Arroyo Corte Madera del Presidio

This article is about Arroyo Corte Madero del Presidio. For Corte Madera Creek, see Corte Madera Creek (Marin County, California).

Arroyo Corte Madero del Presidio
stream
Name origin: Spanish language
Country	United States
State	California
Region	Marin County
Tributaries
- right	Old Mill Creek
City	Mill Valley, California
Source	Knob Hill, Marin County
- location	2.5 mi (4 km) west of Corte Madera, California
- elevation	880 ft (268 m)
- coordinates
Mouth	Richardson Bay
- location	2 mi (3 km) south of Corte Madera, California
- elevation	0 ft (0 m)
- coordinates
Basin	8 sq mi (21 km2)

Arroyo Corte Madera del Presidio is a 4.1-mile-long (6.6 km) year-round stream in southern Marin County, California, USA. 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 8 square miles (21 km²) 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

Old Mill Creek tributary with the old mill in the background.

Arroyo Corte Madera del Presidio non-tidal lower reach through residential area of Mill Valley.

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 100 ft (30 m) 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 (Klamath Resource Information System) 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 (Oncorhynchus mykiss) within the stream. The next Department of Fish and Game survey transpired in 1963, finding numerous steelhead of lengths varying between 2 inches (5 cm) and 6 inches (15 cm); this survey concluded that the lower 3.5 miles (6 km) 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 100 feet (30 m) 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 (0.1-0.7 per square meter). The 1997 stream survey found densities of steelhead ranging from seven to twelve fish per 100 lineal feet (30 lineal meters), 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:

• Feasibility Study to Rehabilitate the Fishery Resources of Arroyo Corte Madera del Presidio
• Bio-assessment of four Marin County Watersheds
• Macroinvertebrate Sampling and Identification Study, Arroyo Corte Madera del Presidio and Old Mill Creek
• Salmonoid Habitat Survey and Erosion Survey, Arroyo Corte Madera del Presidio and Old Mill Creek
• Preliminary Fish Barrier Culvert Modifications and Flood Assessment, Arroyo Corte Madera/Old Mill Creek, Mill Valley, California
• Index of Sediment Impairment to Stream Habitat in the Arroyo Corte Madera Del Presidio Watershed, Marin County, California

See also

• Bay mud
• List of watercourses in the San Francisco Bay Area
• Richardson Bay

External links

• California Coastal Salmon and Steelhead Stream Habitat Distribution Table: including data for Arroyo Corte Madera del Presidio
• Mill Valley Streamkeepers