San Francisco Bay: A Freshwater Starved Estuary

Bay Institute | September 1st, 2016

How Reducing Flows Harms the Ecosystems of San Francisco Bay and Coastal Waters The Bay Institute’s major new study, San Francisco Bay: The Freshwater – Starved Estu

How Reducing Flows Harms the Ecosystems of San Francisco Bay and Coastal Waters The Bay Institute’s major new study, San Francisco Bay: The Freshwater – Starved Estuary, documents how the ecological health of San Francisco Bay and the nearby ocean is at high risk because large-scale water diversion in the Bay’s watershed severely limits the amount of fresh water that reaches the Bay and alters the timing of that flow. Inflow to the Bay from its Central Valley watershed now averages less than half of what it would be without diversions; in some years just one-third of the runoff makes it to the Bay. The result is a nearly permanent drought for the Bay’s fish, wildlife, and their habitats. This radical alteration creates severe consequences for the Bay and marine ecosystems – and Bay Area residents pay the price. The study shows how unsustainable diversion of the Bay’s freshwater inflow: Dramatically cuts production of fish and shrimp that are the food source for marine mammals, like Orca Whales, and birds; Allows pollutants to accumulate to dangerous levels and encourages blooms of toxic algae; Reduces sediment supply to Bay Area wetlands and beaches; Makes it easier for undesirable non-native species to successfully invade the Bay Estuary. The San Francisco Bay Estuary is created by the mixing of fresh water from the Central Valley’s rivers with salt water from the Pacific Ocean. Dramatically reducing the inflow of fresh water generates cascading effects in the Bay’s watershed, the Bay itself, and coastal ocean waters. The report’s major findings include: On average, since 1975 more than half (53%) of runoff from the Central Valley watershed has been diverted, stored, or exported before it can reach the Bay – and in many years two-thirds or more of the Bay’s inflow is captured; As a result of intensive water diversions, the Bay experiences catastrophically dry years almost half the time (only one “supercritically dry” year occurred naturally between 1975-2014, but the Bay experienced nineteen supercritical years during that period); Numerous unrelated fish species – from sharks to salmon, from sturgeon to smelt – show strong positive correlations with Bay Inflow; many of these species are now endangered, and even commercially viable fisheries are in decline; Predators that feed on flow-dependent fish and shrimp are feeling the pinch – for example, dwindling supplies of Central Valley Chinook salmon may restrict the recovery of the local Orca whale population; Blooms of toxic “algae” (cyanobacteria) are becoming more frequent, and other pollutants are becoming more concentrated, as a result of reductions in freshwater flows from the Bay’s watershed; Bay Area beaches and tidal wetlands are deprived of sediment that was once transported by high river flows. The study reports that local businesses are likely to suffer from the Bay’s continued decline, including those related to commercial fishing and tourism. As our Bay, beaches, wetlands, and fish and wildlife populations deteriorate, the quality of life for many Bay Area residents will also be severely – and perhaps permanently – damaged. The study identifies four important approaches to improving Bay inflows: Update the State’s 21 year old water quality standards for the Bay Estuary to ensure adequate inflow Require all those who divert water destined for the Bay, not just a subset, to contribute their fair share of fresh water to support benefits enjoyed by all Californians Invest in local water supplies around the state including conservation, and recycling, that can generate millions of acre-feet of water and reduce reliance on water diverted from the Estuary and its watershed Coordinate management of flows with wetland and beach restoration to more effectively protect shorelines The study was prepared for the San Francisco Estuary Partnership, a coalition of resource agencies, non-profits, citizens, and scientists working to protect, restore, and enhance water quality and fish and wildlife habitat in and around the San Francisco Bay Delta Estuary, which also provided the majority of funding for the project.

Storing and managing water for the environment is more efficient than mimicking natural flows

Nature Portfolio (Springer Nature) | June 27th, 2024

Technical Report for the Interagency Ecological Program (IEP) Pelagic Organism Decline (POD) Workgroup: Assessment of Aquatic Herbicide Use in the Delta

San Francisco Estuary Institute (SFEI) | May 15th, 2006

Since 2001, the California Department of Boating and Waterways (DBW) has conducted an extensive water quality monitoring program in conjunction with its aquatic herbicide

Since 2001, the California Department of Boating and Waterways (DBW) has conducted an extensive water quality monitoring program in conjunction with its aquatic herbicide applications. In this report, the risk quotient calculation method utilized by the Aquatic Pesticide Monitoring Program (a USEPA Tier 1 risk assessment) was used to determine if there are patterns of Level of Concern exceedances that indicate the possibility of adverse impacts on the Delta aquatic ecosystem due to DBW aquatic herbicide applications. Level of Concern exceedances are indicative only of the need for further investigation of an application scenario and do not, in and of themselves, indicate adverse impacts. This type of risk analysis cannot quantify the potential additive or synergistic effects of all pelagic organism stressors (one of which would be aquatic herbicides) within the Delta. This risk assessment indicates that, with the exception of diquat dibromide applications, DBW herbicide applications are unlikely to have the potential to cause Delta ecosystem water quality impacts. While there were a number of Level of Concern exceedances for diquat, DBW and all regulatory agencies involved were aware of this potential prior to application. NOAA Fisheries requested that, when possible, diquat used adjacent to salmon migratory routes should be reduced or avoided when that species is likely to be present. USFWS determined that diquat impact to aquatic invertebrates is minimal, temporary, and not likely to jeopardize Delta smelt but has required avoidance in areas where and when the smelt are known to be present. For 2006, NOAA has allowed DBW to treat sites in April and May with fluridone, which has allowed the use of diquat to be discontinued.

The Economic Value of Nature's Services and its role in Integrated Water Management: Four California Case Studies

California Department of Water Resources (DWR) | July 1st, 2014

Here we present four case studies of integrated regional water management that include enhancement of biological diversity among their goals. Each pilot-scale project foc

Here we present four case studies of integrated regional water management that include enhancement of biological diversity among their goals. Each pilot-scale project focuses on multiple water-related natural resources in a defined geographic area, usually a watershed. A common element of the projects is to show the economic benefits of protecting and restoring natural resources in a manner that allows their continued use over the long term. One of the aims of the projects is to recognize the economic value of the goods and services that nature provides and to incorporate that value into natural resource management decisions. Such recognition includes development of ways to measure the economic value of those services. This can be important information for water managers who normally see only the costs of ecosystem protection and restoration, but not the benefits, in their budgets. The goods and services considered in these projects include water supply, water quality, erosion prevention, wildfire prevention, hydropower generation, wood products, flood attenuation, carbon sequestration, land subsidence reversal, and fish and wildlife. Collectively, the projects constitute on-the-ground efforts to advance several of the objectives in the implementation plan of Water Plan 2009. In particular, they aim to expand integrated regional water management (objective 1), protect surface water and groundwater quality (objective 4), expand environmental stewardship (objective 5), practice integrated flood management (objective 6) and manage a sustainable California Delta (objective 7). The case studies accomplish and document several key ingredients of integrated resource management--although no single study does all of them. They identify and involve watershed stakeholders, both managers and users of natural resources. In turn, the stakeholders come to agreement about how they want the watershed to look or function, usually in terms of the goods and services that they want the watershed to provide. Then they reach agreement on a set of management practices that can support and enhance those services and move the watershed toward the desired condition. Finally, the case studies seek to estimate the amounts of goods and services derived from specific management practices. The pilot projects go beyond most watershed management efforts and most ecosystem services work in laying the foundation for establishment of markets for nature’s services, that is, mechanisms for beneficiaries to pay producers for goods and services they receive. This requires some sort of assessment of the monetary value of the benefits. One desired end product is to put payments in the hands of producers-- that is, resource managers—as an incentive to keep them producing.

Toward climate-resilient fisheries in the Humboldt Current: Developing a scientific foundation for improved adaptive management

Environmental Defense Fund (EDF) | January 2nd, 2020

The HCS covers an area comprised of 55° of latitude off Peru and Chile (3°23.57′ to 58°21.02′) and extends over 200 nautical miles offshore. The dynamics of the HC

The HCS covers an area comprised of 55° of latitude off Peru and Chile (3°23.57′ to 58°21.02′) and extends over 200 nautical miles offshore. The dynamics of the HCS are strongly influenced by seasonal or permanent coastal upwelling. Several features distinguish the HCS from similar ecosystems associated with the Eastern Boundary Upwelling Systems of the world’s oceans (EBUS: California, Canarias, Humboldt and Benguela). First, it extends closest to the equator. Second, it is the most exposed EBUS system to ENSO, the largest source of interannual climatic variability on the planet. Third, although each of the EBUS has similar levels of primary productivity, the HCS contains the most productive fisheries. Lastly, it is associated with the presence of a shallow, intense subsurface oxygen minimum layer that compresses the oxygenated epipelagic habitat to a few dozen meters. Global warming is altering energy and matter exchange between the atmospheric, oceanic, and continental boundaries. 

Upper San Gabriel Valley Municipal Water District v. City of Alhambra et al

Superior Court of California, County of Los Angeles | June 21st, 2012

Background note from An Evaluation of California’s Adjudicated Groundwater Basins by Langridge et al, (UC Davis) 2016 The Main San Gabriel Basin is one of the larges

Background note from An Evaluation of California’s Adjudicated Groundwater Basins by Langridge et al, (UC Davis) 2016 The Main San Gabriel Basin is one of the largest groundwater basins in southern California, providing residents of the greater San Gabriel Valley with about 240,000 AF per year. It is geographically situated in the south-easterly portion of Los Angeles County and bounded on the north by the San Gabriel Mountains, on the northwest by Raymond Basin, on the southeast by Puente Basin, and on the south by the Central Basin. The adjudication of the basin was deemed necessary by water producers to streamline administration, reduce overdraft, and adhere to the Long Beach Judgment and Puente Narrows Agreements, and the adjudication was relatively amenable. One of the most significant concerns in the basin is water quality, with four areas of the valley containing Superfund sites. The 1973 Judgment included water quality as one of the Watermaster’s responsibilities, and since the mid-1980s the Watermaster has coordinated with regulatory agencies to have groundwater remediation facilities constructed, permitted and operated to protect and enhance the groundwater supplies. The 1992 Judgment amendment explicitly required coordination with EPA for a federal cleanup of the Superfund sites.

When the water runs dry: supporting adaptive governance in transboundary river basins

Water International | February 21st, 2021

Impacts of global climate change will primarily be felt through the water cycle. Adaptation to changing conditions in transboundary basins is an important precondition to

Impacts of global climate change will primarily be felt through the water cycle. Adaptation to changing conditions in transboundary basins is an important precondition to ensure regional sustainable development and political stability. However, adaptation measures in one basin country can affect water resources and adaptation options elsewhere, therefore often requiring coordinated or joint responses by riparian countries. The paper examines the potential of climate policy instruments in strengthening adaptation to changes in transboundary river basins in North America’s Colorado River Basin and Southern Africa’s Orange-Senqu River Basin. It finds that climate policy instruments are yet rarely employed to jointly manage adaptation in shared rivers but nonetheless harbour great potential.