WESTFIELD – A local engineering firm is working on the design of an intake system to supply water for the three water cannons installed under the observation deck on the south side of the Westfield River as part of the $60 million bridge project.
City Engineer Mark Cressotti said this morning that the three cannons and pumps were delivered by the manufacturer, but that the plan to draw water from the river by installing the four-foot tall pumps directly into the river was rejected for a number of reasons, including the need to lift the heavy equipment out of the river every fall.
Another concern of the original plan was preventing damage to the pumps which might be caused by debris and gravel carried in the current being pulled into the pumps.
“The manufacturer’s plan to connect to a water source was impracticable,” Cressotti said.
The city looked at other options, including connecting the pumps, which are large enough to push a thousand gallons of water a minute, directly to the city’s water system.
“We did look at that, but it’s a significant waste of city water,” Cressotti said. “The city also treats the water, so there is a residual amount of chlorine in it which would be a concern for the DEP (state Department of Environmental Protection), and it made no sense. The river’s right there, so why not take water out and then return it? It’s a no-harm, no-foul approach.”
Cressotti said that the city had to identify a system for withdrawing river water, then obtain an order of conditions from the Conservation Commission before finalizing the design and releasing the construction work for bid.
“We just got the permitting from the Conservation Commission to do the connecting work,” Cressotti said. “The cannons and pumps are installed, but now we have to connect the feed pipes to that system.”
The feed pipes will be connected to a smaller pump installed into the river that slowly withdraws water from the river, filling the water cannon reservoir over a three-hour period.
“Tighe & Bond is working on a design to implement the revised plan, but it’s not at the point where we can put it out to bid,” Cressotti said.
Part of that design will include controls to shut down the cannons during low flow periods, when the level of the river drops below the small pump intake.
“This option gives us a lot more control to regulate the system,” Cressotti said. “It also provides a means of draining the system so it can be shut down for the winter.”