Abstract: Session F  4:20 pm (Back to Session F)

Restoration of Colorado Rivers Using Principles of Natural Channel Design: Fisheries Case Studies

Matt Kondratieff
Colorado Parks and Wildlife
Fort Collins, CO

Rivers that depart from natural channel forms can limit ecological recovery of aquatic ecosystems and ultimately degrade habitat.Departures include channelization, loss of floodplain connectivity, removal of wood, loss of riparian vegetation, habitat fragmentation, and altered hydraulic conditions. Monitoring results from fish populations occupying impaired rivers have shown that recovery may require decades before populations begin to stabilize and even longer before populations show positive signs of recovery.Fish populations occupying degraded river systems may continue to decline without active restoration intervention, such as application of Natural Channel Design (NCD). Uncertainty exists whether application of NCD result in lasting improvements to ecological function over time.In Colorado, long-term monitoring of NCD projects provide evidence that stream ecological functions have improved, such as increases in fish biomass, density, and species diversity.In addition, NCD project monitoring spanning up to 27 years have shown sustained improvement in fish populations. Restoration of full ecological function on restored as compared to reference quality monitoring sites has not yet been achieved in NCD project sites in Colorado.