Oak Valley-Summerwind Offsite Sewer Project

Oak Valley-Summerwind Offsite Sewer Project

YVWD proposes to construct 14,600 linear feet of 10-inch and 12-inch parallel force mains and 9,500 linear feet of 18- to 21-inch gravity sewer main connecting the Summerwind Ranch residential development in the City of Calimesa to the existing Wochholz Regional Water Recycling Facility (WRWRF) in the City of Yucaipa. Where future Roberts Road is intended to cross the Garden Air Creek at the southernmost Project boundary, the pipeline alignment turns due east south of the creek and continues to the Interstate 10 Caltrans right-of-way; this east-west alignment is located in a strip of land contiguous with the north boundary of the Summerwind residential development. Once the pipeline alignment reaches the Caltrans right-of-way, it turns northerly and continues in a strip of land contiguous to the westerly Caltrans right-of-way until it reaches Sandalwood Drive; those properties are currently owned by the Western Riverside County Regional Conservation Authority (WRCRCA) and the Mesa Verde Project. A portion of the pipeline would be installed underneath the Garden Air Creek using a bored and jacked casing. Once in Sandalwood Drive, the pipeline alignment would continue in public road right-of-way northerly in Sandalwood Drive and 7th Street, westerly along Ave L, then northerly in 7th Place to a discharge manhole at the intersection of 7th Place and County Line Road. From the discharge manhole the pipeline alignment would continue westerly in County Line Road until it reaches the entrance to the WRWRF, and from there would continue westerly in the treatment plant access road until it discharges into the headworks of the treatment plant. The alignment would also extend 1,200 linear feet easterly along County Line Road from 7th Place to Calimesa Boulevard. The majority of the sewer force mains and gravity sewer will be constructed within public road right-of-way. However, that portion of the alignment starting at the north boundary of New Roberts Road until it reaches Sandalwood Drive is located within undeveloped private property that would require property dedications to YVWD to both construct and maintain the force mains. Property dedications will be required from the Summerwind developer along its north property boundary, the WRCRCA along its easterly property boundary, and the Mesa Verde developer on its easterly property boundary starting at Garden Air Creek and continuing to Sandalwood Drive. Because a road will need to be graded along the alignment and there will be dual force mains constructed within a single trench, the property dedication will be 60 feet wide. Construction of the pipeline alignment within the public road right-of-way would include trenches approximately five feet wide. A 20-foot-wide working zone would be required for spoil piles and equipment. Construction along the pipeline alignment outside of the public road right-of-way (south of Sandalwood Drive) would require an average width of 50 feet. The entire Project Area consists of approximately 29 acres. The force main pipeline would follow the alignment described above, from the southernmost Project boundary to the intersection of 7th Place and County Line Road. The force mains are designed to carry a range of flows starting with low flows during initial operation, and then gradually increasing flows, and then finally ultimate flows when the Summerwind residential developments are built-out. Initially, sewage would flow through the 10-inch force main at a rate of 800 gallons per minute (gpm), which is greater than the initial peak sewage flow of 357 gpm. When flows increase and the flow rate approaches the capacity of the 10-inch force main (at approximately 750 gpm) the station discharge will be switched to the 12-inch force main. The sewage would then discharge through the 12-inch force main at a rate of 1,175 gpm until the sewage flow rate approaches the capacity of the 12-inch force main (at approximately 1,100 gpm). Once the 12-inch capacity is met, both force mains would be used and sewage will then discharge from the station through both the 10-inch and 12-inch force mains at a design flow rate of 1,782 gpm. The extended force main would convey the sewage to a new discharge manhole located at the intersection of 7th Place and County Line Road where it can discharge into a new gravity sewer pipeline. The gravity sewer pipeline would then run westerly in County Line Road the remaining distance to the WRWRF. The Project would also extend the new sewer pipeline easterly in County Line Road from the 7th Place manhole to the intersection of Calimesa Boulevard (approximately 1,200 linear feet of 18- to 21-inch pipeline) to divert current flows in the Calimesa Boulevard sewer pipeline to the new sewer pipeline in County Line Road. It is anticipated that construction would take eight months and would occur in 2022.

Calimesa, Yucaipa

Riverside, 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 Water Resources (DWR), California Highway Patrol (CHP), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Regional Water Quality Control Board, Santa Ana Region 8 (RWQCB), Office of Historic Preservation, San Gabriel and Lower Los Angeles Rivers and Mountains Conservancy (RMC), State Water Resources Control Board, Division of Drinking Water

State Water Resources Control Board, Division of Drinking Water

Other (Sewer Facilities)

Site Plan

Air Quality, Biological Resources, Cultural Resources, Geology/Soils, Noise, Transportation, Tribal Cultural Resources