GZA GeoEnvironmental Inc. has worked on countless dams across the U.S. over the years, but it’s hard to beat the combination of historical significance combined with practical urgency of one of its latest projects, repairing and shoring up the Watershops Pond Dam in Springfield.
After three years of planning, GZA has kicked off a $3.6-million overhaul and modernization of the dam, an 1850s granite and masonry structure perched above the city’s South End neighborhood and named a “high hazard” dam by state officials.
The dam dates to 1857, when it was built to service the historic Springfield Armory, the prime manufacturing center for firearms for the U.S. from 1794 until it closed in 1968.
The dam and the 200-acre pond it created provided water power that helped armory workers churn out hundreds of thousands of Springfield rifles during the Civil War. Ringed by a historic building once used by the armory, the pond itself is now mainly used for recreational purposes.
Enter Norwood, Mass.-based GZA, which has worked on more than a thousand dams across the country.
In 2018, Springfield officials turned to GZA to assess potential repairs and potential uses for the dam and the pond.
Built originally to provide a steady flow of water to turn a water wheel, the dam was later used to generate hydroelectricity to power operations at the Springfield Armory.
GZA and the city initially explored harnessing the dam and the water power in the pond behind it to generate hydroelectricity for a local school that would be used as an emergency evacuation center, says Thomas Jenkins, a vice president with GZA GeoEnvironmental who overseeing the Springfield project.
But that idea proved unfeasible, with the potential permitting of the new power plant facing a years-long haul and with the amount of electricity it would generate not enough to make it worthwhile.
The city and GZA dropped that plan and began to focus solely on repairing the dam and improving access to it. (Power for the emergency shelter at the school will be provided instead by rooftop solar panels.)
“We do need to harden the dam and bring it up to current dam safety standards,” Jenkins says. “We shifted gears.”
There were big issues on both fronts, though.
The City of Springfield took over the historic Armory in the 1970s, after the federal government closed the firearms manufacturing plant, but, with the sale of some properties to private owners, wound up losing direct access to the site.
As a result, the city’s access to the control house was limited to a five-ft-wide walkway between a building on one side and the pond on the other.
In addition, the last major upgrades to the dam were made in the 1950s, when the current crest gate was installed. The dam, in turn, holds back Watershops Pond, which is perched above the city’s South End.
“The dam holds back 200 acres of water,” says Peter Garvey, director of Springfield’s Dept. of Capital Asset Construction. God forbid if the dam ever failed—it would wipe out the neighborhood.”
A centerpiece of the project involves replacing the 65-year-old crest gate, built in the 1950s in the wake of a devastating hurricane and while “state-of-the-art” then, is now “woefully inadequate,” Jenkins says.
The crest gate’s steel components had “severely deteriorated due to corrosion and were structurally unreliable,” Jenkins says. In addition, “the semi-automatic hydraulic controls had not been functional for many years and parts and service were not available,” he adds.
The crest gate, currently being fabricated by a firm in Steel-Fab Inc. of Fitchburg under a separate contract with the city, will be trucked to the dam in October, when Gardner Construction & Industrial Services Inc. of Chicopee, Mass., the general contractor, will install the new, 50,000-pound gate, which will come in five sections of 10,000 pounds each.
Bill Fountain, president and owner of Gardner, says one of the biggest challenges of the job is the extremely limited space to work in.
Fountain ranks the Watershops Pond Dam project in the top five of the most challenging his firm has tackled, citing the “logistical issues” involved.
With no space to maneuver on the site, Gardner will bring in sections of the gate two at a time, he says.
“It’s a challenging site—it’s very tight,” Fountain says. “There is not a lot of room to even have our guys to park.”
“There is no staging area here,” Fountain says.
The new 3-ft-tall, 105-ft-long flap will enable city officials to better prepare for potential flooding hazards from major storms, with the ability to lower the level of the pond in advance.
In order to solve the access issue, GZA plans call for the construction of a 250-ft-long berm across the pond, connecting the driveway to the gate control house. It is designed to be big enough to drive a light truck across.
A new hydraulics system is being installed, as well as all new and upgraded electrical service in the gate control house.
Gardner, the general contractor, will also do work shoring up and repointing the historic dam’s masonry as well.
The pond, which was drained last fall, is slated to be refilled next spring, with the project scheduled for completion next June.
“It’s great work to me,” Jenkins says, noting GZA has done work on dozens of dams across Massachusetts. “It combines all the wonderful things about engineering, historic infrastructure, preserving our past and making sure we have resilient infrastructure that is capable of dealing with climate change.”