Although best known for its wetlands and waterfowl conservation work, Ducks Unlimited also takes pride in its ability to navigate complex situations and deliver projects that benefit a variety of wildlife. A great example is currently taking place in California’s Sacramento Valley, where a threatened species happens to live in the middle of an ongoing water-infrastructure improvement project.
The Gray Lodge Water Supply Project will eventually improve the Biggs West-Gridley Water District’s system of canals, allowing the iconic Gray Lodge Wildlife Area to receive its full allotment of water. The wildlife area and surrounding agricultural land provide important habitat for wintering waterfowl while also supporting the state and federally threatened giant garter snake, commonly referred to as the GGS.
This highly aquatic snake is endemic to California’s Central Valley, inhabiting marshes and sloughs that dot the landscape. But like waterfowl, it has suffered population declines due to loss of the state’s historic wetland habitat. Today, the GGS finds surrogate habitat in rice fields, such as those that surround Gray Lodge, and the extensive system of canals that delivers water to them.
Construction in giant garter snake habitat is typically permitted only during the spring and summer, when active snakes can more readily avoid ground disruption activities. But because the Biggs West-Gridley Water District supports local agriculture, the canals cannot be shut down during the summer growing season.
“The challenge with this project is that we’re working in an area with a high density of snakes because the habitat is very suitable for them,” says wildlife biologist Jeff Mitchell of Swaim Biological, DU’s lead consultant on the project. “The bulk of the work has to be done in the winter, when the canals don’t have water in them, and that’s the snake’s inactive season.”
To proactively face the challenge, Ducks Unlimited formed a Giant Garter Snake Working Group composed of species experts, state and federal regulatory agencies, concerned environmental groups, and project partners. The group was tasked with finding ways to complete this important water-infrastructure project while avoiding or minimizing impacts on the GGS.
Focusing on science and the data from the first phase of the project, the working group immediately sought input on how to reduce or avoid any impacts on the GGS. This included radio telemetry data obtained from the US Geological Survey to plot the daily behavior patterns of individual snakes. The group then created a comprehensive plan calling for proactive measures that included conducting as much construction work as possible during summer, as well as extensive site preparation to make the canals unattractive to the snakes in the winter.
As the first year of construction wrapped up, all the planning and preventative measures appear to be working, and all parties—including the GGS—have benefited. “I’m very encouraged by the results,” Mitchell said. “We’ve observed 30 snakes in the project area to date and 13 were relocated away from the work area. The rest were given space to leave on their own. We have not had any snake mortalities. I think everyone agrees it’s been a success so far.”
Ducks Unlimited Inc. is the world's largest nonprofit organization dedicated to conserving North America's continually disappearing waterfowl habitats. Established in 1937, Ducks Unlimited has conserved almost 15 million acres thanks to contributions from more than a million supporters across the continent. Guided by science and dedicated to program efficiency, DU works toward the vision of wetlands sufficient to fill the skies with waterfowl today, tomorrow and forever. For more information on our work, visit www.ducks.org.