Environmental Innovation Restores Wildhorse Creek

Blog originally posted on http://blog.transcanada.com.

Wildhorse Creek is a small waterway that meanders its way across southern Oklahoma. It is neither wild nor particularly scenic, but it has played a role in Oklahoma history (Confederate soldiers captured wild horses along its banks during the American Civil War), and it has been confronted by human intrusion – mainly agricultural runoff – for more than a century.

Wildhorse Creek bisects the area of land that is home to TransCanada’s Cushing Tank Terminal, a key part of the overall Keystone Pipeline System. The Terminal currently comprises seven tanks capable of storing 2.25 million barrels of crude oil.

While efforts were made to minimize impacts on Wildhorse Creek caused by the tank terminal and its construction, erosion issues from decades of previous runoff were noticed early on in the construction process. Some parts of the creek were filling in due to a heavy sediment load from upstream of the tank terminal, and other parts were widening as erosion took bites out of the creek’s banks. “It was our responsibility to fix it,” says Larry Bonazzo, TransCanada project manager.

“There were a number of ways we could have gone. We could have just thrown concrete at it,” Bonazzo recalls. “We could have said, ‘Here’s a set of plans, boys. Have at it.’” That’s not the approach Bonazzo was comfortable with; nor did he think it reflected TransCanada’s values.

Instead of approaching Wildhorse Creek restoration as fundamentally an engineering challenge, he and the team he assembled saw it as an opportunity to try something new and different in terms of environmental stewardship.

“We wanted to do it the right way. We wanted to have the right people at the table every step of the way,” Bonazzo says. “In terms of the design, we wanted an expert who could deliver the ‘natural’ solution we were looking for, but we also needed people on the team who could ensure that the design we preferred could be constructed.”

Bonazzo’s team included several outside contracting services and he also brought in Jackson Lamb, an environmental specialist who is part of TransCanada’s U.S. Environmental Planning and Permitting group in Houston.

“We call him the creek doctor,” Bonazzo says.

“Fluvial geomorphology is the science devoted to understanding rivers, both in their natural setting as well as, in the case of Wildhorse Creek, how they respond to human-induced changes in the watershed,” Lamb says.

A necessary part of the design was to provide a way to strengthen the banks against the effects of flowing water.

“We wanted to use all natural rock,” Bonazzo says, “and we knew where to find it.”

During clearing of the Cushing Tank Terminal site, the natural boulders – most of them the size of a half-ton truck box – were buried offsite. This meant the restoration team had a ready supply of large, natural rock indigenous to the site, and they knew where to get it. In areas where the banks had badly eroded, the natural rock was carefully stacked to stabilize the banks. Then soil was sloped back to form a natural contour that was bolstered by the rock underneath.

After the rock had been installed and the top soil was replaced, side slopes were hydro-mulched with Flexterra (a proprietary erosion control medium that can be sprayed in placed) to prevent erosion and facilitate the growth of natural vegetation.

The result of all this time, planning and effort: A natural waterway that will work in concert with nature over time to ensure a healthy, self-sustaining creek.

“I have to tell you: It was really fun,” Bonazzo says. “And it’s something I’m really proud of. I wish we could have park benches out there so people could see what we’ve been able to accomplish.”

At TransCanada, environmental innovation is has played a key role in reducing and remediating environmental impacts and it’s something for which we’ve been recognized internationally. These innovations include applying directional drilling versus open cut for larger river crossings, pioneering the use of innovative winter construction techniques to reduce impacts through all agricultural lands, prairie and cultivated ecosystems, investing in the preservation and enhancement of endangered species habitats and adopting and developing new technology to reduce greenhouse gas emissions from our operations.

Learn more about environmental innovation and research and development in our corporate social responsibility report.