Technical Approach To Develop Nutrient Numeric Endpoints For California Estuaries

California State Water Resources Control Board (SWRCB) | November 20th, 2007

Eutrophication is one of the top three leading causes of impairments of the nation’s waters, with demonstrated links between anthropogenic changes in watersheds, increa

Eutrophication is one of the top three leading causes of impairments of the nation’s waters, with demonstrated links between anthropogenic changes in watersheds, increased nutrient loading to coastal waters, harmful algal blooms, hypoxia, and impacts on aquatic food webs. These ecological impacts of eutrophication of coastal areas can have far-reaching consequences, including lowered fishery production, loss or degradation of seagrass and kelp beds, smothering of benthic organisms, nuisance odors, and impacts on human and marine mammal health. These modifications have significant economic and social costs. In California, the impacts of nutrient loading on estuaries and coastal waters have not been  wel lmonitored. Without management actions to reduce anthropogenic nutrient loads, symptoms are expected to develop or worsen in the majority of systems, due to projected population increases in coastal areas. The purpose for this report is to outline a conceptual framework for the development of nutrient numeric endpoints (NNE) for estuaries and to highlight data gaps and research recommendations critical for their development. The purpose of NNEs for California estuaries is to provide a scientifically defensible framework that can serve as guidance for adopting regulatory numeric criteria. This framework is founded on an evaluation of risk relative to designated beneficial uses. The objective is to control excess nutrient loads to levels such that the risk of impairing the designated uses is minimized. If the nutrients present–regardless of actual magnitude–have a low probability of impairing uses, then water quality standards can be considered to be met. The ultimate goal of this effort is to develop a set of tools that can be used to support the water quality programs of the California State Water Resources Control Board (SWRCB), Regional Water Quality Control Boards and the regulated community. To reach this goal, we envision the development of a set of estuarine NNE tools, including 1) a classification scheme that groups estuaries according to factors that control their biological response to nutrient loading, 2) risk-based indicators of biological response that can provide quantitative measures of the status of beneficial uses relative to nutrient loads; 3) thresholds that define beneficial use risk categories (BURCs), which provides a framework for regulatory decisions based on quantitative assessments of impairment; and 4) modeling tools that link biological response indicators to watershed nutrient loads. To develop a NNE toolkit for estuaries, the first step in this process was to provide a working framework and to identify key data gaps and research recommendations critical for NNE development. The NNE conceptual framework for estuaries is based on previous work by the SWRCB and US EPA Region IX, which provided guidance for development of NNE in streams and lakes (TetraTech 2005). This framework is founded on the concept that biological response indicators are better suited to evaluate the risk of beneficial use impairment, rather than using pre-defined nutrient limits that may or may not result in mitigation of eutrophication for a particular water body. The advantage of the proposed approach is a more robust link to actual impairment of use, rather than an approach that relies on concentration data alone. The California NNE framework for estuaries is based on three organizing principals: • Biological response indicators provide a more direct risk-based linkage to beneficial uses than nutrient concentrations alone. • A weight of evidence approach with multiple indicators will produce NNE with greater scientific validity. • For many of the biological indicators associated with nutrients, no clear scientific consensus exists on a target threshold that results in impairment.

Technical Guidance for Incorporating Climate Change Information into Water Resources Planning Studies

U.S. Bureau of Reclamation (USBR) | ?

The impacts of climate change are being felt across the Western United States. Warming is affecting water supplies by changing the overall annual volume of precipitation

The impacts of climate change are being felt across the Western United States. Warming is affecting water supplies by changing the overall annual volume of precipitation and altering the balance of rain versus snowfall. Communities are facing increasing problems with water availability and drought, flooding, and increased risk of forest fires. The requirements established by Secretarial Order 3289, Departmental Manual 523 DM 1, Executive Order 13653, and Reclamation’s Directives and Standards CMP 09-02 for feasibility studies reinforces the need for Reclamation's on-going programs to be more resilient to the impacts of climate change and for continued efforts to incorporate climate change information into aspects of our mission where it has not been fully considered in the past such as in decisions regarding ecosystem restoration, reservoir operations, infrastructure investments and planning capacity. This document is an important step to reinforcing Reclamation’s planning capacity by providing guidance to help study teams navigate the range of planning and technical methods available to account for climate change impacts in feasibility studies. The effects of climate change have altered and will continue to alter the basic assumptions underlying Reclamation’s water resources planning. Effective water management and planning rely on an understanding of climate change impacts on water supply, demand, and criteria that govern or guide water management. The guidance in this document may also be applied to environmental compliance studies since they are typically conducted concurrently with feasibility studies. The guidance is organized around the planning and technical framework for conducting a feasibility study as detailed in CMP 09-02, and which occurs in two phases: the scoping phase and the alternative formulation and evaluation phase.

Technical Guidance on Implementing the Stormwater Runoff Requirements for Federal Projects under Section 438 of the Energy Independence and Security Act

U.S. Environmental Protection Agency (EPA) | December 1st, 2009

Stormwater runoff is a leading contributor to water pollution in urban and developing areas in the United States. Section 438 of the Energy Independence and Security Act

Stormwater runoff is a leading contributor to water pollution in urban and developing areas in the United States. Section 438 of the Energy Independence and Security Act of 2007 (EISA)  requires agencies to protect water resources by reducing stormwater runoff from any federal development projects. In December 2007, Congress enacted the Energy Independence and Security Act of 2007. Section 438 of that legislation establishes strict stormwater runoff requirements for federal development and redevelopment projects.  The provision reads as follows: “Storm water runoff requirements for federal development projects. The sponsor of any development or redevelopment project involving a Federal facility with a footprint that exceeds 5,000 square feet shall use site planning, design, construction, and maintenance strategies for the property to maintain or restore, to the maximum extent technically feasible, the predevelopment hydrology of the property with regard to the temperature, rate, volume, and duration of flow.” The intent of Section 438 of the Energy Independence and Security Act of 2007 (EISA) is to require federal agencies to develop and redevelop applicable facilities in a manner that maintains or restores stormwater runoff to the maximum extent technically feasible. Until recently, stormwater programs established to address water quality objectives have been designed to control traditional pollutants that are commonly associated with municipal and industrial discharges, e.g., nutrients, sediment, and metals. Increases in runoff volume and peak discharge rates have been regulated through state and local flood control programs. Although these programs have merit, knowledge accumulated during the past 20 years has led stormwater experts to the conclusion that conventional approaches to control runoff are not fully adequate to protect the nation’s water resources (National Research Council, 2008). Implementation of Section 438 of the EISA can be achieved through the use of the green infrastructure/low impact development (GI/LID) infrastructure tools described in this guidance. The intention of the statute is to maintain or restore the pre-development site hydrology during the development or redevelopment process. To be more specific, this requirement is intended to ensure that receiving waters are not negatively impacted by changes in runoff temperature, volumes, durations and rates resulting from federal projects. It should also be noted that a performance-based approach was selected in lieu of a prescriptive requirement in order to provide site designers maximum flexibility in selecting control practices appropriate for the site.

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.

Technical Report on Barriers: A part of the comprehensive survey of San Francisco Bay and tributaries, California

U.S. Army Corps of Engineers (USACE) | March 15th, 1963

Technical Report on the Scientific Basis for Alternative San Joaquin River Flow and Southern Delta Salinity Objectives

California State Water Resources Control Board (SWRCB) | February 15th, 2012

The State Water Resources Control Board (State Water Board) is in the process of reviewing the San Joaquin River (SJR) flow objectives for the protection of fish and wild

The State Water Resources Control Board (State Water Board) is in the process of reviewing the San Joaquin River (SJR) flow objectives for the protection of fish and wildlife beneficial uses, water quality objectives for the protection of southern delta agricultural beneficial uses, and the program of implementation for those objectives contained in the 2006 Water Quality Control Plan for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary (2006 Bay- Delta Plan). Figure 1.1 displays the project area corresponding to SJR flow objectives and program of implementation and Figure 1.2 displays the project area for the southern Delta water quality objectives and program of implementation. The information and analytical tools described in this report (referred to hereafter as Draft Technical Report or Technical Report) are intended to provide the State Water Board with the scientific information and tools needed to consider potential changes to these objectives and their associated program of implementation. In this quasi-legislative process, State Water Board staff will propose amendments to the SJR flow objectives for the protection of fish and wildlife beneficial uses, southern Delta water quality objectives for the protection of agricultural beneficial uses, and the program of implementation contained in the 2006 Bay-Delta Plan. Also, the environmental impacts of these amendments will be evaluated in a Substitute Environmental Document (SED) in compliance with the California Environmental Quality Act. Any changes to water rights consistent with the revised program of implementation will be considered in a subsequent adjudicative proceeding.

Technical Review of the Draft Staff Report/Substitute Environmental Document in Support of Potential Updates to the Water Quality Control Plan and Associated Modeling

Northern California Water Association (NCWA) | January 18th, 2024

Technical Workshop on Estuarine Habitat in the Bay Delta Estuary

San Francisco Estuary Institute (SFEI) | March 27th, 2012

The Technical Workshop on Estuarine Habitat in the Bay Delta Estuary was initiated by U.S. Environmental Protection Agency (EPA), with support from the Aquatic

The Technical Workshop on Estuarine Habitat in the Bay Delta Estuary was initiated by U.S. Environmental Protection Agency (EPA), with support from the Aquatic Science Center (ASC), to obtain scientific input needed to inform EPA on California’s Comprehensive Review of the 2006 Water Quality Control Plan for the Bay Delta Estuary. Gathering a number of recognized experts on the hydrology and ecology of the Bay Delta was an efficient way to hear current knowledge on estuarine habitat, tools for modeling and assessing conditions, and how biological indicators and ecological processes respond to movement of the low salinity zone.  More specifically, the purpose of the workshop was to: Increase our collective understanding about the attributes of estuarine habitat, and the tools we have for protecting it Characterize the response of biological indicators and ecological processes to changing locations of the low salinity zone (LSZ) Generate scientific information that EPA and others can translate into recommendations that support the State’s Comprehensive Review of the 2006 Water Quality Control Plan (WQCP) for the Bay Delta Estuary The following sections describe planning for the workshop and the workshop process itself. The workshop summary condenses the input from participants during the small workgroup sessions and the final plenary session. It captures the breadth of opinions, judgments, and viewpoints expressed without attempting to fact check statements, or reconcile / synthesize disagreements or contradictions. Finally, the facilitator’s report provides my personal impressions of the workshop and the degree to which it achieved its stated purposes.

Technologies for Passing Fish at Large Dams

California Department of Water Resources (DWR) | June 1st, 2013

Given the possible conditions that may exist in Central Valley streams as the climate warms, many researchers and agencies have recognized the need to evaluate opportunit

Given the possible conditions that may exist in Central Valley streams as the climate warms, many researchers and agencies have recognized the need to evaluate opportunities to provide Central Valley salmonid species access to currently inaccessible habitat (DWR 2008, NMFS 2009, and CA Resources Agency 2009). In addition, Lindley et al. (2007) stated that in order to recover Central Valley salmonids, some populations will need to be established in areas now blocked by dams. “The state should work with dam owners and operators, federal resource management agencies, and other stakeholders to evaluate opportunities to introduce or reintroduce anadromous fish to upper watersheds. Reestablishing anadromous fish, such as salmon, upstream of dams may provide flexibility in providing cold water conditions downstream, and thereby help inform system reoperation.” (CA Resources Agency 2009) The U.S. Bureau of Reclamation dedicates over 1.2 million acre-feet of water, through operation of the Central Valley Project, to fish and wildlife. DWR releases water to meet minimum flow and temperature requirements downstream of Oroville Dam. Climate change may warm rivers and streams, with less water available for ecosystem flow and temperature needs in spring and summer (CA Resources Agency 2009). As temperatures warm, more cold water storage may be needed so that releases can be made to meet temperature requirements downstream. Providing anadromous1 fish passage to areas upstream of reservoirs could eliminate or reduce the need for cold water releases and give water managers additional flexibility in meeting downstream water supply and flood protection needs. In addition, it is prudent to consider fish passage opportunities as part of potential systems reoperations because other agencies are conducting planning efforts for fish passage ...

Tectonic evolution of the Salton Sea inferred from seismic reflection data

Nature Portfolio (Springer Nature) | July 26th, 2009

Oblique extension across strike-slip faults causes subsidence and leads to the formation of pull-apart basins such as the Salton Sea in southern California. The f

Oblique extension across strike-slip faults causes subsidence and leads to the formation of pull-apart basins such as the Salton Sea in southern California. The formation of these basins has generally been studied using laboratory experiments or numerical models. Here we combine seismic reflection data and geological observations from the Salton Sea to understand the evolution of this nascent pull-apart basin. Our data reveal the presence of a northeast-trending hinge zone that separates the sea into northern and southern sub-basins. Differential subsidence (>10 mm yr−1) in the southern sub-basin suggests the existence of northwest-dipping basin-bounding faults near the southern shoreline, which may control the spatial distribution of young volcanism. Rotated and truncated strata north of the hinge zone suggest that the onset of extension associated with this pull-apart basin began after ∼0.5 million years ago. We suggest that slip is partitioned spatially and temporally into vertical and horizontal domains in the Salton Sea. In contrast to previous models based on historical seismicity patterns, the rapid subsidence and fault architecture that we document in the southern part of the sea are consistent with experimental models for pull-apart basins.