Sycamore Canyon Park Slope Erosion Repair

2017 Storm Damage to Sycamore Canyon Park Trailhead

2017 Winter Storm Related Damage

The major winter storms of January 18-23, 2017 caused serious damage to portions of Sycamore Canyon Park. In addition to playground and creek bed damage, the heavy rains created an excessive volume of water at Sycamore Canyon Park that resulted in significant erosion and slope failure near the Diamond Bar Boulevard trailhead. The slope failure undermined two of the four tiers of stairway that lead to the trail, rendering access unsafe. The trailhead and stairway access was subsequently closed to the public, pending repairs. The remainder of the trail remains open to hikers.

Project Eligible for FEMA Reimbursement

The damage associated with these severe storms led the County of Los Angeles, State of California, and federal government to declare a local state of emergency, making the cost of the repairs eligible for reimbursement from the Federal Emergency Management Agency (FEMA). The City of Diamond Bar Public Works Department submitted a claim to FEMA and worked with consulting experts to conduct geotechnical and engineering assessments to determine the best course of action to remediate the damage, concluding that the safest and most effective reconstruction of the hillside requires the removal and replacement of the undermined stairs, recompaction of the slope, and the installation of increased drainage facilities to prevent a similar event from happening again. The competitive bidding process established the cost of the repairs at $1.2 million.

The City’s assessment and remediation plan was submitted to FEMA via the California Office of Emergency Services (CalOES) on March 16, 2017. On October 16, 2017, FEMA responded with the opinion that the submitted project scope constituted an “improved project” and recommended that the undermined stairways be repaired in place rather than be removed and replaced as recommended by the licensed engineers that conducted the assessment. The “improved project” designation limits the City’s funding reimbursement eligibility to approximately $285,000, a fraction of the project cost established in the competitive bid process and original commitments by FEMA.

On November 16, 2017, the City filed a letter with FEMA challenging the “improved project” designation and emphasizing that the originally recommended scope of work is necessary to safely repair the damage. Subsequently, FEMA requested additional information and technical studies, to which the City has responded in full. However, since receiving the letter and participating in several subsequent meetings convened by the City and CalOES, FEMA has yet to respond with a written decision.

Project Repair Status

The City has completed project plans, specifications, and the competitive bidding process, and is prepared to award a contract and commence construction immediately upon FEMA approval. Should the City award a contract and commence work prior to receiving FEMA approval, it would invalidate the claims process and leave the City responsible for the entirety of the project cost. However, if approved, the City’s share of the project will be 6.25 percent of the total project cost of $1.2 million, resulting in taxpayer savings of $1.125 million.

Despite the delays, the City continues its good faith efforts to work with FEMA to reach a conclusion that results in a safe restoration of the Sycamore Canyon Trail and protects the greatest amount of local funding that can be used to fund public safety, infrastructure improvements, and programming for Diamond Bar residents.

Project Contact

Questions or comments related to this project? Contact Assistant to the City Manager Anthony Santos by email or phone at (909) 839-7016