Conroe & The Woodlands (Montgomery County), TX Flood Zone & Drainage Map

Address
Overview

Where does rainwater drain in Montgomery County? This interactive map shows surface drainage patterns across Conroe, The Woodlands, and surrounding 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.

Montgomery County drains south through the San Jacinto River watershed, with Spring Creek and Caney Creek collecting runoff from the piney woods. Lake Conroe acts as a major retention basin, but controlled releases during heavy rainfall can cause downstream flooding along the West Fork of the San Jacinto. 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.
Units
Report a problem
—
Terrain drainage map of Montgomery County, TX: 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
Elevation loading...

Montgomery County flood history

FEMA records 13,035 flood insurance claims in Montgomery County since 1978, with about $633 million paid. 54% 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 Montgomery County, TX, 1978 to 2026, highest in 2017 (Hurricane Harvey) with 2,445 claims.

Biggest flood years

  1. 2017 · Hurricane Harvey · 2,445 claims
  2. 2016 · Early summer severe storms · 1,660 claims
  3. 2019 · Tropical Storm Imelda · 1,297 claims
  4. 1994 · 1,149 claims
  5. 1979 · 998 claims

ZIP codes with the most claims

ZIPClaimsShare
773021,75213.4%
773571,55211.9%
773801,35310.4%
773861,34310.3%
773651,34210.3%
773851,0227.8%
773545294.1%
773725033.9%

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 Montgomery County

Sunlight. Ground here gets about 4.8 kWh of sunlight per square meter per day on average (4.7 to 4.9 across the map), above the middle of the lower 48 (4.5). South-facing slopes get more, north-facing ones less.

Soil. The ground is mostly loamy soil over a clay-rich subsoil (Luvisols 97%). Rain soaks in, then slows at the clay layer.

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

Browse all 64 flood and drainage maps · Flood insurance claims in the 50 largest cities · How Terreflow uses terrain and FEMA data