From the roof, down the gutter, into the street, and eventually into the sewers.
That's how it's supposed to work, but Joe Cory with West Des Moines Public Works says after Thursday's slushy storm, it hasn't been that easy.
"We've had about a dozen calls where people have let us know the intake is clogged,” said Cory.
Storm drains are backed up with slush and the debris it carries on its way to the grates where it creates ice dams, causing water to pool up in the streets and intersections.
It's not the mess that makes it so crucial for public works crews to know about sewer blockage.
It's what happens when the pools of water re-freeze.
"We have ice rinks. People roll right on through because they can't stop,” Cory told Channel 13 News.
Cory says crews can clear them out and get the water flowing and the pools are gone in minutes.
He adds you don't have to work for the city to help out city workers.
"Alert us to where those areas are. We'll send crews right away to get them cleared out,” said Cory.
If you see a clogged storm drain you're asked to call your local public works department.
The number in West Des Moines is 515-222-3480.