PURPOSE
Northern San Benito County is fortunate to have a diverse and well-engineered water supply and distribution system. The system has numerous desirable features that are rarely found in agricultural areas in northern California, including a substantial allocation of imported surface water of high quality, a large groundwater basin available for conjunctive use, numerous river and creek channels already in use for supplemental groundwater recharge, a gravity-pressurized pipeline distribution system for imported water that minimizes leaks and saves energy, metering of groundwater pumping, and groundwater replenishment fees.
These physical and institutional assets provide considerable flexibility in water resources management. Unlike other areas, where groundwater management is an unwelcome encumbrance needed to deal with water supply shortages or forestall imminent resource degradation, northern San Benito County can enjoy the luxury of implementing a groundwater management plan to reap further benefits from their water resources system, including increased yield and reliability, improved water quality, and lower cost.
Development of this plan was prompted by the realizations that groundwater plays an essential role in agricultural and urban activities, that those activities affect the availability and quality of groundwater, and that groundwater, imported water, local surface water, and wastewater are interrelated in a single, complex hydrologic system. Although the overall condition and outlook for water resources in the area is good, certain aspects of available water resources and their management have created problems in the past or could lead to problems in the future.
Current or potential physical problems include local imbalances between recharge and pumping, poor water quality (i.e., salinity, nitrates, and boron), local areas of shallow groundwater or limited percolation capacity, and future increases in water demand. Institutional difficulties have included poor interagency coordination of land and water use and lack of a common understanding of the amount and quality of available groundwater. Even in the absence of physical or institutional problems, however, the groundwater and surface water systems are sufficiently complicated to benefit from a coordinated management plan.
The purpose of this groundwater management plan is to clearly state how local agencies and interest groups in northern San Benito County have agreed to manage groundwater and related water resources in the San Benito County part of the Gilroy-Hollister groundwater basin.
A coordinated, interagency groundwater management plan is a desirable means of protecting groundwater quality and quantity and achieving an ample, reliable, and economical supply of water for all beneficial uses.
This groundwater management plan will necessarily evolve as issues and conditions change. For example, the information used to evaluate the condition of the groundwater basin and characterize management issues consists only of data through water year 1997. Thus, data related to the flood in February 1998 are not reflected in this plan.
Similarly, the plan focuses on issues and potential management actions of greatest importance in early 1998, when the plan was first drafted. As land and water use patterns change and as the effects of management actions become apparent, new issues and management actions will emerge to the forefront. Others may become less important as a result of cost, environmental impacts, or decreased need.
APPROACH
This plan is the result of a collaborative planning process that included representatives from San Benito County Water District, City of Hollister, Sunnyslope County Water District, City of San Juan Bautista, Tres Pinos County Water District, Aromas Water District, San Benito County, San Benito County Farm Bureau, San Benito County Builders and Developers Association, and the Sierra Club. The planning process was initiated in May 1997 by means of a memorandum of understanding (MOU) endorsed by most of the participants. Key clauses in the MOU included:
"The purpose of the Memorandum of Understanding is to establish a process between the signatory parties for developing a policy level Groundwater Management Plan (Plan).
The Plan to be developed will include only information, policies, programs, and recommendations agreed upon by all signatory parties."
"The Groundwater Management Plan is to be a policy level document developed, to the maximum extent possible, from existing county, city, and district plans, reports and documentation and directed to achieve the following goals:
"This Memorandum of Understanding does not address the adoption of any groundwater management."
"The Agency Advisory Group will operate by consensus (unanimity) and shall serve as an advisory body to all signatories."
"Meetings of the Agency Advisory Group shall be open to the public, noticed and conducted in accordance with the Brown Act..."
The planning process was funded by the first six of the aforementioned agencies through a cost-sharing agreement. The process consisted of monthly meetings of the planning group, which began in May 1997 and continued through March 1998. A technical advisory group was convened partway through the process to advise the planning group on the importance of various issues and the feasibility of selected management actions. Jones & Stokes Associates was retained to facilitate the planning process meetings and prepare the plan document.
This plan reflects the consensus of the participants in the planning group. After the group discussed each groundwater management issue and identified potential management actions, the facilitator prepared draft text summarizing his sense of the group's opinions and conclusions. The group then revised the text as needed until all participants found the statements and proposals at least acceptable if not desirable.
Implementation of this plan will consist of voluntary, coordinated actions by the participating agencies’ using their existing powers and authorities. This plan is similar in scope and intent to groundwater management plans developed pursuant to AB 3030 (Water Code Section 10750 et seq.), the Groundwater Management Act passed by the legislature in 1992 (Bachman et al. 1997). This plan does not rely on authority granted by AB 3030 because local agencies in San Benito County already collectively have all of the authority needed to develop and implement a groundwater management plan.
