Since 2004, the BCWA has conducted macroinvertebrate sampling and data collection at up to 14 sites along the mainstem of Bear Creek (BCWA Fact Sheet 32 Stream Macroinvertebrates), including Colorado Parks and Wildlife fish survey sites along Bear Creek: Bear Creek Lake Park, Morrison (west end), Idledale, Lair o' the Bear Park, O' Fallon Park, Bear Creek Cabins, Main Street Evergreen (across from the Little Bear), above Evergreen Lake upstream within Dedisse Park, Singing River Ranch, Bear Tracks near Mount Evans Wilderness, above Singing River Ranch, and Golden Willow Bridge.
There was no macroinvertebrate sampling done in 2013 due to the September flood event. The mainstem of Bear Creek was extensively altered by the flood event, with deep stream bed scouring. Macroinvertebrate habitat was clearly affected by the flood event. In 2014, the BCWA selected ten sample sites to continue the Macroinvertebrate sampling program and has continued sampling these 10 site through 2019.
The BCWA utilizes the Colorado Water Quality Control Division sample collection timed-kick net methodology protocol (WQCDSOP-001 Benthic Macroinvertebrate Sampling Protocols, May 2010; BCWA ME04 Macroinvertebrate Field Sample Method). Only fast riffles are targeted for sampling. Riffle habitat refers to the portions of the stream where moderate velocities and substrate roughness produce turbulent conditions which break the surface tension of the water and may produce whitewater.
A contract laboratory analyzes samples collected by the BCWA for benthic macroinvertebrates. Samples collected by the Association follow the BCWA M04 Macroinvertebrate Field Sample Method. Data for samples are reported as number of organisms per square meter. Percent of total is also reported. The species are counted consistent with the Colorado Water Quality Control Division EDAS import columns for taxa and species. This data is then converted into Multi-Metric Index (MMI) scores. MMI scores were calculated using CDPHE EDAS Access database. All collected species are confirmed against the EDAS database.