In our Mediterranean climate, green grass in the summertime requires irrigation. We recently leased a new pasture near Auburn, and we find ourselves back in the business of making it rain in the summer!
I know old timers who seemed to be able to make water run uphill. Before the days of aluminum pipe and Rainbird (tm) sprinklers, pastures were irrigated out of ditches that ran along the contours of the hills here in our area. Ranchers would use canvas dams to cause water to spill out of these ditches and run across their pastures. This technique wasn't terribly efficient in terms of water use, but it didn't require much capital after the ditches were built. I like the idea of trading labor for capital expenses!
The ranch we just leased uses two types of systems. On the largest field, we're moving aluminum hand pipe. These two inch pipes are 20 or 30 feet long, and we move them once a day - seven days a week. The remaining 15 acres of pasture is irrigated with quick-connect sprinklers. We're finding that these fields haven't been irrigated consistently for some time - many of the risers are difficult to find!
Our irrigation water is delivered by the miner's inch - a vestige of Placer County's mining history. A miner's inch is 11+ gallons per minute, 24 hours a day. The ranch we lease buys 16 miner's inches - a lot of water. The water arrives on the ranch through an open ditch. Gravity feeds the sprinkler system, which means we don't incur any energy costs to get water to the sprinklers! The downside of the open ditch and gravity-fed system is that we get lots of junk in the water - leaves, twigs, frog parts - all of which makes it necessary to clean the sprinkler nozzles frequently. The most disgusting thing I've found in our irrigation system is a whole dead rat!
Why is it necessary to irrigate our pastures? For our lambs, we're trying to put weight on them, which means they need high levels of protein and energy in their diets. Green grass and clover provide these nutrients - dry grass does not. For the ewes, we're approach the time of year when we'll turn the rams in with them to breed them for next year's lambs. About 4-5 weeks prior to breeding, we want the ewes' nutritional intake to improve - this will increase the number of twins born next year.
By August, the summer schedule of working sun-up to sun-down has taken its toll on me. While we often work sun-up to sun-down in the winter, too, the days are shorter (so we get more rest). This time of year, I often work 80-90 hours per week. I find myself looking forward to October 15 - the last day that our irrigation district delivers water!