TO: Governing Board of the Lake Berryessa Resort Improvement District
FROM: Christopher M. Silke - District Engineer
REPORT BY: Christopher M. Silke - District Engineer
SUBJECT: Approval of Professional Services Agreement with GHD, Inc.
RECOMMENDATION
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District Engineer requests approval and authorization for the Chair to sign an agreement with GHD, Inc. for a maximum of $183,051 for the period January 25, 2022 to one year after the completion of Scope of Services which includes the investigation of potential secondary locations within the Putah Creek channel to extract water that are more drought resistant.
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EXECUTIVE SUMMARY
Multiple dry year weather patterns and Upper Putah Creek Basin water depletions forced the Governing Board to declare an Emergency Water Shortage on August 17, 2021. Pools levels at the intake reached critically low status with no recharge. Climate change and competing water use within the basin during exceptional drought hydrology require the District to act to find new supply alternatives for the District. GHD, Inc. has submitted a proposal to perform exploratory work for sub-channel water closer to Lake Berryessa and potentially a deep rock well to augment supply.
FISCAL & STRATEGIC PLAN IMPACT
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Is there a Fiscal Impact? |
Yes |
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Is it currently budgeted? |
Yes |
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Where is it budgeted? |
Program 22009 |
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Is it Mandatory or Discretionary? |
Discretionary |
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Discretionary Justification: |
District needs technical expert assistance in hydrogeology to find potential new water supplies. |
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Is the general fund affected? |
No |
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Future fiscal impact: |
None. |
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Consequences if not approved: |
The community could face expensive trucked water imports for minimum health and safety indoor use. |
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County Strategic Plan pillar addressed: |
Choose an item. |
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Additional Information |
Click or tap here to enter text. |
ENVIRONMENTAL IMPACT
ENVIRONMENTAL DETERMINATION: The proposed action is not a project as defined by 14 California Code of Regulations 15378 (State CEQA Guidelines) and therefore CEQA is not applicable.
BACKGROUND AND DISCUSSION
The District provides treatment and delivery of drinking water to District residents. The District’s sole source of supply in Putah Creek experienced withdrawal problems in 2014 and 2021 creating a risk to public health and safety. Pool levels at the intake facility receded to climate change era lows in 2021. Upstream spring fed pool transfers with temporary pumping equipment were essential to maintain water supply in September and October 2021. Repairs to the existing intake structure to meet moderate drought conditions are underway. When Lake Berryessa surface elevation falls below 402 feet and Putah Creek has no flow, the District’s stationary intake operations are switched over to a floating raft to avert a pump failure.
State Water Resources Control Board, Division of Drinking Water regulations state public water systems shall have a sustainable source of supply that can meet maximum daily demand by customers. When drought restrictions are not in effect maximum daily water demand during arid summer months climbs to approximately 56,000 gallons per day. Ideally, the District must attempt to find and intertie a new water supply that can safely yield 100 gallons per minute or more in times of severe dryness and drainage basin depletions.
GHD, Inc. has proposed a scope of hydrogeological and engineering services to investigate the feasibility of a new sub-alluvial (below creek channel) intake near the bottom of thick gravel deposits closer to Lake Berryessa. Three Putah Creek cross-channel transects will be profiled for thickness and saturation depth. If favorable geology is discovered for naturally filtered water supply smaller diameter slant wells will be bored for performance tests and multiple potable water quality sample sets. Second, a deep rock test well will be drilled to assess hydrogeology and water quality for groundwater supply. A Technical Memorandum will summarize the Consultant’s observations, data analysis, conclusions and recommendations if one or both water source locations appears to be developable for full-scale use.
The investigation is expected to take about 10 months and the results will be reported to the Governing Board for consideration of further actions.