U.S. Fish & Wildlife Service

Sacramento Fish & Wildlife OfficeServing the people, conserving the fish, wildlife, and plants of California

A Unit Of The Pacific Southwest Region

Partnering to Provide a New Place to Roam in the San Joaquin Valley

Photo of people honored by Westervelt Ecological Services

The Service and DWR were among those honored in November by Westervelt Ecological Services for the private-public partnership which created new habitat to help the threatened giant garter snake in the San Joaquin Valley. Pictured above from left to right are Jennifer M. Norris, Ken Sanchez, Terri Gaines Lori Clamurro-Chew and Greg Sutter. Photo Credit: Sarah Swenty / USFWS

In the spirit of strong partnerships and sound conservation, a celebration was held in November 2015 to unveil habitat created to help an endangered species in a critical area of California. The Grasslands Mitigation Bank provides a new home for the threatened giant garter snake (GGS) in the San Joaquin Valley and is a cost effective way for the California Department of Water Resources (DWR) to get ahead of their flood control mitigation needs for projects in the Central Valley of California.

The same week as the celebration, President Obama issued two memorandums encouraging private investment in natural resource conservation. Conservation mitigation banking is a good example of this type of investment, whereby private owners of high quality habitat can set aside and conserve their lands forever, and in exchange can sell "credits" from the bank to developers whose project will have negative species impacts elsewhere. In the case of the Grasslands Mitigation Bank, DWR recognized a need for mitigation in advance of their future flood control work, and their ability to "pre-purchase" many of the bank's GGS credits served as a financial impetus to get the bank established.

The Service's role in this effort was to guide the bank sponsor through the complicated approval process. The Service's Sacramento Fish and Wildlife Office (SFWO) leads the nation in conservation banking efforts, overseeing more banks than any other office in the country.

"Conservation banks are an important tool for protecting natural resources." explained Jennifer M. Norris, SFWO's Field Supervisor. "They allow for landscape-scale conservation to take place where it's needed most. Conservation banks are also more efficient and cost effective to manage than small, isolated properties preserved with tradition mitigation."

Photo of water flowing in Grasslands Mitigation Bank

As water flows, the Grasslands Mitigation Bank will create a mosaic of perennial wetlands and upland habitat that will support the full life cycle of the giant garter snake. Photo Credit: Sarah Swenty / USFWS

This is the first of DWR's advanced mitigation projects, set up to offset the ecological costs of their flood management activities. Forecasted El Niño conditions indicate heavy rainfall may be ahead, putting California at risk for severe flooding. Having the Grasslands Mitigation Bank in place will allow DWR and its partners to perform essential flood management tasks that could impact giant garter snake more quickly and at a lower cost.

"This bank makes good business sense," stated Dave Mraz, acting Chief of DWR's Floodway Ecosystem Sustainability and Statewide Resources Office. "Throughout the Central Valley, DWR and local levee agencies need to maintain and improve the flood control system to protect lives and property. The credits provided at this bank can be used to offset ecological impacts from these activities occurring within the San Joaquin Valley and South Delta."

Mitigating in advance of levee construction allows for more efficient project approvals, lower mitigation costs and, in the case of the Grasslands Mitigation Bank, takes advantage of a valuable conservation opportunity.

Connectivity is an issue for many endangered species, as fragmented habitat plays a major role in their decreasing populations. The Grasslands Mitigation Bank's 281 acres of restored habitat is next to the the last known breeding population of the GGS in the San Joaquin Valley on the California Department of Fish and Wildlife's Volta Wildlife Area. Protection of this important habitat in Merced County is a priority recovery task under the Service's Draft GGS Recovery Plan.

Once found throughout the vast marshlands of the San Joaquin and Sacramento River Valleys of California, GGS is now listed under both the federal and state Endangered Species Acts, as its numbers have seriously declined due to loss of habitat. The species is now absent from 98 percent of its former habitat in the San Joaquin Valley.

The bank is next to the the last known breeding population of the giant garter snake in the San Joaquin Valley on the California Department of Fish and Wildlife’s Volta Wildlife Area. The establishment of the bank in this location will significantly improv the ability to provide protected habitat for this critical population. Photo Credit: David Kelly/USFWS

The conservation bank's location was specially chosen for its ideal soils, hydrology and biological connectivity. It is expected that part of the current GGS population on the state wildlife area will move to and colonize the newly created habitat next door.

"There's no better place a bank could have gone. Establishing it with water supply in the summer and the Volta GGS population next door is one of the most important things we can do to ensure the species survives in the San Joaquin Valley," elaborated Eric Hansen, an independent GGS researcher.

The establishment of the bank within feet of the existing wildlife area will significantly improve the ability to provide protected habitat for this critical population.

Westervelt Ecological Services (Westervelt) has been working with multiple resource agencies, including the Service and DWR to provide the detailed biological studies, water supply availability and planning documents that were provided much of the pre-planning necessary to get a conservation bank approved. The private company has a long history of working to create public/private partnerships that benefit conservation. As Greg Sutter, Westervelt's Executive Vice President put it, "It doesn't matter what your politics are, it's good policy to encourage private investment in conservation."

In addition to acquiring the parcel for conservation and leading the planning effort, Westervelt oversaw the on-the-ground work to create habitat features that will support the GGS.

Photo of Grasslands Mitigation Bank

Multi-agency, public-private partnerships like the Grasslands Mitigation Bank provide a great example and hope to inspire others to work together for the benefit of both the people and the wildlife of the United States. Photo Credit: Sarah Swenty/USFWS

Creating wetlands for GGS from the agricultural fields was a complex process. Portions of the previously-leveled fields were shaped to create complex habitat; channels and depressions were cut in the land and the fill used to create berms and mounds. New water control structures were installed to allow adjustments in the water level in the future emergent marsh sections for the purpose of vegetation management. This new conservation bank will create a mosaic of perennial wetlands and upland habitat that will support the full life cycle of the species.

The Grasslands Mitigation Bank has been a collaborative effort between the DWR, the Service, Westervelt, the U.S. Army Corps of Engineers, the U.S. Environmental Protection Agency and the National Marine Fisheries Service.

As the habitat matures and GGS move into the newly created Grasslands Mitigation Bank, the outlook for species recovery will improve. Multi-agency, public-private partnerships like this one provide a great example and hope to inspire others to work together for the benefit of both the people and the wildlife of the United States.

For a related story, visit: A Day with the Giant Garter Snake:


Story by Michelle Donlan/USFWS

Last updated: December 6, 2017