Research about Copper Creek

USGS2025

The role of bedrock circulation depth and porosity in mountain streamflow response to prolonged drought

Quantitative understanding is lacking on how the depth of active groundwater circulation in bedrock affects mountain streamflow response to a multi‐year drought. We use an integrated hydrological model to explore the sensitivity of a variety of streamflow metrics to bedrock circulation depth and porosity under a plausible extreme drought scenario lasting up to 5 years. Endmember depth versus hydraulic conductivity relationships and porosity values for fractured crystalline rock are simulated. With drought, a deeper circulation system with higher drainable porosity more effectively buffers minimum flow and significantly limits perennial stream loss in comparison to a shallow circulation system. Streamflow buffering is accomplished through extensive groundwater storage loss. However, deeper circulation systems experience prolonged recovery from drought in comparison to storage‐limited shallow systems. Research highlights the importance of characterizing the deeper bedrock hydrogeology in mountainous watersheds to better understand and predict drought impacts on stream ecosystem health and water resource sustainability.

Colorado↗

USGS2009

Status of native freshwater mussels in Copper Creek, Virginia

Previous freshwater mussel surveys conducted in Copper Creek showed a decline in the fauna from 1980 to 1998. In 2004 and 2005, we sampled 47 sites acquiring relative abundance estimates (measured in catch-per-unit-effort) to assess the current status of the mussel fauna relative to previous surveys. We also obtained absolute density estimates for 4 select sites for comparison with future and past surveys. Of the 25 mussel species reported from this and previous surveys, 16 were represented by living specimens, 5 are extant but may soon be extirpated, and 8 are likely extirpated from the creek. Presence-absence analysis showed a significant decline in species per site since 1980. Absolute density estimates (at Copper Creek river km 3.1) decreased significantly from 4.07 mussels/m 2 in 1981 to 0.63 mussels/m 2 in 2005. The cause of this faunal decline is likely due to several factors, including, most notably, the loss of riparian buffers. Nearly half of the stream banks in Copper Creek have inadequate riparian vegetation to provide even minimal sediment control. Precipitous declines of the Clinch River fauna (a likely source population for several species) may be another significant factor influencing the faunal decline in Copper Creek. Despite these declines, populations of several species may be in a state of recovery. Based on 18 comparable sites, average catch-per-unit-effort in 2005 was 25.16 mussels/hr, significantly higher than the 1998 survey (12.92 mussels/hr).

Virginia↗