Galveston County Drainage Analysis & Water Flow Map

Address
Overview

Where does rainwater drain in Galveston County? This interactive map shows surface drainage patterns across Galveston Island, League City, Texas City, 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.

Galveston County's extremely low elevation - averaging just 15 feet above sea level - makes surface drainage a critical concern. The county faces both riverine flooding from Clear Creek and Dickinson Bayou and coastal storm surge from Galveston Bay. The barrier island geography limits natural drainage outlets. 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.
Units
Report a problem
4.0× Horizontal:Vertical
Elevation loading...