When we design a field, we start off getting the elevation and size of the field. That information is then imported into software which we use to model how the system will work in the real world.
We believe that it is better to model the system before it is in the ground, then to install it and find out it has issues from not having a design. Even the most basic field is affected by mainline placement and sizing, valve position and pressure setting.
Drip irrigation applications work with very low pressure. For example, let’s say that we are working with a field that looks pretty flat from the edge. Six feet of elevation gain or loss, which can often be in a field that looks pretty flat, equates to approximately 3psi of pressure gain or loss. If the valve is set to 10psi, that equals a 33% pressure variation, without taking any other factors into consideration. If the field slightly undulates six feet, that equals a pressure variation of approximately 66%. In turn, that pressure variation affects uniformity, which directly affects your crop yield.
We have seen some growers install drip irrigation systems without getting a design and while it sometimes looks like it works, if the ground is reasonably flat, and if the pressure is high enough, but it can also become a disaster. We have received calls where a grower is losing crop and is interested in us investigating an emergency fix to get through the year with at least some yield.
We have seen firsthand how much better a yield a grower can get from a crop if the irrigation system is well-designed and then installed properly. Simply visually examining a field from the edge can be a deceiving way of determining how healthy a field is. In addition, if one ends up applying additional water to compensate for the lack of uniformity one can end up wasting a large amount of money with pumping costs over the course of one year. With additional pumping comes additional water use – something that is becoming increasingly perilous in much of the west.
Just as under-engineering an irrigation system can cost a significant financial loss, over-building a system can be very economically damaging. We focus on building a irrigation design which performs well during Peak ET (evapotranspiration) while balancing initial cost with ongoing pumping cost over the estimated life of the system.
© 2017 Copyright Maxwell Irrigation: Independent Irrigation Design