CDOT unable to finish Basalt flood prep | AspenTimes.com

CDOT unable to finish Basalt flood prep

BASALT ” The Colorado Department of Transportation cleared about 75 tons of rock, gravel and sand from underneath a bridge in Basalt this spring to make more room for the Roaring Fork River’s anticipated high runoff.

The state agency wanted to do even more work near what’s known as the Upper Basalt Bypass Bridge, but challenging and changing weather conditions didn’t allow it to complete the work it needed to obtain a federal permit in time.

The transportation department cleared material that accumulated on the upper channel beneath the bridge on Highway 82 at the east entrance to Basalt, according to D’Wayne Gaymon, a CDOT senior foreman for maintenance for an area that includes Basalt.

Rock and sand had built up in the river bed and allowed only 5 to 6 feet of clearance from the bottom of the bridge when water was flowing in that channel, Gaymon said. The clearance was boosted to about 9 feet, the same as the center channel under the bridge, he said.

That’s important because it provides more clearance for tree trunks and other debris that otherwise could get snagged on the bridge and cause water to rise.

“I believe it will help,” Gaymon said.

If, or when, water reaches a certain level next month, CDOT will station heavy equipment and operators at the bridge to pluck out tree trunks or keep them moving down river, Gaymon said.

The Upper Basalt Bypass Bridge has been identified as a problem area during flooding by two studies performed for Basalt town government. The bridge was constructed at an odd angle to the river, so the area is susceptible to excessive “bed loading,” one study explained. The extra material makes the river’s behavior more unpredictable during high water.

CDOT wanted to remove an estimated 1,500 cubic yards of material that has accumulated upstream from the bridge in the 20 years since it was built. That’s the equivalent of about 150 dumptruck loads.

That work required a special permit from the U.S. Army Corps of Engineers. To obtain that permit, the state agency’s required preparations included taking an inventory of wetlands and propose a mitigation plan for possible disturbance of them. CDOT officials weren’t able to map the wetlands effectively until recently because of the late snowfall, Gaymon confirmed. That delayed the submittal of the application. The Army Corps of Engineers has a mandatory 45-day review period for applications.

The proposed work site is now under water, so CDOT won’t be able to perform the work even if the Army Corps of Engineers issues the permit. The work performed underneath the bridge was exempt from the Army Corps of Engineer’s permit requirements, according to CDOT officials.

Some audience members let out a collectively groan when it was disclosed at a public meeting in Basalt last week that CDOT didn’t have the permit to do all the work it wanted to do.

Gaymon said CDOT would have liked to remove more material this spring to prepare for high water, but he believes that the work that was undertaken will help ease the flooding potential.

CDOT will continue seeking the special permit to work upstream from the bridge. That type of permit is good for two years. Once in hand, CDOT will undertake the work at an appropriate time to prepare for the next high runoff season, Gaymon said.

scondon@aspentimes.com


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