Why rain is a bad thing in a drought

No, I’m not trying to confuse anyone.  Living down here, you learn to take rain whenever and where ever you get it.  We are, arguably, still in the worst drought in recorded Texas history.  The last bad one was in the 1950’s, and it lasted nearly 6 years.  Our current one is about 15 months long…so far. If you look at the last decade, we have been going in and out of a drought on a fairly regular basis.

The other night, we got a pretty decent rain.  It was 1.70 inches  (Yes, I AM a weather geek, thank you.  My weather station can be found here ) over about a 6 hour time frame.

This summer’s drying from lack of rain and temperatures of over 100 degrees for 90 straight days, all of the soil biology (bacteria, protozoa, nematodes, fungi and tons more) has died.  The organic matter, critical to creating the correct soil texture (tilth), has been burned out, literally, from the heat.  The two most important parts of keeping soil the proper tilth to hold water and yet drain properly are gone.  CenTex soil is high in clay and limestone.  The exact materials you use to make bricks.  So, the only things to keep it from becoming a solid sheet of concrete is gone.

Now, add water.

What you get is called runoff.  We beg for rain, but when it falls, it simple cannot soak into the caliche fast enough.  The excess has to go somewhere, and it usually results in temporary streams or creeks.  When there is enough rain, it runs off so fast it creates a flash flood.  These are deadly.  Austin, Texas is known as the flash flood capital of the world.

In my yard, the 1.70 inches of rain looked like this:

And this:

This is wasted water.  I can’t even begin to estimate how much water I lost off of my property.  My property isn’t flat, I drop off about 20 feet over the 400 foot length.  That might not seem like much, but all that runoff creates this kind of water waste:

So, how do you fix this?  Well, first, improving the soil means more water can soak in.  More soak in, less run off.  I’m working on that with things like planting diakon radish to drill through the caliche and soften the soil.  but there are other ways to fix the problem.

Brad Lancaster, author of “Rainwater Harvesting for Drylands and Beyond”, a fantastic 2-volume set of books designed to show how to capture every drop of water, has a great discussion of using earthworks to capture rainwater.  Brad’s website talks about berms and swales as techniques for holding water on the property as long as possible.  The pictures above are from the back of my property.   I haven’t had an opportunity yet to address runoff there, but I’ve already taken Brad’s information and applied it to the front of my property.  So, I will be able to demonstrate a “before and after” view of saving water by changing the land.  I’ll also be able to show how saving that water improved the soil, which allowed me to landscape with low water use perennial and edible plants.  I also added lots of wildlife-friendly plants, and have been able to certify my property as a wildlife habitat and a Monarch way-station.

In my next post, I’ll show how I used earthworks to end the runoff, keep the water in place and transform a typical CenTex caliche slab into a wildscape.


About Jeff

A 30-year Central Texas gardener, an instructor of gardening and urban farming in the Continuing Education program with Austin Community College, holder of a Permaculture Design Certificate and operator of Wild Plum Valley Farm, an attempt to turn an urban acre of land into a more self-sufficient homestead without breaking my back or the bank. And Jeff is forever grateful to his beautiful and loving wife Lori. Too many times, the word "I" is used when it couldn't have been done without her.
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