Blog · October 14, 2026 · Illinois
Washington County Flood Zone Map: checking a property's flood zone
The zone on FEMA's map affects insurance, building and resale near Du Bois.
Main page: Washington County, IL GIS & Parcel Viewer (official map link, county facts and neighboring maps).
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Ahead of any purchase around Nashville, check the Washington County flood zone map: the zone on that map shapes insurance, building rules and resale. This Washington County guide covers: finding the address on FEMA's map, reading the zone codes, and matching it with the county parcel viewer.
The Washington County flood zone map: start here
For a more interactive look, use the National Flood Hazard Layer viewer, where zone shading sits over a photo base, which applies near Hoyleton as much as anywhere. A tract near Elkton without an address can still be found: zoom in from Interstate 64 and click the spot.
Getting to the right map
Go first to the Sidwell Portico - Washington County IL; it covers every assessed parcel from Cordes to Addieville. Without an address in hand, pan along Interstate 64 and click the parcel itself. With a lot near Centralia, save the parcel ID from that panel; each records desk in the county uses it to find the file.
Where the recorded documents are
When the details count, get the recorded deed from the county Recorder of Deeds (in many counties the County Clerk and Recorder); the parcel map near Nashville only summarizes it. For a home near Centralia, bring the document number shown in the record panel to skip a name search.
Who handles what
Questions about value or the owner field for land near Clarmin belong with the Supervisor of Assessments, working with township assessors, since that office keeps the assessment data. Zoning, permits and septic questions near Du Bois go to planning, building or health offices, depending on whether the land is inside town limits.
Decoding the flood zone labels
Closer to Irvington, A and V zones are Special Flood Hazard Areas, meaning a 1% or greater chance of flooding each year. Around Du Bois, minimal risk is not no risk: according to FEMA, floods happen outside mapped zones too.
Use the county map alongside FEMA
FEMA's map shows zones but not ownership, so check the Sidwell Portico - Washington County IL too to see exactly which lot near Du Bois you're looking at.
Lenders and permits
If a building sits in a Special Flood Hazard Area and a federally regulated lender is involved, flood insurance is generally required where the community participates in the National Flood Insurance Program, whether the land is near Nashville or elsewhere in the county. Remodeling a house in a zone near Irvington usually means extra permit review; ask the local floodplain administrator before you plan.
Beyond the mapped zones
Creeks and ditches near Nashville aren't always studied in detail, so ask neighbors about past flooding. Marshy spots near Irvington can limit building too; check the National Wetlands Inventory mapper for a first look.
Questions to ask before you buy
If the land is near Du Bois, ask the listing agent for any Elevation Certificate before closing; an insurance quote early keeps the budget honest.
Reading the legal description
Illinois is laid out under the Public Land Survey System, so rural legal descriptions near Irvington cite section, township and range. A standard section is about one square mile, roughly 640 acres, with 36 sections to a township, though sections near Hoyleton can be irregular. Copy the legal description from the record for the parcel near Centralia when you talk to a surveyor.
When a parcel crosses a boundary
Washington County touches Clinton County, Jefferson County, Marion County, Perry County, and Randolph County, and each of those keeps its own parcel map. A tract near the line by Beaucoup may be split in two county records, so check the adjacent map as well. For acreage around Elkton, our state page links every neighboring county map across Illinois.
A word on accuracy
For a home near Du Bois, listed acreage is a tax-roll number; just a licensed surveyor sets the real lines on the ground. For land near Ashley, owner names and values update on a schedule, so a deed recorded last month may not show yet.
On site with the map
Most viewers work in a phone browser, useful out on a road near Hoyleton, but coverage can be spotty out of town. A printout of the tract near Ashley keeps working without signal.
Questions about the Washington County flood zone map
What is a base flood elevation around Beaucoup?
If you're looking near Cordes, the base flood elevation is the water level expected in the 1% annual chance flood; local rules may require building above it.
Where can I see the Washington County flood zone map for free?
For most people, look up the spot near Elkton in FEMA's National Flood Hazard Layer viewer, and the zone code appears on the map.
Do I need to worry about flooding in Zone X near Clarmin?
On ground around Nashville, shaded X is moderate risk and unshaded X is minimal risk; FEMA notes that a large share of claims come from these areas.
What is the difference between Zone A and AE for land near Irvington?
Out toward Beaucoup, an AE zone has a 1% annual chance of flooding and a base flood elevation; unnumbered A zones don't list one.
Why do offices ask for the parcel ID near Du Bois?
It's the number the Supervisor of Assessments, working with township assessors uses to track a tract near Centralia, and it's on the record panel and tax bills.
Open the official Washington County, IL parcel map See it in the Platbookmapper directory
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey, especially for fences, setbacks, or boundary disputes.