Management and Conservation

Habitat Management

At the Sacramento National Wildlife Refuge Complex, wetlands, uplands and riparian riparian
Definition of riparian habitat or riparian areas.

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forests are manipulated through a variety of management techniques (mechanical, biological, and chemical) to promote diversity of high quality habitats (food resources). Management activities are guided and tracked by each refuge's annual Habitat Management Plan. These plans identify the specific physical attributes, habitat objectives, and species needs for every single pond and field of the refuge.  Each year the plans are updated to specify the necessary management activities to maintain or improve the habitat of each unit.

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Management Activities

Tools that the Complex uses for Habitat Management include:

      • Water management (timing, depth, duration)
      • Mechanical control (mowing, disking)
      • Biological control (grazing)
      • Chemical control (herbicide treatments)
      • Prescribed burning
      • Habitat restoration
      • Monitoring and Research

Water Management

Water management is probably the most important tool the refuge has for maintaining high quality wetland habitat. By controlling the timing, depth and duration of water on each wetland, the refuge can manipulate the production of desirable or undesirable wetland plants. Water management is also critical in providing the proper habitat to specific species at different times of the year.  For example, tricolored blackbirds needs dense stands of flooded cattail during the summer months for their nesting colonies, and shorebirds need shallow open wetlands in the spring and fall when they migrate through the Valley.  In general, refuge flooding regimes are designed to mimic historic wetland availability in the Sacramento Valley.

Physical, Biological and Chemical Control

Each new year is accompanied by new changes in vegetative growth.  Some of this vegetation is beneficial, providing nesting/escape cover or food resources, and some is undesirable and displaces desirable vegetation without any benefits.  Vegetation control is necessary for a wide variety of reasons, including: maintaining biodiversity, enhancement of desirable species (for food and cover), reduction of undesirable species, preparation for habitat restoration projects, reduction of mosquito breeding habitat, and maintenance of safety zones around facilities to communities and assets at risk of wildfire. A variety of techniques are used depending on the habitat type, plant species, and resource objectives. Mechanical techniques, such as mowing and disking can improve loafing habitat, remove weedy species before seed is produced, kill perennial weeds, or improve seed beds for beneficial plants (kind of like tilling your garden). Biological techniques are used to set back native vegetation and to control weedy species, like grazing native grasslands to reduce thatch buildup so new grass shoots can grow each spring, or using beetles to eat invasive Klamathweed. Chemical control (herbicide) is used when other mechanical or biological techniques are ineffective, like when a new and highly invasive species invasive species
An invasive species is any plant or animal that has spread or been introduced into a new area where they are, or could, cause harm to the environment, economy, or human, animal, or plant health. Their unwelcome presence can destroy ecosystems and cost millions of dollars.

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is detected and quick control is critical, or for certain persistent species like pepperweed that have a 10 foot taproot make it impossible to otherwise eradicate.

Prescribed Burning

A prescribed burn prescribed burn
A prescribed burn is the controlled use of fire to restore wildlife habitat, reduce wildfire risk, or achieve other habitat management goals. We have been using prescribed burn techniques to improve species habitat since the 1930s.

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is a controlled burn that is pre-planned by refuge managers in a specific area for a specific resource objective. Prescribed fires may be used to reduce hazard fuels, restore natural processes and vitality of ecosystems, improve wildlife habitat, remove or reduce non-native species, and/or conduct research. They are often used in conjunction with other management tools such as grazing, mowing, and herbicide applications.

Prescribed burns are used in wetlands to control invasive species, for example burning jointgrass during the summer, or to stimulate desirable species, such as burning rank cattail and bulrush over water to allow for fresh new growth. Fire lines and buffers are disked around the burn area to increase controllability. The firing pattern allows for an avenue or direction of escape for wildlife. Follow-up disking is often used to ensure that roots of target species (i.e. hard-stemmed bulrush, cattail, jointgrass, etc.) are killed and enhance germination of desirable species. The result is a desirable mix of vegetation species, stature are more productive and reduces the risk of life and property from larger more destructive wildfires. The frequency of burning wetland units depends on habitat type, vegetation species composition, soil type, and tendency for growth.  

Prescribed burns in grasslands, alkali meadows, and vernal pools are used to reduce invasive species and stimulate native plant species. Resource benefits include maintaining biodiversity (especially native plant communities and the wildlife they support), providing browse for waterfowl, control of invasive species, and removing rank thatch to allow for new growth in native grass restoration areas. These burns may occur at any times of the year, depending on specific objectives and condition of the habitat.

The Fire Crew
The California North Central Valley Fire Management Zone is headquartered at the Sacramento National Wildlife Refuge Complex in Willows, California. The program provides fire management services for the Sacramento NWR, Delevan NWR, Colusa NWR, Sutter NWR, Sacramento River NWR, Stone Lakes NWR, Red Bluff Field Office, Coleman National Fish Hatchery (NFH) and Livingston Stone NFH. The fire program emphasizes fire suppression, prevention, hazardous fuels reduction and prescribed fire. The Zone's fire management mission is to provide a team approach to safe, efficient, and professional fire management program while protecting and enhancing fish and wildlife habitat.

The Fire Management Staff is stationed at the Sacramento NWR. The staff includes: Fire Management Officer, Fire Engine Operators and several Temporary Firefighters.

The fire program operates with two Type-3 engines, one Type-6 fire engine and one water tender. The fire staff participates on interagency incident management teams, refuge fire responses, off-unit assignments across the Nation, interagency prescribed fire operations and interagency training assignments. The zone treats an average of 1,200 to 1,800 acres per year for a range of resource objectives including hazardous fuels reduction, community protection and habitat enhancement.

The fire staff is augmented by a strong contingent of collateral duty fire qualified personnel. Over 10 Complex staff members from biologists, law enforcement, equipment operators and refuge managers assist with wildfire support and prescribed fire operations.

Monitoring and Research

Wildlife and plant monitoring, along with other research activities provide valuable data to help refuge staff evaluate past habitat management actions and refine future management needs.

Refuge biologists conduct long-term monitoring of wildlife populations, wildlife diseases, wetland vegetation, and rare plants to help guide annual management decisions.  Bird diseases that most frequently affect the waterfowl on the Complex include avian cholera, avian botulism, and lead poisoning. These diseases cannot be passed to humans. Dying birds are monitored and dead birds removed with airboats to stop the disease cycle.  Click here to find out more about the refuge's wildlife surveys.

Partnerships with other agencies, non-profit research partners, and universities allow for more in-depth management-oriented research that helps support and inform not only management at the refuge level, but also at a landscape, flyway, and international level as well.

Conservation and Partnerships

The Complex is involved in many conservation endeavors, including Comprehensive Conservation Plans, Private Landowner Programs, and the National Wildlife Refuge System Improvement Act. 

Comprehensive Conservation Plans 

Refuge Planning:  National Wildlife Refuge planning sets the broad vision for refuge management and the goals, objectives, strategies, and actions required to achieve it. Planning ensures that each refuge meets its individual purposes, contributes to the Refuge System’s mission and priorities, is consistent with other applicable laws and policies, and enhances conservation benefits beyond refuge boundaries. 

Comprehensive Conservation Plans (CCPs) are the primary planning documents for National Wildlife Refuges. As outlined in the National Wildlife Refuge System Administration Act, as amended, the U.S. Fish and Wildlife Service (Service) is required to develop CCPs that guide refuge management for the next 15 years. CCPs articulate the Service’s contributions to meeting refuge purposes and the National Wildlife Refuge System mission. CCPs serve as a bridge between broad, landscape-level plans developed by other agencies and stakeholders and the more detailed step-downs that stem from Refuge CCPs.  

CCP: Wildlife Management Areas

The Final CCP and Environmental Assessment for the Butte Sink, North Central Valley, and Willow Creek-Lurline Wildlife Management Areas was completed in 2020. These WMAs include both Service-owned lands and private lands that are protected with conservation easements.  This CCP includes the following WMAs:

      • Butte Sink
      • Willow Creek-Lurline
      • Steve Thompson North Central Valley

CCP: Sacramento, Delevan, Colusa and Sutter NWRs

The Final CCP and Environmental Assessment for Sacramento, Delevan, Colusa, and Sutter NWRs was completed in March, 2009 and includes the following refuges:

      • Sacramento NWR
      • Delevan NWR
      • Colusa NWR
      • Sutter NWR

CCP: Sacramento River NWR

The Final CCP and Environmental Assessment for the Sacramento River NWR was completed in July, 2005.  This CCP includes the Sacramento River NWR.

Step-down Plans 

CCP step-down plans guide refuge-level programs for: (1) conserving natural resources (e.g., fish, wildlife, plants, and the ecosystems they depend on for habitat); (2) stewarding other special values of the refuge (e.g., cultural or archeological resources, wilderness, wild and scenic rivers, etc.); and (3) engaging visitors and the community in conservation, including providing opportunities for wildlife-dependent recreation. Like CCPs, step-down plans contribute to the implementation of relevant landscape plans by developing SMART (Specific, Measurable, Achievable, Relevant, and Time-bound) objectives, strategies, implementation schedules, and decision support tools to fulfill refuge visions and goals. This ensures that refuges are managed in a landscape context and that conservation benefits extend beyond refuge boundaries.  

Private Landowner Programs

Our Private Lands staff works with private landowners, partnering agencies and conservation groups to provide information and assistance for the preservation and enhancement of a variety of habitats throughout the Sacramento Valley. 

Visit ourPrivate Lands Programs page to find out more about our:

      • Conservation Easement Program
      • Partners for Fish and Wildlife Program 
      • Technical Assistance Program 

National Wildlife Refuge System Improvement Act

National Wildlife Refuge System Improvement Act of 1997:The NWRS Improvement Act defines a unifying mission for all refuges, including a process for determining compatible uses on refuges, and requiring that each refuge be managed according to a Comprehensive Conservation Plan. The NWRS Improvement  Act expressly states that wildlife conservation is the priority of System lands and that the Secretary shall ensure that the biological integrity, diversity, and environmental health of refuge lands are maintained. Each refuge must be managed to fulfill the specific purposes for which the refuge was established and the System mission. The first priority of each refuge is to conserve, manage, and if needed, restore fish and wildlife populations and habitats according to its purpose.

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Law Enforcement

U.S. Fish and Wildlife Service law enforcement officers have a wide variety of duties and responsibilities. Officers help visitors understand and obey wildlife protection laws. They work closely with state and local government offices to enforce federal, state and refuge hunting regulations that protect migratory birds and other game species from illegal take and preserve legitimate hunting opportunities. Some other duties include patrolling closed areas, maintaining relationships with neighboring landowners, maintaining refuge boundaries and participating in public events related to refuge issues.

Laws and Regulations

All areas of the Colusa NWR are closed to public entry unless otherwise explicitly posted as an auto tour route, nature trail, hunting area, or parking area. Some areas are closed seasonally and are posted as such.