Flood Irrigation Forever: Farmers provide crucial habitat for migratory waterfowl, recharge aquifer

But Gilchrist’s goal goes beyond irrigation efficiency.

“I’m interested in preserving the habitat for the birds and the various wildlife,” he said.

He has two plots, each about 150 acres. One is bordered on two sides by the Market Lake Wildlife Management Area, more than 6,000 acres of stopover habitat for waterfowl and nesting habitat for some bird species.

His flood-irrigated fields are an integral part of the birds’ survival, providing food and shelter. But habitat for bird species on flood-irrigated agricultural lands across the West is disappearing as more farms are converted to efficient sprinkler irrigation.

About 62% of the wetlands in the Intermountain West are flood-irrigated pastures and hay meadows in floodplains. Those wetlands are concentrated on 7% of irrigated agricultural land, according to Intermountain West Joint Venture.

Privately owned habitat

For example, roughly 80% of the habitat used by sandhill cranes, white-faced Ibis, cinnamon teal and northern pintails is on privately owned, flood-irrigated wet meadows, according to the venture, which coordinates habitat conservation through public-private partnerships.

Maintaining flood irrigation in Gilchrist’s area is a focus of the USDA Natural Resources Conservation Service in Bonneville and Jefferson counties and the Idaho Department of Fish and Game in the Upper Snake Region.

At Fish and Game’s suggestion, Gilchrist applied for NRCS funding and technical assistance to improve his flood-irrigation system to support wildlife habitat. NRCS helped him rebuild an irrigation ditch and install about 25 new headgates.

“The ones I had were old and leaky and not very efficient,” he said.

The project will allow him to better control his flood irrigation water, he said.

He started on the project last year, rebuilding the ditch and installing some of the gates.

“It was quite a bit. I was able to refurbish about a half a mile of ditch,” he said.

NRCS is concerned about waterfowl habitat because so many farmers are going to sprinkler irrigation, Gilchrist said. In his case, the agency provided enough funding to make his project worthwhile, he said.

“The bird usage was a large part of it,” he said.

Helping hand

Flood-irrigation enhancement to support migratory birds was part of a statewide NRCS program that primarily focused on aquifer recharge. The agency used funding from its Environmental Quality Incentives Program, said Josh Miller, NRCS district conservationist for the Idaho Falls and Rigby field offices.

The initiative was part of a series of special projects targeting landscape-level, natural-resource concerns. Once those projects used up their funds, they were phased out, according to the NRCS state office.

Since 2019, his local NRCS team has prioritized flood irrigation over sprinkler irrigation and began diverting a lot of applications to the agency’s Regional Conservation Partnership Program because that’s where they make the most sense, he said.

“It’s just a way for me to maximize bringing in federal money to these two counties,” Miller said.

Funding for flood-irrigation projects was requested at the national level by Idaho Water Resource Board and Idaho Fish and Game. When that funding is gone, the local NRCS team will return to EQIP funding for the program.

Most costs covered

RCPP covers 90% of the costs of a flood-irrigation project. It doesn’t cover land leveling, but it can pay for everything else, Miller said.

The biggest issue for most producers who use flood irrigation is replacing worn-out headgates or replacing siphon tubes with concrete headgates. The funding is also used to rebuild ditches or install pipes so producers are not losing as much water in ditches, he said.

“They need more reliable infrastructure. A lot of the headgates are 40 to 50 years old,” he said.

Since 2016, the NRCS team has entered into 40 contracts through EQIP and RCPP for flood-irrigation projects in Bonneville and Jefferson counties. Those contracts involve 2,273 acres and paid $1.37 million.

A lot of the producers would prefer to have sprinkler irrigation, but there’s often no nearby power source to run a sprinkler system’s pumps. In addition, some fields are oddly shaped and a center pivot wouldn’t fit, he said.

Birds of a feather

The state Department of Fish and Game has worked with NRCS in developing the flood-irrigation program, said Brett Gullett, Fish and Game regional habitat biologist for the Market Lake Wildlife Management Area.

“The benefits of flood irrigation provide foraging habitats for waterfowl and species of greatest conservation need, as well as adding water to the aquifer,” he said.

Those acres are surrogate dwellings providing shallow-water habitat. The majority of the birds in the field are looking for aquatic invertebrates, such as fly, wasp and beetle larvae. Every time it floods, new larvae hatch as the water recedes, he said.

“We want to see more acres staying in flood irrigation instead of switching to sprinkler irrigation,” he said.

The focus is on Bonneville and Jefferson counties to support bird colonies in the Mud Lake and Market Lake wildlife management areas.

That is the area of most concern, with 25% of the western white-faced Ibises using flood irrigation fields for foraging. The Ibis is a “species of greatest conservation need.” Fish and Game deems the species as one it needs to pay particular attention to so it won’t slip onto the federal endangered species list, he said.

“If they range mostly in Idaho, what happens in the state affects the whole population. We want to keep these species under state management. We don’t want them to go under federal management,” he said.

The area is also home to Franklin’s gulls, another species of greatest conservation need, as well as northern pintail duck and the long-billed curlew, he said.

“The whole area is predominantly flood irrigated, and sprinkler irrigation is increasing. In the past three years, there has been a near 5% conversion rate from flood irrigation to sprinkler and development,” he said.

He and Josh Rydalch, another Fish and Game habitat biologist, have been talking up NRCS funding for people who want to upgrade their flood-irrigation systems instead of switching to sprinkler irrigation, he said.

“We would like to see more people sign up, and Fish and Game would probably help out and try to find more incentives,” he said.

The agency could couple funds from another program, the Habitat Improvement Program, with NRCS funding, he said.

Since 2017, Fish and Game has spent roughly $131,000 in HIP funding on flood-irrigation projects statewide. The emphasis is on the Mud Lake and Market Lake area, with a lesser focus on the Emmett Valley, according to the agency’s state office.

Farmers are more concerned about crop yields and prices, and these waterfowl are not their top priority, but Fish and Game wants to pique their interest in keeping flood irrigation, he said.

“It’s making people aware of it and changing the mindset that sprinklers are the only way to go. It’s more than growing crops, it’s also providing habitat,” he said.

Ditches and dikes

Leon Clark, who grows seed peas, wheat and alfalfa on his farm north of Rigby, also had help from NRCS and Fish and Game to make improvements to his flood-irrigation system.

He needed to replace his concrete ditch that feeds 80 acres. It was installed in 1958 and worked well for about 60 years, but frost heaves finally took their toll.

“It broke to pieces, I was wasting so much water, losing so much water,” he said.

He hired a contractor to do the demolition and build a new ditch, and he installed 80 new headgates. NRCS and Fish and Game provided funding, and NRCS provided the engineering, design and inspection of the project.

“It wouldn’t have happened without NRCS and Fish and Game. I probably would have been forced to go to pivot,” Clark said.

Pivots are efficient, but they’re also expensive and come with maintenance and a power bill. They also don’t provide wildlife habitat, he said.

Ground under a pivot is scraped flat. Flood ground has ditch banks that are thick with tall grass that’s really friendly to wildlife, providing protection from weather and predators. And water in the canals is good for ducks, he said.

It also gives birds something to feed on. He has fields flooded with gulls, and there were dozens of trumpeter swans last fall.

Irrigation differs depending on the crop, but he starts putting water on the fields in May and turns it off in September.

Flood vs. pivot

The difference between flood and pivot irrigation is the management. Flood irrigation offers year-round protection for birds with its ditches and dikes and where alfalfa is planted, Clark said.

“We used to have lots of wildlife here. We don’t anymore because land has gone to pivots,” he said. “There used to be ditches everywhere.”

Pheasants used to be prolific in the area, but he only sees one occasionally now. The same is true for cottontail rabbits. Quail and partridge chickens seem to have adapted a little better, he said.

“With flood ground you have dikes, ridges for nesting and forage for protection ... the ditch itself is good cover,” he said.

There’s still quite a bit of flood-irrigated land, but it’s gone from 100% of farms in the area to 50%. And he sees new pivots going in every year, Clark said.

“It’s the upland game birds that suffer the most,” he said.

As part of his agreement with NRCS, he observes wildlife while he’s irrigating using a framework developed by Fish and Game. He reports the time of sightings and number of birds at the end of the irrigation season, and he’s seen more sandhill cranes since he improved his flood-irrigation system.

“I’m very positive on it. I think there’s a place for flood-irrigated ground. In addition to wildlife, it doesn’t use any electricity,” he said.

It takes a lot of water, but it also puts a lot of water back in the aquifer, he said.

Good for aquifer

Gilchrist said he’s noticed over the years that bird numbers in the area seem to be declining.

He is also monitoring birds, identifying species and counting them, as part of his agreement with NRCS.

He hasn’t considered converting to sprinklers. He has ditches and water rights, and sprinklers are expensive.

“I’ve always liked flood irrigation. I think it’s beneficial to the aquifer and beneficial to wildlife,” he said.

“I’m content to flood irrigate and let the birds have a place to hang out,” he said.

The program helped him and hopefully it helped the agencies and the birds, he said.

“I think it’s a beneficial program all the way around,” he said.