Building a Duck Hole

The thought of an inundated farm field would make any farmer cringe. Water-saturated soils during the planting and growing seasons can decrease yields, especially yields of corn and soybeans which are the major crops here in Illinois. Muddy fields cause delays in harvest, resulting in grain losses. A combine, along with its grain-hauling tractor, might plow through the mud, but ruts will be left in their wake, a bad scenario for the next season’s planting attempts.

However, there was this particular farmer who envisioned an inundated farm field as a “duck hole.” Jim Gillespie, owner and operator of Gillespie Family Farms, saw that a section of his land would be a perfect place for waterfowl to feed and rest during migration, a place where 10 acres could be made to hold shallow, standing water.

Gillespie, being an experienced waterfowl hunter, knew that geese and dabbling duck species will flock to harvested corn fields to glean the grain. He also knew that waterfowl were aptly named. Water plus corn field might add up to a duck’s big slice of pie with ice cream on top. But no matter how attractive the duck hole, how realistic the decoys, how camouflaged his clothing, how imitative his duck calling, there would be no roasted wild duck for supper if the ducks weren’t there.

Gillespie remembers lying upon his back in corn fields watching mallards by the hundreds as they assumed a fascinating circuitous flight pattern, swinging past and turning back, deciding upon the best approach and assessing the safety of landing. However, in recent years, Gillespie’s observations, especially during migration and waterfowl season, have led him to fear that duck populations are decreasing. His training in wildlife management made him aware that habitat loss is a major cause of population declines in many species of wildlife. He envisioned the inundated section of his field providing excellent habitat for waterfowl.

With habitat in mind, Gillespie chose the spot. No homes nearby. Relatively flat, contiguous row-crop land. Restored prairie acreages and buffer strips punctuated the surroundings. In that section, a natural basin or waterway existed, and a maintained shallow field ditch served to prevent pooling by draining excess water during rain events. Its watershed was about 30 acres.

Finally, the moment came when plans could be executed. Harvest had been completed. A drought during late summer and early fall had created the dry conditions that made dirt work feasible. The earthmoving machine, a tractor-pulled scraper, removed soil from along the sides of the field ditch, moved the soil to the edge of the field and dumped it so that mounds ran from one high point to the other; thus, the berm began to take shape.

“Wait a minute,” you may say at this point. “A berm will dam up water. Any farmer knows that taking land out of production, by flooding good farmland, does not make profit.” Please, stay tuned. The following reveals a bit of genius.

A water-control structure would be installed. A water-control structure is a 4-foot-tall high-density plastic box-like construction with a rubber-collared opening into which a drainage pipe is inserted. For Gillespie’s purpose, a 10-foot long 12-inch diameter PVC pipe would be suitable.

First things first, two 3-foot-deep post holes had to be dug into brick-hard ground at the juncture of the original field ditch and the waterway between fields. That was accomplished with an old-fashioned wooden-handled, metal-spaded post hole digger, one for himself and one for his son. Eventually, two 7-foot-tall, 6-inch by 6-inch wooden posts were shoved into those hard-earned holes; and between those posts was set the water-control structure. Sandwiched thus, the structure would be less likely to shift in position.

Another precautionary step involved an anti-seep collar, which consists of a rubbery membrane, stretched on a 4-foot by 4-foot wooden frame. The 12-inch-diameter drainage pipe was fitted through a hole of smaller diameter in the collar’s tough, stretchy membrane. Hopefully, that tight collar would discourage water from finding a path along the pipe and through the berm.

The wall opposite to where the pipe would be inserted into the water-control structure is a framework within which are stacked a number of rectangular plates that serve to create a water-retention wall. When the greatest number of plates are stacked within the framework, the greatest depth of water can be achieved. Manually sliding the plates upward and away would reduce the height of the water-retention wall, allowing water to flow out through the pipe and decrease the depth of water within the basin.

Final steps involved setting the bottom of the anti-seep collar’s frame into a narrow trench, inserting the pipe into the structure’s opening through its thick rubber collar, and using a band to tighten the embrace of the collar around the pipe. A level was utilized to determine if the pipe’s downward slope toward the discharge area was adequate.

Construction ended with a bit more dirt work, dumping soil around the structure and shaping and compacting of the berm. The berm was seeded with wheat and redtop grass.

Gillespie’s plan on that day was to stack all the plates into the structure and to inundate the area. Then come early spring (possibly March) he would remove plates gradually over a couple of weeks until none remained in place and all water had flowed out through the discharge pipe. Consequentially, the soil would be dry enough to plant by May. However, Gillespie decided the berm needed to stabilize, so after that long day of working to make a duck hole, he and his son walked away, carrying the plates and disallowing inundation.

The next year, the crop grew and was harvested. Gillespie slid the plates into the water-control structure and then waited for rain, which came in October and in November along with ducks and geese. Then, during a week in February, five rare trumpeter swans loafed there. A northern harrier hunted the grassy berm for prairie voles. In March north-bound sandhill cranes took a break. Killdeer announced their discovery of the lovely shallow water. Surely, crayfish thought it an earthworm-laden smorgasbord, and a mink, a crawfish boil. Perhaps a peregrine falcon would show up in search of duck dinner.

Gillespie spotted an early arriving Wilson’s snipe probing the moist soil for invertebrates “I’ve built a wetland, not just a duck hole,” Gillespie thought. “A wetland, ephemeral in nature.”

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For years, Patty Gillespie shared her enthusiasm for language and nature and got paid for it at a public school and at a nature center. Now she plays outdoors as often as she can and writes for the sheer joy of it.