– The Lower Elkhorn Basin Levee Setback (LEBLS) Project is a multibenefit project that provides broad flood risk reduction and ecosystem benefits for a large region within California’s Central Valley. For this project, the California Department of Water Resources (DWR) has constructed an approximately 11,500-meter setback levee to expand the Sacramento and Yolo bypasses by about 450 meters. Construction started in August 2020, and the existing levees were breached in summer 2023 for use of the expanded bypass in winter. The expansion of the bypasses significantly reduces the risk of flooding for the Sacramento area; when coupled with the U.S. Army Corps of Engineers (USACE) Sacramento Weir Widening Project, the water surface elevation in the Sacramento River will be reduced by nearly 30 centimeters during high-water events. The expanded bypass footprint area will be used for agriculture and habitat, compatible with seasonal flooding. LEBLS is the first state-led project to be implemented from the Central Valley Flood Protection Plan (CVFPP), which was developed to better manage the risk of flooding in California’s Central Valley, specifically in areas classified as protected by the State Plan of Flood Control. LEBLS has been recognized as a well-performing project at state and local levels. (more)
From The Los Angeles Times – In the face of climate change and worsening cycles of drought, California water managers have been increasingly focused on the precise tracking of water resources. Snowpack in the Sierra Nevada is measured with sensors and aerial images, reservoir levels are electronically logged, and the movement of water through aqueducts is apportioned based on rights and contracts. Yet there is another key water metric that California has never adequately measured: the flow of rivers and streams. New research by UC Berkeley scientists has found that only 8% of the state’s rivers and streams are equipped with gauges — devices that measure the level and rate of movement of water. (more)
From mavensnotebook.com: Commentary from Senator Alvarado-Gil, Assemblyman Heath Flora, and Assemblywoman Esmeralda Soria – We all know it. You shouldn’t wait to close the barn door until after the horse has bolted. That’s an important lesson for Central Valley communities today. California didn’t experience floods this past winter like we did in 2023. But given that the legislature is writing a bond now, this is the time to speak up to keep our communities safe from catastrophic flooding in the future. A flooded street in Merced County on Jan. 11, 2023. A year and a half ago, the town of Planada was hit by a devastating flood. When a debris-clogged Miles Creek overflowed, the resulting flood hit like a gut-punch. UC Merced researchers found that 83 percent of all households suffered, and many lost everything. “These were more than houses,” one anguished resident told the media, “they were symbols of a lifetime of hard work.” Climate models predict future floods could be up to five times larger than the historic 1997 flood that drowned nearly 300 square miles of the state. And the San Joaquin Valley will be Ground Zero for the worst of it. The worst-case scenario predicts an almost incomprehensible $1 trillion in damages across the state – in what could be one of the biggest natural disasters ever. Most of that damage could happen in the Valley. (more)
From the City of Roseville – When it comes to water, it pays to plan ahead. You never know when that rainy day—or prolonged drought—may come. Roseville and Placer County leaders are pursuing long-term solutions to bolster water supply reliability while accommodating rapid population growth. “Roseville takes a holistic approach to water supply,” explained Roseville Water Utility Manager George Hanson. “We look at varied sources such as groundwater, alternatives to Folsom Reservoir and water conservation, and how we can be more efficient. “With this approach, we’ve built a robust water supply. The challenge in the future [will be] that we need to anticipate events and needs to ensure our water supply.” Roseville is Placer County’s largest city, with a population of about 155,000 that is expected to top out at 230,000 people—a 48 percent increase. So city leaders don’t need to plan for current residents but those to come. (more)
From USGS (United States Geological Survey) – Imagine you could use just a few drops of water to know what sorts of animals and plants were present in an area. What an incredible tool this would be. It could be used to look for rare species, to catalogue how many were present or to monitor for introductions of new, potentially harmful species. Turns out, we already have this tool. Using a small sample of water, scientists can look for genetic material left behind by anything with a genome—a species’ genetic fingerprint made from DNA—which scientists call environmental DNA, or eDNA. Aquatic biodiversity, or the number of species in freshwater and marine systems, is important culturally and economically as well as to the health of society and ecosystems. Using such a powerful, nondestructive tool as eDNA sampling gives scientists and people managing water, land and municipalities the ability to evaluate and predict trends in biodiversity at the scale they need, from a single pond to a river system and even the oceans. (more)
From USACE (United States Army Corps of Engineers) – The Institute for Water Resources (IWR), part of the U.S. Army Corps of Engineers (USACE), has released a report through its Water Resources Center on improving the use of structured decision-making for water resource management. Titled “Analysis of Tradeoffs Approaches Applicable to USACE Civil Works Planning,” the report outlines methods for comparing the benefits and effects of various planning alternatives to support selecting alternative plans in managing the nation’s water resources. Water resource planning often involves making tough decisions. Projects such as building dams, restoring rivers, or managing flood risks require balancing multiple factors, including economic, environmental, and social impacts. The new report emphasizes the importance of a structured tradeoffs analysis to guide these decisions. The report introduces several approaches for analyzing tradeoffs. Qualitative methods involve discussing and listing the pros and cons of different options. This approach helps teams understand the various factors at play without needing complex calculations. Quantitative methods, on the other hand, use numbers to rate and compare options, providing a more detailed evaluation. Combining these methods offers a balanced approach, using discussions to identify key issues and qualitative and quantitative analysis to compare alternatives. (more)
From aol.com – For well over a century, the Great Flood of 1862 has remained among California’s worst natural disasters — a megastorm that’s been used as a benchmark for state emergency planners and officials to better prepare for the future. A dreaded repeat of the flood — which killed at least 4,000 people and turned the Central Valley into a 300-mile-long sea — would probably eclipse the devastation of a major California earthquake and cause up to $1 trillion in damage, some experts say. Yet even as California scrambles to cope with the effects of climate whiplash and increasingly extreme weather, new research suggests the potential magnitude of such events could be far greater than that of the 1862 deluge. (more)
From mavensnotebook.com – California relies on its rivers and streams for a plethora of services—water supply, flood control, biodiversity conservation, and hydropower generation, to name a few. As a result, understanding the flow of water through the state’s stream network is critical for supporting California’s economy and ecosystems. A new study published by UC Berkeley researchers in Nature Sustainability finds, however, that California’s rivers and streams are critically under-monitored, making it difficult to properly manage water supply and control floods, monitor changes in freshwater biodiversity, and understand how climate change is affecting water supplies. According to the authors’ analysis, only 8% of all rivers and streams in California are monitored by stream gauges, the technology used to measure the flow of water upstream or downstream from their installation site. “As climate change progresses and the demands on California’s water resources and water infrastructure grow, it is critical to have reliable, timely, and comprehensive information about water in rivers and streams,” said lead author Lucy Andrews, a PhD candidate in the Department of Environmental Science, Policy, and Management. “Our work highlights concerning gaps in California’s water monitoring capabilities and proposes tools for addressing those gaps.” (more)
From USACE, Sacramento District – First major upgrade in Sacramento Weir’s 106-year history
The U.S. Army Corps of Engineers is funding expansion of the Sacramento Weir. The approximately $350 million project involves widening the 1,950-foot weir an additional 1,500 feet north. The weir’s 48 manually-operated gates will remain intact. The expansion is constructing a passive weir to essentially allow excessive floodwaters to flow over the river channels and into the bypasses — in turn widening the surface area, and meaning the Sacramento Weir will be used less frequently for more severe flood events.
The Sacramento Weir Widening Project is split into two projects:
1. The Sac Bypass Widening which is currently awarded and under construction by the California Department of Water Resources (DWR).
2. The Sacramento Weir Widening Project is being run by the Sacramento District USACE.
The Corps, Central Valley Flood Protection Board, California Department of Water Resources, and the Sacramento Area Flood Control Agency estimate the project to be complete by December 2026.
From mavensnotebook.com & USGS – With the potential for flooding during present-day winter storms and sea level rise continually inching up on San Francisco Bay Area communities, a team of scientists and engineers have created a new computer model that can inform key decision-making and guide flood prevention efforts both now and in the future. The model can be accessed free-of-charge on the San Francisco Bay-Delta Community website. The computer model synthesizes the complex dynamics that make up the San Francisco Bay-Delta’s environment, including the hydrology, sediment transport, water quality and the many ecosystems that span the region. The new Delft3D Flexible Mesh model simulates conditions across the San Francisco Bay-Delta system from Point Reyes, up to the tidal limits near Sacramento. The high-resolution mesh can capture fine features and variations in the model that allows for detailed computations on hydrodynamics, sediment transport, water quality and ecosystems. (more)
From USGS (United States Geological Survey) – Imagine you could use just a few drops of water to know what sorts of animals and plants were present in an area. What an incredible tool this would be. It could be used to look for rare species, to catalogue how many were present or to monitor for introductions of new, potentially harmful species. Turns out, we already have this tool. Using a small sample of water, scientists can look for genetic material left behind by anything with a genome—a species’ genetic fingerprint made from DNA—which scientists call environmental DNA, or eDNA. Aquatic biodiversity, or the number of species in freshwater and marine systems, is important culturally and economically as well as to the health of society and ecosystems. Using such a powerful, nondestructive tool as eDNA sampling gives scientists and people managing water, land and municipalities the ability to evaluate and predict trends in biodiversity at the scale they need, from a single pond to a river system and even the oceans. 
