Topaz Residential Project

Topaz Residential Project

The proposed project includes construction of seven single-family residences, a 0.42-acre-foot retention basin, paved site access driveway and cul-de-sac, and other associated on-site improvements on a 2.51-acre property and off-site improvements along the property frontage (City of Hesperia Engineering Department n.d.). The project site consists of eight total lots ranging from 7,210 to 13,924 square feet in size. The lot located in the northeastern corner of the project site would be developed with a proposed 0.42-acre-foot stormwater retention basin, while the remaining seven lots would be developed with residential single-family uses. On-Site Improvements: A building pad would be constructed on each residential lot, ranging from 84.9 to 89.3 square feet in area. In addition, each lot would also be constructed with a minimum 25-foot-long concrete driveway. A 6-foot-tall block wall with access gates would be constructed to enclose the rear portion of each residential lot, with the cul-de-sac-facing portion of the wall being adjacent to each residential building pad. Every 10 feet the wall would omit a half-block along the bottom to allow for drainage along the westerly and northerly property lines. The project includes construction of a 191-foot-long access road and driveway approach terminating in a cul-de-sac. This roadway would be named San Luis Street and would be constructed with a sidewalk, curb, and gutter surrounding it per City standards with ramps at each driveway of the residential lots as well as the gated access of the on-site drainage basin. The project would include installation of water, wastewater, and stormwater pipelines within the project site. Each proposed residential lot would include a connection to a centrally located 8-inch-diameter water pipeline beneath the proposed on-site access road, which would then connect to existing 12-inch-diameter off-site City water main located beneath Topaz Avenue directly east of the project site. Similarly, each new residential lot would also include a connection to a centrally located 8-inch-diameter wastewater pipeline that would connect to the 8-inch-diameter City sewer system pipeline located beneath Topaz Avenue directly east of the project site. The water and wastewater pipelines would be located approximately 14 feet from each other horizontally. Water meters would be installed for each residential lot water connection. A proposed 18-inch-diameter storm drain line would be installed on-site to capture on-site stormwater flows and direct them into the on-site drainage basin. A 2-foot-wide rock swale (of varying lengths) and a 9-foot by 9-foot storm drain inlet would be installed on each residential lot which would all be connected by storm drain piping that feeds into the 18-inch -wide storm drain line. The project includes construction of a retention basin located in the northeastern lot on the project site. This basin would be approximately 10,518 square feet in area and have a storage capacity of 18,156 cubic feet (approximately 0.42 acre-feet). This basin system has been designed to provide water quality treatment of 24-hour, 100-year storm event stormwater flows as well as to reduce the volume of stormwater flows leaving the site to be less than or equal to predevelopment conditions (Thatcher Engineering & Associates, Inc. 2021). The proposed drainage basin would be surrounded by a 6-foot-tall block wall with an access gate located at the southern end of the basin, facing San Luis Street. Construction of the retention basin would also include a gravel overflow spillway to direct stormwater flows into the City Municipal Separate Storm Sewer System in the event that the retention basin reaches capacity. Other on-site improvements include, but would not be limited to, the installation of a streetlight on the western end of the proposed cul-de-sac, and the installation of a new three-way fire hydrant on the western end of the proposed cul-de-sac. Off-Site Improvements: The project would include off-site improvements, including the construction of a sidewalk, curb, and gutter along the project site frontage of Topaz Avenue. Sidewalk ramps would be constructed to the north and south of the proposed access road entrance. Residences: The project would include the development of seven single-family residences with attached garages consisting of three different designs. Each proposed residence would have four bedrooms, and a two-vehicle attached garage. Proposed residences would generally have a craftsman architectural style and be constructed with earthtone colors and materials, including, but not limited to, stucco walls, wood trim, masonry veneer, and concrete or clay tile roofing. All proposed residences would be constructed with heating, ventilation, and air conditioning (HVAC) systems, sprinkler systems, and rooftops with solar photovoltaic-ready zones. Construction Details: Project construction activities would result in approximately 2.51 acres of on-site site disturbance, including 3,558 cubic yards of cut and 1,901 cubic yards of fill material, to be balanced on-site. Project grading and trenching activities would result in a maximum depth of excavation of 108 inches. The project would result in an estimated addition of approximately 5,800 square feet of new impervious surface area on-site. With proposed off-site improvements, the project would result in a total of 12,735 square feet of new impervious surface area. Project construction activities would be expected to last approximately nine months. The project includes a preliminary erosion control plan, which identifies several stormwater best management practices (BMPs) to be implemented during construction activities. These BMPs include but are not limited to, the installation of gravel bags along the perimeter of the project site, construction of a stabilized construction entrance to the site, installation of an aboveground concrete washout area, construction of a temporary sediment basin, use of fiber rolls and gravel bags for inlet protection, street sweeping, application of soil stabilizer, and application of wind erosion control sprays.

Hesperia

San Bernardino

Citywide

California Air Resources Board (ARB), California Department of Conservation (DOC), California Department of Fish and Wildlife, Inland Deserts Region 6 (CDFW), California Department of Parks and Recreation, California Department of Toxic Substances Control (DTSC), California Department of Transportation, District 8 (DOT), California Department of Transportation, Division of Transportation Planning (DOT), California Department of Water Resources (DWR), California Highway Patrol (CHP), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Public Utilities Commission (CPUC), California Regional Water Quality Control Board, Lahontan Victorville Region 6 (RWQCB), Colorado River Board, Office of Historic Preservation, State Water Resources Control Board, Division of Drinking Water, State Water Resources Control Board, Divison of Financial Assistance

Residential (7 Single-Family Residences)(Units 7, Acres 2.51)

Site Plan

Biological Resources, Cultural Resources, Land Use/Planning, Tribal Cultural Resources, Utilities/Service Systems