Arroyo Seco

The Arroyo Seco, meaning "dry stream" in Spanish, is a 24.9mi seasonal river, canyon, watershed, and cultural area in Los Angeles County, California. The area was explored by Gaspar de Portolà who named the stream Arroyo Seco as this canyon had the least water of any they had seen. During this exploration he met the Chief Hahamog-na (Hahamonga) of the Tongva Indians.Waterway courseThe watershed begins at Red Box Saddle in the Angeles National Forest near Mount Wilson in the San Gabriel Mountains. As it enters the urbanized area of the watershed, the Arroyo Seco stream flows between La Cañada Flintridge on the west and Altadena on the east. Just below Devil's Gate Dam, the stream passes underneath the Foothill Freeway. At the north end of Brookside Golf Course the stream becomes channelized into a flood control channel and proceeds southward through the golf course.The Arroyo Seco goes through Pasadena, where it passes the Rose Bowl Stadium as it goes through Brookside Park. The Arroyo Seco stream, which is fed by a watershed of 46.7sqmi, helps to replenish the Raymond Basin, an aquifer underlying Pasadena that provides about half of the local water supply. This arroyo is one of two major streams that capture rainfall and storm water in Pasadena, the other being Eaton Wash on the eastern side of the city, which is a tributary of the Rio Hondo watershed.