The Press and Pulse of Climate Change: Extreme Events in the Colorado River Basin

American Water Resources Association (AWRA) | June 21st, 2022

Extremes in temperature and precipitation are associated with damaging floods, prolonged drought, destructive wildfires, agricultural challenges, compromised human health

Extremes in temperature and precipitation are associated with damaging floods, prolonged drought, destructive wildfires, agricultural challenges, compromised human health, vulnerable infrastructure, and threatened ecosystems and species. Often, the steady and progressive trends (or presses) of rising global temperature are the central focus in how climate impacts are described. However, observations of extreme weather events (or pulses) increasingly show that the intensity, duration and/or frequency of acute events are also changing, resulting in greater impacts on communities and the environment. Describing how the influence of extreme events may shape water management in the Colorado River Basin in clear terms is critical to sound future planning and efforts to manage risk. Three scenario planning workshops in 2019 and 2020 were held as part of a Colorado River Conversations series, identifying potential impacts from multiple intersecting extreme events. Water managers identified climate-related events of concern in the Colorado River Basin that necessitate greater attention and adaptive responses. To support efforts to include consideration of climate-change-driven extremes in water management and planning, we explore the current state of knowledge at the confluence of long-term climate shifts and extreme weather in the Colorado River Basin related to the events of concern that were identified by scenario planning participants.

The Resilience Value of Recycled Water for Los Angeles

University of California, Los Angeles (UCLA) | November 13th, 2024

In 2019, the City of Los Angeles (City) announced the development of the Operation NEXT Water Supply Program (Operation NEXT or Program) (City of Los Angeles, 2019), an a

In 2019, the City of Los Angeles (City) announced the development of the Operation NEXT Water Supply Program (Operation NEXT or Program) (City of Los Angeles, 2019), an advanced water recycling project aimed at expanding the use of purified recycled water. The current approach for Operation NEXT (now Pure Water Los Angeles) encompasses several distinct water infrastructure components. One is the construction and operation of an advanced water treatment purification facility at the Hyperion Wastewater Treatment Plant, the largest wastewater treatment facility west of the Mississippi. This project, in partnership with Los Angeles Sanitation & Environment comprises the Hyperion 2035 Program (Hyperion 2035) (LADWP, 2024; LASAN, 2024). Once constructed, potable recycled water flows from this facility will further diversify the City’s water supply portfolio, adding up to 257,636 acre-feet of supply each year once it is fully operational. A second component of Operation NEXT is a conveyance system that will transport this purified recycled water to groundwater basins or further treatment facilities, where it will be stored or blended with other water supplies. Currently, the construction and operation of Operation NEXT is still being estimated, and costs range between $6.4 billion and $24.0 billion USD as of 2020.

The Role of Snowpack, Rainfall, and Reservoirs in Buffering California Against Drought Effects

U.S. Geological Survey (USGS) | August 1st, 2016

California’s vast reservoir system, fed by annual snow and rainfall, plays an important part in providing water to the State’s human and wildlife population. There ar

California’s vast reservoir system, fed by annual snow and rainfall, plays an important part in providing water to the State’s human and wildlife population. There are almost 1,300 reservoirs throughout the State, but only approximately 200 of them are considered storage reservoirs, and many of the larger ones are critical components of the Federal Central Valley Project and California State Water Project. Storage reservoirs, such as the ones shown in figure 1, capture winter precipitation for use in California’s dry summer months. In addition to engineered reservoir storage, California also depends on water “stored” in the statewide snowpack, which slowly melts during the course of the summer, to augment the State’s water supply.

The Role of Water Transfers in Meeting California's Water Needs

Legislative Analyst's Office (LAO) | September 9th, 2008

If water transfers are to help the state meet its water needs, we think that the Legislature should address a number of issues, including impediments to transfers and sta

If water transfers are to help the state meet its water needs, we think that the Legislature should address a number of issues, including impediments to transfers and stakeholder concerns about potential negative impacts of transfers on "third parties." Statutory policy on water transfers should be clarified and made more consistent.

The Salton Sea: A Status Update

Legislative Analyst's Office (LAO) | August 29th, 2018

The Seasonal Cycle of Surface Soil Moisture

American Meteorological Society (AMS) | June 29th, 2022

The seasonal cycle contributes substantially to soil moisture temporal variability in many parts of the world, with important implications for seasonal forecasting releva

The seasonal cycle contributes substantially to soil moisture temporal variability in many parts of the world, with important implications for seasonal forecasting relevant to agriculture and the health of humans and ecosystems. There is considerable spatial variability in the seasonal cycle of soil moisture, yet a lack of global observations has hindered the development of parsimonious theories explaining that variability. Here, we use 6 years of global satellite observations to describe and explain the seasonal cycle of surface soil moisture globally. An unsupervised clustering algorithm is used to identify five distinct seasonal cycle regimes. Each seasonal cycle regime typically arises in both hemispheres, on multiple continents, and across substantially different local climates. To explain this spatial variability, we then show that the observed seasonal cycle regimes are reproduced very well by a simple but physically based water balance model, which only uses precipitation and downwelling surface shortwave radiation as inputs, and includes no free parameters. Surprisingly, no information on vegetation or land cover is required. To our knowledge, this is the first characterization of the seasonal cycle of surface soil moisture based on global observations.

The Stakes are Rising: Lessons on Engaging Coastal Communities on Climate Adaptation in Southern California

Cities and the Environment | November 16th, 2017

Preparing for climate change is rising as a priority for many public policy agendas, driving a demand for information that allows communities to identify both cur

Preparing for climate change is rising as a priority for many public policy agendas, driving a demand for information that allows communities to identify both current and projected vulnerabilities to climate change at local and regional levels. In response, a developing climate change adaptation service sector is bringing science and technical training to policy-makers. Approaching adaptation planning through a regional lens is critical, due to the large number of stakeholders and the intensely interconnected nature of geographies, communities, and economies. Decisions made in one jurisdiction will undoubtedly affect its neighbors. In this emerging field, boundary organizations play a unique role in building capacity across jurisdictions and bridging the gaps among various community, science and government stakeholders. The University of Southern California (USC) Sea Grant Program, located in Los Angeles, has developed a robust stakeholder engagement process to help communities plan for the impacts of climate change along the urbanized coastline. In 2016, USC Sea Grant analyzed its climate change adaptation outreach program to gain insights about its effectiveness. Drawing from this analysis, this paper explores: 1) stakeholder processes; 2) communications methods, particularly the challenges of communicating scientific information; 3) barriers to planning and implementation; 4) how to identify community needs; and, 5) what kinds of investments have been made to meet those needs. Four primary lessons are identified: 1) place-based boundary organizations can be an effective broker in establishing trust among stakeholders; 2) the ever-evolving and complex nature of climate science can overwhelm stakeholders and stall progress, so it is important to emphasize key messages provided by the scientific information, rather than dive deep into technical details and methods; 3) adaptive management is a promising approach to help communities move forward; and, 4) lack of significant and sustained funding for adaptation will continue to limit progress, however, even modest investments made at the right time can be impactful. Finally, the paper discusses the challenges USC Sea Grant faced in the first six years of its climate adaptation outreach program, and provides thoughts on how to help communities continue to advance their adaptation planning goals in the years to come.

The State Water Resources Control Board's Role in Implementing the Delta Plan

California State Water Resources Control Board (SWRCB) | April 5th, 2011

The Delta Plan should identify the authorities of the State Water Board that may be employed to implement its goals, subgoals, and strategies. The State Water Board’s B

The Delta Plan should identify the authorities of the State Water Board that may be employed to implement its goals, subgoals, and strategies. The State Water Board’s Bay Delta Plan and Delta Strategic Workplan should be incorporated into the Delta Plan.

The Sustainability Outlook: A Summary

California Department of Water Resources (DWR) | December 13th, 2018

Whether making water resource decisions or taking action, aligning desirable outcomes with four societal values — public health and safety, healthy economy, ecosystem v

Whether making water resource decisions or taking action, aligning desirable outcomes with four societal values — public health and safety, healthy economy, ecosystem vitality, and enriching experiences — is critical to managing water for sustainability. It can be as simple as being mindful of not wasting water, and as complex as predicting and planning for the next drought or flood. Daily, every Californian is responsible for doing their part. But how will Californians know whether their actions are moving the state in the right direction?  One basic long-standing challenge to water resource resilience and reliability in California is the lack of a consistent and practical method for assessing current and future sustainability (California Department of Water Resources, in prep.). Productive planning and the setting of policy priorities require a mutual understanding of challenges, resource limitations, management deficiencies, and shared intent. Managing for sustainability must be rooted in what Californians value, as expressed by stakeholders and corroborated by extensive outreach. Accordingly, there is a need to identify, through the lens of the four societal values, desirable water management outcomes (intended outcomes) and indicators to track status and progress toward sustainability.  The Sustainability Outlook, described in this document, provides a well-organized and consistent approach for tracking local, regional, and State actions and investments. It will also assist in setting future water management priorities. When applied at a watershed scale, the Sustainability Outlook can increase the effectiveness of State water policies and return on investments. Conducting and reporting watershed conditions will more clearly reveal trends, progress, and return on investment that would be difficult to discern at a statewide scale. Watershed evaluations will also allow for the introduction of additional indicators important to specific regions of the state. Through progressive application of the Sustainability Outlook, decision-makers will be able to identify needed analytical tools and data gaps, expand on the information available to make decisions, and build a common understanding of how individual and collective actions have affected the management of water resources for sustainability.  Because sustainability is not something achieved once and forever, the Sustainability Outlook will help water resource managers adapt to changing circumstances and lessons learned. This document underscores the urgency and rationale for the recommended actions in California Water Plan Update 2018 (Update 2018), Chapter 3, “Actions for Sustainability,” as well as the importance of follow-through by those who would implement those actions.” 

The Water Districts of California

Association of California Water Agencies (ACWA) | April 1st, 1979