Shrinking water supply makes room for birds

 

Note: in the print edition of this issue, this article appears as a sidebar to one of this issue's feature stories, "Attack of the bark beetles."

This year's drought is bad news for most wildlife, but not for the endangered southwestern willow flycatchers at Roosevelt Lake in Arizona.

During the six years of drought since 1996, Roosevelt Lake, Phoenix's main water supply, has shrunk to 12 percent of capacity. As more lake bed has been exposed, tamarisk and willow have sprung up. The result: Flycatchers have moved in en masse. Over the last five years, the Roosevelt Lake flycatcher population - one of just a dozen remaining - has grown fivefold, to 15 percent of the total species population.

This, however, has caused havoc for the Bureau of Reclamation and the reservoir operator, the Salt River Project. In 1996, when the Bureau increased the capacity of Roosevelt Lake by 20 percent by adding 77 feet to the Roosevelt Dam, it worried that 55 nesting flycatchers would be flooded. To keep from violating the Endangered Species Act, the Bureau gave The Nature Conservancy $4.4 million to protect alternate bird habitat in the form of the 800-acre San Pedro River Preserve (HCN, 9/15/97).

Now, with the reservoir almost as low as it can get and tightly ringed by tamarisk and willows, any major rainfall could flood flycatcher nests. So the Salt River Project is looking to purchase some of the Southwest's only remaining healthy riparian habitat in the San Pedro, Verde and Gila river valleys. The utility says the purchase may cost it $20 million - about $29 per customer.

Jon Waldman is a High Country News intern.