Riparian Implementation and Maintenance for Mill and Supply Creek Project 2017-2018

After completing the restoration of Mill and Supply Creeks in 2016 and 2017 respectively, this project allowed for continued planting and irrigation of riparian and upland plants within the restoration footprint. Mill Creek had a very successful riparian establishment through the entire project. Supply Creek had a similar response in the upper reaches, in the lower section the irrigation was the only way that riparian plants were able to get established. As these trees and willows grown they will add additional organic matter to the soil which will aid natural recruitment throughout the site. In some areas of Mill Creek small adjustments to topography were made after the main construction period was completed. This funding allowed the newly denuded areas to be replanted with container stock from the Hoopa nursery.

SONCC in the lower Trinity River are identified in the Recovery Plan as being at high risk of extinction. Restoration of tributary habitat for both natal and non-natal SONCC is therefore of great importance, and restoration or riparian/floodplain plant communities a fundamental part. Planting of native vegetation throughout the restoration project areas will help to support habitat restoration as newly-constructed features adjust during high flows; geofluvial processes – the erosion, transport and deposition of sediments and large wood – in combination with re-growth of riparian/floodplain plants, will result in lasting restoration of self-sustaining ecosystem functions and processes. Restored riparian vegetation will play into geofluvial processes, help to moderate summer and winter temperature extremes, and provide input of leaf litter and terrestrial insects to support aquatic productivity, among other benefits.