Thursday, April 24, 2014
By STEVE HEINZ
CUMBERLAND - On July 26, the Sebago Chapter of Trout Unlimited teamed with the Casco Bay Estuary Partnership to remove Randall Mill Dam from Chandler Brook in Pownal, reconnecting the upper brook to the Royal River.
A dam had stood on that site since 1896 and had supported both grist and lumber mills. The dam was preventing fish and other aquatics from reaching the upper brook.
Before the heavy equipment had left, small fish were already swimming upstream; that weekend, a canoe passed the old dam site without having to portage; as you are reading this, the brook will be continuing to find its new course and again moving the gravels downstream that trout need to spawn successfully.
These events touch the same issues that drove the recent removal of the large Veazie Dam that received so much press. It is not general knowledge that there were many smaller projects carried out first in the smaller waters of the Penobscot River drainage before the big dams came out.
For the last two years, the town of Yarmouth has been engaged in a process to examine the possible removal of its two head-of-tide dams on the Royal River: the Sparhawk Mill Dam and the Elm Street Dam. The latest report has been completed dealing with sediment, and should be released for discussion soon.
John Field, an expert with a doctorate in fluvial geomorphology (how rivers change their course), was present at Randall Mill, and I asked him about the Royal River and its sediments.
He confirmed what I had long thought: "From the steeper brook habitat like Chandler, Collyer and other feeders, the river meanders through a bowl with clay soils for most of its course. The river is slow-moving, somewhat turbid water until the slope increases for its last few miles through Yarmouth where it meets Casco Bay. The river is a continuous conveyor belt for these clay soils, and will be until the next ice age or some major geological event occurs."
Dam removal would have less of an immediate impact than what followed the June 2012 major rain event that flushed much of what had been trapped behind the Yarmouth dams when they overtopped. Nature will continue to flush clay through the system -- removal would allow the release of the sediments under controlled conditions. The amount of sediment released would be minor in the greater scheme of things.
The dams at Yarmouth affect everything upstream. The watershed includes the towns of North Yarmouth, Pownal, Durham, New Gloucester and Gray -- even parts of Freeport, Brunswick, Poland, Auburn and Raymond.
There are few things that have a worse ecological effect than damming a river at its confluence with the ocean. The Royal had an Atlantic salmon run until the lower river was dammed in the 1840s. Alewives are especially important as they bring nutrients from the ocean upstream against the current; their young returning to the ocean feed species such as coastal cods.
Fish ladders are a poor method of effecting upstream fish passage, and they are expensive to install and hard to maintain. The power generated at the Sparhawk Mill will not pay for the long-term maintenance of the dams -- its fish ladder would need to be redesigned and replaced. Alewives, sea-run trout and other species are currently kept out of the river system. They cannot access the quality waters such as Chandler Brook.
The ultimate issue in Yarmouth may be aesthetic: the millponds that people have grown so accustomed to. I live in Cumberland, about 10 minutes from the dams, and attended some of Yarmouth's public meetings. Some feelings ran strong, but the dialogue was calm and rational. I hope that it remains so.
When I waded the reborn stream that used to be the Randall Mill Pond, I heard the sounds of flowing water, and saw the riffles and pools re-emerging that the millpond had so long buried.
Has the time come for Yarmouth to choose to embrace a new aesthetic -- one that is ecologically functional? More discussion will be needed for Yarmouth to reach a consensus.
Steve Heinz of Cumberland was Sebago Chapter of Trout Unlimited's project coordinator for the removal of the Randall Mill Dam.