Blog · October 14, 2026 · Iowa
Reading the Creston Flood Zone Map for a parcel
The zone on FEMA's map affects insurance, building and resale near Shannon City.
Main page: Union County, IA GIS & Parcel Viewer (official map link, county facts and neighboring maps).
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Weighing a property around Cromwell? The Creston flood zone map tells you whether it sits in a FEMA flood zone, and the lookup is free. Covered here for Creston: finding the address on FEMA's map, decoding A, AE and X, and pairing it with the Union County Beacon site.
Where the Creston flood zone map lives
Start with FEMA's Flood Map Service Center: type an address near Lorimor, and choose the dynamic map. Vacant ground around Arispe is still easy to locate: search the nearest road and click the spot.
The free map to start with
Go first to the Union County Beacon site; it includes every assessed parcel from Shannon City to Cromwell. On ground around Lorimor, type a street address, an owner's name or a parcel number, and the matching parcel lights up. With a lot near Cromwell, the record panel typically gives the owner of record, acreage on the tax roll, the parcel number and often a sale date.
Creston and the county around it
Creston is part of Union County, Iowa, which means parcel data comes from the county. As the county seat, Creston hosts the courthouse, so deeds and plats are filed in town. Local government in Creston handles things like zoning, permits and utilities within town limits, while the county keeps the tax map. Lots just outside the city limits out by Afton generally follows county rules, not municipal ones.
Beyond the mapped zones
Creeks and ditches near Thayer aren't always studied in detail, so walk the land after rain. Marshy spots near Cromwell can limit building too; check the National Wetlands Inventory mapper for a first look.
What the map can't tell you
Acreage on the record is a tax-roll number; only a licensed surveyor sets the real boundary for a parcel near Arispe. For acreage around Thayer, records update in batches, so a deed recorded last month might lag behind.
Using it on a phone
Most viewers work in a phone browser, useful out on a road near Arispe, so load it before you lose signal. A saved image of the lot near Arispe and its lines helps when you meet an owner or agent.
Zones on the Creston flood zone map
Zone AE comes with a base flood elevation, and an unnumbered A zone has none; surveyors near Shannon City use that number. For property near Shannon City, a shaded X area is moderate risk, roughly the 100- to 500-year range; unshaded X means minimal mapped risk.
A short flood checklist
Ask the seller whether the home has flooded for the house near Lorimor; getting a quote early avoids surprises.
Use the county map alongside FEMA
FEMA doesn't draw property lines, so check the Union County Beacon site too for the outline of the tract near Lorimor.
Money questions tied to the zone
For a structure inside an A or V zone and the loan is federally backed or regulated, mandatory purchase rules apply in communities in the NFIP, and that holds around Lorimor too. Building or adding on near Lorimor in a mapped zone often needs a floodplain permit; check with the county or town building office before you plan.
Legal descriptions in Iowa
Iowa uses the Public Land Survey System, so rural legal descriptions near Shannon City cite section, township and range. Each section is nominally a mile square, about 640 acres, with 36 sections to a township, though corrections make some sections near Arispe odd-sized. Keep the legal description for land near Arispe before you request a deed or survey.
When a parcel crosses a boundary
Union County borders Adair County, Adams County, Clarke County, Decatur County, and Madison County; every one of them runs a separate parcel map. Acreage along the edge near Arispe may show up across two assessors' files, so check the adjacent map as well. On ground around Thayer, our state page links each bordering county map for Iowa.
Which office to call
Anything recorded against property around Lorimor sit in the index kept by the County Recorder, usually searchable by name or document number. Zoning, permits and septic questions near Shannon City go to planning, building or health offices, depending on whether the land is inside town limits.
Quick answers
Is AE a high-risk flood zone near Cromwell?
In most cases, an AE zone has a 1% annual chance of flooding and a base flood elevation, so builders near Shannon City design to that elevation.
Does the county parcel map show flood zones around Afton?
Short answer: a flood layer may appear in the Union County Beacon site layer list; confirm a lot near Cromwell on FEMA's map either way.
How often are flood maps updated in Creston?
Usually, zones near Thayer can shift when FEMA updates a panel; check the effective date on the panel.
What if the flood map is wrong for my lot near Thayer?
Short answer: FEMA's LOMA process is the usual route when a building near Afton sits above the base flood elevation; a surveyor's elevation data supports it.
Does the parcel map work on a phone near Shannon City?
For acreage around Cromwell, most viewers run in a mobile browser; screenshots help offline.
Open the official Union County, IA 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.