Arroyo de la Laguna is a 7.5-mile-long (12.1 km)[2] southward-flowing stream in Alameda County, California, United States which originates at the confluences of South San Ramon Creek and Arroyo Mocho.

Arroyo del la Laguna is the major tributary to Alameda Creek which in turn flows into the San Francisco Bay.

With development of the valley starting in the 19th century, drainage alterations in this watershed reduced the lake to a watercourse now called the Arroyo de la Laguna.

[3] In the northern portion of the Arroyo de la Laguna catchment basin, the Tassajara Formation underlies Quaternary valley fill material.

Rapid development and other historic changes in the upper watershed have caused severe instability in the lower 5 miles (8.0 km) of the Arroyo de la Laguna.