Newport Bay, located in Orange County, is one of Southern California’s largest and most well-known estuaries, spanning about 1,000 acres. It forms where San Diego Creek meets the Pacific Ocean, creating a shallow, tidally influenced waterbody that plays an important role in local water flow and flood management. The bay receives freshwater runoff from a large urban watershed, and its connection to the ocean means that tides influence daily water levels throughout the system.

The region’s mild, Mediterranean climate—with dry summers and wetter winters—can lead to seasonal changes in water levels, especially during heavy rain events. These dynamics make Newport Bay an important area for understanding how water moves through coastal landscapes, particularly in a developed region. Like many estuaries, it faces challenges related to sediment buildup and changing land use, which can affect drainage and increase flood risk.

Ongoing monitoring and management efforts help maintain the health and function of the bay—not only for the wildlife it supports but also for the surrounding communities that rely on it for recreation, water flow, and protection from flooding.

This water level monitoring site was installed in collaboration with and thanks to the support of the Newport Beach Harbor Department.