Blog · October 14, 2026 · Idaho
Using the Washington County Flood Zone Map
Flood zones are set by FEMA, and checking one near Deer Flat National Wildlife Refuge takes a few minutes.
Main page: Washington County, ID GIS & Parcel Viewer (official map link, county facts and neighboring maps).
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Weighing a property around Midvale? The Washington County flood zone map tells you whether it sits in a FEMA flood zone, and it costs nothing to check. In this Washington County guide: the free FEMA tools, what each zone label means, when insurance is required and how to challenge a map that looks wrong.
Getting started with the Washington County flood zone map
If you'd rather pan and zoom, try the National Flood Hazard Layer viewer, which draws the zones over aerial imagery, and that holds around Deer Flat National Wildlife Refuge too. Vacant ground around Payette National Forest can still be found: search the nearest road and click the spot.
Getting to the right map
Begin with the Washington County ArcGIS parcel map; it includes every assessed parcel around Cambridge and Payette National Forest. With a lot near Cambridge, type a street address, an owner's name or a parcel number, and the viewer zooms to the match. For a parcel near Midvale, the parcel card usually lists the owner of record, assessed acreage, the parcel number and often a sale date.
Decoding the flood zone labels
For a tract near Weiser, any A or V zone mark the Special Flood Hazard Area, meaning a 1% or greater chance of flooding each year. For a parcel near Boise National Forest, minimal risk is not no risk: according to FEMA, many claims come from moderate- and low-risk areas.
The paper trail behind a parcel
The map is an index, not the title: recorded deeds, plats and easements covering ground around Weiser sit with the County Recorder (the county clerk serves as recorder). On ground around Cambridge, use the instrument number listed on the parcel record to skip a name search.
Low spots and local drainage
Low-lying fields near Weiser aren't always studied in detail, so walk the land after rain. Marshy spots near Payette National Forest can limit building too; the National Wetlands Inventory mapper shows mapped wetlands.
Places you'll see on the map
Weiser holds the county offices, which is where the courthouse records live. Smaller places on the map include Cambridge, Midvale, Boise National Forest, and Deer Flat National Wildlife Refuge. Roughly 11,425 people call Washington County home (Census estimate, 2023) across some 1,453 square miles. Washington County dates to 1879, so old deeds can run back a long way. Places such as Boise National Forest are easy to spot when you zoom out.
Questions to ask before you buy
If the land is near Deer Flat National Wildlife Refuge, ask the listing agent whether the home has flooded before closing; getting a quote early keeps the budget honest.
When a parcel crosses a boundary
Washington County borders Adams County, Gem County, Payette County, Baker County, OR, and Malheur County, OR; every one of them runs a separate parcel map. Acreage along the edge near Midvale may show up across two assessors' files, so look at the adjacent map as well. On ground around Cambridge, the Platbookmapper state page lists every bordering county map for Idaho.
Field tips
The parcel map usually runs in a mobile browser, which helps when you're standing on land near Weiser, so load it before you lose signal. A saved image of the lot near Midvale and its lines helps when you meet an owner or agent.
Matching the zone to the lot lines
FEMA's map shows zones but not ownership, so check the Washington County ArcGIS parcel map too to see exactly which lot near Boise National Forest you're looking at.
What the map can't tell you
If you're looking near Cambridge, the acreage figure is an estimate; just a licensed surveyor sets the real boundary on the ground. With a lot near Deer Flat National Wildlife Refuge, owner names and values update on a schedule, so a deed recorded last month might lag behind.
Insurance, lenders and building
For acreage around Cambridge, get the Elevation Certificate if one exists: it can change the insurance price a lot. New construction in a floodplain near Cambridge usually means extra permit review; check with the county or town building office before you plan.
Washington County: common questions
What is a base flood elevation near Payette National Forest?
On ground around Deer Flat National Wildlife Refuge, the base flood elevation is the water level expected in the 1% annual chance flood, and an Elevation Certificate compares the building to it.
Is Zone X safe from flooding for land near Payette National Forest?
With a lot near Deer Flat National Wildlife Refuge, shaded X is moderate risk and unshaded X is minimal risk; FEMA notes that a large share of claims come from these areas.
How do I get a property removed from a flood zone near Payette National Forest?
For land near Deer Flat National Wildlife Refuge, a Letter of Map Amendment (LOMA) from FEMA can remove a structure on naturally high ground, and lenders accept the result.
Do I need flood insurance around Boise National Forest?
Short answer: for a building near Midvale in an A or V zone with a federally backed or regulated mortgage, it's generally required; elsewhere it's optional.
Does the parcel map work on a phone for land near Weiser?
No app is needed for most county viewers; load it before you lose coverage near Deer Flat National Wildlife Refuge.
Open the official Washington County, ID 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.