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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

, , California Environmental Flows Framework

Flow alterations are a significant driver of species population declines and biodiversity loss in California and globally. When stream flows are altered by human intervention, a wide range of physical and biological processes can be affected, triggering fundamental changes to habitat condition, and the distribution, diversity, and abundance of species. Ensuring the preservation of key flow components can improve riparian and freshwater ecosystem health by restoring physical processes and habitat conditions.

Multiple state and local agencies across California share responsibility for setting flow criteria that protect and improve the ecological health of California’s water resources. These approaches historically have not been coordinated at the statewide level, resulting in fragmented and siloed flow management programs. Consequently:

  • There is no overall framework or guidance for estimating flow criteria

  • Agencies tend to focus on site-specific solutions, instead of holistically managing the health of California watersheds

  • Environmental flow data are not readily available or comparable across the state

  • Improving coordination across California is a challenge. Environmental conditions and pressures vary widely, as do the priorities and capacities of agencies responsible for water resource management.

In 2016, a group of experts self-organized to pool knowledge and data, evaluate methods, and ultimately develop a statewide framework for determining environmental flow criteria for California. The strategy is organized into a two-tiered approach that varies in scale and detail.

The two-tiered framework will provide a set of functional flow criteria for all streams in California (Tier 1) and a technical guidance document for estimating refined flow criteria at regional to site-specific scales (Tier 2).

Tier 1: Use the California natural stream classes and the functional flows method to set flow criteria statewide
   » Statewide applicable approach to set flow criteria protective of river-dependent ecosystems


 Tier 2: Provide guidelines for estimating refined flow criteria depending on the regional, local or site-specific context
 » A tailored approach that incorporates specific environmental and water management factors and priorities

The Technical team will continue communicating and collaborating with diverse partners at the state and local level engaged in flow management via the Environmental Flows Workgroup, a sub-group of the California Water Quality Monitoring Council. For more information on this project, visit the CEFF Website