A sewer backup happens when the public sanitary sewer receives more flow than it can carry, and the surge pushes wastewater back up the house connection, usually out of a basement floor drain. In Johnson County the sewer lateral from the house to the public system is generally the property owner's responsibility. Call the county's 24/7 emergency line, keep people and pets out of the water, and document the damage before anything is moved.
Key takeaways
- The sewer lateral connecting a Johnson County house to the public system is typically the property owner's responsibility, so a backup can turn into a private repair.
- The Backup Prevention Program covers a confirmed sanitary sewer basement backup from an intense rain event caused by capacity in the sewer system, and the county decides eligibility.
- JoCo Inflow targets rainwater and groundwater entering private sewer connections and is offered at no cost to the homeowner.
- The Kansas Insurance Department says most homeowners policies exclude water damage from sewer backup, which normally needs an endorsement.
- Water that comes up a floor drain is treated as Category 3, the most contaminated water category, so drying alone does not finish the job.
- Johnson County Wastewater lists a 24/7 emergency line at 913-715-8600 and a separate line for current basement backups at 913-354-7670.
Why do Johnson County basements back up when it rains hard?
A backup starts when the public sanitary sewer gets more flow than it can carry, and the surge has nowhere to go but back up the house connection. In a basement, the first outlets to take it are usually the floor drain, a laundry standpipe and any low fixture.
Sanitary sewers are built to carry wastewater from sinks, toilets and washers, not rain. When heavy rain gets into the system through cracked pipes, loose joints and connections that were never meant to receive stormwater, the flow can exceed what the line can move. The pipe fills, and wastewater rises at the nearest low point. In an Olathe house with a finished basement, that low point is often the floor drain, which sits at the bottom of the drainage system.
Johnson County Wastewater describes its funded cases as capacity-caused backups during intense rain, and that is the pattern to watch for. A backup from one drain while the rest of the house drains normally can point to a blockage in the house line. Several basement drains backing up during a storm points to the public system being overloaded. During the 21-22 August 2017 storm, the National Weather Service reported 5 to 7 inches of rain in roughly six hours across the area, locally 8 to nearly 10 inches. Note the timing, the rain and which drains were affected, because those details decide which program and which insurance question applies. For the cleanup side, see basement flooding cleanup.
Who owns the sewer line between the house and the street?
The lateral is generally the property owner's responsibility. Johnson County Wastewater says the sewer lateral connecting a property to the public system is typically the owner's to maintain and repair.
The lateral runs under the yard, often beneath the roots of mature trees, from the house to the public main in the street or easement. If a root intrusion, a collapsed section or a failed joint caused the backup, the repair falls to the homeowner rather than the county. That is why a backup call often ends with a plumber, not just a cleanup crew. Clearing or replacing the lateral is licensed plumbing work, and it is outside what the crew does.
Before anyone opens a cleanout or digs, use Johnson County Wastewater's map tool to confirm the address is served by the county, because the sewer utility depends on the address. Outside Johnson County, ask the sewer utility that serves the address. Ask the plumber to show the blockage or failure in writing, and keep the invoice and photos. An insurer or a county program may ask what was found and when it was found.
What is the Backup Prevention Program, and who is it for?
It is a voluntary county program that funds eligible homeowners to install a backwater device or modify plumbing so sewage cannot flow back into the house. Eligibility requires a confirmed sanitary sewer basement backup from an intense rain event whose cause was capacity in the sanitary sewer system.
A backwater valve is a one-way device, usually installed on the service line before it leaves the house, that closes when sewage tries to flow back toward the basement. The program can fund that work for eligible homeowners. A backup on a dry day, or one caused by a clogged house line, does not meet the capacity test, so the county is the place to confirm eligibility for your address.
Owners should understand the costs that come after the program. The valve needs regular maintenance, so it should be reachable, and after its one-year warranty all maintenance, repair and replacement is the owner's cost. A valve hidden behind finished drywall or stored in a locked utility closet is hard to service. Ask where the valve will sit before any work starts, and keep a maintenance record. The crew does not sell or install valves, so questions about the device belong with the county and the installing plumber.
What does JoCo Inflow do?
JoCo Inflow targets rainwater and groundwater that enter private sewer connections, adding flow the public system was not built to take during a storm. The program is offered at no cost to the homeowner.
A sewer system takes in more than wastewater. Rain and groundwater can enter through cracked laterals, leaking cleanouts and old connections, and during a storm that extra water arrives all at once. Reducing it is part of keeping the public line from filling up. The inflow program is aimed at those private connections, so it addresses the same storm pressure that causes many basement backups.
Because the program costs homeowners nothing, a call is worth making even after a backup has already happened. Ask Johnson County Wastewater what JoCo Inflow covers at your address and whether it applies to your connection. Keep notes on the storm date, the drains affected and any cleanup records. Those details help the county understand the event, whichever program applies.
What should I do in the first hour?
Protect people first. Keep children and pets out of the water, stay away from standing water near the electrical panel, the furnace or basement outlets, and stop sending water down the drains. Then document the damage before anything is moved.
Water that came up a floor drain should be treated as contaminated, which is what Category 3 means in the restoration standard. That water can carry sewage, so bare feet, open cuts and children playing on the floor are the exposures to avoid. Do not run the washer, dishwasher or showers while the drain is backed up, because more water will only add to the same problem. If water reaches an outlet, the panel or the furnace, leave that area and call the utility first.
For a sewer problem, call Johnson County Wastewater's 24/7 emergency line at 913-715-8600, or the basement backup line at 913-354-7670 for a current backup. Then call the crew at (833) 490-5225: phones are answered 24/7 and a crew is dispatched as fast as one is available. Photograph the floor, the drain, the water line on the walls and any damaged items, and take moisture readings if you can. The crew can help with the cleanup and drying, and sewage backup cleanup explains that work in more detail.
Will homeowners insurance pay for a sewer backup?
Usually not under a standard homeowners policy. The Kansas Insurance Department says most homeowners policies exclude water damage from sewer backup, and that coverage normally comes through an endorsement. Check your own policy and ask your agent before assuming either way.
The department's shopper's guide says most homeowners policies exclude water damage from sewer backup, along with flood and rising water. It also lists sump pump failure and severe backup due to flooding among the costs many policies do not cover. Coverage that does apply is normally added by endorsement, which is a written form attached to the policy that changes what it covers. Ask your agent whether your policy has one and what it says about backups.
Flood is a separate question. FEMA's National Flood Insurance Program says a sewer backup caused by general flooding in the area may be covered, while one caused by clogged pipes is not. The storm date, the rain and any other flooding on your street are worth recording for that reason. If a claim is denied or delayed, the Kansas Insurance Department's Consumer Assistance Division takes complaints at 1-800-432-2484. The crew can give you photos and moisture readings to share with your insurer, but coverage is decided by your insurer under your own policy. The insurance claims guide lays out the claim steps.
Why do clay soils and older trees matter here?
Johnson County soils are clay-rich, and they hold water instead of draining it quickly. Mature trees over older clay laterals are a common cause of slow drains in the inner-ring suburbs, where the houses and the oaks both date from the 1940s and 1950s.
Smectitic clay shrinks in a dry August and swells in a wet spring. That movement opens paths for water to reach the foundation, and dense clay drains slowly, so water stays against the wall instead of moving away. A wet March can saturate the subsoil, which is why a basement that stayed dry all summer can take water in spring. When the ground is saturated, storm flow and groundwater have more chance of finding their way into a private connection. That combination is part of why a basement can back up after a heavy storm even when the house itself looks sound.
In the older inner-ring areas such as Prairie Village, Roeland Park, Fairway, Mission Hills, Merriam and Mission, mature oaks grow over clay laterals, and roots find the joints. A drain that slows over months is a warning sign worth a camera check by a plumber. In the newer subdivisions across Olathe and Gardner, most houses have a sump pit and perimeter drain tile, but the sanitary connection still runs to the same public system, so the lateral question is the same. Check the sump pump too, because a pump that fails during a storm can leave a basement with standing water on top of the sewer problem.
Frequently asked questions
Is a sewer backup the same thing as a flood?
Not quite. A sewer backup comes up through the house's drains from the public sanitary system, while a flood comes from surface water or a creek overflowing. Insurance treats them differently, and a homeowners policy usually does not cover either without an endorsement or a separate flood policy. FEMA's guidance says a backup caused by general flooding in the area may be covered, while one caused by clogged pipes is not. Record the storm and the surrounding conditions so the difference can be shown.
Who do I call first, the county or a plumber?
For a sewer problem that may be outside the house, start with Johnson County Wastewater's 24/7 emergency line at 913-715-8600. If the clog is in the house line, a plumber is the right trade to clear it. The cleanup and drying belong to the restoration crew, which can start once the water is no longer rising. If you are not sure whether the problem is in the house or the street, the county can tell you what it serves and what it does not.
Is the water from a sewer backup dangerous?
Treat it as contaminated. Water that came up a floor drain is Category 3 under the restoration standard, which is the most involved category to clean. Keep children and pets away from it, wear protection if you must enter, and do not use fans to spread it. The cleanup should remove affected porous materials and disinfect what remains before drying. Do not assume a surface looks clean enough to reuse.
How do I check whether a plumber or contractor is licensed in Johnson County?
Use the Johnson County Contractor Licensing online search before anyone starts work. Plumbing, electrical, mechanical and roofing contractors must be licensed with the county, and the search shows whether a company is licensed and allowed to do the work. The office is at 111 S. Cherry St. in Olathe, and the phone number is 913-715-2233. Check the current requirements and fees directly with the county, since those change.
How soon does the drying need to start?
Start as soon as it is safe to do so. The EPA says mold can grow on wood, drywall, carpet and furniture left wet for more than 24 hours, and it advises drying water-damaged areas and items within 24 to 48 hours. Moisture left in a basement wall, subfloor or carpet pad can keep working long after the visible water is gone. If the water has already been sitting, tell the crew so it can check for hidden moisture with meters and thermal imaging.
Does the crew bill my insurance company directly?
Coverage is decided by your insurer under your own policy, not by the crew. The crew can document the damage with photos and moisture readings for your claim, and it explains the emergency work before it starts. Read your policy and ask your agent what applies. If a claim is slow or denied, the Kansas Insurance Department takes complaints at 1-800-432-2484.
Sources
This guide is general information for Johnson County homeowners, not a substitute for an on-site inspection. Prices are estimates. See our disclaimer.