For Water Subcommittee Meeting April 30, 2026
TO: Water Subcommittee Members
APPROVAL: Tanya Williams, City Manager
FROM: Nicole Hemmans, Senior Administrative Analyst
Title
Staff Recommends the Water Subcommittee Receive an Update and Provide Feedback on the Final 2025 Urban Water Management Plan (UWMP)
Body
RECOMMENDATION:
Staff recommends that the Water Subcommittee receive an update and provide feedback on the Final 2025 Urban Water Management Plan (UWMP).
BACKGROUND:
California Water Code Section 10621(a) requires urban water suppliers to update their Urban Water Management Plan (UWMP) at least once every five (5) years, with the 2025 UWMP due to the California Department of Water Resources (DWR) by July 1, 2026.
As previously presented to the Water Subcommittee on March 27, 2025, the City of Rialto participated in a regional UWMP effort led by San Bernardino Valley in coordination with multiple regional water agencies. This regional approach allows participating agencies to streamline costs, share data, and ensure consistency across water supply planning efforts.
Water Systems Consulting, Inc. (WSC) was selected through a regional Request for Proposals (RFP) process to prepare the 2025 UWMP.
Since that time, staff and the consultant team have worked collaboratively to complete the required updates, incorporating current water supply data, demand projections, regulatory requirements, and long-term planning assumptions.
ANALYSIS/DISCUSSION:
The Final 2025 UWMP has now been completed and includes updated information related to:
• Water supply reliability under normal, single-dry, and multiple-dry year scenarios
• Water demand projections and population growth assumptions
• Water shortage contingency planning
• System reliability and infrastructure considerations
• Compliance with State requirements, including water use efficiency standards
The UWMP serves as a critical long-range planning document that demonstrates the City’s ability to meet current and future water demands while maintaining compliance with State regulations.
As required by the Urban Water Management Planning Act, the City must conduct a public hearing prior to adoption of the UWMP. The purpose of the public hearing is to provide an opportunity for community input and to ensure transparency in the City’s water supply planning process.
Staff is preparing to bring the Final 2025 UWMP to the City Council/Rialto Utility Authority Board for consideration of adoption. Timeline is as follows:
Ø Set a public hearing date - Tuesday, May 12, 2026
Ø Conduct the required public hearing - Tuesday, May 26, 2026
Ø Submission to the State - Wednesday, July 1, 2026
This item is being presented to the Water Subcommittee to provide an update on the status of the UWMP and to receive any feedback prior to advancing the item to the City Council.
ATTACHMENTS
Attachment 1 - Regional Context
Attachment 2 - Rialto UWMP
Attachment 3 - Regional Appendices
Attachment 4 - Rialto UWMP Appendices
Attachment 5 - Rialto WSCP Appendices
Attachment 6 - Regional Executive Summary