Modeling the flow of Hall Creek, Humboldt County, California using visualizing ecosystem land management assessments (VELMA) and calculating the channel forming flow using the effective discharge calculation

Due to wide spread stream degradation across the globe, there is great potential for restoring stream and riverine habitat. Land managers often lack necessary information about the stream discharges of ungauged watersheds. This lack of data makes designing stream restoration projects in ungauged watersheds more difficult. This is especially true when trying to determine the channel-forming flow, the discharge that will support a stable channel geometry. In this study, the channel-forming flow was approximated using effective flow. Effective flow is the level of flow that transports to the greatest amount of sediments. One method for calculating effective flow is to use stream discharge and sediment transportation data. Modeled annual discharge data was generated for Hall Creek, an ungauged watershed, by running the Environmental Protection Agency’s Visualizing Ecosystem Land Management Assessments (VELMA) ecohydrology model. The modeled VELMA flow data for Hall Creek and bedload sediment data from a similar nearby creek was used as the inputs for the effective discharge calculation. The effective discharge of Hall Creek was found to be 2.52 cubic meters per second