The Petaluma River Estuary is a tidal river system located in Sonoma County, California, flowing through the city of Petaluma before emptying into San Pablo Bay, an arm 

of the larger San Francisco Bay. Historically, the Petaluma River was a vital waterway for local trade and transportation, supporting a rich ecosystem of wetlands, riparian habitats, and a diverse array of plant and animal species.

The estuary spans about 13 miles from the city of Petaluma to its mouth at the bay and is influenced by tidal fluctuations, which affect water levels throughout the day. These tides play a crucial role in the estuary's ecological health, impacting sediment transport, water quality, and habitat conditions for native species, including migratory birds, fish, and invertebrates. The estuary is also a critical component of flood management in the region, with its wide floodplain absorbing stormwater during heavy rains.

Human activities, such as dredging, urbanization, and agriculture, have altered the estuary's natural state, leading to changes in hydrology and habitat loss. Recent restoration efforts aim to improve water quality, enhance habitat connectivity, and support native wildlife populations. Monitoring real-time water levels is essential for managing these efforts and mitigating flood risks, making the Petaluma River Estuary a dynamic and valuable natural resource for the surrounding communities.