RCMAP - Roaring Fork River at Basalt, Colorado

Science Center Objects

The U.S. Geological Survey was engaged in a program to monitor and assess the long-term geomorphic behavior of selected river and stream reaches that previously had undergone some physical modification.  These modifications included natural channel adjustments to floods as well as intentional channel reconfigurations to alter the function or appearance of a river reach.

The Roaring Fork River at Basalt, Colorado, is a single-thread, high-gradient, cobble/boulder-bed river that presents a natural hazard to the town, nearby residential structures, several bridges and roadways, and the municipal waste-treatment facility. The Roaring Fork has a frequently mobile streambed composed of gravel, cobbles, and boulders. The hazard originates from high velocity snowmelt runoff and a high bedload-transport rate that cause intermittent channel realignment as well as scour and deposition of coarse-grain bars and islands.

Photo of Roaring Fork River at Basalt, Colorado

Roaring Fork River at Basalt, Colorado on May 17, 2001. Discharge: 1130 ft3/s

Recent urban, highway, and recreational development on the flood plain, earlier attempts to realign and confine the Roaring Fork channel with retaining walls and levees, and flow obstructions such as bridge openings and piers have altered the hydrology, hydraulics, sediment transport, and sediment deposition areas of the Roaring Fork. Entrainment and deposition of coarse sediment on the streambed and in large alluvial bars have reduced the flood-conveying capacity of the river. Engineering studies identified flood-prone areas and hazards related to inundation and high streamflow velocity (Matrix Design Group, 2000; McLaughlin Water Engineers, 2000). A USGS study (Elliott, 2002) evaluated the potential response of the channel to discharges that entrain the coarse streambed and identified several subreaches where bed-material entrainment or deposition potentially could create problems.

Location:

The monitoring reach is a 0.8 mile (4,200 ft) segment of the river extending from approximately 1,200 ft upstream from the Highway 82 Upper Bypass Bridge, east of the town of Basalt, downstream to the Emma Bridge near the confluence of the Fryingpan River in downtown Basalt. This reach includes parts of sections 17, 18, and 7, T8S, R86W, Pitkin County. Streamflow gaging station 09081000 Roaring Fork River near Emma, Colorado is approximately 2.9 miles downstream from the Emma Bridge.

Streamflow Data:

Current streamflow: USGS 09081000 Roaring Fork River near Emma

View peak streamflow: 09081000 Roaring Fork River near Emma

Photographic History:

Sediment Surveys

See Sediment Distribution Charts for Roaring Fork River at Basalt

Channel Surveys

See Cross Section Data for sites on Roaring Fork River at Basalt