North Platte River Rehabilitation: From Trash to Treasure
A hundred years ago, a survey of the rivers in the United States found the North Platte in Casper was the worst with refineries, slaughterhouses and other sources of degradation, and that it was most unlikely to be restored, the director of the Natrona County Weed and Pest District said Thursday.
Over the decades, the slaughterhouses, refineries and other pollution sources closed.
But the river remained damaged even though it looks cleaner, Connely, engineers, wildlife advocates and others said at the top of the bank on the north side of the river.
Connely responded to critics that the current rehabilitation between the Poplar and First street bridges is unnecessary if not wasteful spending.
"To leave it like it was in 1917? No way," he said. "It was never left alone."
Jolene Martinez, assistant to the city manager, said the river rehabilitation began in 2006 with the first community river cleanup occurring in September 2007; a coalescing of 27 community, business and government partners; a master plan; and the first three projects completed at Morad Park, Wyoming Boulevard and the water treatment plant phases.
Connely, Martinez and others noted improvements at Morad Park and downstream including the return of native willows and cottonwood trees, the return of native birds, and the creation of nine acres of wetlands that filter the runoff from the streets and businesses near Wyoming Boulevard and CY Avenue before that water enters the river.
Those projects and their benefits were tough, but not like the current $2.6 million half-mile phase between the Poplar Street Bridge and BNSF Railway bridge.
The work has uncovered far more contamination than expected, which will add a year before completion and cost at least $1 million more than budgeted, Martinez said. The city is in talks with BP, which bought the former refinery from Amoco, about reimbursing the city for the cleanup.
Project engineer TC Dinkins, a hydraulic modeler for Stantec, said the project organizers had to do a lot of negotiating with the Wyoming Department of Environmental Quality because of the contamination left from the refineries.
For example, the earthwork uncovered brick and lumber from long-gone coking and other facilities. The destruction of the banks -- riparian areas -- from this industrial activity left rubble and created a vertical drop from the Platte River Trail along the Jonah Bank parking lot, Dinkins said. The river kept washing out soil and debris and releasing contamination, he added.
To remedy that problem, the construction crews built a road in the middle of the river, dammed the north side to stop the current, build "wood debris toe" structures, cover the new bank, and plant willows to strengthen the bank, Dinkins said. "We will build a living bank that will be self-sustainable."
Other improvements including riffle structures will increase aquatic habitat
Randy Walsh, a restoration scientist with Stantec, said the changes in the river over the past century have created a homogeneous environment, but a restored river will have a variety of qualities to make it heterogeneous.
The wood used in the toe structures will serve as food insects and micro invertebrates that become fish food. That in turn creates a place where fish want to stay.
Martinez said that the project is using a "natural channel design" that works with the river. "We're mimicking nature."
The DEQ, she added, would not grant a permit for the work if fish weren't protected because their presence indicates a health habitat. "Fish are the canary in the coal mine."
Walsh said the public needs to realize that the project isn't done when the earthmoving equipment leaves the river. The willows and vegetation will need several years to take hold, he said.
"We set the stage for the biology to take over," he said. "It's not an overnight success."
Matt Pollock, a habitat biologist with the Wyoming Game and Fish Department, echoed the importance of patience.
"The river didn't get this way overnight," Pollock said. "It won't get fixed overnight."