Santa Maria River (California)

Santa Maria River on the Central Coast of California, is formed at the confluence of the Sisquoc River and Cuyama River, just east of the city of Santa Maria, and flows 24.4 miles (39.3 km)[1] to its delta at the Pacific Ocean.

Santa Maria River
Santa Maria River as seen from a bike trail on the Santa Barbara County side, with the 101 Freeway bridge visible
Map of the Santa Maria River watershed
Location
Country	United States
State	California
Cities	Santa Maria, Guadalupe
Physical characteristics
Source	Confluence of Sisquoc River and Cuyama River
• location	South of Twitchell Reservoir
• coordinates	34°54′11″N 120°18′45″W
• elevation	354 ft (108 m)
Mouth	Pacific Ocean
• location	Guadalupe Dunes County Park
• coordinates	34°58′15″N 120°39′01″W
• elevation	0 ft (0 m)
Length	24.4 mi (39.3 km)
Basin size	1,760 sq mi (4,600 km2)
Discharge
• location	Guadalupe
• average	30.2 cu ft/s (0.86 m3/s)
• minimum	0 cu ft/s (0 m3/s)
• maximum	32,800 cu ft/s (930 m3/s)

The entire river defines the border between northern Santa Barbara County and southern San Luis Obispo County, up to the Sisquoc River, with a major bridge on Highway 101 passing over it. The Santa Maria River Fault is a tectonic fault that roughly corresponds with the course of the river.

There are no dams or lakes on the Santa Maria River itself, although Twitchell Reservoir is formed by a dam on the tributary Cuyama River. Twitchell Dam was built by the United States Bureau of Reclamation and provides flood control and groundwater recharge of the aquifer. The Sisquoc River is also free-flowing, and a National Wild and Scenic Rivers System.

During much of the year, the Santa Maria River has very little water, but it can swell greatly during winter storms.