CIAB/PUBLIC WORKS COMMISSION
SUBMITTED TO: MEMBERS OF CIAB/PUBLIC WORKS COMMISSION
SUBMITTED BY: Chau Vu, Director of Public Works
PREPARED BY: Kristen Schroeder, Water Quality Supervisor
Subject:
title
Review of the Interagency Water Transfer Feasibility Study with Mesa Water District
body
Statement of Issue:
This item provides an update to the Public Works Commission on the results of a completed feasibility study conducted in coordination with Mesa Water District to evaluate a potential interagency groundwater transfer using the existing OC-44 pipeline. The study examined technical feasibility, regulatory considerations within the Orange County Water District basin, and long-term implications for water supply reliability and cost management.
Financial Impact:
The feasibility study estimates that the proposed water transfer program could provide approximately $1,951,661 in annual cost savings for the City, with continued long-term financial benefits projected through 2050. These projections do not include initial program costs, such as required infrastructure construction, legal and regulatory compliance, and SCADA modifications. When all costs are considered, the study anticipates a return on investment in less than five years.
Recommended Action:
recommendation
No action needed. This is informational only.
end
Alternative Action(s):
Not applicable.
Analysis:
Water producers in the Orange County Groundwater Basin are currently allowed to meet up to 85 percent of their water demand using local groundwater, purchased from the Orange County Water District (OCWD) at a cost of $711 per acre-foot (plus power and treatment). The remaining 15 percent must be supplied using imported water from the Municipal Water District of Orange County (MWDOC) at a much higher cost of $1,528 per acre-foot.
Mesa Water operates the Mesa Water Reliability Facility (MWRF), which pumps from a deeper aquifer that is not subject to the 85 percent pumping limitation. This allows Mesa Water to produce 100 percent of its water supply from groundwater. Because the MWRF currently uses only about 25 percent of its total treatment capacity, Mesa Water has significant unused production-more than 17,000 acre-feet per year available through 2050. Mesa Water approached Huntington Beach to explore whether it would be interested in purchasing some of this surplus supply. Such an arrangement would be financially beneficial to both parties: Mesa Water would generate revenue on water that otherwise goes unused, and Huntington Beach could purchase potable water at a lower cost than imported supplies.
The feasibility study confirms that an interagency transfer using Mesa Water’s existing groundwater production and the MWRF is both technically and financially viable. The study also estimates that, for the City, the capital investments required for participation could achieve a return on investment in less than five years, once all associated costs are included. Two infrastructure options were identified as feasible: (1) a gravity-flow connection using a pressure-reducing valve, which may require limited supplemental imported water during peak demand periods, or (2) continuous deliveries supported by a booster pump station.
Further evaluation is still needed, including confirmation of OCWD requirements related to the transferability of MWRF-produced water, detailed hydraulic and surge modeling, operational delivery planning, and the development of a partnership framework to establish purchase agreements, delivery volumes, and transfer terms. Overall, the findings support continued coordination with Mesa Water to refine the most cost-effective and reliable approach for a potential regional groundwater transfer program.
Attachment(s):
1. Interagency Water Transfer Feasibility Study
2. PowerPoint Presentation