Blog · October 14, 2026 · Nebraska
Sioux County Flood Zone Map (Nebraska)
How to check whether a property in Sioux County sits in a FEMA flood zone, and what the answer means for a buyer near Agate.
Main page: Sioux County, NE GIS & Parcel Viewer (official map link, Sioux County facts and neighboring maps).
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The Sioux County flood zone map question tends to arrive at a bad moment: a lender's letter, an insurance quote, or a permit counter in Andrews. FEMA's free Flood Map Service Center and the Sioux County parcel viewer answer it together.
The sections below go from the FEMA search to the Sioux County parcel record, then cover insurance, permits and map changes near Agate.
Look up the Sioux County flood zone map step by step
The authoritative source for a Sioux County flood zone map is FEMA, so begin at the FEMA Flood Map Service Center. Search returns the effective FIRM panel for the spot in Sioux County, plus any pending changes FEMA has posted. For an interactive view of the county, try FEMA's National Flood Hazard Layer viewer and reports the zone wherever you click near Agate. Then open the Sioux County gWorks map for Sioux County to confirm the parcel near Agate. If the Sioux County viewer has a floodplain layer, treat it as a convenience copy and confirm on FEMA's map.
Step one: the free Sioux County viewer
For land around Harrison, open the Sioux County gWorks map (a gWorks county GIS site); it's the map Sioux County itself publishes. The Sioux County site shows a disclaimer before the map; click through to reach parcels near Andrews. Use the search box for an address in Andrews or a parcel number, or simply zoom in and click a parcel near Harrison. For a backup route to the map covering Harrison, our Sioux County directory entry keeps the link current.
Sioux County at a glance
Courthouse business for Sioux County runs through Harrison. Smaller places such as Agate, Andrews, and Glen appear on the county map as little clusters of lots. Sioux County had an estimated 1,154 people in 2023 (Census Bureau), spread across about 2,067 square miles. Beyond the town lots in Harrison, expect big rural parcels across the county.
What the flood zone letters mean
Any Sioux County parcel shaded as Zone A, AE, AH or AO sits in what FEMA calls a Special Flood Hazard Area, defined by a 1-percent annual chance of being flooded. A surveyor working near Agate uses the base flood elevation printed for AE zones; unnumbered A zones do not have one. Shaded Zone X around Agate sits in the moderate band between the 100-year and 500-year floods. Unshaded Zone X near Harrison is minimal risk.
Neighboring maps around Sioux County
Near the edge of the county, check the next map over: Box Butte County, Dawes County, Scotts Bluff County, Fall River County, SD, and Goshen County, WY all border it. Every map bordering Sioux County is listed on our Nebraska directory.
Where Sioux County land records are kept
For land near Andrews, the deed itself lives in the county recording office, and the map is an index to it. A deed book and page or instrument number on the county record is the fastest way to pull the document for a lot in Andrews.
Waterfront parcels near Harrison
In Sioux County, look closest at tracts along Niobrara River. Don't assume a parcel near Harrison is clear as its road frontage sits high. Small streams and ditches near Agate may not be studied in detail can still flood; FEMA says moderate- and low-risk areas still carry risk.
What a flood zone means for a Sioux County buyer
Insurance is the practical stake for a Sioux County buyer. Where a building in Agate falls inside an A or V zone and carries a federally backed mortgage, a flood policy becomes a loan condition, as long as Sioux County or the town participates in the NFIP. Outside the A zones around Harrison, federal rules do not require a policy, although a lender in Nebraska can still ask for it. If a building near Harrison sits above the flood line, the owner can ask FEMA for a Letter of Map Amendment (LOMA), supported by elevation data from a licensed surveyor. Adding on to a house near Harrison inside the zone has to meet local floodplain rules; the county floodplain administrator can say what applies.
Sioux County, NE: common questions
My house near Harrison is in Zone X. Is insurance required?
Not under federal rules; Zone X in Sioux County is outside the Special Flood Hazard Area, although a lender can still require coverage.
Is there a floodplain layer in the Sioux County gWorks map?
Check the layer list in the Sioux County gWorks map; if Sioux County includes a floodplain layer, confirm the zone on FEMA's map anyway.
Where do I get an elevation certificate in Sioux County?
Hire a licensed surveyor or engineer who works in Sioux County; ask the local floodplain office first in case one exists.
Do I need a permit to build in the floodplain near Andrews?
Often, but local floodplain rules apply; ask the county or town building office in Andrews well before you buy.
Is my Andrews address in a flood zone?
Look it up at FEMA's Flood Map Service Center, then match the parcel lines in the county gWorks map; for land near Harrison, a zone starting with A or V is high risk.
What does 100-year flood mean for Sioux County land?
No, ground around Andrews mapped that way carries a 1-in-100 chance in any single year, and two floods in one decade near Andrews are possible.
Open the official Sioux County, NE parcel map Sioux County 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.