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Projects Worked On

Project Name Description
Shasta River

Interdisciplinary teams of Center scientists are investigating the causes for the decline of salmon and steelhead in Shasta River, historically one of the most productive tributaries in the lower Klamath Basin. A large spring complex (Big Springs Creek) provides the majority of its water, particularly during the summer.

Researchers are developing innovative approaches to restoring and sustainably managing this unique resource for both native fish and for irrigating local ranches and farms.

Though Shasta River provides only 1 percent of the Klamath River’s streamflow, it historically produced 50 percent of the Chinook salmon  -- and it still produces enough fish to support a large proportion of California’s commercial and recreational salmon fishery. Improving freshwater habitat in the Shasta results in disproportionally large benefits for the lower Klamath Basin.

Big Springs Creek

In 2008, Center researchers seized a rare opportunity to quantify the results of conservation action on a large scale. The Nature Conservancy bought ranchland along Big Springs Creek, a Shasta River tributary that had been degraded by cattle grazing. The conservancy continued ranching but fenced out cattle along the 2.2 mile stream.

Since then, Center researchers and partner Watercourse Engineering, Inc. have been extensively monitoring the creek's recovery, collecting data and analyzing changes in geomorphology, hydrology, hydraulics, water temperature, water quality, aquatic vegetation, aquatic invertebrates, fish assemblage and habitat distribution.

The research:

  • Provides valuable insights to large-scale restoration for salmon.
  • Documents the importance of spring-fed streams as refuges for cold-water fish in a warming climate.
  • Demonstrates how salmon can recover while maintaining a working landscape.
Management of the Spring Snowmelt Recession

In managed river systems in the Sierra Nevada, increased understanding of the fundamental relationships between the spring snowmelt flow regime and abiotic and biotic stream conditions is needed to aid water resource managers in making the complex decisions required to balance multiple water resource needs.

In this project, we seek to improve our understanding of the impacts of varying spring flow regimes on stream ecology, through empirical field studies, and water management, through hydropower optimization modeling.

Specifically, we are:

  1. assessing the effects of the spring flow regime on abiotic and biotic stream conditions through analyses of empirical field data at six river study sites with varying degrees of regulation, and
  2. applying and enhancing existing systems analysis techniques for multi-reservoir hydropower operations with ecologically meaningful instream flow constraints.

We expect the results from these tasks to be directly applicable in future relicensing projects where recent ecological knowledge and various modeling applications will be utilized to guide instream flow determinations.

We aim to provide resource managers not only with increased knowledge regarding the ecology of the spring recession, but with a series of methods that help predict the impacts of various spring flow regimes on the diversity of aquatic and riparian species and the economics of hydropower production.

Spring-Fed vs. Snowmelt Rivers: Ecosystem Productivity

This project measures and compares ecological productivity in two types of river systems in the Upper Sacramento River watershed. The project's team of ecologists, geologist and biologists is comparing the food-web dynamics of three spring-fed systems - Hat Creek, Fall River and tributaries of the upper Sacramento River - with those of rivers that receive mainly snowmelt and stormwater runoff in the same watershed.

The study aims to improve understanding of spring systems and their role in sustaining salmonids in California. Spring systems are expected to become increasingly more important for the survival of these and other cold-water fishes as the climate changes and the runoff-fed rivers run low and warm.

Spring rivers are more resilient to long-term warming and changes in precipitation because they receive a constant source of cold water from underground. They often have unique water chemistry that promotes the growth of aquatic plants and insects.

Little Shasta River

, , The California Environmental Flows Framework


Project Description:

Identifying ecological flow prescriptions (i.e., recommendations) is necessary for the protection of freshwater ecosystems and the associated services they provide to society. Multiple state and local agencies across California share responsibility for quantifying flows needed to protect and improve the health of freshwater ecosystems. Yet, the vast majority of streams and rivers in California do not have ecological flow prescriptions, mainly due to the substantial resources required to evaluate ecological flow needs at a high number of diverse locations. Historically, where ecological flow criteria have been developed, efforts have been poorly coordinated and have resulted in fragmented, inconsistent, and ultimately ineffective protection of freshwater ecosystems. To improve the coordination and effectiveness of flow management in California, this technical team has pooled data, evaluated methods, and developed a statewide approach for establishing ecological flow criteria and guidance on developing ecological flow prescriptions. The products of this effort can aid in water management decision-making processes and the development of environmental flow objectives.

The California Water Quality Monitoring Council established a statewide technical workgroup to strengthen linkages between research and agency needs and to provide support for resource managers working to secure environmental flow protections in the state’s rivers and streams. A key product of this workgroup is the development of this document, the California Environmental Flows Framework (CEFF), which provides an approach for developing consistent science-based recommendations for setting ecological flow prescriptions statewide. CEFF provides guidance, data, and tools for users to develop hydrologically representative and ecologically-relevant functional flow metrics that can be used to inform the establishment of environmental flow objectives aimed at protecting aquatic life while supporting human uses. CEFF has the following features:
  • is based on a functional flows approach that considers all aspects of the annual hydrograph, focusing on flow components that are linked to ecological function in streams,
  • has a structure that allows for the flexible development of ecological flow criteria based on reference hydrology and provides tools and guidance for developing ecological flow prescriptions,
  • can be applied across a broad diversity of geographic and water management contexts and desired ecological outcomes,
  • provides guidance for balancing multiple management objectives, and
  • includes recommendations for and examples of monitoring and adaptive management programs.
CEFF provides ecological flow criteria that support ecosystem function using reference hydrology. In addition, CEFF offers guidelines for refining ecological flow criteria aimed at supporting specific species or habitats. The resulting ecological flow prescriptions can then be used to establish environmental flow objectives that balance ecological and human water needs.

       Process for developing ecological flow criteria and prescriptions in California. CEFF process in green and blue. Orange box indicates additional  considerations stakeholders should take outside of the technical process to ultimately arrive at environmental flow objectives.
Key CEFF products:
  • Reference-based ecological flow criteria: Uses the California natural stream classes and the functional flows approach to set flow criteria statewide
    • Statewide applicable method to set flow criteria protective of river-dependent ecosystems
  • Refined ecological flow criteria and ecological flow prescriptions: Provide guidelines for estimating ecological flow prescriptions depending on the regional, local or site-specific context
    • A tailored approach that incorporates specific environmental and water management factors and priorities
Once complete, the CEFF Guidance Document will be made publically available. Further information about CEFF is provided at