Water Resilience Plan: Rapid Assessment — Preliminary Identification of Needs and Strategies with Significant Impact on the Region’s Water

This document represents one of the items set forth in the Water Resilience Work Plan presented to the Board of Supervisors in June 2016. The Rapid Assessment presents some of the early findings of the research to identify the most promising approaches and related financial need. As a piece of the larger Water Resilience Plan, a first draft of which Public Works plans to present to the Board in summer 2017, the Rapid Assessment provides a targeted snapshot of the research outcomes and underscores the greatest perceived needs relevant to building regional water resilience.

The context of climate change and unpredictable rainfall in Southern California has greatly diminished the reliability of imported water supplies and our ability to replenish groundwater in recent years. This new reality calls for practical, effective strategies to access significant amounts of locally available water to supplement and build resilience in the region’s water supply . Currently, the County of Los Angeles manages to capture and store enough stormwater to meet the demand of one and a half million residents each year. Research has shown that implementation of a portfolio of regional stormwater capture projects could increase this amount between two- and three-fold by ensuring the region can capitalize on less regular, more intense rain events.

While other sustainable sources of water should be considered and integrated into a comprehe nsive water management strategy for the region, stormwater represents an accessible, abundant resource with limited funding opportunities. Potable and recycled water are underwritten by ratepayer revenue that also supports improvement and expansion of related infrastructure. Available funding for existing stormwater capture supports current County operations and maintenance, but is insufficient for any significant expansion. Desalination has limited dedicated funding , but relies on costly treatment options that have unclear environmental impacts for the region. Significant investment in regional stormwater capture projects would have substantial impact on local water supply while contributing to improvements in overall watershed health. Stormwater capture strategies, in particular, provide unparalleled opportunities to improve water quality and enhance communities through the integration of multi-benefit approaches. New funding opportunities will be necessary to facilitate the design, implementation, and operations of centralized projects with regional benefits.