What is the extent of California's wetlands?
According to the State of the State’s Wetland, there are approximately 2.9 million acres of wetlands in California today. Although vast, this represents only 10% of the estimated historical extent of wetlands. The numbers in the graph are from a more recent estimate of modern wetlands that uses new data. This estimate sets the total to about 3.8 million acres of wetlands, which is about one million more than the previous number, yet still less than 20% of the historic wetland extent.
Wetland Extent Questions Answered
The wetlands present today include a diverse array of types. Wetlands that occur at the margins between the land and the ocean are known as estuarine wetlands, and those that are found on beaches and dunes overlooking the ocean are called marine wetlands. Riverine wetlands occur along the edges of streams and rivers, and include a range of wetland types, from vast forests to small streamside marshes. Other wetland types occur at the edges of lakes (lacustrine), in low points (depressional), and on hillsides (slope). Wetlands range from shallow ponds to springs, vernal pools, and willow swamps. Each wetland type supports a distinct group of species and performs important watershed functions such as sediment and water storage and filtration.
The majority of wetlands by area are depressions (e.g. freshwater marshes, ponds) and lakes. Together, these wetland types make up 90% of the total wetland extent. The remaining 10% are split between riverine, estuarine, and marine wetlands.