Tally Ho Creek, a key tributary to Arroyo Grande Creek, has been significantly affected by channel modifications, floodplain encroachment and an increase in sedimentation. These impacts have directly affected streamside landowners and reduced the functional value of aquatic and riparian habitat, as well as increased the flood risk in the Arroyo Grande flood control channel, located downstream of the project site.
The RCD was awarded funding from the Department of Water Resources Urban Stream Restoration Program in 2020 to restore a prioritized 220-linear-foot reach of stream channel and riparian habitat on Tally Ho Creek. The project will increase the channel’s high flow capacity, reducing pressures on the flood control channel, and prevent approximately 2,500 cubic yards of sediment and bed material over a span of 10 years from depositing downstream in the flood control channel.
Restoration activities include repair of a four-foot head cut, excavation of a low-flow channel, lowering the channel base to meet the grade downstream of the head cut, and restoring native riparian habitat by removing invasive species and revegetating with natives. By lowering the channel base, flood capacity of the channel is increased and upstream migration of the head cut would be controlled. Repairing the head cut reduces sediment mobilization, and excavation of a low-flow channel removes existing accumulated sediment.
Partners: City of Arroyo Grande, Creeklands Conservation
Funders: Department of Water Resources
RCD Contact: Hallie Richard, firstname.lastname@example.org