From Maven’s Notebook
By 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 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. (more)
From American Society of Civil Engineers
The Sacramento River East Levee (SREL), part of the American River Common Features (ARCF) 2016 Project, was executed by USACE under four different contracts. The project assumes significance due to its location and importance for public safety and asset protection. The first two contracts were supported by GEI and HDR who provided engineering during construction services related to civil and geotechnical engineering. The third and fourth contracts were supported by Kleinfelder and Stantec, which are the topic of this presentation. Contract 3 involved construction of 2 miles of seepage cutoff walls in the Pocket area in 2022 and Contract 4 involved construction of seepage cutoff walls at 4 separate locations in 2023 and 2024 from the Broadway Avenue area to the Freeport area. Contracts 3 and 4 flood protection features are intended to reduce the flooding risk to critical infrastructure in Sacramento, California. The project was constructed through a USACE Sacramento District contract. This presentation will summarize the contract design and construction stages. Various types of cutoff walls will be reviewed and design and construction challenges will be discussed. (more)
From California Water Blog
Tidal wetlands in the Sacramento – San Joaquin Delta used to be vast. You may have seen artistic renditions of how the landscape may have looked with meandering channels weaving through a mosaic of land and water and with teaming wildlife. In fact, prior to European colonization, the Delta used to be a whole 95% tidal freshwater wetlands covered in tule and cattail vegetation, stewarded by a number of Indigenous Tribes. We know this historical landscape was forever changed when settlers forcibly removed Indigenous people and their stewardship practices from the landscape, and spent the subsequent hundred and fifty years diking and draining the wetlands to create farmland. In one of the most ambitious restoration efforts of the State, and to help reverse the ecological decline this transformation caused, a network of California State agencies, Federal agencies, private institutions, and non-governmental organizations have spent the last decade trying to restore some of these wetlands. (more)
From NOAA Research, From Maven’s Notebook
For more than 75 years, high-hazard structures in the United States, including dams and nuclear power plants, have been engineered to withstand floods resulting from the most unlikely but possible precipitation, termed Probable Maximum Precipitation or PMP. More than 16,000 high-hazard dams and 50 nuclear power plants are located in the United States, many of which are approaching or exceeding their design lifetime. Failure of any one of these structures will likely result in loss of life and could impose significant economic losses and widespread environmental damage. While engineers continue to rely on PMP estimates when designing these large, critical facilities, the estimates themselves and the science behind them are based on outdated work. As climate change continues to supercharge storms, including rainfall amounts, that threaten existing infrastructure, there’s an urgent need to modernize PMP estimates and improve the science behind them, according to a new report by the National Academy of Sciences, Engineering and Medicine. (more)
From Environmental Monitor
When it comes to environmental monitoring, new stream survey methodologies have revealed a great deal about water quality and streambed conditions over time. Such information can be particularly important in leading restoration initiatives and prioritizing management decisions. Historically, stream surveys have been conducted at a single point along the stream, with data then extrapolated for miles up and downstream. However, Brett Connell, Hydrologist and Director of Sales at Trutta Environmental Solutions, started developing a more intensive stream survey format in his master’s program in 2010 at the University of Tennessee. Having grown up fishing in Lake Erie and the Maumee River, Connell chose to pursue a career initially in fisheries biology because he loved being outdoors and working in the landscape he was studying. (more)
From the Department of Water Resources
The California Water Plan, updated every five years, is the State’s strategic plan for sustainably and equitably managing and developing water resources for current and future generations. California Water Plan Update 2023 (Update 2023) promotes climate resilience across regions and water sectors with a statewide vision, clear goals, watershed planning framework and toolkit, and progress-tracking dashboard of indicators. It also includes updated resource management strategies, regional planning and performance tracking tools, water balances, future scenarios, and other technical and policy-related activities related to water resilience and sustainability. (more)
From the Association of California Water Agencies
With overdraft causing big problems in the San Joaquin Valley, and groundwater recharge among the most promising ways to protect against hotter, longer dry periods, is California socking away enough water during wet periods? Answering that question was the subject of a June 11 virtual panel discussion hosted by the Public Policy Institute of California (PPIC) and now available for viewing online… The discussion followed up on PPIC surveys in 2017 and 2023 of dozens of urban and agriculture water managers who were asked how recharge efforts were going, how much progress they’ve made and what they thought was needed next. (more)
From the Department of Water Resources
With warm temperatures here to stay in Northern California, runoff into Lake Oroville from snowmelt has significantly dwindled with outflows currently exceeding inflows. The Department of Water Resources (DWR) continues to meet water delivery and environmental requirements while optimizing water storage to allow for carryover storage into next year. Releases from Oroville Dam’s main spillway ceased in May with water being routed through the Hyatt Powerplant for power generation. When the main spillway is not in use, water may still be seen on the main spillway outlet as the seals on the eight radial gates are not designed to be watertight. The gate seals do not play a role in the structural integrity of the gates, which continue to operate as intended. Visitors to Oroville Dam may also notice minor amounts of water flowing from drains built into the emergency spillway. This is normal and expected given the emergency spillway design. The dam and emergency spillway continue to operate as intended. (more)
From Engineering With Nature: by US Army
Engineer Research and Development Center
– 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)
