What Is a Watershed?
A watershed is an area of land that water flows across, through, or under on its way to a stream, river, lake, or ocean. American explorer John Wesley Powell described a watershed as "that area of land, a bounded hydrologic system, within which all living things are inextricably linked by their common water course and where, as humans settled, simple logic demanded that they become part of a community."
Every part of the landscape - ALL land areas - are part of a watershed. Watersheds can be larger than a state or smaller than even a single neighborhood, but all rain that falls or springs that emerge within one of these areas ultimately flows to the same point at the bottom of the watershed, carrying with it everything that is washed away from the surrounding landscape.
The Plum Creek Watershed
Plum Creek is a 52-mile stream that begins in Hays County north of Kyle and flows southeast through Caldwell County, passing Lockhart and Luling before meeting the San Marcos River near the Caldwell-Gonzales County line. With additional flow from Clear Fork, West Fork, Bunton Branch, Town Branch, Salt Branch, and other small streams, Plum Creek and its tributaries drain an area of 397 square miles. Other municipalities with all or part of their city limits within the watershed include Buda, Niederwald, Uhland, Mustang Ridge, and Mountain City.
The natural landscape of the watershed is typical of Texas Blackland Prairies and East Central Texas Plains, and the Carrizo-Wilcox formation is a significant local aquifer, with the Edwards Aquifer underlying far northern parts of the watershed. Climate in the Plum Creek Watershed is considered semi-humid subtropical.