CHATTANOOGA (WRCB) -- When the rain clouds cover the sky, it's a race against the clock for Chattanooga Public Works. Crews were hitting the streets Friday in preparation for all the rain that's going to come during the weekend.

It was just another day on the job for Shannon Ford and Travis Bell. They were cleaning out catch basins to make sure the roads don't flood during the rain.

Chattanooga Public Works Storm Water Operations Manager Danny Grier said this work never stops.

"We're always in preparation for heavy rain. The maintenance program that we have, where we're cleaning cross drains and driveway tiles and catch basins just to be sure those systems are functional," he said.

Grier said he's always monitoring weather right here on local news to make sure he staffs enough workers. With nearly five inches of rain heading to Chattanooga by Tuesday, he might need some extra help.

"There's an emergency crew that works 24 hours a day, seven days a week in different shifts. And as the rain begins to come, or we have flooding issues, then we'll call these guys in that are on standby," Grier said.

Shannon and Travis are just part of the crew that has to maintain thousands of these catch basins.

While this work is done every day, sometimes it's not enough to stop flooding.

"In many cases what happens, especially if we have the amount of rain that they're calling for this weekend, where you have three to four inches of rain in a short period of time, the systems just aren't prepared or able to take that amount of water," Grier said.

But that won't keep the crews from getting the job done.

The workers said they're going to continue cleaning the catch basins until they get every single one cleaned out.