A Synthesis of Aquatic Science for Management of Lakes Mead and Mohave

U.S. Geological Survey (USGS) | January 29th, 2013

Lakes Mead and Mohave, which are the centerpieces of Lake Mead National Recreation Area, provide many significant benefits that have made the modern development of the So

Lakes Mead and Mohave, which are the centerpieces of Lake Mead National Recreation Area, provide many significant benefits that have made the modern development of the Southwestern United States possible. Lake Mead is the largest reservoir by volume in the nation and it supplies critical storage of water supplies for more than 25 million people in three Western States (California, Arizona, and Nevada). Storage within Lake Mead supplies drinking water and the hydropower to provide electricity for major cities including Las Vegas, Phoenix, Los Angeles, Tucson, and San Diego, and irrigation of more than 2.5 million acres of croplands. Lake Mead is arguably the most important reservoir in the nation because of its size and the services it delivers to the Western United States. This Circular includes seven chapters. Chapter 1 provides a short summary of the overall findings and management implications for Lakes Mead and Mohave that can be used to guide the reader through the rest of the Circular. Chapter 2 introduces the environmental setting and characteristics of Lakes Mead and Mohave and provides a brief management context of the lakes within the Colorado River system as well as overviews of the geological bedrock and sediment accumulations of the lakes. Chapter 3 contains summaries of the operational and hydrologic characteristics of Lakes Mead and Mohave. Chapter 4 provides information on water quality, including discussion on the monitoring of contaminants and sediments within the reservoirs. Chapter 5 describes aquatic biota and wildlife, including food-web dynamics, plankton, invertebrates, fish, aquatic birds, and aquatic vegetation. Chapter 6 outlines threats and stressors to the health of Lake Mead aquatic ecosystems that include a range of environmental contaminants, invasive species, and climate change. Chapter 7 provides a more detailed summary of overall findings that are presented in Chapter 1; and it contains a more detailed discussion on associated management implications, additional research, and monitoring needs.

Accounting for Water "Wasted to the Sea"

University of California, Davis (UC Davis) | April 19th, 2018

Freshwater outflow from the Sacramento–San Joaquin Delta is a contentious management issue. Once mixed with salt water of San Francisco Bay, outflow is often characteri

Freshwater outflow from the Sacramento–San Joaquin Delta is a contentious management issue. Once mixed with salt water of San Francisco Bay, outflow is often characterized as having no value for urban and agricultural water supply, and thus “wasted to the sea.” In the July issue of San Francisco Estuary and Watershed Science, Cloern et al. (2017) showed how outflow from the Delta provides multiple and diverse benefits to the San Francisco estuary. Rather than being “wasted,” this outflow improves ecosystem conditions and water quality, and reduces wastewater treatment costs. The Cloern et al. (2017) essay highlights the importance of considering the multiple benefits of water as it moves within and out of the Delta. To do this, however, California needs a better water accounting system. In this report, we present an alternative approach. For the period 1980–2016, we assign inflow to the Delta to four categories: 1. Water used for diversions, 2. Outflow needed to meet salinity standards for diversions, 3. Outflow to meet ecosystem regulations, and 4. Water that results in outflow because of a lack of capacity for diversion. This approach highlights that much of the outflow from the Delta — particularly during dry periods — achieves multiple economic and environmental benefits and is hardly “wasted to the sea.”

Adaptation Pathways: San Leandro Operational Landscape Unit

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

Given the diverse uses and conditions of San Francisco Bay’s 400-mile shoreline, a framework is needed to guide development of adaptation strategies appropriate to loca

Given the diverse uses and conditions of San Francisco Bay’s 400-mile shoreline, a framework is needed to guide development of adaptation strategies appropriate to local conditions. Operational Landscape Units (OLUs), outlined for the San Francisco Bay in the San Francisco Bay Shoreline Adaptation Atlas (SFEI and SPUR 2019), share common physical characteristics and therefore can benefit from being managed as individual units. OLUs cross traditional jurisdictional boundaries (cities, counties), and instead follow the boundaries of natural processes like tides, waves, and sediment movement. By planning at the OLU scale, it is possible to prioritize adaptation strategies that work synergistically. Coordinated OLU planning can help avoid unintended impacts on neighboring locales and identify synergies to make use of limited resources in a more efficient manner.

Adaptive Management and Science for the Delta Ecosystem

University of California, Davis (UC Davis) | October 1st, 2013

Using science to adaptively guide management for the Sacramento-San Joaquin Delta is widely talked about as good public policy.  Almost every agency, stakeholder, and pl

Using science to adaptively guide management for the Sacramento-San Joaquin Delta is widely talked about as good public policy.  Almost every agency, stakeholder, and planning process professes support and has its own adaptive management and science efforts.  But highly fragmented adaptive management and science cannot solve such urgent complex problems. California’s 2009 Delta Reform Act recognized that meeting the co-equal goals of a sustainable ecosystem and water supply reliability in the Delta required major changes in governance, planning, and management. Such changes also require major changes in how science is organized and employed in management. Here is a straw proposal for integrating the many parochial science and adaptive management programs for the Delta.

Adaptive Management for Ecosystem Restoration: Analysis and Issues for Congress

Congressional Research Service (CRS) | March 4th, 2011

Adaptive management is the process of incorporating new scientific and programmatic information into the implementation of a project or plan to ensure that the goals of t

Adaptive management is the process of incorporating new scientific and programmatic information into the implementation of a project or plan to ensure that the goals of the activity are being reached efficiently. It promotes flexible decision-making to modify existing activities or create new activities if new circumstances arise (e.g., new scientific information) or if projects are not meeting their goals. The complex and dynamic nature of ecosystems make their restoration and management amenable to an adaptive management approach, and the concept is being implemented at scales that include entire regions or river basins. Adaptive management has been used to guide several major ecosystem restoration efforts with involvement by the federal  government, including those on the Colorado and Platte rivers. Some of these adaptive management efforts have been specifically authorized by Congress, whereas other efforts have been formulated by agencies. Adaptive management has also been proposed as a guiding principle for several new and ongoing major restoration efforts, including those in the Chesapeake Bay and Lake Tahoe. The concept of adaptive management is straightforward, but its implementation can be difficult. A preliminary review of federal adaptive management efforts related to ecosystem restoration projects suggests that governance structures, management protocol and other factors vary widely.  Additionally, the scope and timing of efforts employing the term “adaptive management” seems  to vary among these projects. Where adaptive management has been implemented, it has encountered challenges. While adaptive management theoretically uses the best available science and monitoring to guide a project or program towards its stated goals, in practice the process can be affected by a number of outside factors. As the number of federal adaptive management efforts grows, Congress may revisit its role in shaping adaptive management programs in legislation. Some argue that Congress should do more to provide specific direction for major adaptive management initiatives in order to make adaptive management more consistent among these efforts. Others contend that Congress should allow federal agencies or restoration governing bodies to shape their own adaptive management programs, thus providing them with flexibility to match their program to their restoration needs. In addressing adaptive management, Congress may face decisions regarding the implementation guidelines and authorizations it provides these efforts, funds to establish and carry out these programs, and oversight issues. This report provides an introduction to the concept of adaptive management. It focuses on the application of this concept to large, freshwater aquatic ecosystem restoration projects with multiple stakeholders. A summary of the benefits and drawbacks of adaptive management for these projects is provided, along with analysis of potential issues associated with various governance models for these efforts. The potential role for Congress in addressing adaptive management is also discussed. As an appendix, the report summarizes the structure and implementation of federal adaptive management efforts to date five ecosystems: Glen Canyon/Colorado River, Platte River, Lower Colorado River, Missouri River, and Florida Everglades.

Addressing Multiple Stressors and Multiple Goals in the Delta Plan

Delta Stewardship Council (Delta Council) | January 26th, 2011

Advancing Ecosystem Restoration with Smarter Permitting

Public Policy Institute of California (PPIC) | August 16th, 2021

California’s ecosystems form the bedrock of the state’s well being and prosperity. Yet many of these ecosystems—which are vitally important to the state’s water s

California’s ecosystems form the bedrock of the state’s well being and prosperity. Yet many of these ecosystems—which are vitally important to the state’s water supply, agriculture, wildlife, and economy—are in dire health. Climate change and accelerating biodiversity loss threaten to further disrupt these natural systems and the benefits they provide. While the state urgently needs to speed the pace of ecosystem restoration, such projects often find themselves mired in regulations that were originally intended to prevent environmental destruction.

Alternative management paradigms for the future of the Colorado and Green Rivers

U.S. Department of Agriculture (USDA) | January 28th, 2021

The Colorado River is among the most extensively managed river systems in the world. The river’s headwaters are within the Rocky Mountains in the United States. From t

The Colorado River is among the most extensively managed river systems in the world. The river’s headwaters are within the Rocky Mountains in the United States. From there, it flows through the arid lands of the Colorado Plateau and the Basin-and-Range to its delta in northwestern Mexico. Here, the river is the only significant water supply in an otherwise starkly arid landscape and has long been called “America’s Nile.” It provides a critical water supply for nearly four million acres of irrigated land, municipal supplies for 30 million people located within and outside the basin, and more than 4,200 MW of hydropower generation capacity. The Colorado River and some of its tributaries also provide an existing or potential water supply for at least 15 Native American tribes. The river flows through seven National Wildlife Refuges, four National Recreation Areas, and five National Parks. Today, the annual consumptive uses and losses of streamflow in the basin typically exceed the amount of water available, and the river rarely flows into the Gulf of California. The impacts of climate change are likely to decrease future runoff and intensify droughts, thereby threatening current and future uses in the basin. Clearly, new ways of thinking about and managing the river need to be sought and implemented.

American River Group (ARG) Annual Report of Activities

Delta Stewardship Council (Delta Council) | November 14th, 2018

Amoral Water Markets?

Georgetown University | June 15th, 2023

Severe water scarcity in the western United States is prompting legitimate questions about the best way to decide which places, people, industries, and species need it mo

Severe water scarcity in the western United States is prompting legitimate questions about the best way to decide which places, people, industries, and species need it most. Water markets, which allow for trading water like a commodity, are perennial proposals during times of scarcity. Water markets have an innate allure: promising to efficiently reallocate water to the highest value uses, minimize risk, and preserve the environment, while relying on the invisible hand to brush aside politically painful values-based questions. This view portrays markets as an amoral arbiter of the best use of water. But water markets are not amoral; they express the historic value judgments baked into the existing western water law system, and layering market approaches over the existing system will both exacerbate the negative impacts of those values and further entrench existing law. In this Article, we show that the West is not ready for water markets.