in the suit) commented, “They [the landowners] are asking for taxpayers to pay for their damages and forgo any other use of the river.”