Petaluma Reservoir is a small, man-made lake

Lake

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

 located about 5 miles (8 km) northeast of Petaluma

Petaluma, California

Petaluma is a city in Sonoma County, California, in the United States. In the 2010 Census the population was 57,941.Located in Petaluma is the Rancho Petaluma Adobe, a National Historic Landmark. It was built beginning in 1836 by General Mariano Guadalupe Vallejo, then Commandant of the San...

 in Sonoma County, California

Sonoma County, California

Sonoma County, located on the northern coast of the U.S. state of California, is the largest and northernmost of the nine San Francisco Bay Area counties. Its population at the 2010 census was 483,878. Its largest city and county seat is Santa Rosa....

, United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. Also known as Lawler Reservoir, its waters are impounded by Lawler Dam, a rock fill dam 40 feet (12 m) high and 1150 feet (350.5 m) long which was built in 1910. The City of Petaluma owns the reservoir.

In 1992, the State of California declared the reservoir unsafe in the event of an earthquake. Rather than perform a seismic retrofit of the dam, the City decided to stop using it for water supply.