For Water Subcommittee Meeting August 27, 2026
TO: Water Subcommittee Members
APPROVAL: Yazdan Emrani P.E., Director of Public Works
FROM: Nicole Hemmans, Senior Administrative Analyst
Title
Staff Request Water Subcommittee Receive an Update on the River Ranch Basin Recharge.
RECOMMENDATION:
Staff recommends that the Water Subcommittee receive an update on the River Ranch Basin Recharge.
Body
BACKGROUND:
The City of Rialto, West Valley Water District, and Fontana Water Company are retail water agencies providing water services within their respective service areas and have wells located in the Lytle Creek Basin, which is a subbasin to the San Bernardino Basin, as part of their respective water supply portfolio. The San Bernardino Municipal Water District (Valley District), a regional water agency, is a State Water Contractor with access to State Water Project (SWP) supplies, which is a primary supplemental water source to the region.
Valley District and the three above mentioned water agencies (collectively “Water Agencies”) are interested in enhancing recharge of SWP supplies and stormwater in the Lytle Creek Basin. These Water Agencies are parties to the San Bernardino Basin Groundwater Council (Council) and each pay their respective proportionate share to the Council for uses on purchases of SWP supplies for recharge and costs related to operation and maintenance of facilities for recharge in the San Bernardino Basin.
ANALYSIS/DISCUSSION:
As part of the River Ranch Development, Lennar Homes constructed three (3) stormwater detention basins-Basin 0, Basin 1, and Basin 2. Upon completion of the development, Basin 0 is anticipated to be transferred to Lytle Development, while Basins 1 and 2 are anticipated to be transferred to the Homeowners Association (HOA) for long-term operation and maintenance.
The Water Agencies and Lennar Homes have expressed interest in collaboratively utilizing the onsite detention basins to enhance stormwater management and State Water Project (SWP) recharge. Under the proposed arrangement, the Water Agencies, through the City Council, would be responsible for the long-term operation and maintenance activities associated with SWP recharge, including, but not limited to, scarifying basin bottoms, maintaining slope vegetation, and performing other related recharge activities. Flood control-related responsibilities would remain with the respective basin owner and would include, but not be limited to, operations during storm events, storm debris removal and clearing, stormwater flow management, and applicable permitting requirements. Lennar Homes or its successor, including the HOA, would remain responsible for the operation and maintenance of areas outside the top of the basin slopes and within the respective basin parcels.
Exhibits A & B on Attachments 1 & 2, identify the location of the SWP supply facilities and their proximity to the River Ranch detention basins. The Water Agencies are currently negotiating a long-term facility use agreement that would establish the respective responsibilities and terms for utilizing the basins for SWP recharge. The agreement is anticipated to be presented to the Water Subcommittee and City Council for consideration prior to the end of 2026.
ATTACHMENTS
1. Exhibit A
2. Exhibit B