Arroyo Corte Madera del Presidio


Arroyo Corte Madera del Presidio is a year-round stream in southern Marin County, California, United States. This watercourse is also known as Corte Madera Creek, although the actual stream of that name flows into San Francisco Bay further north at Point San Quentin. This watercourse has a catchment basin of about and drains the south-eastern slopes of Mount Tamalpais and much of the area in and around the town of Mill Valley; this stream discharges to Richardson Bay.

History

Arroyo Corte Madera del Presidio is named for the Spanish corte de madera meaning "a place where wood is cut". In this case the wood was cut for the building of the Presidio of San Francisco. In 1834, the governor of Alta California José Figueroa awarded to John T. Reed the first land grant in Marin, Rancho Corte Madera del Presidio.

Ecology

A 1965 stream survey indicated presence of steelhead within of the dam. A 1990 study indicated the water quality of upper Richardson Bay below the discharge of Arroyo Corte Madera del Presidio to be impaired by high nutrient and coliform levels; This same study indicated that Arroyo Corte Madera del Presidio is subject to periodic flooding.
A private organization, the Mill Valley Streamkeepers, is active in research and conservation of this creek. Some historic information about Arroyo Corte Madera concerning water quality and fish habitat is found at the KRIS website.

Watershed

Arroyo Corte Madera del Presidio Creek is joined by Old Mill Creek on the right in Mill Valley. Old Mill Creek, and its Cascade Creek tributary, begin high on the east peak of Mt. Tamalpais. Cascade Creek has a small dam and reservoir which was built by noted engineer Michael M. O'Shaughnessy for The Tamalpais Land & Water Co. for water supply to Mill Valley.

Land uses

The stream's discharge location, into Richardson Bay occurs within the Mill Valley municipal Bayfront Park. The Arroyo Corte Madera del Presidio enters Richardson Bay from the west, while Mill Creek enters Richardson Bay nearby from the north via Bothin Marsh. Bayfront Park features many active uses including a bicycle path, walking paths, a dog park and picnic areas. The park also features a pedestrian/bicycle bridge across the tidal portion of Arroyo Corte Madera del Presidio, which is the best single viewing location of the creek in its lower reaches. Slightly further upstream the stream winds through moderately dense single family development, with backyards offering terraces and decks on the banks of Arroyo Corte Madera del Presidio.

Fish stream surveys

The first recorded stream survey occurred in the year 1946; this survey by the California Department of Fish and Game found some healthy steelhead within the stream. The next Department of Fish and Game survey transpired in 1963, finding numerous steelhead of lengths varying between and ; this survey concluded that the lower of the creek represented an important nursery and rearing habitat for steelhead and possibly for Coho salmon. The next survey in August 1965 concluded that the habitat was an excellent resource, with deep shaded pools and an average of 75 steelhead per of lineal stream. In 1984, steelhead were still found to be present. A 1991 stream survey documented the historical presence of Coho salmon. The next survey in 1994 found abundant steelhead, ranging from densities of 0.1 to 0.6 fish per square yard. The 1997 stream survey found densities of steelhead ranging from seven to twelve fish per 100 lineal feet, depending on stream reach. In its 2004 "Recovery Strategy for California Coho Salmon" the California Department of Fish and Game recommends restoration of Arroyo Corte Madera's historic coho salmon habitat. This is one of only two San Francisco Bay Area streams considered in the Department's Strategy to be essential to the recovery of coho salmon in California.

Role of Mill Valley Streamkeepers

The Mill Valley Streamkeepers is a private non-profit organization established to promote research, awareness and conservation of streams in the Mill Valley area. This group includes scientists and laymen and has participated in the following specific studies involving Arroyo Corte Madera del Presidio: