Chapter 6: Conclusions and Recommendations

A. CONCLUSIONS
Conjunctive use management of the surface and groundwater in Yolo County could provide these benefits to the County as a whole:

1. Reduce or eliminate areas of continuous overdraft of the groundwater basin, particularly in Lower Cache-Putah sub-basin;
   
2. Control current land subsidence and protect areas from further subsidence in Lower Cache-Putah and Colusa sub-basins;
   
3. Increase storage of groundwater for water needs during drought years and surface water shortages;
   
4. Protect the aquifer capacity by controlling compaction of water-bearing materials, and preserving storage capacity in critical areas;
   
5. Control and prevent deteriorating groundwater quality in localized areas of the groundwater basin;
   
6. More intensively and effectively use the groundwater available to the County to meet its water demands (in conjunction with available surface supplies) at an overall cost likely to be lower than importing new surface water; and
   
7. Turn the County from a reactive agent to proposed water transfers outside the County, to a pro-active agent in managing the impacts of future planned water transfers.

There are a wide variety of conjunctive use possibilities for Yolo County to draw from to achieve these beneficial outcomes. A number of these possible alternative schemes have been described conceptually in this report. The County now faces an important decision in choosing the future direction of the planning and management of its water system. It can choose to carry on in its current mode and ignore the opportunities offered by conjunctive use management. In the long-term this path of action typically leads to often very costly adjudication of the groundwater basin, after substantial damage to the aquifer has occurred and overdraft conditions become intolerable. In effect, this has been a common historical pattern of water resource management in California (Kletzing, 1988).

On the other hand, Yolo County is in a relatively advantageous water position, with good groundwater resources, and adequate supplies of surface water to be able to conjunctively manage its water system. Using the kinds of conjunctive schemes described in this report, the County should be able to cost-effectively resolve groundwater overdraft problems, handle expanding urban water demands, and manage droughts and water transfers. To realize these potential benefits, the County should considered the recommendations below and initiate the processes that will move the County in the direction of effective conjunctive use management.

B. RECOMMENDATIONS
Among the recommendations emerging from this investigation are some that run parallel to recommendations contained in the Yolo County Water Plan Update Draft (Borcalli and Associates, 1992a). The orientation in this report has however been much more towards the County's groundwater resources, and their important role in the County's water supply system. Therefore, some of the following points will differ in emphasis and perspective from those in the Water Plan Update Draft.

1. Begin public and technical dialogs and discussions about the direction of future County-wide water planning for Yolo County and the opportunities presented by a conjunctive use management approach.
   
2. Establish a task force to study alternative institutional forms for integrated County-wide water management in Yolo County, with special attention to institutional considerations related to managing groundwater.
   
3. Develop a technical groundwater program, including comprehensive County-wide central data collection, analysis, and groundwater modeling Particular attention should be given to making this program readily accessible and prominently featured to all agencies and the public, and coordinated at appropriate levels of every water agency in the County.
   
4. Continue to supply M&I water demands with groundwater in Yolo County. Groundwater is less costly and more reliable than using imported surface water supplies. Opportunities to assure M&I users with adequate local groundwater supplies using the many different types of conjunctive use schemes proposed in this report should be investigated before finalizing any new plans to develop surface water supply projects for M&I users in Yolo County.