Water Rites (part two)
There are a LOT of methods for irrigating, ranging from huge "Pivot Lines" which are ginormous stainless steel systems on wheels, powered electrically which can water many acres continuously (and which can cost in the 100's of thousands of dollars) to flood irrigation as we discussed last week, which is what we do.
Flood irrigation, though, is probably the oldest and most straight-forward of systems. As explained in the previous post, the basic idea is to run your irrigation water through a ditch, creating dams at various points where you can get the most spread of water. Obviously, the ditch is typically on the uphill side and you try to direct water downhill. Most irrigation water in the West (or at least in Oregon and Montana where the pictures are from), comes either from the major river in that area, or from high mountain lakes. It's seldom diverted from local streams or lakes due to the impact on those small systems. Each landowner has a certain amount of water allocated to him, based on acreage and historical use (meaning the longer that property has used water, the more right it has to the water).
Once the water is in your main ditch on your property, you may decide to divert it to various side ditches to direct to the area you want to water. It is commonly asserted that you never deviate from your irrigation schedule. Even if it's rained for 2 weeks straight, you just keep moving your dams at the same schedule. As the summer progresses, your available water decreases and so you must decide where & how much you want to irrigate as you will likely not have enough water for everything.
At certain times of the year, there is more water than others. During those times, at the ranch on which this example is based, we set 3 dams, one on each of 3 ditches. (There are more ditches but in this case, we haven't yet diverted water to them). Following is the pattern my daily irrigating follows:
First of all, make sure you have the one ESSENTIAL piece of equipment... a good pair of irrigation boots. Here are my brand new Bogs.
1. Start 4-wheeler & wait for all the dogs to come running... they LOVE to irrigate.
2. Strain myself opening the wire gate to get into the pasture.
3. Ride out to the main (upper) ditch & pull the dam. (There are a number of different types of dams, although what you'll see here is the most common. Locally, there is a mechanical dam, created by a man name "Love" in the 60's that some farmers & ranchers use. It's called the "Love Machine" and basically straddles the ditch & runs on a motor that slowly follows the ditch, keeping a dam in place but moving is slowly along.)
4. To pull a dam, I first try to find the rock that was used to hold it down (I'll explain that further down).
5. After I reach in & pull out the rock, I remove the other 4 rocks from the 4 corners & slowly start lifting the pole. The weight of the water will then push against the tarp & eventually blow out the other side.
6. Once the dam is released, I can pick it up, roll the tarp around the pole and put it on the 4-wheeler to transport to the next location.
7. Now you drive around looking for the next set.... Is that it? No.....
Maybe... a little further?
AHA! I see 2 rocks! That's a good sign (although there are a LOT of rocks in the pasture, so it's not foolproof).
8. Now that we've found the new location, we can work on re-setting the dam. First I unroll the tarp & place the pole against the 2 anchor rocks. Then, I stretch it out & put a rock on all 4 corners.
9. Then, I place a smaller rock in the center at the edge, to start pulling the tarp down into the water. As the water starts to flow in, the weight of that water continues to pull the tarp down into the ditch.
10. Now I sit and wait for the water to backup & start to overflow. While I wait, I watch the scenery.
And... some more scenery. (Yes, it's tough job, but someone really does have to do it.)
11. Finally, the water is starting to flow.
12. Josie expresses her approval.
13. The final check.
14. Another look around.
And then I head out to the next ditch to reset that dam.
What a great morning!