"Site D" Specific Plan - Willow Heights

Last Updated June 4, 2014

UPDATES: City staff will post updates here as additional information becomes available. 

Willow Heights (Site D) Project                                             

Project Overview: Lennar Corporation is currently in escrow to acquire the 30-acre site (currently referred to as Site D) located on the southeast side of Diamond Bar Boulevard and Brea Canyon Road. Lennar proposes to develop Willow Heights – a master-planned, gated residential community consisting of 182 for sale dwelling units within three distinct neighborhood settings, as well as a neighborhood park to be dedicated to the City. The proposed development will serve as a visual gateway into the city with its distinctive identity, which incorporates a significant landmark entry feature near the corner of Diamond Bar Boulevard and Brea Canyon Road. It will also create public right-of-way enhancements in accordance with specific Citywide Streetscape Design Standards, currently being developed by City staff. The precise location of the entry feature will be determined when the park design is finalized.


Site Plan




Landscape Plans -


    Edge Conditions 

  Interior Slope

Updated 6/4/14 - Conceptual Park Design Final dated 4/30/14

Neighborhood Park Design: The proposed Willow Heights development incorporates a 4.7 gross-acre neighborhood park, which contains a 0.9 acre of land located west of the Brea Canyon Flood Control Channel, and 3.8 acres of land located east of the Brea Canyon Flood Control Channel. Its specific boundaries are along Brea Canyon Road and along a linear pathway from the end of the cul-de-sac at Pasado Drive to the southwesterly boundary of the site, with a pedestrian bridge crossing over the Brea Canyon Flood Control Channel.

As proposed, the park will feature a detention basin that will capture and store stormwater on site and empty into the Brea Canyon Channel during non-peak periods. This basin will also serve as a passive public recreational facility with an educational, recycled water feature; landscaping incorporating drought-tolerant native habitat; walking trails; shade structures; and benches.

Park Features in Detail:

  • Rain Garden.  This feature will serve the dual purpose of stormwater collection system for the residential development, and public recreational amenity.
  • Walking Trail. An approximately 600-foot long, 38-foot wide pedestrian trail/emergency access road is proposed along the southwesterly boundary of the site.  Access is restricted to pedestrian-only at the end of Pasado Drive, which leads to the Rain Garden and pedestrian bridge over the Brea Canyon Flood Control Channel.   A gate to prohibit vehicle access will be installed.
  • Pedestrian Bridge.  A bridge over the Brea Canyon Flood Control Channel will provide pedestrian and maintenance vehicle access, and link the neighborhood park to the 0.9 acre park area along Brea Canyon Road, west of the Channel.
  • Trail Head Parking.  The precise configuration and number of parking spaces for the neighborhood park, along with the connection to the trail system along Brea Canyon Road, will be finalized at a later date.  Vehicular access to the park will be limited to one entrance only, via Brea Canyon Road.

Conceptual park plans were derived from the community consensus design resulting from two neighborhood workshops. The precise plan for the park is not finalized, and will be presented to the Parks and Recreation Department and City Council at a later date.  Lennar will be required to construct the park to City standards and dedicate it to the City after a 120-day landscaping establishment period.  The park will be required to be in turn-key condition prior to the issuance of building permits for the 100th dwelling unit.

willow heights
Proposed neighborhood public park design incorporates passive open space, rain garden with signage and foot trails, picnic tables under shade structures, and four tot lots - Conceptual Park Plan

Neighborhood Workshops: As directed by the City, Lennar solicited input from Diamond Bar residents on the neighborhood park design and amenities.  Two workshops were conducted – one to seek input and the other to provide feedback from the first workshop.

Workshop # 1:  A community workshop was held on Saturday, January 26, 2013 from 1:30 p.m. to 4:30 p.m. at Castle Rock Elementary School. Its purpose was to solicit public input, study site opportunities and constraints, discuss potential park improvements, and share creative ideas. The 34 people in attendance had the opportunity to take part in the following interactive activities that provided design and programming input:

  • Site Awareness Tour:  A walking tour of the site was conducted, during which time participants had the opportunity to record their observations of the physical environment situated along the walking trail, with a focus on existing features, constraints, and opportunities.
  • Group Activities:  Following the site tour, participants were divided into four groups and presented with three topics regarding their observations and potential park opportunities and amenities.  Each group listed the top responses from the three topics posed and reported their summary to all groups. 
  • Planning/Design Charrette:  Each group was then asked to develop a conceptual plan and design of what they envisioned for the site on a topographic map.  Most groups came up with consistent site amenities, with the top five being: trails, benches, fitness stations, interpretive panels, and tot lot/playground.

Workshop #2:  A feedback workshop was held on May 9, 2013 at 6:30 p.m. at Heritage Park.  There were 21 people in attendance, many of whom participated in the first park design workshop.  The purpose of this workshop was to review the community input process, and present both the summary consensus plan and preliminary concept plan developed during Workshop #1.

willow heights

Two public workshops provided the community the opportunity to obtain an overview of the project, tour the development site, discuss potential park ideas, and share creative ideas.

Community Workshop Summary - 

     Part 1 of 4  

    Part 2 of 4 

     Part 3 of 4 

      Part 4 of 4   


Diamond Bar City Hall
Community Development Department
Senior Planner Grace S. Lee
909.839.7030 • glee@diamondbarca.gov

 Updates/Timeline -

  • June 17, 2014 - The City Council will be reviewing the Site D Park concept plan at this meeting. After input from a neighborhood meeting on May 29, the concept plan remains unchanged from the plan presented to the City Council on May 6, 2014 for approval. Site D Park conceptual plan dated 4/30/14 Final
  • May 6, 2014 - The City Council will be reviewing the Site D Park concept plan at this meeting. The Council took action to approve the rain garden portion of the project but requested staff conduct a neighborhood meeting to receive any additional input regarding the location of the parking lot, playground, and park name.
  • November 19, 2013 - Lennar's proposed Willow Heights project is scheduled for consideration by the City Council during the public hearing period of its regular meeting of Tuesday, November 19, 2013. 
  • October 8, 2013 - Diamond Bar Planning Commission recommended, by a 5-0 vote, that the City Council approve the vesting tentative tract map and architectural and landscape plans for a 182-unit residential development on Site D based on the finding that the project is in substantial conformance with the Site D Specific Plan.
  • January, 2013 - Wanut Valley Unified School District-sponsored Outreach Workshop & Site Tour Saturday, January 26, 2013 from 1:30pm to 4:30pm to solicit public input on the public park design at Site D Development VIEW FLYER
  • May 2012 - Final Site D Specific Plan is available. View/download these documents.
  • February 21, 2012 - City Council approves the Site D Specific Plan (SDSP), which sets forth regulatory criteria to guide the development of Site D, which consists primarily of Walnut Valley Unified School District property. The SDSP provides for the development of up to 200 for-sale dwelling units, and requires at least two acres to be set aside and developed as a public neighborhood park.
  • January 2012 - City is in receipt of an updated DRAFT Site D Specific Plan as well the Response to Comments No. 2 Vol. 1 (Document) and Vol. 2 (Technical Appendix).
  • December 21 - Public Hearing closed. Matter continued to a later date to be determined.
  • December 7 - City Council approved eliminatiion of commercial component from project. Public Hearing will remain open and be continued to the December 21 City Council meeting and amended Specific Plan and MOU will be brought before the Council for consideration.
  • November 16 - City Council continued Public Hearing to December 7, 2010 meeting.
  • October 19 - City Council continued Public Hearing to the November 16, 2010 meeting.
  • October 16 - The Walnut Valley Unified School District is hosting an outreach workshop at Castle Rock Elementary. All interested parties are welcome to provide input and tour site. More details.
  • July 20 - City Council continues Public Hearing to October 19, 2010
  • June 15 - City Council Opened Public Hearing and continued to July 20, 2010 Council meeting.
  • May 11 - The Planning Commission recommended certification of the the EIR and Statement of Overriding Considerations, adoption of the General Plan Amendment/code change, and approval of the Specific Plan with the added recommendation to incorporate a 1.3 acre public park within the area of the project site designated for commercial development.
  • April 13, 2010 - PUBLIC HEARING NOTICE -  - continued to May 11, 2010 Planning Commission meeting.
    The City of Diamond Bar Planning Commission will conduct a public hearing on Tuesday, April 13 for the purpose of receiving input from the general public concerning the "Site D" Specific Plan ("Project"). Please refer to the attachment for time, location, and other details.

About the Project: site d
The Walnut Valley Unified School District is currently proposing the development of a 28.7-acre surplus vacant parcel, (Site D), located at the southeast corner of Brea Canyon Road and Diamond Bar Boulevard in Diamond Bar.

The proposed project for Site D seeks to change land use designations for an approximately 30-acre site for a potential mix of 154,000 square feet of commercial use, and maximum of 202 residential units.

The project site is composed of three adjacent properties…A 28.7 acre parcel east of the flood control channel owned by the Walnut Valley Unified School District since its unification in 1970, a City of Diamond Bar owned 1.0 acre parcel located west of the flood control channel, and the channel separating the City and District properties owned by the Los Angeles County Flood Control District.

Additional information:

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