Artificial wetlands raise hopes for Platte waterfowl

WIGGINS — After years of declines in the number of ducks visiting Colorado, wildlife advocates are hoping to woo the waterfowl back with artificial wetlands designed to give the birds places to nest and rest.

“We’d like to get it back to what it was,” said Greg Kernohan, manager of the projects for Ducks Unlimited, a national hunting and conservation group.

Otherwise, he said, “we’ll lose our wildlife heritage.”

The loss of duck habitat in the South Platte River basin, which is at least partly the result of man-made alteration of the river to make it flow like a channel, is likely a major reason for a decline in duck populations by as much as 50 percent in some parts of eastern Colorado.

The newly created duck habitat is designed to mimic natural conditions. Colorado has gained 16,000 acres of artificial wetlands at about 100 areas along the South Platte, with plans for another 11,000 acres by 2014, funded in part by $1.5 million from the Colorado Water Conservation Board.

Hundreds of duck hunters held banquets and auctions statewide, and ponied up $150,000 for the effort.

Water is pumped and piped from the South Platte to ponds carved out of adjacent prairie. This water then is routed through sloughs and filtered back into the river’s main stem.

Diversion of water into wetlands is done during low-demand periods and builds water credits for participating landowners, giving some the ability to draw water for farming.

A gradual decline has reduced Colorado’s duck populations from about 500,000 in 1980, which included at least 250,000 along the South Platte.

The long-term future for waterfowl looks bleak, said Dave Sharp, a U.S. Fish and Wildlife Service biologist.

“Our needs for water are only going to grow,” Sharp said.

Dams and diversions for cities and farming “take away those natural pulses, like in the spring. The flooding that used to occur no longer occurs,” he said. Woody vegetation also is taking over sand bars essential for ducks.

Colorado Division of Wildlife tables show duck populations across the central flyway bird migration route in parts of Colorado decreasing from an average of 104,207 between 2003 and 2008 to 85,695 last year.

But in northeastern Colorado, where the South Platte meanders for about 300 miles to Nebraska, a duck population that decreased to 36,689 from a 2003-08 average of 79,114 may be swinging back up.

State wildlife officials counted 129,447 ducks in January, according to Jim Gammonley, avian research leader for the wildlife division. Duck numbers fluctuate widely year-to-year, depending largely on climate conditions here and elsewhere, Gammonley said.

Overall, “the hydrology and habitat conditions associated with the South Platte River have changed dramatically and negatively, from a duck’s perspective,” he said. “There’s likely less waste corn and other grains left in agricultural fields, and corn is being picked later every year, so there may be less food available to attract and hold wintering mallards. “

State biologists have been studying the effects of duck hunting, but “no new hunting regulations have been proposed, based on midwinter counts,” Gammonley said.

Meanwhile, Ducks Unlimited crews are delighted at evidence that their artificial wetlands may be making Colorado more attractive to waterfowl. Kernohan recently checked out new work around Wiggins, including ponds by Jackson Lake and a 62-acre series of ponds and sloughs leading into the river.

A wood duck called. Pintails pulled up over a berm. Five gadwalls whooshed overhead.

“It gives you so much satisfaction, when you see that,” Kernohan said. “We will see a lot more.”

Bruce Finley: 303-954-1700 or bfinley@denverpost.com