REPORT/RECOMMENDATION TO THE BOARD OF SUPERVISORS
OF BOARD GOVERNED COUNTY SERVICE AREAS
AND RECORD OF ACTION
January 27, 2026
FROM
NOEL CASTILLO, Director, Department of Public Works - Special Districts
SUBJECT
Title
Amendment to Professional Design Services for the CSA 70J Oak Hills Reservoir - Reservoir 3A Site Expansion Project
End
RECOMMENDATION(S)
Recommendation
Acting as the governing body of the County Service Area 70J Oak Hills, approve amendment No. 1 to Contract No. 24-657 with Albert A. Webb Associates, increasing the contract amount by $70,590, from $472,255 to $542,845, for additional professional design services and construction support services for the CSA 70J Oak Hills Reservoir - Reservoir 3A Site Expansion Project, with no change to the contract’s term of July 23, 2024 through July 23, 2029.
(Presenter: Noel Castillo, Director. 387-7906)
Body
COUNTY AND CHIEF EXECUTIVE OFFICER GOALS & OBJECTIVES
Ensure Development of a Well-Planned, Balanced, and Sustainable County.
Provide for the Safety, Health and Social Service Needs of County Residents.
Pursue County Goals and Objectives by Working with Other Agencies and Stakeholders.
FINANCIAL IMPACT
Approval of this item will not result in the use of Discretionary General Funding (Net County Cost) as all costs, including the recommended professional engineering design and services contract, for the County Service Area 70J Oak Hills (District) - Reservoir 3A Site Expansion Project (Project) will be funded by the District through revenue from service charges. Sufficient appropriation for the Project is included in the District’s 2025-26 Capital Improvement Program budget and will be included in future recommended budgets, as needed.
BACKGROUND INFORMATION
The Project involves the design and construction of a new two-million-gallon water tank, booster station, equipment control building, stormwater/overflow detention basin, and other appurtenant devices necessary for the tank’s operation. The new tank will allow the District to expand the potable water infrastructure, better serve the community, and increase the County’s fire suppression capabilities.
On July 23, 2024 (BAI Item No. 72), the Board of Supervisors approved the competitively procured professional engineering design and service contract with Albert A. Webb Associates (Consultant) for $472,255 for the Project through the County’s Electronic Procurement Network (ePro), reference: Bid No. SPD124-WATER-5044, Notification No. 955712.
During the course of design development and site investigation, additional site conditions and engineering requirements were identified that were not reasonably foreseeable or fully defined at the time the original scope of work was prepared. Specifically, subsequent hydrology evaluations and field investigations revealed that off-site runoff entering the Project area could not be adequately managed by the originally proposed detention basin, which had been designed based on limited information available during preliminary scoping. Further analysis confirmed that additional mitigation measures are required to safely address off-site stormwater flows and to protect existing and proposed facilities. To address these conditions, the Consultant performed additional hydrologic and hydraulic analyses consistent with the San Bernardino County Hydrology Manual to evaluate off-site runoff for multiple storm events (2-year through 100-year). Based on these findings, the design required modifications to include off-site runoff diversion and storm drain improvements to ensure that off-site flows bypass the proposed detention basin and do not compromise the project’s functionality or downstream properties.
In addition, further field investigations identified the need for previously unanticipated improvements and design refinements, including modifications to an existing valve vault and piping configuration, restoration and stabilization of an existing maintenance road experiencing significant erosion, evaluation and design of a new 24-inch storm drain culvert with associated inlet and headwall structures, and the addition of alarm sensors and related Supervisory Control and Data Acquisition (SCADA) components for existing tanks and vault access. These efforts required additional site visits, coordination with County staff, structural and civil design updates, and revisions to plans, specifications, and cost estimates.
The proposed contract amendment reflects these additional professional services, including project management, hydrology and hydraulic evaluation, civil and structural engineering design, preparation of revised plans and specifications, and construction support associated with the newly identified improvements. The amendment also includes a reallocation of previously scoped but no longer necessary work, resulting in a net contract increase of $70,590, raising the total contract amount from $472,255 to $542,845, with no change to the contract term ending July 23, 2029.
Approval of this amendment will allow the project to proceed with a complete and constructible design that appropriately addresses site conditions, regulatory requirements, and long-term operational reliability for CSA 70J facilities.
PROCUREMENT
Not applicable.
REVIEW BY OTHERS
This item has been reviewed by County Counsel (Aaron Gest, Deputy County Counsel, 387-5455) on December 19, 2025; and County Finance and Administration (Mathew Dalton, Administrative Analyst, 387-5050) on January 8, 2026.