The Balcones Fault runs just west of MoPac through the center of Austin.  To the west we find hills and canyons, rocks and oak trees and cedar.  To the east flatter terrain and deeper soil.

The higher rock content of the soil tends to provide a solid opportunity for a foundation.  Still, the clays between the rock do expand and contract as moisture levels vary.

On the east side of the fault line, soil movement is more significant, making managing the moisture content even more important. 

Gutters, proper drainage, and watering between rains can help give your home’s foundation a more stable base.  Don’t let water pool along the house when it rains.  Keep the grass green within 5 feet of the house even during droughts.