TARPLEY,AQCAN Texas–Margo Denke set out to rally the town when she learned that a Christian youth camp planned to build a wastewater treatment plant and discharge its effluent into the pristine Hill Country creek that ran through her small ranch.

Denke, a 1981 graduate of Harvard Medical School who moved to the Hill Country in 2013, printed fliers, put them in Ziploc bags and tied them to her neighbors’ cattle gates in the tiny community of Tarpley, population 38. A coalition of families pooled resources, hired a lawyer and dug in for a yearslong battle. 

Theirs was one of many similar struggles that have unfolded in recent years across Central Texas, where protection of creeks and rivers from treated wastewater discharge often falls to shoestring community groups as an onslaught of population growth and development pushes ever deeper into the countryside.