Cloudy and rainy today. About 0.25 inches of rain last night, as measured in my new rain gauge in the garden, and I’m grateful for every last drop.
I was trying to explain my jerry-rigged water catchment system to a contractor on the phone yesterday. “I have one 750-gallon tank on the southwest side of the barn, and another 750-gallon tank on the northeast side of the garden by the shop. Then there’s a downspout going to a 75-gallon water trough in the paddock, and another downspout that can reach one of the stall water buckets, oh, and the downspout going to the other water trough by the gate where I want to put the frog habitat. And there are some 50-gallon buckets that I can run a downspout to, to catch some more.”
There was a pause. Then he said, “Well, you certainly have a variety of systems.”
Yes, I do. But it’s hardly enough. Our area gets about 20 inches of rain a year, and after twenty years in Las Vegas, that sounds like glory and eternal springtime. But most of that rain falls between October and March, and when the temperature hits 100 in August and the grass in the pasture is drying up, I search the skies for any sign of a wet water-laden cloud. Just about every other year, on average, we have 60 consecutive days without rain. And in an agricultural area, that’s not good news.
Oregon has a maternalistic attitude about its water. The rain that falls on Oregon’s ground belongs to everyone in Oregon; therefore, you can’t just dig a pond and let it fill with groundwater, or divert a stream to water your livestock. (“Now be nice,” Oregon says, “it belongs to all of us so we all have to share.”) However, you can trap all the water that falls on impervious surfaces, like roofs and pavement. And that, my dears, is a lot.
Try it for yourself — the formula is easy:
- Measure the footprint of your roof. Let’s say your house is 60 feet long and 30 feet wide. So your roof’s footprint is 60 x 30, or 1800 square feet.
- Multiply the square footage by the inches of rainfall your location gets in a year. If your house is in Las Vegas, you might get 4 inches per year, so 1800 square feet x 4 inches/year = 7200 gallons landing on your roof.
- But you’re not going to capture all of that rainwater — in fact, you don’t want the rainwater that washes all the accumulated dust and bird poop and leaf debris off your roof and out of your gutters. So multiply your total gallons by 0.46, just to be realistic. Your Las Vegas house with the 1800 square foot roof could give you around 3300 gallons of free water a year.
As it happens, we have several outbuildings with metal roofs – ideal for setting up a catchment system. Using that formula, I calculated that I could harvest over 45 thousand gallons a year. That’s staggering. That means green grass for the horses even in the hottest part of the summer, and a lovely long growing season in the garden, as well as a potential life-and-property-saver during fire season. IF I can get it set up.
I’m no engineer, so I’ll need technical help on this. But those resources are available around here. And after living in Nevada, and driving through California, and seeing the miles of starved, depleted, thirsty fields and dying orchards, and reading the reports of projected “mega-droughts” in the West in years to come…I cannot think of anything more important to do here this year.