Cobb’s Hill Reservoir drained for cleaning

ROCHESTER, N.Y. — There’s something different about the Cobb’s Hill Reservoir. There’s no water in it!

The Rochester Water Bureau says they had to drain it to clean it.

This is one of the cleanings that they do for the reservoir every seven years. But a lot goes into it.

The Cobb’s Hill Reservoir is one of the two main supplies of water for the city of Rochester, holding 144 million gallons.

“So it’s a it’s a great way to provide us with extra storage and a factor of safety in the event of anything catastrophic happening. We would still have plenty of water to last quite a while,” Manager of Water Production for the Rochester Water Bureau David Rowley said.

When the algae that settles on the bottom of the reservoir becomes too thick, it’s time for the workers to drain it and clean it all out.

And at 17 acres, it’s a big job.

“So we actually got a crane and lowered in some equipment that we’re using right now. We first plowed the algae using some bobcats and side by side, ATVs. And somewhere behind me right now, there’s a street sweeper actually going back and forth, putting the final touches on the cleaning that we’re doing this time,” Rowley said.

Keeping the reservoir clean is extremely important because the city uses 20 to 24 million gallons of the water it holds a day.

“When the water leaves the reservoir, it passes through a chamber where we screen out leaves and things that might have gotten in the water. We also add chlorine to the water in order to make sure it’s properly disinfected, and then it goes directly into the piping network that provides drinking water to everybody’s home in the city,” Rowley said.

And they don’t have to use any extra power to get it to people.

“So, one of the amazing things about Rochester’s water system is it’s pretty much entirely gravity fed. When it was designed in the 1870s. The engineers at the time had the foresight to realize that gravity was a very green concept,” Rowley said.

Along with cleaning the reservoir, they’ve also replaced the roof on the gate house and are working on some maintenance on the fountain in the middle.

And they plan to begin refilling the reservoir sometime in November.