If you live in the Wimberley Valley, your property is part of the Blanco River Watershed. But “watershed” is a misleading way to describe it. The word implies getting water off the land as quickly as possible. Instead we should re-conceptualize our valley as a “water catchment area.” This term, used by most of the rest of the world, suggests capturing water before it flows downstream.
Raingardens are just one good way to keep water on your land. The Wimberley Village Library has two excellent books, Rainwater Harvesting for Drylands and Beyond, Volumes 1 and 2. The author, Brad Lancaster, describes various ways to retain more water on your land. For instance, diversion berms can redirect water into depressions, called diversion swales. And a series of swales on a gentle hillside can gently overflow one into the other.
Such techniques are advantageous in times of too little or too much rain. Certain Texas natives like to occasionally “get their feet wet” and will thrive in a raingarden or diversion swale. Plants around the edges of such moister areas also benefit from increased water infiltration. In times of heavy rains, such areas, especially once plantings become deep rooted, will slow the water down, an essential factor in dissipating floodwaters. And soil is good at filtering pollutants. So between rains, as some of the water that soaked in re-emerges from our seeps and springs, it will be cleaner.
Is there some place on your property you can put a raingarden, build a diversion berm, dig a diversion swale? These are techniques that will allow you to capture more precious rain.