Knowledge Nook: Sediment-Stopping Superheroes in the South Platte

Knowledge Nook: Sediment-Stopping Superheroes in the South Platte

June 22, 2012 by RMFI

In June 2002, the Hayman Fire burned over 130,000 acres and was the largest forest fire in Colorado history.  Through a partnership with the US Forest Service, National Forest Foundation and the Coalition for the Upper South Platte, RMFI staff and two dedicated, hardworking crews have been building erosion control structures in ephemeral draws on the site of the Hayman Burn, near West Creek, Colorado.

The fire burned in the headwaters of the Upper South Platte River, which provides drinking water for the Denver metropolitan area.  In many areas the fire burned the entire forest over-story and groundcover.  With no vegetation in the ephemeral drainages to hold back the soil, sediment build up in the South Platte drainage has increased dramatically, greatly impacting downstream water sources. It is estimated that sediment flow has increased 19,588 tons/year as a result of the fire.

RMFI, with crews from Mile High Youth Corps and AmeriCorps NCCC, have been combating this sediment deposition by stabilizing head cuts along Trail Creek, a tributary of the South Platte River.  Head cuts are an abrupt vertical drop in a stream or draw.  With no structure to stabilize the soil, head cuts will continue to erode uphill.  To treat the head cuts, the gully below the head cut is filled with logs from dead or downed trees.  Once the head cut is filled to within 90 percent of the bank height, the banks are broken down and drawn in to cover the log structure.  The final step is to seed the head cut with a native grass mix, transplant bunch grasses, and stake down erosion control matting.

The AmeriCorps National Civilian Community Corps crew is based out of the Denver campus.  The nine-member crew now heads up to Pikes Peak to spend three weeks working in the Severy Creek drainage.  The Mile High Youth Corps crew is based out of Colorado Springs.  We would like to extend a HUGE THANK YOU to the members of these crews and we wish them well in their next projects.