Glen Canyon National Recreation Area next week commences dredging the boating passage known as Castle Rock Cut, but conservationists question whether the $500,000 project will do more harm than good.
The National Park Service has hired Loa-based Brown Brothers Construction to remove 70,000 cubic yards of material blocking the passage that enables a 10-mile shortcut between Wahweap Marina and points north on Lake Powell, such as Padre Bay and Rainbow Bridge. The goal is to dig down a few feet to an elevation of 3,600 feet above sea level, but if lake levels keep dropping the park service may return to cut out another 20 feet.
Fluctuating reservoir levels have left the cut impassable at times for the past decade, but park service officials believe it would be used by hundreds of boaters if it can be kept open.
"The intent is to allow passage at lower levels. We as a service have to plan for high and low inflow events," NPS project manager Carl Elleard said. "This cut saves a huge amount of time and that translates into reduced fuel costs and reduced environmental impacts, and allows people to access the upper lake without going through the Narrows."
The current lake level is 3,602 feet above sea level, or 98 feet shy of capacity and the cut, about two-thirds of mile in length, is currently dry.
The cut was first dredged in the early 1970s, but has required further excavation and some blasting, most recently in 2009. The current project involves no new blasting and is expected to last through April, but the passage won't re-open until lake levels allow.
And there's the rub. Declining flows in the Colorado River could leave the channel impassable again soon with little leeway for further dredging which damages the landscape, according to the project's critics at the Glen Canyon Institute.
"They are spending lots of money and time on this cut that hasn't been [regularly] usable in years," said Mike Sargetakis, project manager with the conservation group. "According to the Bureau of Reclamation, the reservoir levels will continue to drop."
Climate change and over-allocation of the Colorado's water will reduce future inflows, he said.