Harris County Drainage Analysis & Water Flow Map

Address
Overview

Where does rainwater drain in Harris County? This interactive map shows surface drainage patterns across Houston 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.

Harris County's flat terrain and clay-heavy soils (Beaumont Clay) create poor drainage infiltration, amplifying surface water runoff through the bayou system. The county drains primarily through Buffalo Bayou, Brays Bayou, White Oak Bayou, and Greens Bayou into the San Jacinto River and Galveston Bay. Enter any address to see parcel-level surface drainage analysis and water flow direction based on terrain shape.

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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