San Antonio's limestone aquifer is porous and vulnerable to surface pollution, and it recharges just north of downtown in a rapidly developing area. As an advocate for greater protection of the aquifer, every week I spoke out at City Council hearings on new developments being built no regard to the natural resource buried beneath. One day I brought pictures. This photo is of an area once part of the Hill Country, a region of reserved beauty, rolling hills covered in live oak and ash juniper, and charismatic inhabitants such as armadillos, roadrunners, and golden-cheeked warblers. On a spring evening you are warmed by a southern breeze sweet with huisache blossom, while various croaks and chirps are a reminder of what else is there. It's a dry landscape that's developed over years of slow accumulation, sustained only by the limited quantities of water stored underground. Texas may be known for its oil, but water is its most precious resource.