A dry Bexar County crossing can rise fast in heavy rain

Bexar County sits in the region often called Flash Flood Alley. The San Antonio River Authority explains why: steep ground, shallow soils, and narrow channels move runoff downhill quickly. A crossing may flood even when the hardest rain fell somewhere upstream.

The regional HALT network watches monitored low water crossings. On SARiverFlood.org, green means the monitored road is open, yellow means water is rising, and red means it is closed. You can also choose crossings and subscribe for text or email alerts.

The map is a planning aid, not permission to drive through water. If water covers the road or a gate, light, sign, or barricade says it is closed, turn around. Bexar County's wet-weather guidance is the right same-day check before a storm commute.