The Frenchman‑Cambridge Irrigation District’s Radio Communications Towers

The Frenchman-Cambridge Irrigation District’s Radio Communications Towers

The FCID raises a repeater tower near Oxford, Nebraska.

Frenchman-Cambridge Irrigation District (FCID), headquartered in Cambridge, Nebraska, diverts around 60,000 acre-feet of irrigation water a year to a service area of 45,669 irrigated acres. To make its delivery system more efficient and to save water, it is implementing a Rubicon Water automated gate system, with the end goal of achieving total channel control (TCC) capabilities. To enable its gates to communicate with each other and with the office, the FCID is also building radio communication towers. In this interview, FCID Manager Brad Edgerton tells Irrigation Leader about the capabilities the gate system gives the district and details the factors that went into selecting and installing its towers.

Irrigation Leader: Please tell us about your background and how you came to be in your current position.

Brad Edgerton: I started out in the water business in 1983, working for the Nebraska Department of Natural Resources. In 2009, I was named general manager of the FCID.

Irrigation Leader: Please tell us about the FCID.

Brad Edgerton: The FCID is a federal project built in the late 1940s and early 1950s by the Bureau of Reclamation. We serve 45,669 acres under four canal systems. We have a contract with Reclamation to take storage water out of three reservoirs. We have nine ditch riders and an office manager in addition to myself.

Irrigation Leader: Would you tell us more about the size and scale of your canal system?

Brad Edgerton: We have two bigger canals: Cambridge Canal, which serves 18,000 acres, and Meeker-Driftwood Canal, which serves a little less than 18,000 acres. We have two smaller canals: Red Willow Canal, which serves about 4,700 acres, and Bartley Canal, which serves about 6,500 acres. Cambridge, Bartley, and Red Willow divert directly off the Republican River, while Meeker-Driftwood Canal comes directly out of Swanson Reservoir.

Irrigation Leader: Please tell us about your Rubicon gate system. When did you install it and why?

Brad Edgerton: We learned about Rubicon at the Four States Irrigation Council conference in Fort Collins, Colorado, in 2012, where its product was on display. We had two check structures on Cambridge Canal with which it was difficult to adjust the flow each day, and there was also a safety issue with regard to the depth of the logs and the strength needed to remove logs. We bought two gates and installed them just to test them out, and we really liked them. Then we aggressively pursued grant money, mostly through Reclamation’s WaterSMART program and Nebraska’s water sustainably grants, to install more Rubicon gates and to automate our system. We knew up front that the ultimate goal was to automate the entire canal so that we could operate with what is called TCC, which involves the gates communicating with each other and making adjustments continuously without human intervention. This would help us eliminate the spill at the bottom of the canals. Today, the Cambridge Canal operates with TCC, and we have eliminated more than 95 percent of the spill at the bottom of that canal. The spill we do have is mostly due to rain events that put extra water in the canal. We are making these investments because the Republican River basin is overdeveloped and our water supply is half of what it once was. We currently allocate 8 inches per acre, so every drop of water we save has value to our farmers.

The completed repeater tower.

Irrigation Leader: Do the automated gates also save the ditch riders time and labor?

Brad Edgerton: Our number 1 goal was saving water, but the gates do save them time and labor. Typically, when we had big changes over the course of a day, the ditch riders had to spend about 3 hours each morning logging water through the system. The Rubicon system saves them that time. Our intention was not to replace the ditch riders—we’re shorthanded as it is—but it has shifted the ditch riders’ workload during the irrigation season. The gate system has other benefits that we only recognized after installing it. Prior to 2020, we only allowed users to order water 5 days a week, since our ditch riders didn’t work weekends. Now that we are automating our canals, they can make changes to their water orders 7 days a week. Further, that means that water use is more evenly distributed across the days of the week, rather than peaking on Monday and Friday. That makes our deliveries more efficient and allows irrigators to be more efficient and to have more scheduling options.

Irrigation Leader: Please tell us about the communication towers you have installed for your Rubicon system.

Brad Edgerton: The Rubicon gates all communicate with our office and with our SCADA system. They also communicate with each other via a radio network. Each gate has a radio that operates at a 450‐megahertz bandwidth. To enable that, we have installed several repeater towers. We purchased a used tower near Arapahoe that is the backbone of our radio network. When we installed the gates just east of Oxford, we needed another repeater in that area to relay the data back to our office. Our research showed that we needed a tower of about 100 feet, and we found a 100‐foot freestanding aluminum tower that is able to tilt over to enable repairs and adjustment, which eliminates the need for us to hire someone to climb the tower and do the work. We have a mechanism that allows us to raise and lower it in a safe way. It’s worked really well. We have also been awarded another grant to automate our system near McCook, so we will be installing two more 100‐foot aluminum towers in that area. We are getting that project underway.

Irrigation Leader: Did you always know that you would need towers like this for your gate system, or did you realize that you needed them based on the performance of the gate system?

Brad Edgerton: We knew we would need something on the bottom end of Cambridge Canal because our tower near Arapahoe, even though it is 180 feet tall, only has a range of about 25–30 miles. However, we didn’t know exactly what we would need to do. We looked around to see if we could rent space on existing towers, but there wasn’t room. We talked to people who owned grain elevators to see if we could put antennas on top of the elevators, but it seemed that most people either had something on the elevators already or weren’t interested in renting space. We did find a pretty-goodsized tower, but the owner wanted a lot of money to rent space on it. The best solution was just to do our own thing.

The jig used to hold the tower while concrete was run.

Irrigation Leader: Did you erect the tower on land that you already owned?

Brad Edgerton: Yes. There was a fenced-off section along the canal in the Oxford area that we thought would work well. Rubicon staff can help forecast the coverage that various setups will provide, and the elevation-profile feature on Google Earth can also help you analyze different locations. I picked out this location and had Rubicon run it through its computer program to see what kind of coverage it would provide. I did the same sort of thing with the McCook location: I first looked at it on Google Earth and then looked into more specific information about coverage and how tall the tower needed to be. We found a small surplus shipping container, 4.5 feet by 8 feet in size, that we used to house the radio equipment. We then had to put electrical service into this container to operate the radio equipment.

Irrigation Leader: You talked about how the tower can bend down for maintenance. What kind of regular maintenance do the towers require?

Brad Edgerton: I’m hoping that little maintenance is required, but we may have to change an antenna, and there’s always the possibility of a lightning strike.

Irrigation Leader: What are the next steps for your canals and gate system?

Brad Edgerton: We are currently installing automation on the Meeker-Driftwood Canal, which comes right out of the reservoir. We installed Rubicon gates on the first 14 miles before the 2020 irrigation season. After the 2020 season, we began installing the remaining two-thirds of the gates. Those should be ready by the beginning of the 2021 irrigation season. Then we can start getting the gates talking to each other and implementing TCC.

Irrigation Leader: What results are you seeing from your gate system?

Brad Edgerton: The 2020 season was a big test for the Cambridge Canal. Once TCC was fully implemented, our spill stopped and the gates worked very well. We are finetuning things as we go, and we’re looking into using water ordering software from Rubicon. That would allow our producers to order water and check their water balances online. That’s the next phase of the Cambridge Canal automation project.

Brad Edgerton is the manager of the Frenchman-Cambridge Irrigation District. He can be contacted at bradley.edgerton@gmail.com or (308) 697‐4535.