Thursday, May 13, 2021

Guiding the Water: Making it Rain in the Summer

I love visiting new bookstores - browsing should be a physical activity (as opposed to a click and point activity), in my experience. Last month, while helping my daughter move from Montana to New Mexico, we visited a great bookstore in Las Cruces. Occupying at least a half-block on Main Street, Coas Books has an incredible collection of new and used books. Including a signed, first-edition copy of English Creek, by my favorite author, Ivan Doig (a Montanan). Needless to say, I bought the book! Among my many favorite passages from this wonderful novel is this:

“...Ben English in his fields across from us here, moving the water. Guiding the water, it might be better said. For Ben English used the water of his namesake creek as a weaver uses wool. With care. With respect. With patience. Persuading it to become a product greater than itself.”

I thought of this passage this morning while I was irrigating (as I often do). We irrigate about 15 acres of hilly, foothill pasture near Auburn, California. Over the course of my sheep-raising career, I’ve irrigated leveled pasture north of Lincoln, sloping pasture near Newcastle, and (since 2008) these hills just west of Auburn. I’ve flood irrigated, moved aluminum hand-pipe sprinklers, and dragged K-Line movable pods. I’m not an expert, by an stretch of the imagination, but I’ve done it long enough now to have some sense of what Doig describes.

Our current system consists of five K-Line pod lines. This system, developed in New Zealand, works especially well in our foothill pastures. Topography and trees make irrigating challenging; these same features, plus the shallow soils, make it next-to-impossible to grow more valuable crops on this landscape. With flexible pipe and sprinklers in pods, we can drag each line to a new location each day. Our water, purchased from the Nevada Irrigation District (NID), originates high in the Yuba River watershed (a vestige of the Gold Rush era - we still pay for it by the “miner’s inch”). Each morning, from April 15 through October 15 (at least in “normal” years), I move each of the five lines to a new location. And I keep the grass growing. To feed our sheep. On good days, this takes about 45 minutes. On normal days, it takes an hour. Some days, it takes more than that.

You’ll hear irrigators talk about “set” and “rotation.” Set refers to the length of time that water is applied to a particular portion of a field. Rotation refers to the frequency that water returns to that particular location. Set and rotation can be engineered according to the quantity of water delivered, as well as to site-specific soil properties and water demands of the plants being irrigated. Our system was designed to run on a 24-hour set and 10-day rotation. But irrigation engineers are seldom the ones who do the actual irrigating.

Our pastures are incredibly diverse - in topography, vegetation, and soil. Our K-Lines are also diverse - we have a small area that we irrigate with a 4-pod line on a 9-day rotation. On the other extreme, we have a line with 11 pods. The low spots sometimes have frost (early and late in the irrigation season). The high spots - with thin soils and low water pressure - often dry out. In some zones, our rotation is 10 days. In others, we can’t get back to the first “set” for 15 days. Irrigation is complicated.

Despite our technology (K-Line pods, Rainbird sprinklers, a Honda ATV to pull the lines), simple things can be challenging. With the wind we’ve had over the last 10 days here in the foothills, we’ve had lots of leaves and other debris fall into the canals that deliver our water (which subsequently clog our sprinklers). As the weather warms, many of the canals in the NID’s system fill with aquatic weeds. Some of these clog our sprinklers, too; NID’s use of copper-based products to control the weeds present problems for our sheep.

All of this (and more) was circulating in my brain this morning, as I moved water before heading into my day job. Driving an ATV on a steep side hill takes most of my concentration - but I usually find room to let my mind wander. And this morning, I thought about Doig’s description of Ben English’s irrigation. Of guiding the water. With K-Line, guiding the water resembles fly-fishing. When I’m doing it well, I loop the lines back and forth across the pasture. When I forget where I am - or let my mind wander too much - I get knots (or kinks) in the pipe.

In a drought year like this, irrigated pasture usually gets criticized as an inefficient use of water. The water I spread over my pastures, the thinking goes, could be better used to produce a higher-value crop - or to flow to the ocean. As with most things, though, the devil is in the details. The pastures I irrigate grow tremendous forage; the soils are ill-suited to grow anything else. There are other benefits, as well - our pastures support wildlife, sequester carbon, and provide 15 acres of fuel break to our community. And they feed our sheep!

Some summer mornings, I would rather sleep in. During the work week, I’m sometimes embarrassed to show up at a meeting with mud on my shoes and with my pants soaked from the knees down. But then I think about Doig’s fictional Ben English. I think about my full-time rancher friends who work with water as a weaver works with wool - who can persuade water to become something greater than itself. Who are respectful and patient. I know there’s an amazing amount of science that we apply to irrigating; I’m drawn to the art. And that’s what Ivan Doig describes in English Creek!

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