Valley of the Moon Water District Hiring Firm to Evaluate SDC Water System

In advance of an approval of the Sonoma Developmental Center (SDC) proposal by Eldridge Development to create nearly 1,000 homes, a hotel and commercial space, the Valley of the Moon Water District (VOMWD) is “requesting proposals from engineering firms, to evaluate the water system facilities at SDC and make recommendations on needed repairs, upgrades, process changes, etc., and provide an opinion of probable cost (OPC) for the recommended work. For the purposes of this RFP, it is assumed that the distribution system will be replaced concurrent with development including all design work. Therefore, the scope of this evaluation will focus on the diversions, lakes/dams, and raw and treated water transmission systems including storage tanks. The OPC figures will help inform both the District and the Developer of the likely scope and total cost of bringing the water system back online.”

Although no project has been approved, and a lawsuit has been filed asserting that the anticipated use and redevelopment of SDC violates regulations such as the Public Trust Doctrine, evaluation of the SDC water system is proceeding as if development will be approved.

The SDC water treatment plant has been de-commissioned for years, and the amount of money required to address environmental remediation on the site is unknown.

The Request for Proposals (RFP) includes the following components to be addressed:

Facilities Descriptions:

Water Diversions:

• Hill Creek: includes a diversion structure, raw water conveyance (enclosed pipe and open channel) to
  Fern Lake
• Asbury Creek: includes a diversion structure, raw water conveyance (enclosed pipe and open channel)
  to Fern Lake
• Roulette Springs: includes collection piping, a spring box, and conveyance pipe to the water treatment
  plant (WTP) head box
• Sonoma Creek: includes collection piping and pumps to transfer water from Sonoma Creek to
  Suttonfield Lake via a raw water transmission line. This site also had a dam to make water diversions
  possible for a greater portion of the year until the 1980’s. It is possible that this could be
  reconstructed.

Lakes:

• Fern Lake: this is the smaller of the two lakes consisting of 240 acre-feet of storage, and includes two
  earthen dams, a spillway, and a draw-off tower with multiple intake depths. This lake’s elevation is
  above the WTP allowing for gravity feed to the headbox via a raw water transmission line.
• Suttonfield Lake: this is the larger of the two lakes consisting of 600 acre-feet of storage, and includes
  two earthen dams, a spillway, and a draw-off towner with multiple intake depths. This lake’s elevation
  is lower than the WTP, necessitating pumping the raw water to the WTP headbox via a raw water
  transmission line.

Raw Water Transmission:

• Water can be transferred by gravity from Fern Lake to Suttonfield Lake via a raw water transmission
  line and “breaker tank”, which breaks the head pressure at roughly the elevation of the WTP.
• The water flow can be reversed in the line by the use of a raw water booster station located at the
  Sonoma Creek Diversion. These pumps can pull water from Suttonfield Lake and deliver it to the WTP.

Notes: It is likely that additional assessments and field investigations will be required under the scope of this work; the chosen consultant will coordinate those site visits, if needed, with the California Department of General Services (DGS) and the District.