The Scituate Reservoir holds the gift of life for hundreds of thousands of Rhode Island families and businesses.
David Nickerson of the Providence Water Supply Board said the security of the water supply is the top priority.
"There's a lot to keep in mind, a lot to watch out for and a lot to protect," Nickerson said.
On Tuesday, water security concerns surfaced when seven college students from Pakistan, Saudi Arabia and Singapore were arrested for trespassing while visiting the Quabbin Reservoir in Massachusetts after midnight.
People are allowed to boat, fish and visit the Quabbin Reservoir, but not after dark.
In Rhode Island, recreational activities are prohibited on the Scituate Reservoir. Even though there are parts where people can get very close to the water, there are yellow signs are to remind people they could face trespassing charges.
"What happened in Quabbin I think can happen anywhere, where I think someone can just wander onto a restricted area. I think the good thing about the Providence Water System is that we have a small security force that's on 24/7," Nickerson said.
There's fencing, and cameras keep watch. The 41 billion gallons of water are tested 100 to 200 times a day.
"It would be awfully hard to threaten the water supply," Nickerson said. "You'd probably have to have a caravan of 18 wheelers come in and drive into the reservoir before you might even have a problem."
Nickerson said there's never been a direct threat to the water supply, but there is an emergency plan in place that involves local and state police.
Occasionally, security does have to remove people from reservoir property.