Asheville (Buncombe County), NC Flood Zone & Drainage Map

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Overview

Where does rainwater drain in Buncombe County? This interactive map shows surface drainage patterns across Asheville and surrounding mountain areas based on terrain shape - where gravity directs rainwater based on elevation and slope. For official flood risk information, see the FEMA flood zone layer on the Hazards tab.

Buncombe County's steep mountain terrain funnels rainfall rapidly into narrow valleys along the French Broad and Swannanoa Rivers. Hurricane Helene in 2024 demonstrated the devastating consequences - mountain runoff converged through Asheville's valley floor with catastrophic force. Stony clay soils on steep slopes shed water quickly, creating flash flood conditions with little warning. Choose a location to see surface drainage analysis and water flow direction based on terrain shape. The first three locations are free.

Interpretation

Select a location on the map or enter an address to see terrain analysis.

3D Terrain Visualization
Where does rainwater flow based on terrain shape? Blue areas show where water collects and drains downhill.
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Terrain drainage map of Buncombe County, NC: modeled paths where rainwater runs and collects, from USGS 3DEP elevation data, with the county boundary Click any spot on the map to analyze it
4.0× Horizontal:Vertical
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Buncombe County flood history

FEMA records 1,192 flood insurance claims in Buncombe County since 1978, with about $104 million paid. 25% of the claims with a rated flood zone came from moderate- or low-risk zones (X, B or C), outside the high-risk areas on FEMA’s flood maps.

Bar chart of FEMA flood insurance claims per year in Buncombe County, NC, 1978 to 2026, highest in 2024 (Hurricane Helene) with 506 claims.

Biggest flood years

  1. 2024 · Hurricane Helene · 506 claims
  2. 2004 · 257 claims
  3. 2021 · Tropical Storm Fred · 85 claims
  4. 1995 · 52 claims
  5. 2018 · 38 claims

ZIP codes with the most claims

ZIPClaimsShare
2880330225.3%
2880519616.4%
287781048.7%
28806968.1%
28711847.0%
28804826.9%
28801786.5%
28715594.9%

How to read this. These are National Flood Insurance Program claims, so they count only insured buildings and miss flooding where owners had no flood insurance. FEMA publishes them without names or addresses: they show which years and areas flooded, never whether a particular house did. ZIP codes are as reported on the claims, and a ZIP code can extend beyond the county. The “rated” flood zone is the one used to price the policy and may come from an older map. Data as of 2026-09-08, from FEMA OpenFEMA.

Sunlight and soil in Buncombe County

Sunlight. Ground here gets about 4.5 kWh of sunlight per square meter per day on average (4.3 to 4.6 across the map), close to the middle of the lower 48 (4.5). South-facing slopes get more, north-facing ones less.

Soil. The ground is mostly loamy soil (Cambisols 67%), with loamy soil over a clay-rich subsoil (Acrisols 31%). Rain soaks in at a moderate rate.

Sunlight: long-term average on flat ground from the National Solar Radiation Database (National Laboratory of the Rockies, formerly NREL). Soil: most likely soil types from ISRIC SoilGrids, a 250 m model, not a survey of any lot. Both cover the map area above.

Explore more flood and drainage maps

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