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(1998 dollars) |
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Produce water from alluvial aquifers, groundwater basins, or upland bedrock sources. Injection/recovery is also considered, which includes injection of an offsite water source (such as excess Carmel River flow in winter) into a basin (such as the Seaside Coastal Subareas) for later recovery in dry periods. Facilities include wells, pipelines, pump stations, power source, and treatment. Additional Cal-Am facilities are needed to receive increased supply from Seaside area. Operations for injection recovery (Carmel River water diversions) must be coordinated with fish life cycle and river hydrology.
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SWRCB Order 95-10 precludes additional yield from Carmel Valley alluvial sources. Upland sources have very low production rates. Fractured bedrock sources are unproven. Reliable yield in Seaside Basin is presently exceeded. Other areas unproven or minimal. Injection/recovery in Seaside Coastal Subareas could increase reliable yield by 1,700-2,100 af in an average year with proper facilities. An MPWMD pilot project is underway to confirm initial estimates. Report anticipated in summer 1999. |
Capital costs for injection/recovery range of $8.1-15.9 million. Cal-Am facilities needed at a cost of $9.0-18.7 million (total cost of $17.1-34.6 million). O&M costs estimated at $433,000-596,000 per year. These estimates do not include any costs for environmental mitigation or O&M costs associated with Cal-Am system improvements. Cost estimates to be refined based on pilot test project results. |
Up to 2 years needed for environmental review and to obtain permits. 2-5 years for project design, well drilling, and Cal-Am system upgrades. Once installed, project life of injection well is 10-20 years. |
Major Benefits: Carmel River streamflow diverted in winter with low impact; greater reliance on Seaside Basin in summer helps reduce impacts on river system during low-flow season. Relatively small facilities with relatively low impacts and cost compared to other projects. Major Adverse Effects: Construction impacts on Seaside residents. Timing of diversions must be carefully developed; geochemical compatibility with receiving aquifer must be ensured.
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Injection/recovery appears to be feasible based on initial studies. Locations for injection wells may be limited. Yield and cost refinements to be based on pilot project results. Other groundwater options are not considered as viable. Advantages of injection and recovery include efficient use of resources at reasonable cost. Disadvantages include modest potential yield, which is limited by diversion triggers. Only a portion of the 10,730 af cited in Order WR 95-10 would be replaced. Does not qualify for exemption from one-for-one requirement. |
* "Feasible" means project is a reasonably foreseeable means to provide lawful supply for Cal-Am water system. See text for further discussion.