Gone fishin': stream rentals restore trout.

THE UPPER reach of Montana's Wasson Creek is home to a purestrain population of westslope cutthroat trout. But overzealous irrigators regularly dried up the creek downstream during the summer. This kept the trout from migrating to and populating Spring Creek, another tributary that eventually connects with the Blackfoot River. The solution: water leasing, a property-based approach that lets ranchers and farmers profit from leaving water in a stream, where it sustains fish populations.

In the past, riparian rights in the American West have followed the principles of "first come, first served" and "use it or lose it": If you don't divert water from a stream for some use, you lose your right to it. Such rules encourage farmers and ranchers to consume water profligately, drying up streams and leaving fish homeless.

Enter the private conservation group Trout Unlimited. It arranged with ranchers Dave and Randy Mannix for a 10-year water lease, acquiring a flow of 224 gallons per minute through the Mannixes' portion of Wasson Creek during the summer and fall months. The results were immediate: Westslope cutthroat trout returned to Spring Creek for the first time in decades. Leasing is not a panacea for fisheries restoration, Trout Unlimited notes, but it "has proven itself to be an effective and workable approach in helping to restore or enhance stream flows on Montana's rivers and streams."