Ariey Lane Minor Subdivision, Rezoning, and Development Plan (County File CDMS20-00010, CDRZ22-03264, and CDDP22-03002)

Ariey Lane Minor Subdivision, Rezoning, and Development Plan (County File CDMS20-00010, CDRZ22-03264, and CDDP22-03002)

Background: An Initial Study and draft Mitigated Negative Declaration was circulated for public review on August 16, 2024, extending through September 16, 2024. Comments on the Initial Study were received from the California Department of Fish & Wildlife (CDFW) on September 16, 2024. The applicant also proposed changes to the drainage and stormwater control design. As such, the Initial Study and Draft Mitigated Negative Declaration for the project has been revised to address CDFW’s comments and recommended mitigations, and the proposed design changes. Project Description: The applicant is requesting approval of a vesting tentative map to subdivide a 6.18-acre parcel into three new parcels, resulting in an approximately 2.86-acre (gross) Parcel A, an approximately 2.48-acre Parcel B, and an approximately 0.84-acre Parcel C. Access to the minor subdivision would be from Ariey Lane, a private road, via an existing bridge that crosses Grayson Creek. Proposed site improvements include extending Ariey Lane from the bridge as a 20-foot-wide private road within a 25-foot private access easement, with slopes up to a 20% gradient. No improvements are proposed for the existing bridge. Water, electricity, telecommunication, and other utility extensions, as needed, would be attached beneath the bridge using an existing utility trapeze. Curbs, gutters, four bioretention basins and two energy dissipator outfalls (61 linear feet and 165 linear feet, respectively) would be installed for drainage and stormwater control. The dissipator outfalls will discharge treated water to the uplands north of the creek via overland sheet flow. In addition, approximately 15 retaining walls over three feet in height and up to eight feet in height would be constructed. Approximately ±3,500 cubic yards (CYS) of cut and ±3,100 CYS of fill for a net 400 CYS of grading is anticipated for the future road and residential foundation pads. As a result of two existing easements on the property, development is limited to less than half of the property’s gross acreage. The applicant is seeking approval of an exception to County Code Division 914 to construct approximately 945 square feet of access road, curbs, and road-supporting retaining walls (if needed) within the CSS easement. The scenic easement area in the northern corner of the property will remain undeveloped and no changes are proposed that would reduce the size of either easement. The applicant also requests a rezone of the property from R-10, Single-Family Residential to P-1, Planned Unit District (P-1) and approval of a Final Development Plan for development of each parcel. Up to five dwelling units are proposed, including two attached accessory dwelling units (ADU). Future approval of any ADU will require a separate ministerial application. The proposed development of each parcel is described as follows: • Parcel A: 6,244-square-foot, two-story, single-family residence up to 26 feet in height, an 886-square-foot garage, driveway, pool, and seven retaining walls ranging between 1 foot and 6 feet in height. • Parcel B: In addition to a driveway, and five retaining walls ranging between 1 foot and 6 feet in height, a single-family residence, garage, and attached ADU with an approximately 5,275 square-foot building footprint is shown on the final development site plan; however, the applicant has not submitted architectural drawings for the residence. • Parcel C: 4,424-square-foot, two-story split-level, single-family residence stepping up the existing grade with a height up to 28 feet, an approximately 747-square-foot ADU within the residential structure, a 974-square-foot garage, driveway, and three retaining walls ranging between 2 feet and 8 feet in height. In addition, the applicant requests approval of a tree permit for project-related impacts to twenty-nine code-protected trees, including the removal of fourteen code-protected trees (one (1) Aleppo pine tree, three (3) incense cedar trees, three (3) Arizona cypress trees, and seven (7) coast live oak trees) and work within the driplines, including construction, trenching or grading, of fifteen code-protected trees (one (1) valley oak tree, two (2) California bay trees, and twelve (12) coast live oak trees) located on the subject property. Project impacts would primarily be due to the trees being located within the footprint of site improvements or new residential structures. The project arborist also recommended removal of several trees due to poor health or condition.

Lafayette, Pleasant Hill

Contra Costa

San Francisco Bay Area

California Department of Conservation (DOC), California Department of Fish and Wildlife, Bay Delta Region 3 (CDFW), California Department of Forestry and Fire Protection (CAL FIRE), California Department of Parks and Recreation, California Department of Toxic Substances Control (DTSC), California Department of Transportation, District 4 (DOT), California Department of Water Resources (DWR), California Fish and Game Commission (CDFGC), California Governor's Office of Emergency Services (OES), California Highway Patrol (CHP), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Regional Water Quality Control Board, San Francisco Bay Region 2 (RWQCB), California State Coastal Conservancy (SCC), Delta Protection Commission, Delta Stewardship Council, Office of Historic Preservation, State Water Resources Control Board, Division of Drinking Water

Residential (Single-Family Residential)(Units 3, Acres 6.18)

Planned Unit Development, Rezone, Land Division (Subdivision, etc.), Tree Permit

Aesthetics, Biological Resources, Cultural Resources, Drainage/Absorption, Geology/Soils, Hydrology/Water Quality, Tribal Cultural Resources, Wetland/Riparian, Wildfire