Today, there's really no doubt we must pay more attention to our skies as a source of water to meet our needs. Over these past few years, we've experienced a rude awakening as to the reliability of our ground water supply – both from persistent drought conditions and, more recently, from massive assaults on our aquifers from commercial interests.
"Rainwater harvesting" — There aren't many topics with more appeal around our Valley or possible approaches to translating the gift of rain into helping sustain our quality of life.
With such a huge consideration at hand, best to define what this article is and isn't.
It's intended to add a little "been there, done that" to the subject of practical harvesting, with some examples from around the Wimberley Valley…and to offer some "big picture" approaches to capturing, storing and using rainwater.
It's not intended to take the place of detailed how-to guidance from professionals or excellent published sources which ought to be consulted and understood as a first step to getting serious about any level of harvesting (see link references).
Like so many potentially expensive, time-consuming, life-supporting projects, there are basically two ways to go about rainwater harvesting [compare to building a home]. First would be to do it yourself by gathering solid information and perhaps starting small to learn the principles and benefit from a modest, inexpensive system. The second would be to locate professionals, check references, ask lots of questions, compare bids, then stand back and make sure your installation is going as agreed.
The "home-building" analogy is intentional. Referring to those who've done it, incorporating a rainwater collection system into a home construction plan sure beats a retro-fit in every regard. For example, roof design and materials, along with provisions for storage tanks, figure significantly in costs and results.
Even If you're happy with your main home water source you could still benefit greatly and get a lot of enjoyment and additional security from a modest system. One "hidden away" example of the benefit of having a modest storage tank is it can act as a "lifeboat" storage asset. Let's say it hasn't rained in ages, your well is dry and there's no water in your storage tank. That has happened and could happen in the future. But, with a tank on hand, at least you'd have a ready-made place for the bulk water delivery truck to put the water you need.
Some, who I envy around our valley, have already taken the belt & suspenders approach of installing a rainwater system that could meet their usage needs entirely and indefinitely if their well system went down for any reason. One, with a 20,000 gal capacity, has been going great for 11 years.
A couple of basic "givens" are essential starting points for calculating rainwater yields. Here's the most fundamental: a 1-in. rainfall collected efficiently from a 1,000 sq. ft. surface will yield about 550 gal. Another key factor is the average annual rainfall for our area. Using Austin data, it's been 33.57 in. since 1856, and 32.15 in. for the last 30 years.
Other rainwater harvesting variables are almost endless. The many considerations include: types of roofs, collection systems, filter systems, storage tank materials and sizes of families or other needs to be met.
As one successful whole-home system owner put it, "There are 5 steps to the best water you've ever tasted…. 1. gathering it; 2. prefiltering before it reaches the cistern; 3. storage; 4. pumping into the home, and 5. final filtering."
Again, for a good leg up on each of these, check the links below.
The accompanying photos illustrate some of the big and small; plain and fancy, complex and simple systems that are in use around Wimberley. Some are homely, some downright good-looking, but they're all a big plus for the owners.
Refer back to this space in the future, because we're encouraging tried and true suggestions and recommendations to add to our wealth of rainwater harvesting examples around our Wimberley Valley. You are encouraged to contact us with suggestions.
Rainwater Harvesting references:
Visitwimberly Water Guide
Texas Water Development Board's Texas Manual on Rainwater Collection Harvesting – 3rd Edition, 2005
Texas A&M Rainwater Harvesting Guide
Hill Country Home - One Individual's Water Catchment Approach
Hill Country Home - Water Resources
With appreciation to:
Texas Water Development Board
The Cole Ranch
Katherine Anne Porter School
Larry Morris & Michelle Smith – Roadrunner Ranch
Wimberley Medical Plaza