Thousands of geese fly and squawk overhead, and the crisp air is punctuated by the rattling, prehistoric calls of Sandhill cranes, foraging in flooded corn fields. Insects buzz in the morning light, and I see that the tide is chasing water from the Old River back into the expansive San Joaquin River. River otters hunt for fish amongst tules and cattails. These are the sights and sounds of a February morning in the vibrant Sacramento-San Joaquin Delta, one of California’s largest and most biodiverse watersheds. My field crew and I are on the Palm Tract, one of Contra Costa County’s many Delta Islands, planting thousands of wetland plants below the cottonwoods and willows. This is one of many wetland restoration projects underway in the Delta region that provide a vast array of ecosystem services to communities, human and animal alike.

Picture water, beginning as rain or snow, flowing downward from California’s mountain ranges, down into the Central Valley, through the Sacramento-San Joaquin Delta, and eventually downstream into thePacific Ocean. Along the way, this surface water accumulates pollutants and excess nutrients from urban and agricultural runoff. These compounds can pollute important drinking water supplies, cause toxic algal blooms, and endanger important fish and wildlife species. The Delta’s few remaining wetlands act as the “kidneys of the watershed”. As polluted waters flow through, wetland vegetation slows down the water. Excess pollutants and nutrients are taken up by plant roots, and suspended sediments can settle to the bottom of the wetland. Microbes in the soil work to break down toxins and pollutants. By filtering out contaminants and capturing eroded sediment, wetlands send cleaner, clearer water downstream.

Humans have always relied on the abundance that wetlands provide. In the place now known as Contra Costa County, wetlands have always been vital to the life ways of the Bay Miwok, Ohlone, and Yokut peoples, who have stewarded these lands since time immemorial. Since European colonization, Contra Costa County has lost over half of its historic wetlands, and with it, much of the life and clean water that these wetlands supported. Wetland restoration, however, gives us a way to heal the vital organs of our watersheds, and strengthen our connections to the lands we live on.