Anglers fish along the Deerfield River downstream of Fife Brook Dam, where hydroelectric releases can quickly raise water levels. A federally required warning system would add sirens and flashing lights at several river access points to alert people before flows rise.

FLORIDA — A federally required warning system is coming to the Deerfield River to protect people from sudden flow changes — but the proposed sirens, flashing lights and 50-foot poles could alter the experience that river users and nearby landowners know now.

In particular, the prospect of sirens — proposed at up to 130 decibels, a volume akin to standing near a jet engine — comes as an unwelcome requirement to homeowners who live on River Road, which winds alongside the Deerfield River in Florida.

The system would warn anglers, paddlers, swimmers and other river users when water levels are about to rise because of upstream hydroelectric operations.

The final regulatory answer is: Put warning devices where people are — not just at the dam.

The Fife Brook Dam in Florida releases a minimum flow of 125 cubic feet per second, a level popular with wading anglers.

At least once a day, most days, the dam releases more water. Anyone in the water who isn’t aware of the schedule posted online, doesn’t heed the warning signs or is not paying attention can find themselves in deep, fast water in short order.

The releases can reach 600 to 800 cubic feet per second or more — a level popular with rafting companies because it turns the Deerfield into a whitewater river.

This week, about a dozen residents who live along the Deerfield River told the Select Board that they support river safety measures, but the proposed sirens sound excessive.

Melissa Curtin and her husband live along the Deerfield, near Carbis Bend, a popular fishing hole where one of the five warning systems is planned. The Curtins would hear the sirens every time water is released from an upstream dam. That would be at least once a day, most days, but could be several times a day.

News about the warning system came to light June 3, when the company that owns and operates the hydroelectric dam system on the Deerfield River posted a notice online and sent letters to residents along the river telling them about it and asking for their input.

“The flow release warning system will feature alarm speaker units that are expected to be exceptionally loud (approximately 120-130 decibels) to penetrate the ambient noise of the river and effectively alert river users of flow changes,” the notice states.

“The speakers, solar panels and associated equipment will be mounted on poles approximately 50 feet in height, located as close to the river’s edge as permitting allows, to ensure both audible and visual coverage through strobe lighting. Although typical flow changes occur once daily, they may occur at any time. BSPC’s preference would be to only operate the system during daylight hours.”

The Federal Energy Regulatory Commission issued a new license to Bear Swamp Power Co. in November. The license gives Bear Swamp Power permission to operate its hydroelectric system on the Deerfield for the next 40 years.

Bear Swamp Power, owned by Brookfield Renewable, said the license came with a mandate for the company to install the warning system by this November.

The Federal Energy Regulatory Commission is requiring the warning system because an existing siren at Fife Brook Dam does not adequately warn recreation users when higher flows are released. The siren is audible only under ideal conditions at the Fife Brook Fishing and Boating Access Area, about 0.4 miles downstream, and is not audible at other downstream recreation sites.

The new license requires warning stations with sirens and flashing lights at key river access points, after years of complaints that sudden dam releases could strand anglers and surprise recreation users on the river.

Bear Swamp Power said it was surprised that the requirement was added as a license condition without a defined period for study or consultation with affected neighbors and river users. It has begun gathering public input and comments and plans to submit them to the Federal Energy Regulatory Commission as part of a request to delay installation of the system.

“Considering the complexity and broad stakeholder impact, a one-year timeframe is not sufficient to study, design, permit and install the system,” the company said.

Leading up to the relicensing, the Federal Energy Regulatory Commission received input from several groups that wanted a warning system, citing safety concerns for river users when the water rises.

The Franklin Regional Council of Governments, which represents the 26 cities and towns in Franklin County, recommended an improved warning system. Trout Unlimited, which represents the interests of anglers, recommended installing a flow release warning system using lights at formal and informal recreational areas.

Bear Swamp Power agreed to assess whether such a warning system would be feasible. But the Federal Energy Regulatory Commission subsequently included it as a new condition in the license — sirens included.

At Wednesday night’s Florida Select Board meeting, residents were eager for more information about the warning system and hopeful that board members would support them.

Sympathetic board members gave a verbal commitment to stand behind residents and their concerns, including a letter of support and an invitation to officials to brief the town about the plan. Board members said they had not been formally briefed about the plan.

The warning systems would be placed at the Fife Brook Fishing and Boating Access Area, the Zoar Whitewater Access Area, the Zoar Picnic Area, Carbis Bend and Bridge to Nowhere.