Crooked Creek Residential Subdivision

2 Documents in Project


SCH Number
Lead Agency
City of Diamond Bar
Document Title
Crooked Creek Residential Subdivision
Document Type
MND - Mitigated Negative Declaration
Present Land Use
RL-PD (Low Density Residential-Planned Development)
Document Description
The proposed residential project includes the development of seven single-family residences and associated infrastructure including a southward expansion of the existing Crooked Creek Drive at a 12.9-acre undeveloped site. Five of the seven residential structures are proposed to include an attached Accessory Dwelling Unit. The following entitlements are being requested: 1. Vesting Tentative Tract Map No. 54081 to subdivide the subject property into nine parcels for the following purposes: seven (7) single-family residential lots; one lot designated for the roadway (i.e., southwesterly extension of Crooked Creek Drive); and one lot which includes a maintenance access and approximately 10.4 acres of preserved open space area. 2. Development Review of the proposed architecture and landscape design in compliance with all applicable Development Code standards and design guidelines. 3. Tree Permit to remove 62 existing protected trees consisting of 58 Southern California black walnuts and four coast live oaks, and to replace them at a 3:1 ratio with 201 Southern California black walnuts and 12 coast live oaks, totaling 213 replacement trees to be planted on-site. 4. Conditional Use Permit to approve development on a site subject to a Planned Development overlay district and allow modifications to the retaining wall height limit to allow a maximum of 17 feet (where 6 feet is the maximum allowed), reduce the front setback for Lots 4 and 5 to 14 feet and 13’-9” (where 20 feet is required), and reduce the minimum lot size for Lots 1 and 3 to 8,294 square feet and 8,482 square feet (where 10,000 square feet is required).

Contact Information

Mayuko Nakajima
Agency Name
City of Diamond Bar
Contact Types
Lead/Public Agency


Diamond Bar
Los Angeles
Southern California
Cross Streets
Crooked Creek Drive and Gold Run Drive
Total Acres
Parcel #
State Highways
Castle Rock Elementary, Evergreen Elementary, Shelyn Elementary,
Brea Canyon Flood Channel
Yorba Li

Notice of Completion

State Review Period Start
State Review Period End
State Reviewing Agencies
California Air Resources Board (ARB), California Department of Conservation (DOC), California Department of Forestry and Fire Protection (CAL FIRE), California Department of Housing and Community Development (HCD), California Department of Parks and Recreation, California Department of Toxic Substances Control (DTSC), California Department of Transportation, District 7 (DOT), California Department of Water Resources (DWR), California Highway Patrol (CHP), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Regional Water Quality Control Board, Los Angeles Region 4 (RWQCB), Office of Historic Preservation, State Water Resources Control Board, Division of Drinking Water, California Department of Fish and Wildlife, South Coast Region 5 (CDFW)
State Reviewing Agency Comments
California Department of Fish and Wildlife, South Coast Region 5 (CDFW)
Development Types
Residential (Units 7, Acres 12.9)
Local Actions
Use Permit, Land Division (Subdivision, etc.), Development Review, Tree Permit
Project Issues
Aesthetics, Air Quality, Biological Resources, Cultural Resources, Cumulative Effects, Drainage/Absorption, Energy, Geology/Soils, Greenhouse Gas Emissions, Hazards & Hazardous Materials, Hydrology/Water Quality, Land Use/Planning, Mandatory Findings of Significance, Noise, Population/Housing, Public Services, Recreation, Schools/Universities, Sewer Capacity, Solid Waste, Transportation, Tribal Cultural Resources, Utilities/Service Systems, Vegetation, Wildfire


Notice of Completion [NOC] Transmittal form
State Comment Letters [Comments from state reviewing agencies]

Disclaimer: The Governor’s Office of Planning and Research (OPR) accepts no responsibility for the content or accessibility of these documents. To obtain an attachment in a different format, please contact the lead agency at the contact information listed above. You may also contact the OPR via email at or via phone at (916) 445-0613. For more information, please visit OPR’s Accessibility Site.

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