Editors’ note: This segment first appeared on Texas Monthly Presents, a television program airing on Texas PBS stations and on PBS.org. Senior writer Forrest Wilder wrote “Who’s Killing Jacob’s Well?” during the middle of a drought. In many ways, Jacob’s Well and other springs from Central Texas aquifers are the canaries in the coal mine, alerting us early to major threats to our water resources. And while drought exacerbates the problems, Wilder explains how development endangers an increasingly vulnerable water system.