by Steve Luebeck

On December 17, 1997, history was made in Divide, Montana. That date marked the final approval, by the Big Hole Watershed Committee, of the Big Hole River Drought Management Plan, more commonly known as the Dry Year Plan. The plan calls for an organized effort by all interest groups to "mitigate the effects of low stream flows and lethal water temperatures on fisheries," problems which have plagued this nationally renowned stream for years. Finalizing this plan is a major accomplishment, and has been a goal of our chapter for the last three years.

The plan will help to maintain minimum flow levels in the main stem of the Big Hole River during drought years. The droughts of 1988 and 1994 saw some of the lowest flows ever recorded on the Big Hole River. The flow at the Melrose gauging station in 1988 was recorded at 53 cubic feet per second (cfs), and in 1994 the flow reached 146 cfs. These two events brought about the creation of the Watershed Committee.

Based on information provided by Fish, Wildlife and Parks, 150 cfs and 20 cfs were established as the bare minimum flows necessary to maintain the fishery in the lower river and upper river respectively. Below this flow, the fish are concentrated in the few remaining pools, where they are more susceptible to predation from larger fish, ospreys, herons, and otters - not to mention humans. These low flows cause high water temperatures and low oxygen content. The aquatic insects in the river also take a beating, and dewatering may be the main reason for the less-than-prolific salmon fly hatches seen during the last decade.

The Dry Year Plan aims to alleviate these problems through a voluntary effort by irrigators to reduce water diversion and increase the use groundwater for watering cattle. The plan will also put in place a mechanism to close the fishing season on the Big Hole River during a catastrophic drought.

Since the river flows for over 100 miles through vastly different types of terrain and geology, the plan splits the river at the Dickey Bridge. The area upstream of the bridge will be managed based on flows recorded at the Wisdom Gauge. This part of the river is predominantly a brook trout and fluvial Arctic grayling fishery, and is of particular interest to the U. S. Fish and Wildlife Service because of the diminished numbers of fluvial grayling in the lower 48 states. Crop irrigation in the upper basin generally ends around July 4th, and later withdrawals are used to water cattle in distant pastures. The area downstream from Dickey Bridge will be managed based on flows recorded at the Melrose Gauge. This part of the river is predominantly a rainbow and brown trout fishery and supports a much longer irrigation season.

The plan creates a three-step process to raise public awareness of impending drought conditions and institute conservation measures. These steps will be triggered based on flows recorded at the two gauges:

Step 1: When flows drop to 60 cfs at the Wisdom Gauge or 250 cfs at the Melrose Gauge, the plan calls for statewide press releases to raise the public awareness of impending drought conditions. FWP will meet with the Big Hole Watershed Committee to present data and formulate options including voluntary reductions in irrigation, municipal water use, angling, and increased use of stock watering wells. A phone tree will keep irrigators and outfitters advised of stream flows.

Step 2: When flows drop to 40 cfs at the Wisdom Gauge or 200 cfs at the Melrose Gauge, the plan requires a notice to outfitters and anglers statewide, requesting that fishing be voluntarily limited to morning hours. Ranchers will begin using stock water wells.

Step 3: When flows drop to 20 cfs at the Wisdom Gauge or 150 cfs at the Melrose Gauge, the plan calls for closing the fishing season on the affected section of the river until flows reach step 2 levels for seven days. Irrigators will begin voluntary reduction of irrigation withdrawals.

In 1994, FWP used similar measures with some success, although the plan was thrown together at the last minute. Having the Dry Year Plan in place ensures that future efforts will be far more organized. Also, requests will come from local irrigators who are on the committee, avoiding the perception of government interference.

The success or failure of this plan lies in the hands of the members of the committee. All members have made a commitment to communicate with their respective groups, and will try to win support and compliance. While 100% compliance will be difficult to achieve, most irrigators seem willing to participate in conservation efforts. Even a 5% reduction in irrigation withdrawals across the board would probably maintain minimum flows.

The plan is not the final solution to dewatering in the basin, but it is one important component in a final solution. The current committee is made up of ten irrigators from the Big Hole Basin, as well as representatives from Trout Unlimited; The Big Hole River Foundation; Butte Water; Anaconda/Skyline Sportsmen; Beaverhead County; the Beaverhead Conservation District; an outfitter representative; FWP; and the Beaverhead National Forest.