Mitigation Projects

Gilsizer Slough South GGS Conservation Bank

The Bank is part of the overall Gilsizer Slough Giant Garter Snake Conservation Complex - a group of conservation banks and preserves in Sutter County, established and operated by Wildlands providing giant garter snake (“GGS”) habitat mitigation values to both public works agencies and private developers as a mitigation solution to fulfill permit obligations.

The Complex comprises over 620 acres of created and preserved habitat for the aquatic GGS, which includes four completed phases: Gilsizer Preserve (162 acres), which straddles Gilsizer Slough, was completed in 2004; Gilsizer Slough South GGS Conservation Bank (380 acres in two phases) was completed in 2006 and 2009; and Gilsizer North Preserve (80 acres) was completed in 2009. Restoration completed within the complex included the creation of a mosaic of emergent and open water habitat with uplands, and the preservation of some existing wetland areas. Each phase of the Complex required coordination with federal, state, and local regulatory agencies for permitting and entitlement. Approvals and/or permits were obtained from the USFWS, USACE, CDFW, and the County of Sutter.

Construction and Performance

Giant Garter Snake
  • Wetlands were created through the excavation of basins, and the excavated material was deposited and shaped into upland mounds.
  • Salvaged native bulrushes were planted in the created emergent wetlands, while native grasses were planted in the upland areas.
  • Native aquatic bed plant species are expected to colonize in the deeper pond areas.
  • Emergent marsh plant species establishment and use by the giant garter snake have been documented in both phases of the Bank.

380 acres

Location: Sutter County, California

Mitigation Types

  • Giant Garter Snake

Service Area

Credits at the Bank are SOLD OUT.

Approving Agencies

  • U.S. Fish & Wildlife Service

For additional information on the Gilsizer Slough South GGS Conservation Bank, please contact Julie Maddox at (916) 435-3555 or