Arroyo Seco (Salinas River tributary)

The Arroyo Seco ("dry stream") is a major tributary of the Salinas River in central California. About 40 miles (64 km) long, it drains a rugged area of the Coast Ranges east of Big Sur before flowing through the agricultural Salinas Valley.

"Arroyo Seco" means "dry stream" or "dry wash" in Spanish. The river probably got its name because it disappears into the ground more than 10 miles (16 km) above its mouth for most of the year, however, it reaches the Salinas during the rainy season. The river above the Salinas Valley is actually a fairly large perennial stream. The common name, Arroyo Seco River or Arroyo Seco Creek, is actually a tautology because the name contains two mentions of "watercourse", thus "Arroyo Seco River" literally translates to "dry streambed river".

The river rises in several unnamed forks in the Santa Lucia Mountains of the Coast Ranges near the Pacific Ocean. It flows generally north, cutting into a steep gorge, receiving Lost Valley Creek and Tassajara Creek both from the left. After the confluence with Rocky Creek, the Arroyo Seco swings abruptly east, passing a pair of intermittent natural lakes simply known as "The Lakes". Here, the valley begins to widen and the stream lazes out onto a shallower, sandier bed, passing the unincorporated communities of Millers Ranch and Sycamore Flat. Another major tributary, Piney Creek, enters just downstream of the former. Meandering east between low bluffs, the river receives Vaqueros Creek and Reliz Creek from the right, emerging from the mountains about 3 miles (4.8 km) southwest of Greenfield. The river flows north into the Salinas Valley, where much of its water is diverted for irrigation. Turning northwest, it begins to parallel U.S. Highway 101 as a seasonally dry wash. It joins the Salinas just south of the city of Soledad. The source, mouth and entire course of the river are entirely within Monterey County. There are no dams on the Arroyo Seco, making it prone to flash flooding.

Flows through: United States.

River data from Wikidata (CC0); lengths normalised to a common unit.