Reach 6, which is along the South St. Vrain, begins upstream along the South Saint Vrain from the Andesite Quarry to the Townsites of Riverside and Raymond. The stream channel is constrained along this reach due to canyon geometry and the highway and there are a number of issues along this reach related to embankments along State Highway 7. Emergency road repairs resulted in large stretches of channelization and removal of organic materials that will have a long-term impact on the natural recovery in those areas. Aggradation occurred downstream of Reach 6 and opportunities exist to mitigate the accumulation of sediment at the choke of the canyon.
There are currently no projects in progress in Reach 6.