Blog · October 14, 2026 · Iowa
Using the Mason City Flood Zone Map
Flood zones are set by FEMA, and checking one near Plymouth takes a few minutes.
Main page: Cerro Gordo County, IA GIS & Parcel Viewer (official map link, county facts and neighboring maps).
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Weighing a property around Rockwell? The Mason City flood zone map tells you whether it sits in a FEMA flood zone, and the lookup is free. What this Mason City guide covers: finding the address on FEMA's map, decoding A, AE and X, and pairing it with the Cerro Gordo County Beacon site.
The Mason City flood zone map: start here
The official source is FEMA's Flood Map Service Center: type an address near Clear Lake, then open the map view for that panel. Vacant ground around Swaledale can still be found: pan from the closest town and click inside the land.
Getting to the right map
Begin with the Cerro Gordo County Beacon site; it includes each assessed parcel in the county, Ventura included. For a parcel near Ventura, enter a street address, an owner's name or a parcel number, and the viewer zooms to the match. For a parcel near Plymouth, a pop-up or side panel normally shows the owner of record, assessed acreage, a parcel ID and often a sale date.
Land on the county line
Cerro Gordo County touches Butler County, Floyd County, Franklin County, Hancock County, and Mitchell County, and each of those keeps its own parcel map. Acreage along the edge near Ventura can be split across two assessors' files, so look at the neighboring map too. For property near Ventura, our state page lists every bordering county map for Iowa.
Water near Swaledale
Creeks and ditches near Ventura may not have detailed mapping, so walk the land after rain. Marshy spots near Plymouth can limit building too; the National Wetlands Inventory mapper shows mapped wetlands.
Mason City and the county around it
Mason City lies within Cerro Gordo County, Iowa, so its parcels are on the county's map. Mason City is also the county seat, which puts the County Recorder close by. Closer to Clear Lake, City or town hall handles things like zoning, permits and utilities within town limits, while the county keeps the tax map. Lots just outside the town limits toward Ventura generally follows county rules instead.
Using it on a phone
Most viewers work in a phone browser, handy when you're parked on a road near Swaledale, but coverage can be spotty out of town. A saved image of the lot near Rockwell and its lines is a good backup.
What the zone letters mean
An AE label includes a base flood elevation (BFE), while plain Zone A does not; surveyors near Swaledale use that number. With a lot near Swaledale, shaded Zone X marks moderate flood hazard, between the 1% and 0.2% annual chance floods; unshaded X is minimal risk.
Use the county map alongside FEMA
FEMA doesn't draw property lines, so pair it with the Cerro Gordo County Beacon site to see exactly which lot near Clear Lake you're looking at.
Sections, lots and bearings
Iowa uses the Public Land Survey System, so rural legal descriptions near Rockwell cite section, township and range. Each section is nominally a mile square, about 640 acres, and a township holds 36 of them, though real sections near Ventura vary in size. Copy the legal description from the record for the parcel near Rock Falls when you talk to a surveyor.
Cerro Gordo County in a few facts
Mason City holds the county offices, home to the main records offices. Smaller places on the map include Rock Falls, Plymouth, Clear Lake, and Rockwell, each with its own cluster of lots. About 42,406 people live in Cerro Gordo County (Census Bureau estimate, 2023) across about 568 square miles. The county was formed in 1851, and some chains of title near Clear Lake are long.
Who handles what
For assessment questions about property around Swaledale are handled by the County Assessor, the office behind the parcel record. Building or septic questions for a lot near Swaledale are for the local planning and health departments, and the answer depends on jurisdiction.
Questions to ask before you buy
Ask the seller about past flood claims for the house near Ventura; getting a quote early avoids surprises.
What a flood zone means for a buyer
For property near Ventura, an Elevation Certificate from a surveyor helps: it can change the insurance price a lot. Remodeling a house in a zone near Plymouth often needs a floodplain permit; check with the county or town building office before you plan.
Frequently asked
What does an AE label mean for a lot near Ventura?
For most people, AE is a Special Flood Hazard Area with a published base flood elevation, so builders near Rockwell design to that elevation.
Can I see flood zones on the Cerro Gordo County Beacon site?
For most people, the parcel map near Rockwell might show FEMA zones; confirm a lot near Plymouth on FEMA's map either way.
Can a flood zone near Plymouth change?
A new study can move a zone line near Ventura; your community is notified before changes take effect.
Do I need to worry about flooding in Zone X near Rock Falls?
It depends, but X zones around Plymouth are lower risk, not no risk; many owners near Clear Lake buy coverage anyway.
Is the parcel map a survey near Rockwell?
No; boundary questions near Rock Falls need a licensed surveyor; a survey sets the real corners
Open the official Cerro Gordo 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.