Past Management Practices

Historically, wetland habitat was often seen as only a breeding ground for disease-carrying mosquitos. Federal, State, and local policies to drain, fill, or somehow convert wetlands to more "productive" uses was the norm. For example, the federal Swamp Land Acts of the 1800s gave 65 million acres of wetlands to 15 states, including California, for reclamation. As recently as the 1960s and 1970s, the federal Agricultural Stabilization and Conservation Service (ASCS) promoted drainage of wetlands through cost-sharing programs with farmers.

As a result of these and other activities, many of California's wetlands were converted to agricultural and urban uses, and water that had naturally flooded the wetlands was diverted for other needs. Estimates of wetlands that historically existed in California range from 3 to 5 million acres. The current estimate of wetland acreage in California is approximately 450,000 acres; this represents an 85 to 90 percent reduction-the greatest percentage loss in the nation.