The River Authority is Bexar County's flood-data partner

The San Antonio River Authority does more than care for parks and trails. It maintains more than 40 dams and other flood-control works. It also studies streams and drainage areas. The agency shares floodplain data with Bexar County, San Antonio, nearby cities, and FEMA.

This work gives residents two useful tools. The Floodplain Viewer shows FEMA's flood layer and local study data. SARiverFlood.org shows watched low water crossings. Green, yellow, and red dots show the road status. The dots are tied to HALT sensors across the four-county river basin.

Use the floodplain map for a land question. Use the crossing map for a road question during a storm. Neither one replaces a permit decision or a road barricade. Still, the right map can save a lot of wandering.