RUMFORD — A dearth of rain this spring and summer has finally created ideal conditions in the Androscoggin River, enabling a Bancroft Construction crew to install a new crest gate system on the upper Rumford Falls Hydro dam.

The water behind the dam was so low on Wednesday that a large section of river bottom was visible to Route 2 drivers about 5 miles upriver.

Plant Manager Dave Lavorgna said late Thursday afternoon in Rumford that this is Brookfield’s third attempt in as many years to get the job done. High river flows due to rainy springs and summers have prevented the work.

The 600-foot-long dam, which was built in 1918, currently uses a wooden flash-board system to raise and lower water levels as needed, but that’s no longer efficient.

That’s why they are trying to install an Obermeyer bladder system gate — 300 feet of inflatable flash boards — which releases water more safely and precisely by remotely deflating large air bladders.

The new system will offer more consistent river flows for boaters and anglers, help maintain water supply to the NewPage paper mill in Rumford, enhance flood control and offer safer working conditions.

Lavorgna said the new system would help over the old system, say when they have high water and lose the flash boards.

“If we lose the boards but the river flow never drops below station capacity — we can’t go out there and walk on the dam with water running over it — so we have to wait for it to pass, all the river flow, to get out there,” he said.

“So one real good benefit of this is we should be able to maintain a more constant river level, which keeps everybody happy, whether you’ve got fins, feathers or a fishing pole.”

Additionally, if the power station goes off line or trips, the bladder bags will start deflating and spill water.

“So, it’s a big environmental improvement,” Lavorgna said.

Currently, workers are installing coffer dam pins to work on a section of the dam closest to Route 2 atop Falls Hill where ice and woody debris carried downriver have been pounding the dam for years, breaking off chunks of concrete and a concrete trench that will be used to install an air line for the bladders.

“Most of the trench has been broken away due to the ice and whatnot hitting the concrete, so that needs to all be repaired,” Lavorgna said.

Additionally, during the winter, air is blown through the dam to circulate water up from the bottom to help prevent ice from adhering to the flash boards.

“If it adheres to them and then the water level comes up, it lifts the boards up and you lose them,” he said.

On Thursday, the river level was down nearly 4 feet. But once the coffer dam is built, the water level will be raised to the dam crest.

Low water flows mean needed maintenance can be done, but it also means no electricity is being generated.

“We’re suffering on power generation right now because we don’t have enough flow,” Lavorgna said.

“Today, the river flow is at 1,800 cubic feet a second and the station can pass 4,600 cubic feet per second before we spill over the dam, and that’s a lot of water. The flow of 1 cubic foot per second is 488 gallons a minute.

“The higher the water level you can get, the more pressure we’ll have down at the turbines, so we can generate more power, so, by having the pond way down, it really hurts us, too.”

Since 2006 when Brookfield took over dam operations, the company has “done very extensive environmental work,” power generation and control upgrades, and “a great deal of public safety,” Lavorgna said.

One facet of that safety now involves preventing access on the walking trail off South Rumford Road, which is posted No Trespassing, but many people ignore that and do so anyways.

Lavorgna said they have to try and prevent that due to heavy equipment that will be using the path to work on the dam.

The project, which began on July 17, is expected to be completed by Oct. 1, which means that during construction, water levels in the impoundment will be lowered upstream of the dam, possibly affecting boat trailer access to the river.

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