WHAT HAVE BEEN ACCOMPLISHED:

The Buena Vista Creek empties its flow downstream through a 14' tall x 10' wide corrugated steel culvert underneath Park Lane. Under the current condition, the flow capacity will be reduced if the culvert is partially blocked by debris. The proposed debris basin is designed to capture the washed out materials, with a debris rack built in front of the existing culvert, and allow the water to flow into the downstream flood control system located at the base of the mountains where the creek empties onto the alluvial fan deposits that extend to the coast to the south.

The improvements involve excavating the original ground from an approximate elevation of 710' to elevation 674', and three stretches of retaining walls (RW1, RW2 and RW3) will be built to provide the required storage capacity based on FEMA hydraulic modeling. Due to the existing topography, stage construction is required to construct the retaining walls without temporary shoring using a top-down construction method. Wall types include soldier pile walls with ground anchors and soil nail walls with height up to 40' tall. The new retaining walls will tie-in with the wingwalls of the existing culvert at the downstream end and a rock slope protection (RSP) structure will be constructed on the upstream end of debris basin.

Schedule:  Design was completed in 2023