Due Diligence Support for Various Water Bank Locations, Santa Clara County

Since 2020 EKI has supported Valley Water in the assessment of multiple water banking opportunities. Work efforts have included in-depth analysis of existing water bank performance and risk factors, including those related to water quality (including treatment cost estimates) and declining groundwater levels, and systemizing the process to support Valley Water’s on-going assessment of water bank performance and risk factors.

Due Diligence: EKI provided due diligence and technical support to assess potential groundwater banking sites. The work included analyzing existing water bank performance and risk factors, estimating projected storage changes using numerical groundwater modeling and volumetric calculations, and evaluating groundwater elevation and water quality data through custom analytical tools for statistical analysis. EKI also developed conceptual cost estimates for various treatment scenarios and assessed new water banking opportunities by reviewing hydrogeologic conditions, infrastructure requirements, operational strategies, and potential recharge basin locations.

Water Bank Siting and Feasibility Study. EKI is supporting the District with groundwater banks siting within Valley Water’s area of interest in the Central Valley and conducting due diligence study on potential sites. EKI has developed a geographic information system (GIS)-based screening tool to systematically identify and rank potential sites for groundwater banking using a set of key hydrogeologic, institutional, and infrastructure criteria. This involves estimation of storage and recharge capacities of the potential sites, identification of potential partners, and evaluation of potential constraints and next steps.

Outcome

Based on EKI’s work and recommendations for target sites and next steps, Valley Water is now moving forward with the development of new water banking, transfer, and exchange opportunities. This will eventually help the district manage wet year water supplies, and to provide critically important dry year supplies to meet demands and to protect Santa Clara County’s groundwater basin from overdrafting and subsequent land subsidence.