In the past, vegetation and sediment were periodically removed to maintain Tally Ho Creek in its altered condition. It became difficult to obtain approval for this type of management due to increased concerns from regulatory agencies regarding the impact of such actions and the need to protect species listed under the Endangered Species Act (ESA). Because the low gradient valley condition had not changed and sediment inputs to the valley floor likely increased, the increased density of vegetation resulted in sediment accumulation on the valley floor that has increased the risk of flooding increased to the point where it is an annual occurrence.
In response to the increased risk, the City of Arroyo Grande contracted with Waterways, the Coastal San Luis Resource Conservation District (CSLRCD) and Central Coast Salmon Enhancement (CCSE) to identify a solution to reduce flooding risks to landowners within a framework that emphasizes enhancements to the ecological value of Tally Ho Creek. Waterways performed mapping, modeling, preliminary engineering designs, and prepared permit applications.