Flood Prevention

Umbrella with rainFloods are one of the most common hazards in the United States. Effects can be local, limited to a neighborhood or community, or very large, affecting entire river basins and multiple states.  

Flood reduction efforts 

In response to large-scale flooding in 1998, our staff developed Rain to Recreation, a proactive, watershed-based, stormwater management program that works to reduce flooding and protect water while preserving wildlife habitat and providing recreation and education opportunities. Rain to Recreation addresses flooding by implementing Stormwater Best Management Practices (BMPs), as well as restricting development in floodplains, and reducing runoff volume and pollution.  

Stormwater Maintenance staff also works to restore and maintain 22 miles of streams in Lenexa to ensure adequate capacity for large storms. We also maintain more than 160 miles of pipe, more than 9,000 storm drains and nearly 29 miles of roadside ditches as part of the storm drain system. Stormwater crews proactively inspect underground pipes to prevent issues, routinely clean pipes, storm drains and ditches, and fixes drainage problems when they occur. 

Know your flood risk

As a public service, the City of Lenexa will provide you with the following information upon request: 

  • Whether a property is in or out of the Flood Hazard Area (FHA) as shown on the current Flood Insurance Rate Map (FIRM) of Johnson County. 
  • Whether a property is in or out of the floodway or near an area where the problems are not shown on the FIRM.
  • Additional flood insurance data for a site such as the FIRM zone and the base flood elevation or depth if shown on the FIRM.
  • Whether a property is in or near an area of historical flooding and/or natural functions floodplain.
  • A handout on the flood insurance purchase requirement that can help people who need a mortgage or loan for a property in the FHA. Flood insurance is required for federally backed loans.

To find out if you are in a floodplain or floodway, for flood depth data and/or to discuss property protection measures within the floodplain, contact Tom Jacobs, stormwater engineer, at 913.477.7644.

You can help reduce flooding 

Keep water flowing: Most stormwater BMPs, such as neighborhood ponds, are owned either by a homeowners association or by all lot owners in the neighborhood. Keeping these in good repair can make a big difference in preventing flooding issues. 

Our staff is available for technical assistance and to clarify ownership and maintenance responsibilities. For more information, email Tom Jacobs, stormwater engineer, at [email protected].  

Report illegal dumping: Our stormdrain system eventually drains untreated water into ponds, lake and streams, which can pollute natural habitats.  
If you witness illegal dumping or a strange substance flowing into a stormdrain, please report through our Service Request System or call the Municipal Services Department at 913.477.7680. If it is after business hours, please call Johnson County’s 24-hour hotline at 913.715.6900.  

After-hours environmental complaint online form 

Flood plain development  

  • You must obtain a permit to build within a flood plain in Lenexa. Call our customer service permitting staff for assistance at 913.477.7500.  

  • To report an unauthorized flood plain development contact the city’s Community Development Department at 913.477.7500.  

  • See the Unified Development Code for complete information on our building codes and ordinances, including rules for new construction.  

Flood insurance 

Several major streams flow through Lenexa. These larger streams have an associated floodplain that is identified by the Federal Emergency Management Agency (FEMA). If you live along these larger streams, you are required by your home mortgage lender to purchase flood insurance. If you live close to a stream, you should take a careful look at your flooding risk and consider whether or not you should buy flood insurance. 

You can pick up a copy of the FEMA Elevation Certificates at City Hall on all buildings constructed or substantially improved in the floodplain since January 2010. If you think your house is in a floodplain, call our Community Development Department at 913.477.7500 for assistance with floodplain boundaries. 

Yard flooding 

You may be impacted by nuisance yard flooding issues that are unrelated to stream flow. The public drainage system typically begins after neighborhood drainage reaches the street, and it is not uncommon for several yards to drain through each other before reaching the public system. In this case, it is your responsibility to protect your property from flooding. Some things to consider are: 

  • Ensure the ground drains away from your foundation. 

  • Ensure that window wells are adequately covered. 

  • Consider adding French drains or yard inlets to remove water more quickly between storms. 

If you would like information on flooding issues or flood-proofing your property, City staff are happy to visit your property to offer advice. Call 913.477.7500 to speak to staff about a site visit.

Roadway flooding 

You may encounter water over the road at some locations in Lenexa during extremely large rain events. Never try to drive across flooded roadways. Just 6 inches of fast-moving flood water can knock over an adult. Twelve inches of rushing water can carry away a small car, while two feet of rushing water can carry away most vehicles. It is never safe to drive or walk into flood waters. Know your evacuation routes in the event of roadway flooding.

Flooding Resources 

Frequently asked questions


What is a floodplain?

A floodplain is a naturally occurring area near a river or creek that floods periodically. When development adds pavement, roofs and other hard surfaces, less rainfall is filtered into the ground. Runoff to the nearby river or creek increases, and any development within that area can be subject to flooding.

Will the city fix my drainage problem?

We will fix drainage problems if the water is caused by or is on public property, such as a street or drainage system, and fixing it benefits the public in general.

Problems that we will generally address include:

  • Flooding in living spaces 

  • Severe stream bank erosion from city property affecting a structure or home

  • Blocked creeks, storm drainage pipes or drainage ditches

  • Undersized storm drainage pipes or culverts

  • Sinkholes over storm drainage pipes

Problems that we will not fix include:

  • Yard flooding

  • Natural stream bank erosion

  • Drainage concerns caused by roofing or gutter problems

  • Water that flows from adjoining property

  • Wet areas due to underground springs, wetlands or sump pumps

  • Standing water in a drainage ditch

Please note, this is not a complete list, and every site has different causes and issues. Final determination of whether a problem qualifies is made in a field inspection by city staff. If you have questions about this process, please email Stormwater Engineer Tom Jacobs, [email protected].

How do I find out if my problem qualifies?

You can report a drainage problem through our Service Request System or call our Municipal Services Department at 913.477.7880.

We will work with you to set up a time for a city employee to visit the site to determine if it qualifies for repairs. We are happy to provide technical expertise in these matters and will evaluate any drainage problem to help you determine the source. 

If my problem qualifies, how soon will the problem be fixed?

We make repairs based on priority, which is determined by the type of flooding, its frequency and its severity. Projects within the same priority ranking are fixed in the order that they are received.

Examples of high-priority requests include:

  • Living space flooding or flooding of nonresidential structures with electricity and permanent foundations

  • Street flooding

  • Failure of drainage structures within 10 feet of a house or roadway or in the right of way

  • Public safety hazards

  • Complete blockage in the storm sewer system

  • Sinkholes

Examples of low-priority requests include:

  • Failure of drainage structures more than 10 feet away from a house/roadway or outside the right-of-way

  • Sediment build-up that causes partial blockages and redirects flows

  • Structural damage to a headwall (cracks, leaning)

  • Partial blockage in the storm sewer system or in natural stream channels

  • Stream bank erosion