A few lessons in the agricultural uses of water
As with any course of education there is a required level of prior knowledge necessary before entering the 101 level. Typically, prior to level 101 there would be the 095.
095- WOO HOO the water is here!
This level of knowledge is usually gained at around 7-8 years old. We learned that those cool little black irrigating boots were not really good for more than crossing a wet supermarket parking lot. We learned that those 6” tall boots didn’t stop us from sinking to our knees as we tried to follow dads, moms, brothers, sisters, uncles or whoever made the strides look simple. The final exam of the 095 level, was a story problem: Realizing the sand between your toes and in your little boots hurts like crazy after just a few steps, can you carefully lean on a shovel while emptying the now nearly impossible to remove wet socks and boots?
We realized that water had some alternatives to our original thinking that all was fun and games. We began to step very carefully around the water and determine when we were getting in too deep.
Often the “water world’s” terminology can get too deep. So here are a few terms that must be understood.
1) Priority- like it implies, there are certain users of water that get priority over others. This priority system is based on “first come, first served.” The earlier in history that someone put water to a good (beneficial) use, the lower their priority number. This number however, is like the placing in a tournament- #1 is best or senior and so on. A water right can however be both senior and junior. For example the #2 priority is senior to the #3, yet junior to #1. The actual physical location along the river is basically irrelevant. The priority number determines who gets the water in what order.
2) Decree- this term is used to define how much water, and to what purposes the water is used. For example, you cannot use water for raising fish unless this purpose is expressly granted in your decree. You also cannot take from the source (well or river) all that you want. Your decree states how much water to which you are entitled. The term decree is applicable to both river (surface) water and well (ground) water.
3) Compact- this is a legal term for a federally recognized interstate or international agreement. The Rio Grande River Compact dictates how water from the Rio Grande River is divided between Colorado, New Mexico, Texas, and Mexico. It was developed to be as equal and fair as possible. (This topic is always up for coffee shop discussion!)
4) Unconfined aquifer- this is the area of water that exists from immediately below the surface of the ground to a depth that varies from about 75 to 200 ft. At the bottom of this “layer” is a boundary of clays and Malpais lava flows that really slows water from moving up or down.
5) Confined aquifer- this is the area that is below the unconfined. Where the unconfined is relatively shallow, the confined can be thousands of feet deep. This is where artesian water comes from because of usual upward pressure.
6) Diversion- Diversion describes the location and method used to get water from a river or the ground. A headgate on the river is a diversion for surface water and a well is the diversion for the ground water.
Now the final principle for our class:
A SPRINKLER IS NOT A WELL!!!
It is always wrong to interchange these terms in any discussion. Just like the ones we ran through as children, sprinklers must be connected to a water source (hose) to do any good. A sprinkler is a method to apply water for irrigation. An irrigation sprinkler does not imply well. The Valley is full of examples of surface (river) water being pressured with a pump and put through a sprinkler for irrigation.
The other method of irrigation is flooding. This is what everyone did before sprinklers were invented. A ditch brings water from a diversion (river or well) to flood a portion of land with water about 3-5 inches deep. Then the water is moved to another section and the process repeated. This method of irrigating puts a lot of water into the unconfined aquifer because of its inefficiency, about 40 percent is lost to the ground. A sprinkler on the other hand over applies only about 15 percent more water than the plants need.
With water nothing is as it may seem on the surface but with some proper knowledge, it is somewhat easier to understand the conversations around us. The thing to remember: “ water is fluid”, wear tall boots and keep an open mind!
Nathan, his wife Charlotte and their four children have a small alfalfa, cattle, and grain operation northwest of Manassa. He has managed the Conejos Water Conservancy District since 2010.
Coming up June 12th at 2 p.m. is the next Rio Grande Round Table monthly meeting at the Ramada Inn, former Inn of the Rio Grande in Alamosa. Please visit the Water 2012 in the Rio Grande Basin’s website www.rgwcei.org to see past Water 2012 articles, learn about upcoming events, and to find out how to be a part of Water 2012.