San Francisco Bay

Large Landscape Urban Irrigation: A Data‐Driven Approach to Evaluate Conservation Behavior

American Geophysical Union (AGU) | April 30th, 2019

Do businesses, multifamily residences, and homeowners associations irrigate differently than single‐family residences? Do customers who have recycled water irrigate di

Do businesses, multifamily residences, and homeowners associations irrigate differently than single‐family residences? Do customers who have recycled water irrigate differently than if they have potable water? How does water use change during drought and under different policy regimes? Is neighborhood affluence related to conservation behavior by nonresidential irrigation customers? These questions are all important for water managers planning how much water they need when and where, in the present and in the future. In this paper, we statistically investigated and modeled water use in a case study service area to examine how water demand for nonresidential large landscapes changed during a historic drought. The findings of this paper can help water managers understand urban water use behavior, which is useful for supply planning, targeting conservation efforts, and optimizing infrastructure investment.

Large Landscape Urban Irrigation: A Data‐Driven Approach to Evaluate Conservation Behavior

American Geophysical Union (AGU) | January 30th, 2019

Do businesses, multifamily residences, and homeowners associations irrigate differently than single‐family residences? Do customers who have recycled water irrigate di

Do businesses, multifamily residences, and homeowners associations irrigate differently than single‐family residences? Do customers who have recycled water irrigate differently than if they have potable water? How does water use change during drought and under different policy regimes? Is neighborhood affluence related to conservation behavior by nonresidential irrigation customers? These questions are all important for water managers planning how much water they need when and where, in the present and in the future. In this paper, we statistically investigated and modeled water use in a case study service area to examine how water demand for nonresidential large landscapes changed during a historic drought. The findings of this paper can help water managers understand urban water use behavior, which is useful for supply planning, targeting conservation efforts, and optimizing infrastructure investment.

Left Out in Drought: California Fish Impacts of the California Drought on Freshwater Ecosystems

Pacific Institute | September 7th, 2022

California is deep into the third year of another major drought. Rural and urban areas again face water use restrictions and financial losses. Less water and hotter tempe

California is deep into the third year of another major drought. Rural and urban areas again face water use restrictions and financial losses. Less water and hotter temperatures also stress ecosystems, increasing the prevalence of wildfires, air pollution, dry streambeds, and loss of wildlife. Impacts to rural and urban areas frequently mask the disproportionate ecological impacts of the drought and the related policy and management responses that have exacerbated those impacts. The lack of acknowledgement and de- prioritization of ecosystem water needs during drought has led to insufficient actions taken to protect the natural systems on which we all depend.

Lessons from California’s 2012–2016 Drought

American Society of Civil Engineers (ASCE) | October 1st, 2018

California’s 5-year drought has ended, even as its aftermath lingers. From 2012–2016 much or all of California was under severe drought conditions, with gre

California’s 5-year drought has ended, even as its aftermath lingers. From 2012–2016 much or all of California was under severe drought conditions, with greatly diminished precipitation, snowpack, and streamflow and higher temperatures. Water shortages to forests, aquatic ecosystems, hydroelectric power plants, rural drinking water supplies, agriculture, and cities caused billions of dollars in economic losses, killed millions of forest trees, brought several fish species closer to extinction, and caused inconvenience and some expense to millions of households and businesses. The drought also brought innovations and improvements in water management, some of which will better prepare California for future droughts. This paper summarizes the magnitude and impacts of the 2012–2016 California drought. The paper then reviews innovations arising from the drought in the larger historical context of water management in California. Lessons for California and for modern drought management are then discussed. Droughts in modern, well-managed water systems serving globalized economies need not be economically catastrophic, but will always have impacts and challenges, particularly for native ecosystems. In California and every other water system, droughts usefully expose weaknesses and inadequate preparation in water management. In this regard for California, managers of ecosystems and small rural water supplies had the most to learn.

Letter from National Marine Fisheries Service: Re: Proposed Modification to the Annual Review Schedule Required as Part of the Reasonable and Prudent Alternative in the National Marine Fisheries Service’s 2009 Biological Opinion on the Coordinated Long-term Operation of the Central Valley Project and State Water Project (June 30, 2016)

Delta Stewardship Council (Delta Council) | June 30th, 2016

Letter from U.S. Bureau of Reclamation: Proposed Modification to the Annual Review Schedule Required as Part of the Reasonable and Prudent Alternative in the National Marine Fisheries Service’s 2009 Biological Opinion on the Coordinated Long-term Operation of the Central Valley Project and State Water Project (April 25, 2016)

Delta Stewardship Council (Delta Council) | April 25th, 2016

Letter to State Water Board re: Flow Criteria that use Percent of Unimpaired Flow

Delta Stewardship Council (Delta Council) | May 22nd, 2012

The proposed use of percent of unimpaired flow is a step toward improving the outlook for fish and other wildlife utilizing the San Joaquin River and its tributaries. Fal

The proposed use of percent of unimpaired flow is a step toward improving the outlook for fish and other wildlife utilizing the San Joaquin River and its tributaries. Fall-run Chinook salmon are likely to benefit from February-through-June flows that are more natural in timing and variability than current flows. Compared with the existing maze of flow standards for the San Joaquin River and its tributaries, unimpaired flow comes closer to approximating natural flow, and it does so more transparently. Caveats include: (1) flow is but one of many stressors affecting fish and wildlife; (2) the choice of flow criteria and metrics needs to serve the broader needs of ecosystems as well as individual species; (3) a chosen percentage of unimpaired flow may fall short of the minimum needed by fish and wildlife in some years; and (4) such critical years are likely to become more common as Sierra Nevada snowpacks diminish as a consequence of climate change. This qualified endorsement is based on our reading of the “Technical Report on the Scientific Basis for Alternative San Joaquin River Flow and Southern Delta Salinity Objectives” (State Water Resources Control Board, February 2012).

Levee Decisions and Sustainability for the Sacramento-San Joaquin Delta

University of California, Davis (UC Davis) | August 15th, 2010

Levee Failures in the Sacramento-San Joaquin River Delta: Characteristics and Perspectives

Texas A&M University | December 15th, 2011

Between 1850 and 1922, agriculturalists built 1,700 kilometers of levees to convert 250,000 hectares of tidal marsh to farmland where the San Joaquin and Sacramento River

Between 1850 and 1922, agriculturalists built 1,700 kilometers of levees to convert 250,000 hectares of tidal marsh to farmland where the San Joaquin and Sacramento Rivers enter the San Francisco Bay (the Delta). Drained, farmed and isolated from the water channels, the organic soils behind the levees subsided to elevations as low as 8 meters below sea level, turning "levees" into "dams" that hold back water constantly. Engineers built water transfer projects in the mid-20th century, transferring water from the south Delta to 25 million Californians who now rely on the "dams" accidentally converted into supply channels. In 1972, however, a levee failure caused a salt-water intrusion into the Delta, raising the prominence of the polemic Peripheral Canal which, if built would replace the levees in the trans-Delta water transport role. Levee failures in 2004 (the Delta) and 2005 (New Orleans) have re-ignited the debate, fueled by comments made by public officials who warned that the Delta levees posed more risk of failure than did the pre-Katina Louisiana levees. This background motivates two research questions: What are the social perspectives regarding levee failures of the experts managing the Delta; and what is the history of levee failures that might support their perspectives? The research employed Q-Method to identify and describe four social perspectives: Delta Sustainers, Abandon the Levees, Levee Pragmatists, and Multi-Purpose Levee Advocates. A critical element underlying differences among the perspectives revolved around the perceived history of failures of Delta levees. This dissertation employed semi-structured interviews, archival record searches, and historic map and aerial photograph comparisons to compile a history of 265 levee failures since 1868, many of which are referenced to location, segment, and levee type. In addition, the dissertation compiled a list of emergency repairs and successful flood-fights. The history of failures indicates that important levees of the Delta have performed significantly better than previously identified. Sharing these social perspectives and research results among the key actors addressing Delta issues may lead to improved consensus decisions.

Leveraging Wetlands for a Better Climate Future

San Francisco Estuary Institute (SFEI) | July 15th, 2022

Managing Natural and Working Lands (NWL) to enhance carbon sinks and limit greenhouse gas (GHG) emissions is a key component of California’s ambitious strategy to achie

Managing Natural and Working Lands (NWL) to enhance carbon sinks and limit greenhouse gas (GHG) emissions is a key component of California’s ambitious strategy to achieve net carbon neutrality by 2045. The California Air Resources Board (CARB) Climate Change Scoping Plan includes 7 NWL categories in its GHG emission reduction scenarios, one of which is wetlands. Coastal wetlands in California are a high- leverage NWL type for GHG management relative to their small spatial footprint. These ecosystems have high rates of carbon sequestration and can accumulate large stocks of carbon, due to high productivity, efficient sediment trapping, and low decomposition rates (Chmura et al. 2003, Mcleod et al. 2011). In the absence of management interventions focused on wetland conservation, however, conversion of coastal wetlands to other land uses such as agriculture, grazing, development, impounded wetlands, or subtidal or upland habitat can halt or reverse carbon sequestration, and can shift these ecosystems from long-term GHG sinks to large GHG sources (Hatala et al. 2012, Tan et al. 2019). Filling of wetlands for infrastructure and development was a common practice throughout the early 20th century (Goals Project 1999), dramatically reducing the state’s coastal wetland area and associated carbon sink.