Flood Irrigation Forever: Farmers provide
crucial habitat for migratory waterfowl, recharge aquifer
ROBERTS, Idaho — Richard Gilchrist
raises a small herd of Angus cross cattle about 20 miles
northwest of Idaho Falls.
He also flood irrigates his pasture
and the alfalfa and grass he grows for hay, a practice that
is falling out of favor among irrigators who seek efficiency
in their operations.
But Gilchrist’s goal goes beyond
“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
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.
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
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
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.
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
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
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
Birds of a
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
“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
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
“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,”
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
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
“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,
“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
“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.
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
“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.
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