Butte Basin NAWCA II: Butte Sink NWR Enhancement

Legendary "Bean Field" area of Butte Sink National Wildlife Refuge

This project is one of 10 individual project sites included in the Butte Basin and Colusa Trough Wetland Habitat Project.  New work conducted by the overall project improved 2,573 acres of habitat in this region.  The region is extremely important for migrating and wintering waterfowl, shorebirds, and other waterbirds.  The Central Valley, which includes this region, winters up to 90% of the Pacific Flyway's population of northern pintails and about 60% of its overall population of waterfowl.  At times, the Central Valley supports 20% of the continent's waterfowl population.  In addition to providing critical habitat for waterfowl, the Butte Basin and Colusa Trough region is also of major importance to several special-status species including the giant garter snake, spring-run chinook salmon, winter-run chinook salmon, and Central Valley steelhead.

The habitat improvement work accomplished by the overall project is extremely important.  The project increased wetland acreage for migrating and wintering waterfowl and other waterbirds, increased riparian acreage for neotropical migrants, improved water quality, improved water conveyance and control capabilities to allow better habitat management and improve efficiency of water use, and provided fish-safe water to many acres of wetlands and wildlife-friendly agriculture (i.e., winter flooded rice).

Butte Sink National Wildlife Refuge (NWR) is located in the Butte Basin and is owned and managed by the U.S. Fish and Wildlife Service.  This project was located in the legendary "Bean Field" portion of Butte Sink NWR.  Work at the site enhanced 700 acres of palustrine emergent wetlands.  Project work consisted of  installing numerous water control structures, repairing approximately 0.5 mile of an existing degraded levee, excavating low flow channels, and installing erosion protection around water control structures and a section of perimeter levee.  This work greatly improved water and vegetation management capabilities.

The project work completed in the Bean Field improved habitat conditions for a variety of wildlife, but is particularly important for waterfowl.  The area typically supports peak waterfowl populations of 500,000-750,000 birds.  The most abundant species are northern pintail, American wigeon, green-winged teal, northern shoveler, and snow and Ross' geese.