Rats in Sewer Lines and Basement Floor Drains

Norway rats can and do use sewer lines to get into basements, especially in older neighborhoods where clay sewer laterals have cracked or separated. If you find rat droppings or activity near a basement floor drain, laundry drain or cleanout, and the outside of the house shows no burrows or gaps, the sewer may be the route. Traps catch the rats that arrive, but more follow until the line is fixed or the drain is blocked.

Here is how it happens, who maintains what in Cleveland, and what to do.

How rats travel through sewers

Norway rats are strong swimmers and climbers. The University of Florida's extension guide says rats are excellent swimmers and that Norway rats can climb the inside of vertical pipes 1.5 to 4 inches across. Sewers give them shelter, water and a steady supply of food waste.

The connection from a house to the public sewer is called the lateral. In older Cleveland homes, many laterals are clay pipe, which can crack, shift at the joints or be broken by tree roots over the decades. A rat in the public sewer can follow a damaged lateral toward the house and exit through a break into the soil, or follow the pipe all the way to an open floor drain.

Signs the sewer is the route

Rat droppings, about three quarters of an inch long, concentrated near a floor drain, laundry drain, sump pit or cleanout
Grease marks or wet tracks around the drain
A missing, loose or broken drain cover
No burrows outside along the foundation, and no obvious gaps at the sill or utility lines
Repeated catches near the drain even after outside gaps are sealed
A slow drain, sewer smell or a past basement backup

Rats coming up through a toilet are rare, but it does happen in buildings with older drain lines.

Who maintains the sewer line in Cleveland

Cleveland's code splits responsibility for sewer connections. Under the ordinance adopted as Ord. No. 609-17, the portion of the connection from the public sewer to about one foot beyond the curb line is maintained by the city's Division of Water Pollution Control. The portion from that point toward the property is maintained by the property owner whose premises are drained by the connection.

So if the break is under your front yard or beneath the house, repair is generally on the owner. Suburbs have their own rules, so check with your city if you live outside Cleveland. Either way, a plumber with a sewer camera can find where the line is broken.

Want a technician to look at it?

Your call goes to an independent rodent control provider serving Cleveland and Cuyahoga County. Describe what you are seeing and ask for a written quote before any work starts.

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How to block the route

Cover floor drains with a secure, screwed-down grate or a drain cover designed to keep rodents out.
Keep drain traps filled with water. A dry trap gives rats and sewer gas a path. Pour water into rarely used floor drains every few weeks.
Have a plumber run a camera through the lateral to look for cracks, root intrusion or separated joints.
Repair or line the damaged section.
Ask the plumber about a backwater valve, which can help keep sewage and animals from coming back up the line.
Seal any gaps around pipes where they pass through the basement floor or wall.

Meanwhile, trap near the drain with rat-size snap traps placed where pets and kids cannot reach.

When it is not the sewer

Most rats in Cleveland basements still come in from outside, through gaps at the foundation, sill, window wells and utility lines, or from burrows under a garage or porch. Check those first. A technician can tell you which route the evidence points to. See basement and garage rodent control and rat control.

If a neighbor's yard, an alley or a vacant lot is feeding the rats, that is a separate problem to report through 311. See our reporting guide.

Cleanup after a sewer rat or backup

If rats came through a drain, or the basement flooded with sewer water, clean carefully. The CDC says leptospirosis bacteria spread through animal urine and can be in water and soil after floods. Wear boots and gloves, and for droppings follow the CDC method: air the space out, wet droppings with disinfectant, wait five minutes, wipe up and bag the waste. See droppings cleanup.

Frequently asked questions

Can rats come up through a basement floor drain?

Yes, if the drain connects to a damaged sewer line or has no secure cover or water in the trap. A drain cover and a plumber's inspection are the fix.

Who fixes a broken sewer lateral in Cleveland?

Cleveland's code says the city maintains the connection from the public sewer to about one foot beyond the curb line, and the property owner maintains the rest toward the house.

Will a backwater valve stop rats?

A backwater valve is designed to stop backflow from the sewer. Ask a licensed plumber whether one fits your home and how it works with your drains.

How do I keep a floor drain trap from drying out?

Pour a bucket or a few quarts of water into rarely used floor drains every few weeks. A filled trap blocks sewer gas, and a secure cover adds a physical barrier.

Can rats come up through the toilet?

It is rare but possible in buildings with older drain lines. Keep the lid closed and call a technician and a plumber if it happens.

Get a rodent technician on the phone

Free to call. You are connected with an independent provider serving Cleveland and the Cuyahoga County suburbs. Same-day appointments are often available.