BASALT – The big rocks that form the Robinson Ditch diversion structure in the Roaring Fork River near Basalt were moved around April 15 by the ditch company to create a welcome gap — middle river left — that appears big enough for recreational boaters to float through with relative ease.

The result is what appears to be the cleanest, and most obvious, low-water path through the diversion structure in years, although expected high water this spring could still move some of the rocks and create unforeseen challenges.

The work done April 15 was in response to concerns raised after the ditch company had used an excavator to go in the river March 25 to repair damage to the structure from an ice flow this winter. In repairing the structure, boat passage was not considered, and the resultant, nearly solid line of rocks presented a daunting prospect for boaters.

Now, the rocks have been rearranged again, and instead of a dicey sneak on river right — as there was before the repair — there is a wide passage toward river left.

The new passage is river right of a large debris pile of logs and sticks that juts out from the left bank of the river. And the passage is river left of a line of big boulders that still stretch to the right bank. The passage also is now more or less in line with the main flow of the current in the river at that spot, which is helpful.

“We tried to do the right thing,” said Bill Reynolds, the director of the Robinson Ditch Co. and the Mid Valley Metropolitan District. “We’re trying to make sure we have access for all the users. The Robinson Ditch is trying to be a good community member.”

Work done in the river with heavy machinery to repair existing irrigation diversion structures is usually exempt, under national regulations, from having to obtain a permit to work in the river.

The rocks across the Roaring Fork River in Basalt as part of the Robinson Ditch diversion structure, on April 6, 2019. This was the result after repairs to the diversion structure in late March, but before an adjustment on April 15. Credit: Brent Gardner-Smith/Aspen Journalism

Tricky obstacle

The Robinson Ditch diversion structure, called Anderson Falls by raft guides at Blazing Adventures, is downstream of the tall Colorado 82 bridge that spans the river between Old Town Basalt and Willits. And it’s upstream of the Hooks Lane bridge and the boat ramp near the FedEx facility on Willits Lane.

The boulders placed in the river are to help raise the level of the riverbed, in order to send water down a side channel on river right toward the Robinson Ditch headgate.

That channel, sometimes used in the past by boaters as a way around the diversion structure, is no longer navigable at low flows — and probably even high flows — because the rocks at the end are bigger and taller than they used to be.

The line of rocks across the river at Anderson Falls have long presented a tricky obstacle for rafters, anglers in drift boats, or dories, and even those paddling inflatable kayaks, or duckies, and especially at low water.

Vince Nichols, the owner of Blazing Adventures, which runs both raft and duckie trips down the stretch, has seen the new gap in the rocks, and he’s pleased with how things have worked out.

“It looks a heck of a lot better,” he said.

Nichols said he contacted Reynolds at the ditch company after seeing photos in the newspaper of the rocks in the river after the March 25 repair job and told him that the new rock configuration had created a real hazard for boaters.

“He was pretty receptive and a nice guy,” Nichols said of Reynolds. “He was willing to help us out and work with us. Then he called me up last week and said, ‘Check it out, I moved some rocks around.’”

At first, Nichols was just expecting the right-side sneak to be re-established, but now the obvious gap is toward the left side of the river.

“It looks great,” said Nichols, adding he was “cautiously optimistic” that high water won’t create havoc with the rocks still in the river.

Reynolds also was looking to see what high water brings.

“We have to see how the river is going to react, and we have to make sure we can get water into the ditch, so it’s one step at a time,” Reynolds said. “There might be a time when we have to go back into the river, and put a few rocks back in place. We’ll see.”

Even if the fix holds through high water, it may still be temporary, because Pitkin County is working on an $800,000 project to make a definitive fix to the Robinson Ditch diversion-structure situation.

The county is intent on securing a variety of state and local grants to pay for the project, but it still has about $370,000 left to go and the work may not occur until 2020.

Once the money is in hand, the county plans to build a smaller diversion structure upstream of the current structure and then build a second small structure where the big rocks are today. And both of the new lower structures will be built with boat passage in mind.

Aspen Journalism covers rivers and water with The Aspen Times and other Swift Communications newspapers. The Times published this story on Wednesday, April 24, 2019.

Brent Gardner-Smith, the founder of Aspen Journalism, and who served as AJ’s executive director until August 2021 and as editor from 2011-2020, is the news director at Aspen Public Radio. He's also been...