Wireless flow system promotes conservation

“Intelligent Design Enables Conservation” (pdf) by Gerald W. Knudsen, General Manager of AgriTech Consulting, describes an application where open ditch irrigation was replaced by a closed pipe system and precise flow control via wireless communications.

Open ditch irrigation canals were replaced with a closed poly pipe water distribution system. The piping system saves water by reducing evaporation, cutting seepage and eliminating end of channel water losses.

The transit time flow meters use two transducers mounted on the outside of the pipe, both of which function as an ultrasonic transmitter and receiver.

The system was employed by the Montezuma Valley Irrigation Company (MVIC) in Cortez, Colorado, U.S., to save water in the arid region. As much as 60% of the water that enters an open ditch irrigation canal is wasted via evaporation, seepage and losses at the end of the canal. By replacing five miles of open irrigation ditches with closed polyethylene pipe and flow control, MVIC is saving 1,000 acre-feet of water per year.

Each branch turnout from the main header to a farm has a Dynasonics ultrasonic flow meter and two butterfly valves. The meter measures the amount of water passing through the turnout. The first butterfly valve is controlled by the MVIC and is used to set flows according to the number of shares of water allocated to that particular farmer. The second butterfly valve can be used by an owner to shut off or reduce water volume.

Flow control and measurement is implemented via a wireless supervisory control and data acquisition (SCADA) system. The SCADA system consists of a telemetry receiver and master control center in the main office connected to field equipment via a wireless data link.

Each flow meter is either solar or battery powered, providing substantial savings by eliminating power wiring. This green feature not only saved on installation, but will also provide ongoing savings in the form of lower energy use. The key component of each branch turnout is the flow meter.

The closed pipe network project has been so successful that the US Bureau of Reclamation is providing $2.1 million in stimulus grants to the MVIC for construction of a second similar 7-mile pipeline project.

Here is the the story (pdf)