Floodplain Information

In the Village of Riverwoods, the Des Plaines River can contribute to flooding. However, most flooding results from overwhelmed storm systems during heavy rainfall.

Severe storms also can overwhelm the sanitary sewer systems, causing flooding in basements. Once the storm sewers are backed up from excessive rainfall, water collects on the streets and can enter the sanitary sewers. This increases the chances of basement floods for homes connected to a gravity sanitary sewer. Other culprits of flooding in residents’ homes include water seeping in through garages, exterior stairwells, and basement window wells. Residents are encouraged to install backup systems for additional protection.

In the past, gravity draining tiles were installed around homes as a first defense to remove groundwater. Newer basement installations require a sump pump ejection system to remove groundwater. Gravity sewer backup or sump pump failure likely will lead to basement flooding.

Spring, fall, and winter rains can sometimes cause flooding. While we have some floodplains in Riverwoods, they are usually limited to two areas of the Village. FEMA Floodplain Maps and information are available at the Village Hall. Please visit during regular office hours to see if you are affected.

We want to remind you that flood insurance is required if you're building in the floodplain and getting a loan from a federally regulated or insured bank. Contact us, and our Building Department staff will gladly assist you with this information. The Village Engineer can also help provide details on how to obtain an Elevation Certificate from a qualified professional. They are also available to discuss possible solutions for flooding issues. Please call the Building Department at 847-945-3990 if you have any questions.

Click here to view floodplain maps.

The lowest floor of buildings in flood zones must be elevated to or above the BFE.

CISA maps can provide more accurate and forward-looking information than existing Flood Insurance Rate Maps (FIRMs).

For questions contact:

Carissa Smith, P.E.
Gewalt Hamilton Associates Inc.
Office: (847) 478-9700 | Direct: 847-821-6259

An EC provides property-specific grade elevations and can indicate flood risk.

This standard expands the floodplain of concern and requires new construction and substantially improved structures within the FFRMS floodplain to be elevated or floodproofed to a higher elevation.

You can access FEMA flood maps and other resources through the FEMA Flood Map Service Center.

Flood insurance is crucial in flood-prone areas, as standard homeowners' insurance typically doesn't cover flood damage.

FEMA maintains and updates flood maps to show flood risk and identify high-risk areas.

Elevated Structures: Buildings in flood zones may need to be elevated on open foundations (columns, piers, or piles) to allow floodwaters to pass underneath.

Dry Floodproofing: Non-residential buildings in A zones may need to be dry floodproofed to the BFE.

Substantial Improvement/Damage: If a building is substantially improved (cost of improvement equals or exceeds 50% of the building's value) or substantially damaged, NFIP requirements must be applied.

The USACE (Army Corps of Engineers) offers floodplain management services, including identifying areas subject to flooding.

Floodplain management is a community-based effort to reduce flood risks, involving zoning, building codes, enforcement, and education.

In addition to NFIP requirements, Riverwoods may have its own floodplain management ordinances.

The NFIP sets minimum floodplain management standards for communities participating in the program.

All construction or development in floodplains requires a permit from the Community Development Department, even for minor alterations like landscaping.

These are high-risk areas shown on flood maps as zones beginning with "A" or "V.”

Please see the attached Mapped Special Flood Hazard Areas Map for a visual understanding.

View All FAQ's

If your home or business is in a high-risk area, you will likely need an Elevation Certificate (EC). An Elevation Certificate documents important features of your property, including its location, flood zone, building characteristics and, most importantly, the elevation of its lowest floor.

An Elevation Certification is needed to know your building’s elevation compared to the estimated height floodwaters will reach in a major flood helps provide a true picture of the status of compliance with floodplain ordinances so as to determine your flood risk and the cost of your flood insurance premium.

How to get an Elevation Certificate

Contact your local floodplain manager. There might already be an elevation certificate on file for that property. Every community participating in the National Flood Insurance Program (NFIP) has a floodplain manager, although that person might have a different title or serve in multiple capacities. To get started, call your town or city government office and ask for the floodplain manager or the person who handles Elevation Certificates for that community.
If you have trouble connecting with your local floodplain manager, you can contact your state’s floodplain management office. The state floodplain manager is also referred to as the NFIP state coordinator. Find your state coordinator here.
Ask the sellers. When buying a property, ask the sellers to give you their Elevation Certification. If they don’t have an EC, ask if they can provide one before settlement.
Ask the developer or builder. In a high-risk area, the developer or builder might have been required to get an Elevation Certification at the time of construction.
Check the property deed. Elevation Certifications are sometimes included with the property deed.
Hire a licensed land surveyor, professional engineer, or certified architect who is authorized by law to certify elevation information. For a fee, these professionals can complete an EC for you.

Raise Your Elevation to Lower Your Risk

Building code requirements may change over time as flood risk changes and maps are updated. If you are remodeling or rebuilding, you will likely need a new Elevation Certificate to reflect the new building characteristics and lowest floor elevation. While remodeling, consider elevating to lower your flood risk, which, in turn, can lower your flood insurance rates and reduce the financial impacts of flooding.

FEMA’s Elevation Certificate Fact Sheet – 2023

See a sample Elevation Certificate

The National Flood Insurance Program provides insurance to help reduce the socio-economic impact of floods.

The National Flood Insurance Program (NFIP) is managed by the FEMA and is delivered to the public by a network of more than 50 insurance companies and the NFIP Direct.

Floods can happen anywhere—just one inch of floodwater can cause up to $25,000 in damage. Most homeowners insurance does not cover flood damage. Flood insurance is a separate policy that can cover buildings, their contents, or both, so it is important to protect your most important financial assets—your home, business, and possessions.

The NFIP provides flood insurance to property owners, renters, and businesses, helping them recover faster when floodwaters recede. The NFIP also works with communities required to adopt and enforce floodplain management regulations that help mitigate flooding effects.

Flood insurance is available to anyone living in one of the almost 23,000 participating NFIP communities. Homes and businesses in high-risk flood areas with mortgages from government-backed lenders are required to have flood insurance.

For more information about what’s covered and to find a policy, visit FloodSmart.gov.

How to Purchase Flood Insurance

To purchase flood insurance, call your insurance company or insurance agent, the same person who sells your home or auto insurance. If you need help finding a provider go to FloodSmart.gov/flood-insurance-provider or call the NFIP at 877-336-2627.

Plan ahead as there is typically a 30-day waiting period for an NFIP policy to go into effect, unless the coverage is mandated it is purchased as required by a federally backed lender or is related to a community flood map change.

www.FloodSmart.gov

The Village participates in FEMA’s Community Rating System (CRS) Program. This program provides credit for the Village’s floodplain management regulations and other efforts. Property owners in the regulatory floodplain may qualify for a reduction on premiums, while all other policies could receive a smaller reduction since the property is located outside of a floodplain. Please review your policy to ensure you are receiving the discount.

Use FloodSmart to calculate your risk of flooding, learn what a flood insurance policy may cost, and find local agents who offer flood insurance.

Safeguarding Your Possessions

Create a personal flood file containing information about all your possessions and keep it in a secure and safe place, such as a safe deposit box or waterproof container. This file should have:

A copy of your insurance policies with your agent’s contact information
A household inventory: For insurance purposes, be sure to keep a written and visual record of all major household items and valuables. Include serial numbers and store receipts for major appliances and electronics. Have jewelry and artwork appraised. These documents are critically important when filing insurance claims.
Copies of all other critical documents, including finance records or receipts of major purchases

Prepare Your House

Check to see that the sump pump is working properly and consider installing a battery-operated backup and water alarm alert you if water is collecting in the basement.
Clean gutters, downspouts, and inlets
Raise electrical components (switches, outlets, circuit breaker, furnace, water heater, washer/dryer) to Flood Protection Elevation (FPE = Base Flood Elevation (BFE) + 2 feet; or 627.3 North American Vertical Datum of 1988 (NAVD 88))
Move furniture and valuables to a safe place.

Develop a Family Emergency Plan

Create a safety kit with drinking water, canned food, a first aid kit, blankets, a battery-operated radio and a flashlight.
Post emergency telephone numbers by the phone and teach your children how to dial 911.
Plan and practice a flood evacuation route and know safe routes from home, work and school that are on higher ground.
Have an emergency family contact.
Have a plan to protect your pets.

Stay Informed

Help protect you and your family by monitoring local news and weather reports during a flood event
Avoid driving through flooded areas
Follow any evacuation orders if issued

Water in Your Home

If your home or property is experiencing flooding in the form of ponding water, basement flooding by surface waters, seepage or through the floor drains, there are certain steps you can take to help minimize the problem.

If you are experiencing ponding water on your property, consider installing a storm inlet in the low area on the property to collect stormwater and discharge it into the public storm system. If there is already an existing storm service to the property, and if grade elevations allow for positive drainage and the storm service is in good condition, then you may be able to tie the inlet into the existing storm service. Otherwise, a new storm service can be brought to the site, disconnecting any existing storm service at the main.
If you are experiencing water entering the basement over window wells or seeping through the foundation wall/footing, providing positive drainage away from the foundation and/or maintaining the foundation’s drain tiles may help in this case.
If you are experiencing water entering through the floor drain in the basement, most likely the sanitary sewer service is the issue and will need to be investigated. Ensure that the storm sewer and sanitary sewer services are not interconnected in any way. If it is found that they are, they must be separated immediately, in accordance with the Village Municipal Code.

It is important to note that any alteration to a structure or land requires a permit from the Community Development Department be issued with approval by the Public Works Engineering Division. Also, any alteration, regrading or filling in the flood plain requires a permit.

Methods of Protection

Different measures are appropriate for different flood hazards, building types and building conditions. All methods must comply with the Village’s Flood Hazard Protection Ordinance and applicable Building Codes. Please always check to see what permits are necessary from the Village. The protection of your home and property could include the following methods:

Elevation of the building above the Flood Protection Elevation, which is 2 feet above the Base Flood Elevation
Elevation of damage-prone components, such as the furnace, air conditioning units, or other attendant utilities
Protect window wells and exterior stair wells from receiving overland flooding and keep well drains free of debris
Dry flood-proofing of the building so that water cannot get into it
Wet flood-proofing portions of the building so that water won’t cause damage
Construct a berm or redirect drainage away from the building
Notify the Village of any observed maintenance issues relating to streams, ditches, and public storm drains; and maintain all privately owned storm drains so that debris does not obstruct them
Correct sewer back-up problems

Residents of the Village of Riverwoods can help manage the negative effects of heavy rainfall through their planting methods around their property.

By using native plants instead of turf grass, you can see many benefits that help protect your home. Turf grass has tiny roots, meaning that planting it does not help manage large streams of water around your home. Native plants, on the other hand, have long roots that act as a sponge in the soil. Longer roots can absorb and hold larger quantities of water, helping reduce the amount of water entering your home.

Some other benefits of native plants include that they:

Filter pollution
Resupply groundwater
Maintain stream flows to prevent water backup
Live longer with less maintenance
Provide valuable habitat

ComEd, the main electric utility provider for the Village of Riverwoods, offers extra safety tips for residents to stay secure when their basements flood.

Some important tips include:

There is a higher risk of electrocution when entering a flooded basement due to critical systems and electronic devices placed in basements.
Call ComEd at 1-800-EDISON-1 (1-800-334-7661) to disconnect power before entering a flooded basement.
Never attempt to turn off power at the breaker box if you must stand in water to do so.
Check on elderly and other sensitive family members and neighbors to ensure their safety, and if there is an extended outage, assist them in reaching an alternate location.

USGS Monitoring Station Des Plaines River at Lincolnshire, IL - 05528100

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Floodplain Information

Constructing in the Floodplain FAQ

Related Questions

Elevation Certificate

How to get an Elevation Certificate

Raise Your Elevation to Lower Your Risk

Flood Insurance

Community Rating System Discount

Protect Your Property