Permanente Creek

Permanente Creek is a 13.3-mile-long (21.4 km)[3] stream originating on Black Mountain in Santa Clara County, California, United States.

An expedition led by Colonel Juan Bautista de Anza passed through this area in March 1776 as he forged the first overland route from Monterey to San Francisco Bay.

[7] From its origination at 2,421 feet (738 m) in headwaters protected by the Midpeninsula Regional Open Space District just north of the peak of Black Mountain (and just east of the Black Mountain Trail), Permanente Creek descends along the Permanente Quarry (currently known as the Lehigh Southwest Cement Plant and Quarry), and continues easterly through unincorporated County land for about five miles (8 km), then turns to the north at the base of the foothills and continues another eight miles (13 km) along the valley floor.

Except for sakrete (bagged concrete) banking and several weirs, Permanente Creek's upper mainstem runs about 8 miles (13 km) in a relatively unmodified natural channel until reaching Portland and Miramonte Avenues at the north end of Heritage Oaks Park.

Permanente Creek's original channel then goes on to pass under U. S. Highway 101, along the west side of the Google campus, and out to the Bay at the Mountain View Slough just east of Shoreline Park, the latter built on a reclaimed San Francisco garbage dump in 1983.

[17] Federally threatened California red-legged frogs (Rana draytonii)) inhabit the upper watershed of Permanente Creek[18] and the US Fish and Wildlife Service in 2017 asked the Army Corps of Engineers to assure that sufficient riparian habitat, specifically near ponds 14 and 21 along the Permanente Quarrry, would be set in a conservation easement to ensure their survival.

[19] In fact, a 2011 biological resources assessment of the quarry property found six California special status wildlife species, including the California red-legged frog, dusky-footed woodrat {Neotoma fuscipes), white-tailed kite (Elanus leucurus), olive-sided flycatcher (Contopus cooperi)), yellow warbler (Setophaga petechia), and grasshopper sparrow (Ammodramus savannarum).

Also of relevance, the cement company operating in the upper part of the watershed has discharged sediment-laden water into Permanente Creek and has undertaken corrective actions.

[22] As recommended by Becker in 2007 and Higgins in 2012, modification of the Permanente Creek Diversion Channel would enable steelhead trout to return to the protected upper reaches of Permanente Creek beginning above Heritage Oaks Park and including Rancho San Antonio County Park and Rancho San Antonio Open Space Preserve.

[24] Leidy's 2007 report also recorded the fish still inhabiting Permanente Creek - including native California roach (Lavinia symmetricus), Sacramento sucker (Catostomus occidentalis occidentalis), threespine stickleback (Gasterosteus aculeatus), and non-native bluegill (Lepomis macrochirus), common carp (Cyprinus carpio), rainwater killifish (Lucania parva), and western mosquitofish (Gambusia affinis).

Shoreline Park meadows near the mouth of Permanente Creek provide critical remnant habitat for the western burrowing owl (Athene cunicularia), a bird that has vanished from many counties in the Bay Area.

Although there were hundreds of burrowing owls in Santa Clara County when monitoring began in the 1980s, now there are only 35, with three breeding pairs raising ten eggs at Shoreline in 2011 (less than half the number of young in 2003).

[27] The cement plant at the Permanente (Lehigh Hanson) Quarry is responsible for 29% of total Bay Area airborne mercury emissions and was shown to impact a rural site, Calero Reservoir, 20 miles (32 km) away.

[28] Mercury, a neurotoxin and pollutant which is concentrated in the aquatic food web, was found to be 5.8 to 6.7 times higher in precipitation near the cement plant than at a control location 2.0 miles (3.2 km) away.

[29] A 2011 study showed a significant geographic association between the occurrence of autism in local school districts, such as the Cupertino Union School District, and higher levels of ambient mercury generated by coal-fired power plants in Bexar County, Texas and the Permanente Quarry cement plant in Santa Clara County, California.

[32] Anthropomorphic activities related to quarry operations and the cement plant have resulted in sediment discharges into Permanente Creek that are 3.5 times what would be expected under normal conditions.

Portion of San Francisco & San Jose Railroad (Allardt) map showing historic connection of Permanente Creek (Arroyo Permanente) to Stevens Creek (Cupertino Creek) circa 1862. These creeks ended in marshes that were likely hydrologically connected to the Bay at times of high winter flows. Hale Creek and Arroyo San Antonio ( Adobe Creek ) are shown to the west of Cupertino Creek.
Looking east along Permanente Creek Diversion Channel as it approaches the box culvert under Highway 85
The confluence of Hale Creek (right) and the reduced Permanente Creek (left) in Los Altos, viewed from Mountain View
Most of the creek's route through Mountain View is channelized as here by Crittenden Middle School.
Permanente Creek where it can overflow (to the left) into the McKelvey Park retention basin.
Looking west, from east side of Stevens Creek , at terminus of Permanente Creek Diversion Channel as it exits beneath Highway 85 . Here Permanente Creek drops about ten vertical feet over cemented boulders, an impassable barrier to in-migrating steelhead trout, 2013.
Egrets are a common sight in the creek near the bay. There is an egret rookery in the trees on Shorebird Way a few blocks away.
The Permanente Creek Trail underpass at Old Middlefield Way