Department of Water Resources Study

The Montara Water Supply Study which the Commission ordered Citizens to review and incorporate in its Master Plan was a cooperative effort between MSD and DWR. The study and report were completed as part of DWR's Central California Water Management Program. DWR examined technically feasible options for improving water supply reliability within the coastal communities, including Montara. The following are noteworthy conclusions derived during the study:

· According to the entities involved, the Montara water system is inadequate for the current level of development. Water needs exceed the available water supply, including peak demand periods. The capacity inadequacies are related both to infrastructure and water sources.

· Future water needs are based upon the future population connected to the Montara water system. Population changes will be influenced by the water system connection moratorium, the San Mateo County Local Coastal Plan limitations, and the county development review process, including the public response to development proposals. Citizens estimates that yearly water demands will increase by approximately 130 acre-feet by 2030. This projected demand increase does not include the existing system shortage.

· Water development in and around the Montara area has historically been very difficult. Water resources are limited, water development can be competitive, and anti-growth sentiment is significant. Cooperation between various interests and agencies is an important tool that can provide cost savings, improved protection of resources, and increased opportunities.

· MSD has attained legal status as a county water district with the ability to develop, acquire, and sell water. The benefits of public agency status include compliance with the Raker Act private utility exclusion,

more public participation in the planning process, and independence from Public Utilities Commission regulation.

· Hydrologic information and data (both surface water and groundwater) for the area in and around Montara is limited. In many cases, the information currently available may not be sufficient for making water management decisions.

· A number of water supply development options to augment the Montara area supply appear to be feasible. Feasible options include local surface water development, groundwater development, desalination, and negotiation of a water transfer.

· After cursory review, groundwater development and negotiation of a water transfer appear to be most favorable. The most easily developed option appears to be groundwater development. The economic component of the groundwater option is especially attractive, as the cost of preliminary investigation and cost per acre foot seem significantly less than other options.

· Extracting additional groundwater from the Denniston sub-basin appears to be feasible.

· Exploratory drilling can answer a number of immediate questions related to the feasibility of the McNee Ranch and Wagner Valley groundwater options at minimal cost. A pump test, hydrogeologic information derived during the drilling, and minimal analysis should provide adequate information to decide whether to proceed with a design.

· The amount of additional groundwater available may not be sufficient to provide for all projected future demands for water in the Montara area. Cursory estimates by DWR of the yield from the McNee Ranch and Wagner Valley options indicate an annual supplemental supply of 120 acre-feet. If both options were developed, the supplemental yield is slightly less than the additional supply estimated by Citizens Utilities as necessary to meet future population needs.

· The amount of water available through negotiation of a water transfer is limited by conveyance space in relevant pipelines and aqueducts. A water transfer is a negotiated agreement, and therefore can be most effectively and efficiently implemented in a spirit of cooperation. A water transfer would likely be more expensive than groundwater development, but is feasible and could potentially provide a larger long-term yield.

· Conjunctive use¹ may provide significant benefits to local water users including protection of environmental resources, stabilization of groundwater levels, and increased water supply. In the Denniston sub-basin, these benefits may be available if a surface water source can be identified for recharge, and regulators and water users can reach agreement on alternative management strategies.

· Conjunctive use does not appear to be feasible under current groundwater management practices for the Denniston sub-basin, due primarily to an apparent lack of available storage space. However, conjunctive use may be feasible if the sub-basin can be pumped to lower levels without adversely impacting Pillar Point Marsh and a surface supply is identified.

· A more limited approach to conjunctive use in the Denniston sub-basin may provide more limited benefits. Recharge and recovery of surface water during a specific drought year (when water levels are lowered) would provide the above-mentioned benefits, excluding increased water supply. This type of management approach may also provide improved flexibility, but no additional supply as compared to simply delivering the surface or imported supply directly to the water system."

DWR concludes that MSD's Board of Directors and the District's customers need to assess the Montara and surrounding communities' water supply and make a number of decisions about the future. DWR reasons that the reliability of Montara's water supply will impact MSD. DWR recommends that MSD work closely with Citizens in this decision-making process. DWR makes the following recommendations based upon its study:

· An important preliminary step for MSD will be to work closely with the community and San Mateo County to determine the amount of additional development that residents and appropriate agencies would be willing to support.

· MSD should make every effort to work cooperatively with the appropriate organizations to circumvent potential political roadblocks. Organizations include Citizens, Coastside County Water District, San Mateo County, various landowners, as well as the public. Dialogue with each of these entities should begin as soon as practical.

· MSD should develop and encourage public participation and support during the supplemental water supply planning process.

· MSD should support any efforts to improve water resource data and information (especially data collection) for the area in and surrounding the Montara District service area. The district should also monitor current efforts by the landowners and Coastside County Water District² to develop local surface and groundwater hydrology data and information.

· An approved monitoring program for the Denniston sub-basin should be implemented as soon as possible. After approval, an additional 23 acre feet per year may be extracted, according to the Citizens Utilities permit. If monitoring indicates that an additional 5 percent may be extracted without harm to the aquifer or Pillar Point Marsh, Citizens Utilities should apply for a new permit.

· Discussions should be initiated with landowners regarding the potential groundwater development options. If an agreement can be reached for further investigation of a specific option, exploratory drilling should proceed. If the exploratory drilling and review indicates a feasible option, an agreement to develop the option should be negotiated and design should proceed.

· Discussions should be initiated among local water entities regarding potential water transfer options. If participants can agree on terms for additional investigation, a water marketing consultant should be retained to assist in negotiations.