By the Lapera Insurance Team · Reviewed by Joe Lapera, Licensed Illinois Insurance Agent (IL Lic #100722394)
In July 2017, the Des Plaines River set records at three Lake County gauges, and hundreds of homeowners learned that their homeowners policy did not cover the water in their basement. This guide is what we wish every Lake County homeowner had read before the next big storm: how often it floods here, how to check your map, what a flood policy pays and why the 30-day wait matters.
A homeowners policy in Grayslake or anywhere in Lake County never covers flood. You need a separate NFIP or private flood policy, and NFIP coverage normally starts 30 days after purchase. Lake County has a long flood history along the Des Plaines and Fox rivers, and nearly a third of NFIP claims nationally come from outside high-risk zones, so homeowners near creeks, low spots or finished basements should price a flood policy before storm season.
We cover the local flood record first, including the 2017 storm that left hundreds of Lake County homes with major uninsured damage. Then how to check your flood map, why mapped risk is not the whole story, what an NFIP policy pays and costs, how flood differs from sewer backup in a Grayslake basement, and how to buy coverage in time.
Do You Need Flood Insurance in Grayslake or Lake County?
TL;DR: If a lender requires it you must carry it, and if your home sits near a creek, river, lake or low spot, or has a finished basement, it is worth pricing even when it is not required.
Flood insurance is required when a federally backed mortgage covers a building in a high-risk flood zone. Everyone else decides for themselves. In Lake County, that decision deserves real thought. The county drains through two major river systems, has dozens of lakes and creeks, and has a lot of homes with finished basements below grade.
The geography explains a lot. The Des Plaines River watershed drains 204 square miles, about 44% of Lake County, and the Fox River watershed covers about 163 square miles, about 35%, including the Chain O'Lakes. Grayslake itself sits in the Mill Creek watershed, about 31 square miles that drain to the Des Plaines, according to the Lake County Stormwater Management Commission.
Lapera Insurance Agency is a Farmers Insurance agency at 530 Barron Blvd in Grayslake, Illinois. Our team has served Illinois families since 1993, with over 40 years of combined experience, and we have helped Lake County homeowners through water claims and flood questions for decades. We would rather tell you honestly that you do not need a flood policy than sell you one you will never use. Every guide on this site is reviewed by a licensed Illinois agent before it publishes.
How Often Does Lake County Flood?
TL;DR: Lake County has been included in at least five federal flood-related disaster declarations since 1986, plus a record 2017 flood that received no federal disaster aid.
Lake County's 2022 All Natural Hazards Mitigation Plan lists the federal disaster declarations that included the county. The flood-related ones span nearly four decades:
- 1986 (DR-776): severe storms and flooding.
- 1993 (DR-997): the Great Midwest Flood.
- 2007 (DR-1729): severe storms and flooding.
- 2008 (DR-1771): severe storms and flooding.
- 2013 (DR-4116): severe storms, straight-line winds and flooding, April 16 to May 5, 2013.
Lake County has also spent decades moving people out of harm's way. The county's flood-prone property buyout program has purchased more than 200 homes and parcels, with FEMA funding since 1997.
What Did the 2017 Flood Teach Lake County Homeowners?
TL;DR: After record river crests in July 2017, 233 Lake County homes had major uninsured damage, and federal disaster aid was denied, so most owners without flood policies paid themselves.
On July 11 and 12, 2017, two-day rain totals of 4 to more than 7 inches were common across northern Lake County, including 7.22 inches at Gurnee and 7.11 at Lake Villa, according to the National Weather Service in Chicago. The Des Plaines River then set record crests at Russell (12.15 feet), Gurnee (12.09 feet) and Lincolnshire (16.53 feet).
The lesson we draw from it: when federal aid does not come, the flood policy you bought months earlier is what pays. A low-interest loan still has to be paid back. Flood insurance claim payments do not.
How Do You Check Your Flood Zone in Grayslake and Lake County?
TL;DR: Look up your address on the FEMA Map Service Center or Lake County's online maps; Lake County's countywide flood map took effect in 2013 and was revised in 2023, including for Grayslake.
Lake County's countywide flood insurance rate map took effect on September 18, 2013. A revision took effect October 5, 2023, and the Federal Register notice lists the Village of Grayslake among the affected communities. If you have not looked at your map since you bought the house, look again.
- FEMA Map Service Center. Enter your address at the FEMA Flood Map Service Center to see the effective map and your zone.
- Lake County resources. The county's NFIP page points to Lake County Maps Online and notes that 52 of the county's 53 communities participate in the NFIP.
- Ask us. We can help you read the map and tell you whether a lender is likely to require coverage.
Should You Buy Flood Insurance Outside a High-Risk Flood Zone?
TL;DR: Often yes, because nearly a third of NFIP flood claims come from outside high-risk areas, and coverage there is usually far less expensive.
A flood map shows where flooding is most likely, not the only place it happens. According to FEMA FloodSmart, about 29% of NFIP flood claims from 2014 to 2024 came from properties outside high-risk flood areas, and the average claim paid from 2020 to 2024 was $82,614. In Lake County, that risk tends to show up in low spots, near creeks and retention ponds, and in neighborhoods where storm water has nowhere to go during a 5-inch rain.
Homes outside high-risk zones usually qualify for lower flood premiums. Get the number before you decide it is not worth it. For many Grayslake homes, it costs less than people expect.
What Does Flood Insurance Cover and Cost in Lake County?
TL;DR: NFIP policies cover up to $250,000 on a home and $100,000 on contents, priced by each property's own risk under Risk Rating 2.0, with discounts in some Lake County communities.
National Flood Insurance Program limits for a home are up to $250,000 on the building and up to $100,000 on contents, and coverage normally begins 30 days after purchase, according to FEMA. Basement coverage is limited: it generally includes the furnace, water heater, electrical panel and similar equipment, but not finished walls, flooring or most belongings. Our Illinois flood insurance guide explains the full NFIP policy terms and when private flood can fill gaps.
Since FEMA's Risk Rating 2.0, NFIP premiums are based on each property's individual flood risk, including distance to water, elevation and rebuild cost, rather than just the zone. That is why two Lake County homes in the same zone can pay very different amounts.
Some Lake County communities earn NFIP premium discounts through FEMA's Community Rating System. The county's NFIP page lists seven participating communities, including Gurnee, Lake Forest, Lincolnshire and unincorporated Lake County. Grayslake is not on that list, so Grayslake policies do not get a community discount.
Is It Flood or Sewer Backup When Water Gets Into a Grayslake Basement?
TL;DR: Water rising from outside is flood and needs a flood policy, while water backing up through a drain or failed sump needs a water backup endorsement on the homeowners policy.
| Basement water source | Flood policy | Homeowners with water backup endorsement |
|---|---|---|
| Creek or river rises into the house | Covered | Not covered |
| Surface water floods the neighborhood and pours through a window well | Covered | Not covered |
| Sewer backs up through a floor drain | Not covered | Covered |
| Sump pump fails during a storm | Not covered | Covered |
| Groundwater seeps through the foundation | Not covered | Not covered |
During a big Lake County storm, both can happen to the same basement on the same night. That is why we usually recommend a water backup endorsement on every home with a basement and a flood quote on top. Our guide to cheapest home insurance in Grayslake covers the homeowners side. If a water claim has already been denied, see what to do after a denied claim in Illinois.
A Grayslake family with a finished basement near a retention pond gets 6 inches of rain overnight. The sump pump cannot keep up, and by morning the yard has also flooded against the foundation. With a water backup endorsement on their homeowners policy and an NFIP flood policy bought the previous spring, both sources are addressed, subject to each policy's limits and the basement restrictions in the flood policy. Without either, the cleanup would be theirs. This scenario is illustrative only. It is not a coverage determination.
How Do You Buy Flood Insurance in Grayslake Before You Need It?
TL;DR: Buy well before storm season, because NFIP coverage normally starts 30 days after purchase, and you cannot buy it once a flood is on the way.
- Do not wait for the forecast. The 30-day waiting period means a policy bought when the rivers are rising will not cover that flood.
- Bring an elevation certificate if you have one. It can help with pricing on some homes.
- Ask about private flood. Private flood policies may offer higher limits or different basement and contents terms than the NFIP.
- Renters and condo owners need it too. Contents-only flood coverage is available. See our Illinois renters insurance guide and Illinois condo insurance guide.
- Insure the car separately. A flooded car is a comprehensive claim on your auto policy, covered in our Lake County car insurance guide.
New to how Illinois homeowners coverage works? Start with our Illinois home insurance guide.
The Bottom Line
No homeowners policy in Grayslake or Lake County covers flood. Lake County has a long flood record along the Des Plaines and Fox rivers, and after the July 2017 floods, 233 homes in the county had major uninsured damage with no federal disaster aid to fall back on.
Check your address on the current flood map, price a flood policy even if you are outside a high-risk zone, add a water backup endorsement to your homeowners policy, and buy before storm season because of the 30-day wait. Send our Grayslake office your address, or visit our home insurance page, and a licensed agent will help you read the map and price the coverage.
Related Questions
Do I need flood insurance in Grayslake, IL?
It is required only if you have a federally backed mortgage on a building in a high-risk flood zone. Otherwise it is optional, but Grayslake sits in the Mill Creek watershed draining to the Des Plaines River, and about 29% of NFIP claims nationally come from outside high-risk areas, so it is worth pricing.
Does homeowners insurance cover flooding in Lake County, Illinois?
No. Standard homeowners policies exclude flood, meaning surface water rising from outside. You need a separate NFIP or private flood policy. Water backing up through a drain or failed sump is a different claim covered only with a water backup endorsement.
How long is the waiting period for flood insurance in Illinois?
NFIP flood coverage normally begins 30 days after purchase, according to FEMA. NFIP rules allow limited exceptions, such as coverage required when a loan closes. That is why flood insurance should be bought well before storm season.
Did FEMA help Lake County after the 2017 flood?
No. According to the Illinois Emergency Management Agency, the request for federal disaster aid was denied. An SBA assessment found 233 Lake County homes and 21 businesses with major uninsured damage, and the state then sought low-interest SBA disaster loans instead.
How do I check my flood zone in Lake County, IL?
Enter your address at the FEMA Flood Map Service Center or use Lake County's online mapping tools. Lake County's countywide flood map took effect September 18, 2013, and a revision effective October 5, 2023 included the Village of Grayslake.
Last reviewed October 2026 by Joe Lapera, Licensed Illinois Insurance Agent (IL Lic #100722394). Figures verified against the sources linked above on that date.