Santa Cruz, CA
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  Portland, OR
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Tally Ho Channel Assessment

P7080089 webClient: Coastal San Luis Resource Conservation District

Channel and riparian conditions along Tally Ho Creek within the project area look much different today than they did several hundred years ago. Pressure to utilize flat valley bottoms for agriculture and, later, suburban development, resulted in removal of much of the riparian vegetation, filling of wetlands, road building, and straightening and deepening of Tally Ho Creek. Cleared portions of the valley bottom now consist of single family homes and Tally Ho Road, and Tally Ho Creek has been confined to the eastern edge of the valley floor.

To maintain Tally Ho Creek in its altered condition, vegetation and sediment were periodically removed. This type of management has been more difficult to obtain approval for 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 has not changed and sediment inputs to the valley floor have likely increased, the increased density of vegetation has resulted in sediment accumulation on the valley floor that has increased the risk of flooding to homes adjacent to the creek. In fact, for some landowners, the risk of flooding has 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 CSLRCD, and Central Coast Salmon Enhancement (CCSE) to identify a solution that will 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.

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