LA’s Water Resource Future Workshop Series
In support of UCLA's Sustainable LA Grand Challenge, the Center for Climate Change Solutions is co-hosting a two-part workshop series investigating how more local stormwater can be harnessed to decrease the Los Angeles region's dependence in imported water. The workshops are co-hosted by the Institute of the Environment and Sustainability and the Luskin Center for Innovation and co-organized by the UCLA Water Resources Group. Partial support for the series is provided by the Office of Interdisciplinary and Cross Campus Affairs.
Workshop 1: Understanding Local Stormwater Capture Potential
Date: February 19, 2016
In this workshop, participants will explore the following questions:
- State of stormwater management: How much stormwater flows into LA's groundwater basins now, naturally and through spreading projects? How much stormwater flows out to the sea uncaptured? Where are existing and planned spreading grounds? Can the built flood control system be retrofitted and repurposed for more capture?
- Stormwater capture and infiltration in the urban space: What is the potential for stormwater capture and infiltration on streets and highways, public lands, and privately owned lots across the region?
- Climate change impacts on precipitation: Although precipitation averages are not expected to change in the future, is the character of precipitation events likely to change (e.g., fewer but more intense storms)? How can this be modeled for the LA region? What are the possible implications for stormwater capture and infiltration?
- Stormwater and ecosystems: What are the stormwater needs of the region's rivers and coastal wetlands? What is the potential for increased stormwater capture to have negative impacts on river and wetland ecosystems?
The program will consist of talks and panel sessions by invited speakers, each followed by Q&A periods and discussion by all attendees.
Session 1: Overview of Recent Regional Stormwater Capture Analysis and Plans
Panelists: William Steele, Bureau of Reclamation (invited); Lee Alexanderson, LA County Department of Public Works; Rafael Villegas, Los Angeles Department of Water and Power; Renee Purdy, Los Angeles Regional Water Quality Control Board
Session 2: Modeling Tools Currently Used in Stormwater Capture Planning: Strengths and Limitations
Panelists: TJ Moon, LA County Department of Public Works; Scott Mansell, Geosyntec Consultants; Tracy Nishikawa, US Geological Survey; Dustin Bambic, Paradigm Environmental
Session 3: Recent, Ongoing, and Planned Academic Research on Stormwater Issues
Speakers: Alex Hall, UCLA Center for Climate Change Solutions and Dept. of Atmospheric and Oceanic Sciences; Dennis Lettenmaier, UCLA Dept. of Geography; Terri Hogue, Colorado School of Mines; Peter and Hadley Arnold, Arid Lands Institute, Woodbury University
Session 4: Ensuring Ecosystem Benefits from Stormwater Capture
Speaker: Richard F. Ambrose, UCLA Dept. of Environmental Health Sciences and Institute of the Environment and Sustainability
Session 5: Policy Barriers to Increased Stormwater Capture and Potential Solutions
Speaker: JR DeShazo, UCLA Luskin Center for Innovation
Space is limited and reservations are required. For more information and to RSVP, contact Katharine Reich at firstname.lastname@example.org by February 12.
Workshop 2: Understanding Local Groundwater Storage Potential
Date: Coming soon
In this workshop, participants will explore the following questions:
- Physical state of groundwater basins: Which of the region's groundwater basins are currently suitable for increased storage of stormwater? How much capacity do these groundwater basins have? Which parts of the region's groundwater basins are currently unsuitable for increased storage because of contamination? What are the barriers to making these basins suitable? How much could they store if they were made suitable?
- State of groundwater governance: Who gets the water from various basins in the region? What are the sources of that water? What is the potential for changing groundwater rights? Are governance arrangements adequate for increasing capture and storage potential of water to be made available to LA residents?
- Climate change impacts on sea level: Which groundwater basins are vulnerable to sea level rise with climate change? Can saltwater intrusion be avoided or mitigated?
More About the Workshops
Currently, most of the water used in the Los Angeles region is imported from distant sources such as the Sierra Nevada, where the abundance, quality, and cost of water are likely to be adversely affected in the coming years by climate change and other pressures. Meanwhile, the region does not take full advantage of local water resources: By some estimates, half of local stormwater runs off to the ocean without being captured or used. Research by Center for Climate Change Solutions Faculty Director Alex Hall indicates that, compared with water from distant sources, Los Angeles's local water is not as vulnerable to climate change. In 2050 and beyond, we can expect roughly the same amount of local precipitation, on average, as we receive now, and warming won't significantly alter runoff from our mountains or evaporation from our streams and soils.
Local stormwater is an underexploited resource in the Los Angeles region.
Recognizing the relative stability of the local water resource, a key aim of the Sustainable LA Grand Challenge Project is to decrease reliance on distant sources while increasing reliance on local ones. Local stormwater is an underexploited resource in the Los Angeles region. In response to past catastrophic flooding events, our current infrastructure was designed to conduct stormwater out to the ocean as quickly as possible. In theory, increased stormwater capture could expand LA's local water supply, but one barrier to stormwater use is that it becomes polluted very quickly as it moves through urbanized areas. Allowing stormwater to infiltrate into aquifers before reaching roads and highways, where it is polluted, is one way to address the pollution issue, since water is filtered as it percolates through soil. In recent years, efforts have been made to direct stormwater onto spreading grounds in order to replenish aquifers, but to meet the Sustainable LA Grand Challenge goal of increasing reliance on local water, more needs to be done.
But to understand how much imported water can be replaced by local water, we must quantify how much local stormwater we can realistically capture, infiltrate, store, and use. Undertaking this analysis is a truly interdisciplinary enterprise, requiring the expertise not only of the climate and earth system scientists who model the flow of water through natural systems, but also of the scholars of engineering, urban planning, and policy who study its flow throughout human systems. It also requires input from the agencies that make decisions about how our water is collected, stored, and managed. Today those same agencies are working to “retrofit” the flood control system for more stormwater capture, coinciding with the goals of the Sustainable LA Grand Challenge Project.
To understand how much imported water can be replaced by local water, we must quantify how much local stormwater we can realistically capture, infiltrate, store, and use.
This workshop series will explore what is currently known and what remains to be discovered about the potential for stormwater capture and groundwater storage in the region. Participants will discuss the current state of stormwater management and of groundwater basin capacity and governance, assess the potential for increased capture and infiltration, assess potential climate change impacts, and consider potential impacts of increased stormwater capture on the region's ecosystems. The first workshop will focus on stormwater capture, and the second will focus on groundwater storage and governance issues. This discussion will inform the implementation of the Sustainable LA Grand Challenge Work Plan by identifying research capabilities and gaps, as well as opportunities for collaboration.