The Community Plan lies within the Sullivan Creek and Curtis Creek watersheds. Existing natural channels and on-site, man-made reservoirs should be utilized for storm drainage. Improvements to the storm drainage system may include culverts, covered channels, sedimentation control facilities and storm drains. The use of retention or detention basins will be discouraged within the Community Plan. National Pollution Discharge Elimination System (NPDES) requirements will be met.
The storm drainage system within the Community Plan should be designed to minimize effects on creek or drainage channels. Best management practices for grading on steep slopes, maintaining sediments on-site, reducing substantial run-off over neighboring properties and revegetating and/or terracing on larger cut-and-fill slopes should be considered in the design of the project.
Mountain Springs Community, in conjunction with Tuolumne Utilities District (TUD) is proposing an on-site wastewater treatment facility that will also provide tertiary treated water for irrigation of the existing Mountain Springs Golf Course and potentially other community landscaped areas. The size of the treatment facility and the quantity of tertiary water generated will be based on 897 homes, a 154 room hotel facility, and up to 35,000 square feet of related office and commercial and could provide approximately 65% of the total irrigation needs for the existing golf course. The treated water could correspondingly reduce the need for raw water purchased by the golf facility from TUD in the summer months. The on-site sewage treatment facility would be constructed to State of California and TUD Specifications and then turned over to TUD to manage and operate. Homes and uses that are served within the Mountain Springs Community would pay hookup fees and sewer rates that would support the construction and operation of the facility. The waste water treatment plant would be engineered so that it can be phased with the growth of the community, substantially buried and/or enclosed, and located within the boundary of the golf course. Under current State of California requirements all tertiary treated water will be stored and disposed of on site even during unusually wet years at full build out of the Community. The recycled water would be treated and stored in an upper lake contained within the golf course. Water for irrigation could be blended with additional agricultural water in the upper lake and lower lakes or at the pump location or pumped directly from the upper lake to irrigate the golf course.
Planned sewage facilities serving the Community include trunk collection lines, force mains and pump stations. This internal wastewater collection system would be linked to the on-site treatment facility managed by TUD. A gravity flow system would serve the majority of the Community Plan. Lift stations within the Community Plan are necessary to convey sewage flows through force mains connected to the major gravity components of the system. The lift stations work in conjunction with the main sewer trunk system to convey effluent to the on-site treatment facility. Topographically diverse, remote and lower-density planning areas may utilize individual or joint septic systems, independent of the backbone system. Except for small isolated areas, the only portion of the Community Plan where this may occur is in the Rural Residential and Estate Residential designation located in the southwest corner of the Community Plan. The conceptual sewer collection system is depicted in Figure 8-2.
