Understanding the Dam Releases on the Deerfield River

Timing the releases at Fife Brook Dam | How the dam releases Work

How the dam releases work There are 10 hydroelectric dams along the 73-mile length of the Deerfield River, earning it its nickname, "The Hardest Working River". The river originates in southern Vermont where the two largest storage reservoirs, Somerset and Harriman, are located. These two reservoirs are managed on an annual cycle. In early spring they are generally at their lowest, having been used to produce hydropower through the winter and in anticipation of the spring snowmelt and rain. They fill to their highest levels by mid June. For the months of July and August the utility company utilizes the water stored in them to produce power to meet the peak summer demand. Throughout the fall and winter the reservoirs are drawn progressively lower until the early spring, when the cycle starts over again.

As of May, 2006, the dams on the Deerfield River are owned by three utility companies: Transcanada owns most of the dams (Somerset, Searsburg, Harriman, Sherman, #5, #4, #3 and #2); Brookfield Power owns the Bear Swamp Pump Storage project and Fife Brook dam; and Consolidated Edison owns Gardner Falls Dam. Despite this split in ownership of the projects, release patterns on the river as a whole are generally driven by release patterns at Harriman dam since Harriman Reservoir is the largest storage reservoir in the system.

• Somerset Dam Class II section below the dam at a spill of 150 cfs.
• Searsburg Dam Class III section below the dam at a spill of 800 cfs. Above 1400 cfs becomes class III-IV.
• Harriman Dam Class III-IV section below the dam at a spill of 800 cfs.
• #5 Dam Aka "The Dryway" or "The Monroe Bridge Section". Medium levels at a flow below the dam of 900 cfs; high from about 2000 cfs and up.
• Fife Brook Dam Aka "The Zoar Gap Section". Medium levels at a flow below the dam of 700 cfs. Above about 2000 cfs Zoar Gap becomes class III+ to class IV.
• #4 Dam Class II-III at a spill below the dam of 700 cfs.
• #3 Dam This is the dam at the Potholes in Shelburne Falls.
• #2 Dam This is the lowest dam on the river; #1 was planned, but never built. Class I-II at a flow below the dam of 600 cfs.

The most heavily used section of the river by kayakers, canoeists, whitewater rafters, and others, is the section below Fife Brook Dam. This section is the longest undammed stretch on the Deerfield River and there is a schedule of water releases below Fife Brook that includes 106 days from April through October. The power company often releases water on unscheduled days as well to meet peak power demands.

The Waterline flow forecast for Fife Brook gives the time they expect to be releasing from the dam, but if you plan to put in at Zoar Gap or at another location well downstream of the dam, you need to add time to the dam release time in order to allow for the time it takes the water release, known as the "bubble" to move downstream. Depending on the release level (higher releases move downstream more quickly) the rate at which the release moves downstream will vary somewhat, but it generally moves at between 2 1/2 and 3 miles an hour downstream. Following is a chart showing approximate times the water release reaches certain locations on the river: