Underneath Des Moines

9/6/2017

More than 1,300 miles of pipes, drains and sewers are underneath the city. It can get messy underground, but this unseen network keeps the surface clean and flood-free.

Ever wonder about the city’s sewer system and what really goes on down there? Is it like the movies? Is there a world of people with their own underground society? Do massive alligators populate there? We sent our fearless intern Adam Rogan down below to investigate. Rogan was led safely through the tunnels by a 38-year veteran of the Des Moines Department of Public Works through the seemingly endless miles of pipes. You might be surprised to learn what goes on beneath our city streets, but don’t become too curious. Clearly, this should not be attempted without permission or supervision.

What is a sewer?

There are two primary types of sewers, and only one of them carries what you’re thinking of.

1. Storm drains

Also known as a storm sewer, a storm drain’s main function is to carry rain and groundwater liquids away from the city into bodies of water. This is where the water from grates on the side of the road lead to. In central Iowa, most drains lead to the Des Moines River or one of its tributaries. Every photo in this feature was taken from a storm drain.

Storm drains keep cities from flooding constantly, although massive rains like Cedar Rapids had in 2016 and 2008, and Des Moines had in 1993, can overwhelm the system.

Still, the majority of significant rainfalls result in only some pooling of water — no flooding — and that’s thanks to a system that’s a century old, made up of a hodgepodge of current and decades-old pieces.

Large storm drains are usually made with concrete; smaller ones often use metal. There are still some old drains underneath the city made from brick and wood that were constructed during the New Deal Era at the tail end of the Great Depression, but these tend to be less stable.

2. Sanitary sewers

These are the ones you’re thinking of. They carry waste away from the city itself but don’t dump directly into rivers and lakes like storm drains do. Instead, they lead to sewage treatment facilities, which clean up the waste so that it can be released into the environment safely. Maintenance workers commonly use manholes to access sanitary sewers.

Safety, workers and explorers

It’s the job of people like Ed Jacobe, a 38-year veteran of the Des Moines Department of Public Works, to inspect drains and address damage to sewers. In his nearly four-decade tenure, Jacobe says he’s never found himself in imminent danger. Flash floods won’t occur underground unless a main breaks, which has never happened while Jacobe was in a sewer. Danger is minimalized as long as the workers keep their wits about them and remember to follow procedure.

Carbon monoxide is a concern, but workers make sure that the detector is on at all times. Hard hats, gloves, plastic coverall suits, knee-high boots and flashlights are necessities.

Exploring storm drains is a somewhat popular (and illegal) pastime for some urban explorers, particularly in Los Angeles and Australia where the sewers tend to be wider. Still, Jacobe has never run into anyone exploring the sewers who wasn’t supposed to be there. The ceilings aren’t higher than 4 feet in most of Des Moines’ drains. Besides the size, he says the ones that can be walked in usually have at least a couple inches of water flowing through them.

Helpful tip

The manhole (above) that led down into an antiquated drain made of wood and brick (right) is actually in a residential neighborhood, built into a driveway. The home is currently unowned, and Jacobe thinks there’s a reason for that.

“If you ever buy a house, know where the sewers are,” Jacobe says.

During backups, these outlets are more likely to flood. This is especially problematic if a sanitary sewer gets overloaded, which can lead to sewage spitting backwards through the pipes directly into homes. ♦