On Friday, April 15, our irrigation district (Nevada Irrigation District, or NID) turned on our irrigation water. Unlike the last several years, NID has plenty of water in storage (both in reservoirs and as snowpack) - we don't have to worry about getting enough water this year. Even more importantly, NID expects to have enough carry-over water in storage at the end of this season to ensure adequate supplies for next year. After four years of drought, having enough water is a huge relief! But while I'm thankful for the water, early season irrigation with our K-Line irrigation system is a challenge - largely because of type of water delivery system we have in the foothills.
First, let me extol the virtues of NID's system. Our irrigation system is a legacy of the first settlers (miners and farmers) in our part of the Sierra foothills. Miners, mostly, dug canal systems to provide water for mining - which farmers later used to grow crops. The NID canal that runs through the north end of our home property was built sometime in the late 1800s (the easement on our deed dates to the 1880s, as I recall). This system is almost entirely gravity based. Except when I step on the scale, I'm a huge fan of gravity! With respect to our irrigation system, gravity means that we use very little energy to deliver water to our ranch. Gravity moves water from NID's high country reservoirs to the canals that provide our water. Gravity moves water from our diversion box on the canal to our mainline pipe. And gravity delivers water to our K-Line sprinklers. It's a pretty efficient system!
Unfortunately, gravity also makes leaves, grey pine cones, oak catkins and other debris fall into the open canals that carry water from the high country to our pastures. This detritus is small enough to flow through our 6-inch mainline and 2-inch risers. It's small enough to flow through our lateral feeder pipes. It's not small enough, however, to flow through our pressure regulators and sprinkler nozzles. And this is the "but" in the title of this post. When I move water at this time of year, I invariably have plugged sprinklers. It's easiest - and less time consuming - to unplug the sprinklers while the system is running. Which means I come home wet most evenings! Sometimes, gravity makes larger things fall into the canal and end up in our system - over the years, I've had pond weeds, acorns, frog and fish parts, and even a whole rat end up in our irrigation system. I suppose a filter might be in order - but in the meantime I'll trade my time for the extra expense of a filter system.
When it comes to irrigation, there are many measures of efficiency. Our K-Line system, which consists of flexible above-ground pipe and pods with sprinklers, delivers an even amount of water across our hilly pastures. In that respect, it's highly efficient. I have friends who still flood irrigate. While this technique may seem inefficient, it definitely has its advantages in our foothill landscapes. The best flood irrigators can push water uphill (or at least it seems that they can to me). They don't worry too much about clogged sprinkler nozzles, either! And flood irrigation, done well, can help recharge groundwater aquifers.
And so as spring becomes summer, and you see lush pastures, bountiful orchards and plentiful vegetable farms as you drive through the Placer County foothills, join me in being thankful for the water that grows our food! And join me in thanking the farmers and ranchers - and NID staff - who keep the water flowing!