Early on, troubles with water-logged soils and the like led the Harrimans (http://www.deltafarmpress.com/corn/double-h-farms-family-friends-and-improving-operation) to say their southern Arkansas operation suffered “the curse of the creek.” However, after reevaluating what the creek bisecting their farm could mean for surface water irrigation projects, the father/son team found their old nemesis to be much friendlier.
“This was a challenging year in that we had so much rain during the summer,” says Steven, who farms with son Kyle outside Hamburg. “The tropical depressions set in some and we lost a few beans and had some that were damaged, including Xtend beans we planted. We planted about 200 acres of dicamba beans just to see what they’d do around here.”
Even with the excess moisture, though, “the beans did well and so did our corn. We’d have had a phenomenal soybean crop if we’d have avoided the rains at the end. That knocked them down to just the ‘good’ category.”
With all the rain “we didn’t have to irrigate as much as normal but we still turned water on some,” says Kyle. “Our corn was irrigated once, sometimes twice. With soybeans, it depended on location – some were watered four times but most were watered two or three times.”
The second phase
“We’re blessed around here with a lot of groundwater and farmers here pay close attention to what’s happening with the (alluvial) aquifer,” says Steven. “We want to protect it and, at the same time, cut back on expenses.”
The first phase of the Harriman/NRCS water project – funded through the EQIP program -- was also a tail-water recovery ditch on the north side of Highway 82. The new ditch is to the south.
“We have used the first (tail-water) ditch and it’s done extremely well for us,” says Steven. “Per gallon of water, it’s about 30 percent the cost to irrigate. Going with surface water instead of pumping water from 100-something feet deep – all our wells are electric, by the way -- makes that big a difference. I can pump the first pit at 2,000 or 2,200 gallons per minute and struggle to move the level.”
The pair thought there might be some hiccups but worries were soon eased. In fact, “the transition was so nice and easy we wanted the second ditch to be set up the same,” says Steven.
A few hundred yards from the Harriman shop, a work crew is finishing up the second phase of the project.
“They’re putting the meter and last risers in, right now,” says Steven. “They’re running all the underground for it and should be done within an hour. The digging started in early September.”
The second pit “makes use of the same creek as the first one. All the overflow out of the original reservoir – and it’s a lot, I can’t pump it down – will feed the new pit.”
As a general rule, “you can take a 40-acre reservoir, 10-feet deep, and water about 400 acres,” says the NRCS’ Mark Robinson. “That’s without any recharge.
“Here, there’s about 1,740 acres coming down this ditch. There’s another 200 to 400 acres on the other side. You’re looking at 2,000-plus acres of worth of water coming to this pit. The design calls for it to be able to pump for 17 hours without any recharge. If possible, we’d like to get 24 hours.”
With the first tailwater ditch, “we dropped in and put it below the drainage and rocked on,” says Robinson. “The second location was a little harder to design and place than the first.” Grant Barnes, also with the NRCS, “was the brainchild for this one. It really takes a team to get these projects done.
“We do the fieldwork, come out and take a look, then bounce ideas around. We came up with about four different ways to set this pit up. Every pit is different and many of them present challenges.
“There was a six-foot fall from where we wanted to tie it into the road. That big a fall would give us a lot of freeboard. We’d hold a lot of water on the front end but it was going to be very ugly.
“Grant said ‘let’s shorten it up.’ So, we did.”
Barnes, with the NRCS out of McGehee, Ark., says the main thing was tying into the aforementioned big creek. “Without that, it wouldn’t have worked. We also had to have more drainage to keep them in the water.”
“We put a 10-to-one slope on the backside so we could catch water easier,” says Robinson. “It averages around 10-feet deep, although it gets more than that because the ground level jumps.”
The potential for the formerly problematic feeder creek to still harm row-crop acres couldn’t be neglected. That’s why a levee has been built between the creek and new tail-water ditch. Dirt to build it came from the freshly-dug pit.
With these projects, say the NRCS employees, one of the first steps is to drive out and see what the farmer wants to do and what the landscape will actually allow.
“Sometimes what they want to do in a particular spot won’t work,” says Barnes. “Other times, they might want to put a tail-water ditch in where an aboveground reservoir would work better. It’s sometimes hard to convince them otherwise – not too many are willing to give up 40 acres of their field.”
You also want a clay base, says Robinson. “Put one in sand and the water can’t be held well. A lot of times the soil type determines how deep we can dig a pit. Around here, go deeper than 10 foot and your chances of running into sand are greater.”
The new pit had no such problem. “It was put into red clay so it’ll hold water well,” says Kyle. “It’s really interesting the differences in soil types just over short distances.”
The ultimate scenario, says Barnes, is to have an aboveground reservoir and tail-water pit working together. “The ditch water is pumped into the reservoir and then water is pumped onto fields.”
However, on farms with topography like the Harriman’s “they don’t need an aboveground reservoir,” says Barnes. “Most farms don’t get nearly the runoff as this one and tail-water recovery is the way to go.”
Once it looks like a project will be funded, “we’ll return and (survey) the land,” says Robinson. “With this particular project, that step told us ‘Hey, we can’t make this pit as long as we thought.’ We knew the water was available but we had to squeeze the pit in. Most of the pits we work with are pretty long – 1,500 feet, maybe 2,000 feet, long.”
On the current project, “we found because the supply of water is ample, we didn’t need as long a pit. The supply is the difference. The second pit holds 18,000 gallons and the first one holds 36,000.”
So far, so good for the new ditch. When it was tied into the creek, “it back-fed and put about a foot of water into the new ditch,” says Steven. More would have flowed in but we hadn’t had any rains in weeks.”
Sufficiently excited, the Harrimans are now hoping to put a third water-holding project. “Hopefully, we’ll hear something soon,” says Kyle.