Estimating reservoir sedimentation rates at large spatialand temporal scales: A case study of California
Keywords:American Geophysical Union (AGU), flood control, sediment, storage, University of California Berkeley
Analysis and simulation of regional subsidence accompanying groundwater abstraction and compaction of susceptible aquifer systems in the USAAdd to Downloads
Analysis and simulation of regional subsidence accompanying groundwater abstraction and compaction of susceptible aquifer systems in the USABoletín de la Sociedad Geológica Mexicana | January 17, 2013...Summary
Regional aquifer-system compaction and land subsidence accompanying groundwater abstraction in susceptible aquifer systems in the USA is a challenge for managing groundwater resources...
Regional aquifer-system compaction and land subsidence accompanying groundwater abstraction in susceptible aquifer systems in the USA is a challenge for managing groundwater resources and mitigating associated hazards. Developments in the assessment of regional subsidence provide more information to constrain analyses and simulation of aquifer-system compaction. Current popular approaches to simulating vertical aquifer-system deformation (compaction), such as those embodied in the aquitard drainage model and the MODFLOW subsidence packages, have proven useful from the perspective of regional groundwater resources assessment. However, these approaches inadequately address related local-scale hazards—ground ruptures and damages to engineered structures on the land surface arising from tensional stresses and strains accompanying groundwater abstraction. This paper presents a brief overview of the general approaches taken by the U.S. Geological Survey toward understanding aquifer-system compaction and subsidence with regard to a) identifying the affected aquifer systems; b) making regional assessments; c) analyzing the governing processes; and d) simulating historical and future groundwater flow and subsidence conditions. Limitations and shortcomings of these approaches, as well as future challenges also are discussed
Navigating Groundwater-Surface Water Interactions under the Sustainable Groundwater Management ActAdd to Downloads
Navigating Groundwater-Surface Water Interactions under the Sustainable Groundwater Management ActBerkeley Law Center for Law, Energy & the Environment (CLEE), UC Water Security and Sustainability Research Initiative | March 28, 2018...Summary
California’s Sustainable Groundwater Management Act (SGMA), passed in 2014, recognizes and addresses connections between surface water and groundwater. The statute is California’s first...
California’s Sustainable Groundwater Management Act (SGMA), passed in 2014, recognizes and addresses connections between surface water and groundwater. The statute is California’s first statewide law to explicitly reflect the fact that surface water and groundwater are frequently interconnected and that groundwater management can impact groundwater-dependent ecosystems, surface water flows, and the beneficial uses of those flows. As such, SGMA partially remedies the historically problematic practice of treating groundwater and surface water as legally distinct resources.
SGMA requires groundwater sustainability agencies (GSAs) to manage groundwater to avoid six undesirable results, including significant and unreasonable adverse impacts on beneficial uses of surface water. While this aspect of SGMA is clearly important, significant uncertainties exist regarding how GSAs will actually define and achieve this goal.
Addressing SGMA’s requirements for groundwater-surface water interactions will be difficult. Defining the issues at stake in any given basin, let alone successfully balancing the range of uncertainties and potentially conficting interests, will pose challenges for many GSAs. No clear, pre-defned formula exists to guide GSAs in determining what significant and unreasonable depletions of interconnected surface water will be, or whether planned actions will sufficiently avoid them.
Yet they are required to do so. Many GSAs will face pressure to aggressively address impacts on surface water in their basin. Many will face equal or greater pressure not to draw the line. Nevertheless, it will fall to the GSAs to make a determination, and to defend it in their groundwater sustainability plans (GSPs).
Therefore, GSAs will likely take on some level of risk—of successful political opposition to their GSP, of successful legal challenges to their GSP, of their GSP performing ineffectively, or of all of these outcomes.
Given the aggressive timeline inherent to SGMA, addressing this risk early will be crucial for preserving management options. Challenges and risk are not the whole story, however.
The process of addressing groundwater-surface water interactions also ofders GSAs an opportunity to help communities and other stakeholders resolve, or avoid, difficult conflicts, and to do so in lasting ways. While California law has only recently begun to seriously address conflicts between surface and groundwater uses, those conflicts have been occurring for decades, and in some places for over a century.
SGMA, in other words, did not create conflict between groundwater pumping and beneficial uses of surface water; instead it created an opportunity—as well as an obligation—to respond to those challenges. Embracing that opportunity will not be easy, but GSAs that take SGMA as an opportunity to resolve longstanding issues can do lasting good.
The research presented here examines some of the legal and institutional questions that will inevitably arise as GSAs seek to address groundwater-surface water interactions under SGMA. The core goal of this report is to help parties identify and address these questions, and ultimately to let GSAs and stakeholders manage groundwater-surface water interactions proactively and effectively.
Delta Region Integrated Flood Management: Key Considerations and Statewide Implications$0.00 Add to Downloads
Delta Region Integrated Flood Management: Key Considerations and Statewide ImplicationsCalifornia Department of Water Resources (DWR) | September 1, 2012...Summary
This Background / Reference Memorandum (BRM) presents highlights from flood-related technical, legislative and funding information regarding the Sacramento-San Joaquin Delta (Delta), with emphasis...
This Background / Reference Memorandum (BRM) presents highlights from flood-related technical, legislative and funding information regarding the Sacramento-San Joaquin Delta (Delta), with emphasis on activities by the California Department of Water Resources (DWR).
The BRM is intended to provide historical and existing conditions (year 2011) context for DWR’s use in conveying strategies for future investments in integrated flood management in the Delta under a separate document.
The State of California has entrusted DWR as the agency with the responsibility for managing water flow through the Delta and for representing State interests in Delta levees.
DWR invests in the Delta levee system to protect clear and identifiable State interests, including but not limited to:
• Human life, public health, and property within the Delta;
• Water quality and water supply for agriculture, ecosystem, and municipal and industrial water users within the Delta and water users outside of the Delta;
• Ecosystem protection and enhancement, including protection and recovery of threatened and endangered species;
• Critical infrastructure such as highways, railroads, aqueducts, and pumping plants;
• Other infrastructure such as transmission lines (electric & petroleum), shipping channels, and public infrastructure (water and wastewater treatment plants);
• Agriculture and recreation; and
• Cultural, historical, aesthetic, and other values included in “Delta as a place.”
State legislation and modifications to the California Water and Public Resources codes have repeatedly demonstrated the State’s interest in preserving the Delta and the importance of Delta levees. The legislation and modifications to the codes have made strong statements about the importance of the Delta, provided direction for the DWR’s levee programs, and provided funding for flood management activities and environmental stewardship in the Delta.
This BRM should be considered a reference document. Due to the large number of existing documents on the Delta and its levees, this BRM provides highlights of important material with references to other documents for more detailed information.
This base information should be useful when considering modifications to investment strategies for integrated flood management in the Delta.
California Water Supply And Demand: Technical Report$0.00 Add to Downloads
California Water Supply And Demand: Technical ReportStockholm Environment Institute | February 10, 2011...Summary
The California Water Supply and Demand Model (CWSD) examines the ways in which California’s water supply and demand are likely to be affected...
The California Water Supply and Demand Model (CWSD) examines the ways in which California’s water supply and demand are likely to be affected by climate change; its purpose is to serve as a base for quantifying these impacts in economic terms. California’s water future is modeled under conditions of no adaptation to climate change, and under several projected water use adaptation scenarios taken from the literature; climate change adaptation scenarios include water used for energy, the urban or residential sector, and agriculture.
The main CWSD compares key categories of water inputs and outputs on a month-by-month basis to capture seasonality in water availability. A supplementary model allows for the main model’s beginning surface reservoir storage to result from water supply and demand interactions over a stylized previous 100 years. Three areas of water use are both especially critical and vulnerable to climatic change: the energy, agriculture, and urban sectors. In the energy module, water demand is a based on different scenarios of coal, nuclear and renewable power use, conservation technology, state population trends, and projected temperatures. In the agriculture module, crop and animal water use by county is a function of projected summer temperatures by county. In the urban module, residential, industrial/commercial, and public water use are based on projected levels of socio-economic growth.