But don't worry, they know how to put the stopper back in. The authority plans to lower the water in the reservoir, starting today, by about ten feet in an attempt to control the dread Eurasian watermilfoil, an invasive weed that, if left unchecked, can choke the reservoir.
The goal is to allow for "a successful depth freeze" that would kill enough of the weed to reduce the need for an herbicide or other weed-control methods.
The authority expects the drawdown to last through Dec. 1, after which experts will cross their fingers and hope for a deep enough freeze by sometime in February, after which the MWRA will turn a spigot and let water flow back into the reservoir.
The reservoir, which holds 500 million gallons of water, was once part of the Boston water-supply system. Today it serves as an emergency backup - it sprang into use in 2010 when an exploding connector in Weston cut off much of the area's drinking water from the Quabbin and Wachusett reservoirs.