One of the most important factors in efficient management of farm irrigation systems is measuring irrigation flow and water usage. Measuring and monitoring water use is an effective way to ensure that irrigation systems are functioning as they should and being operated in the most efficient manner possible. Irrigation flow can be measured in ag irrigation systems either by using flow meters or manually. It is recommended that all crop growers monitor water flow and track water usage for best irrigation results.
Measuring Irrigation Flow with Flow Meters
There are two different types of flow meters that can help growers measure their irrigation flow and monitor water usage as follows:
Propeller Flow Meters - A propeller flow meter is a device that is installed into the pipeline of ag irrigation systems to measure the amount of water passing through the meter. They are available in specific sizes, for specific pipe capacities, and measure water velocity inside the pipe to provide a reading of flow rate on the meter dial. Saddle and flanged meters are available for different pipe installations. Propeller type meters track flow rate in gallons per minute or cubic feet per second over a specific time span to determine water flow. Meter dials typically display gallons per minute and the total water volume that passes through the meter.
Ultrasonic Flow Meters - Ultrasonic flow meters, also known as USFMs, are newer devices that mount outside a water pipe with a clamp and measure water velocity and volume. This type of application reduces the possibility of pressure loss caused by an inline meter and can be moved from location to location. These meters work by measuring transmissions caused by water movement. This provides data that can be configured into whatever scale necessary to determine flow rate and the amount of water that passes through the pipe at that point. Because of the high cost of these units, they are primarily used by irrigation system technicians or by larger farming operations that have multiple farm irrigation systems.
Other Ways to Measure Irrigation Flow
Although propeller flow meters are very popular and USFMs are not very affordable for smaller operations, there are other manual ways to measure irrigation flow. The “plumb bob method” utilizes a plumb bob hanging over the end of an open and flowing irrigation pipe, measuring the amount of water flowing past the plumb bob. Correctly executed, this method is usually fairly accurate, within five percent. It can also be adjusted to measure flow on partially flowing pipes. There are a number of mathematical calculations that can be used to determine flow rate on an open, vertical pipe. Flow rate can also be calculated based on how long a pipe takes to fill a specific area of ground with one inch of water.
Regardless of how it is done, measuring irrigation flow is an important step in monitoring water use in irrigation and estimating fuel consumption and costs. Flow meters do make measuring water flow rates of irrigation systems much easier; however, there are simpler, manual ways to estimate water and fuel use. For most of today’s farm irrigation systems, it seems that propeller flow meters are the most affordable and easily used option. To learn more about flow meters and measuring irrigation flow, contact an experienced dealer of ag irrigation systems!