Big Thompson Canyon Stream Assessment

Big Thompson Canyon Stream Assessment

Blue Mountain utilized the Stream Visual Assessment Protocol of the Natural Resource Conservation Service to provide a rapid assessment of the Big Thompson River in Larimer County, Colorado. The Stream Visual Assessment Protocol is a national protocol that provides an initial evaluation of the overall condition of wadeable streams, their riparian zones and their instream habitats. The protocol is used to evaluate criteria for conservation planning, identify potential resource concerns and assess trends in stream and riparian conditions over time.

In September 2013, Colorado's Front Range received heavy rains and suffered from catastrophic flooding. The 500-year flood spread across a range of almost 200 miles, affecting 17 counties in Colorado. In Larimer County, approximately 1,500 homes and 200 businesses were destroyed. Extensive damage to Highway 34 in the Big Thompson Canyon completely cut off road access to the communities of Drake, Glen Haven and Cedar Park.

A healthy stream will look and function differently depending on its location or ecological setting. Impacted streams are assessed in relation to historic or potential conditions. Sites that are not impaired and represent the range of conditions that potentially exist for a particular stream are used for reference. Elements that affect a streams classification include channel condition, hydrologic alteration, bank condition, riparian areas, canopy (tree) cover, water appearance, pools, fish habitat, and more.