Keywords:basin characterization, groundwater dependent ecosystems, Groundwater Exchange
The San Francisco Bay and Sacramento-San Joaquin Delta form one of the largest estuaries in the United States. The “Bay-Delta” system provides water...
The San Francisco Bay and Sacramento-San Joaquin Delta form one of the largest estuaries in the United States. The “Bay-Delta” system provides water to more than 25 million California residents and vast farmlands, as well as key habitat for birds, fish, and other wildlife. To help ensure the health of this crucial estuary, the U.S. Geological Survey, in close cooperation with partner agencies and organizations, is providing science essential to addressing societal issues associated with water quantity and quality, sediment transportation, environmental contamination, animal health and status, habitat restoration, hazards, ground subsidence, and climate change.
Covering only about 1 percent of California’s area, the Sacramento-San Joaquin Delta, including Suisun Bay and Marsh (hereafter referred to as Delta-Suisun), contributes...
Covering only about 1 percent of California’s area, the Sacramento-San Joaquin Delta, including Suisun Bay and Marsh (hereafter referred to as Delta-Suisun), contributes much more to the state and nation than one might expect from its small size.
The Delta-Suisun provides a set of environmental and economic services whose benefits extend well beyond its borders. To help people gain a common understanding of these services, this report provides an overview of the existing status of these services and a perspective about how these services may change in the future.
This report was prepared to highlight observations and to present a common understanding about the status and trends of key Delta-Suisun services. The Delta Risk Management Strategy (DRMS) is considering these observations while conducting a risk assessment for the Delta-Suisun and will report on its findings in spring 2007.
Having a common understanding of the area’s services will benefit ongoing and new Delta-Suisun studies and initiatives. Information in this report will be considered by members of the Delta Vision Blue Ribbon Task Force and Stakeholder Coordination Group as they begin work on the Delta Vision and Strategic Plan.
Adaptive management is the process of incorporating new scientific and programmatic information into the implementation of a project or plan to ensure that...
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.
Large-scale fish kills and habitat destruction aren’t an unusual occurrence at the giant federal and state pumps that export water from the Sacramento-San...
Large-scale fish kills and habitat destruction aren’t an unusual occurrence at the giant federal and state pumps that export water from the Sacramento-San Joaquin Delta to agribusinesses and cities in the southern half of the state. These events are business as usual.
• Every day, between 870 and 61,000 fish – including from 200 to 42,000 native and endangered fishes – are “salvaged” at the pumps. Most die in the process.
• On average, over 9 million fish – representing the twenty fish species considered in this report – are “salvaged” each year at the pumps. As many as 15 million fish of all species encountered are “salvaged” each year.
• Up to 40% of the total population of the endangered delta smelt and 15% of the endangered winter-run population of Chinook salmon are killed at the pumps in some years. In the first half of 2011, over 8.6 million splittail were salvaged.
• Salvage estimates drastically underestimate the problem. The numbers do not factor in the results of “indirect” mortality, as high levels of export pumping disrupt fish migration, shrink the amount of non-lethal habitat available to fish species, and remove vast amounts of biomass, including fish eggs and larvae too small to be screened at the pumps.
• Export pumping causes the lower San Joaquin River to flow backwards most of the year and removes the equivalent of 170 railroad boxcars of water – and the accompanying fish, other organisms, and nutrients – from the Delta ecosystem every minute.
• Large numbers of fish being entrained is a problem even for species that are not currently listed as “endangered.” Killing large numbers of fish year after year cuts off population growth in response to favorable conditions and can start the species on a downward path to extinction. As the species declines, the population impacts of entrainment become proportionately larger.
• Entrainment is a real problem. But the same interests in the Delta export community who claim that it isn’t also back constructing expensive new conveyance facilities such as a peripheral canal or tunnel to solve the problem that they say doesn’t exist.