Sycamore Canyon Park Trail Repair Project

2017 Storm Damage to Sycamore Canyon Park Trailhead 
STATUS - Project completed October 31, 2019


Project Update Short - September 2019

Time Lapse Video - August 2019

Project Overview - June 2019


November 5, 2019 - Project Completed
TRAILHEAD REOPENS - A ribbon cutting event was held on Tuesday, November 5 at 9 a.m. to celebrate the reopening of the trail access.


October 16, 2019
- A major portion of the project is complete with the stair cases on both the upper and lower slope having been poured. The final phases of one more landing area will get concrete this week with landscaping set over the next couple of weeks. 

October 11, 2019
– Concrete pouring has taken place for the new staircases at both the upper and lower slopes. Concrete work will continue next week with the final phase of drainage being set in place on the upper slope.

October 8, 2019
STAIRCASE FORMING BEGINS - Crews have continued to trench out new drainage paths and start preparation to form staircases on the upper and lower portion of the slopes.

September 19, 2019
– Crews are putting the finishing touches on the final grooming of the hillside along with trenching a new concrete pathway for water runoff along the lower slope. Forming for the new stair cases is planned for late next week with the completion of the project still slated for mid to late Fall.

September 13, 2019
- Concrete for the new drainage system has been completed with cleanup and grooming slated for this new pathway along with final grading for the hillside.

September 5, 2019
-Construction crews are pouring over 500-feet of concrete as part of the new drainage path along the hillside of the trail. This new addition will help alleviate any major rain runoff from cascading down the hill and will give it a directed pathway to the main drainage system.

August 30, 2019
DRAINAGE WORK CONTINUES - The installation of the upper terrace pipe/inlets has been completed. Crews are now working on concrete forming for the v-ditch.

August 23, 2019
With the slope grading completed, crews will now work on the installation of the upper terrace pipe/inlets. Concrete work will take place next week.

August 16, 2019
The key way or structural supports for the upper slope have been installed and grading and installation of the geogrid or soil reinforcement material is currently underway.

August 9, 2019
-  Work continues at mid-slope with the installation of geogrid or soil reinforcement material and excavation. Crews anticipate completing this phase of the project in approximately 2 - 3 weeks.

August 2, 2019
SLOPE GRADING REACHES MID-WAY POINT - Grading and installation of geogrid (soil reinforcement material) at the mid-slope area continues for several more weeks, along with construction and installation of the new concrete stairs, terrace inlets, construction of block retaining walls, wooden fencing and landscaping.

July 26, 2019
- After a two-week waiting period, the Los Angeles County Public Works Department has approved changes to avoid/minimize damage that may have occurred during the original construction path to an existing storm drain pipe. Grading work at the upper slope resumed this week and will continue for the next couple of weeks. 

June 28, 2019
- While grading mid-slope, crews uncovered an existing 78” storm drain pipe at a shallow depth. The pipe is part of the Los Angeles County system and a permit is required to approve the proposed mitigation construction plan to ensure the grading work will not cause any damage to the pipe. During the delay, crews will move to the upper slope area to continue construction.

June 21, 2019
Grading and fill placement on the lower slope are completed. Excavation of the terrace keyway on the middle slope and construction layout and surveying of bottom terrace v-drain and stairway are now underway.

June 13, 2019 - SOIL COMPACTION UNDERWAY - Crews have been adding new shelves to the eroded slope through soil compaction and adding geo-grid which helps keep soil tied together. 

June 3, 2019 - LOWER SLOPE AREA GRADING COMPLETE - Grading and soil testing at the lower slope area and the first bench key has been completed. Crews are now preparing to begin grading the next step up, or mid-slope.

May 20, 2019 GRADING WORK BEGINS - Grading work begins this week at the lower portion of the slope and will continue for the next two weeks. Following will be the construction of the concrete drainage improvements.

May 13, 2019 - CLEARING SLOPE AREA - Vegetation has been removed within the grading are to allow construction equipment access to the repair site to begin the demolition of the hardscape elements such as the terrace drains and stairways.

May 2, 2019 - CONCRETE DRAINS REMOVED - Demolition of the concrete terrace drains from the upper and lower slopes began this week, including relocation of the irrigation line on the upper slope. 

April 18, 2019 - SLOPE REPAIR PROJECT BEGINS - Construction repairs begin on the slope and failed stairway on the Sycamore Canyon trail. Crews started brush clearance today to provide access to the construction equipment needed to remove the concrete staircase. The Diamond Bar Boulevard trailhead entrance will remain closed during construction that is anticipated to be completed by fall 2019. The remainder of the trail is accessible from the Golden Springs Drive park entrance.


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 (Cal OES) 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 Cal OES, FEMA has yet to respond with a written decision.

Project Repair Delay

The City completed project plans, specifications, and the competitive bidding process, and prepared to award a contract and commence construction immediately upon FEMA approval. If the City awarded 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 continued its good faith efforts to work with FEMA to reach a conclusion that would result in a safe restoration of the Sycamore Canyon Trail and protect the greatest amount of local funding that can be used to fund public safety, infrastructure improvements, and programming for Diamond Bar residents.

FEMA Approves Project for Funding

In December 2018, the City received Federal Emergency Management Agency (FEMA) approval of the project scope which allows for the commitment of the funds necessary to commence construction of the Sycamore Canyon Park Slope and Trail repair project. At its January 15 meeting, the City Council approved the design and plans, and awarded a contract to CEM Construction Corporation to begin the repairs at the park and trail. The project began in spring 2019 and is scheduled for completion in fall 2019.

Project Contact

Questions or comments related to this project? Contact the Public Works Department at (909) 839-7040.