 = Islais Creek = 
 
 Islais Creek or Islais Creek Channel ( previously known as Du Vrees Creek , Islais Channel and Islais Swamp ) is a small creek in San Francisco , California . The name of the creek is derived from a Salinan Native American word " slay " or " islay " , the name for the Prunus ilicifolia wild cherries . Around the time of the Gold Rush , the area became an industrial hub , and the condition of the creek worsened . After the devastating earthquake in 1906 , the city decided to reclaim the creek using earthquake debris , reducing the waterbody to its present size . Though much of Islais Creek has been converted to an underground culvert , remnants still exist today at both Glen Canyon Park and Third Street . Several community organizations are dedicated to preserve these remnants , as they are important wildlife habitats . 
 
 = = Course = = 
 
 The historic Islais Creek , the largest body of water in the city covering an area of nearly 5 @,@ 000 acres ( 7 @.@ 813 sq mi ; 20 @.@ 234 km2 ) , had two main branches . One originated near the southern slope of Twin Peaks , slightly north of Portola Drive . It flowed downstream southeastward through the Glen Canyon Park paralleling Bosworth Street and eventually reaching the bottom of the Mission Street viaduct at I @-@ 280 . The other branch began at the intersection of Cayuga Avenue and Regent Street . It flowed generally eastward along Mission Street and reached the I @-@ 280 viaduct . Together , as a wider creek , it ran parallel to Alemany Boulevard and I @-@ 280 and emptied into the Islais Creek estuary , near Industrial Street and Oakdale Avenue . Precita Creek , a nearby creek that originated from Noe Valley , also joined Islais Creek at the César Chávez Boulevard and Evans Avenue intersection . 
 From its sources in the Glen Canyon , the entire creek stretched about 3 @.@ 5 miles ( 5 @.@ 6 km ) to the San Francisco Bay . The mouth was nearly 2 miles ( 3 @.@ 2 km ) wide , providing up to 85 % of the drinking water in San Francisco . Due to urban development , however , the watershed of Islais Creek has been reduced by roughly 80 % from its historical extent . A large number of neighborhoods in San Francisco today , such as Bernal Heights , Hunters Point , Visitacion Valley , parts of the Mission and Potrero Hill , was once covered by the extent of the creek . 
 In 2007 , the San Francisco Public Utilities Commission , which manages the city 's water , began investigating the possibility of " daylighting " underground portions of the creek . As of 2009 , remnants of the creek remain inside the Glen Canyon Park and a 1 @-@ mile ( 1 @.@ 6 km ) channel near Third Street where Islais Creek emptied into the bay . 
 
 = = History = = 
 
 The history of Islais Creek dates to the 18th century . The name Los Islais first appeared on Mexican maps in 1834 , named for the Islay cherries that grew wildly in the area . By 1850 , water from the creek was used by farmers to irrigate crops . The Gold Rush marked the decline of the creek as large numbers of gold rushers swarmed into the city . 
 A railroad trestle was built over the creek and tidal flats in the 1860s and in a lawsuit that went up to the California Supreme Court called The People of the State of California ex relatione The Board of State Harbor Commissioners VS . The Potrero And Bay View Railroad Company , Islais Creek was declared a non @-@ navigable waterway in 1883 . 
 In 1871 , the area along the creek became known as the city ’ s " New Butchertown " when more than 100 slaughterhouses opened . Since then , the condition of the creek deteriorated , literally becoming a dumping place of garbage , sewage , animal waste , and unsold meat products . The condition became so bad that the creek was commonly referred to as " Shit Creek " by San Franciscans , according to historian Karl Kortum . 
 After the 1906 earthquake , San Francisco Board of Supervisors voted to fill the creek with earthquake debris , reducing the creek to its present size . During World War II , it served as docking areas for large ocean @-@ going tugs . The area also located the largest copra coconut processing plant in the United States West Coast . In fact , the abandoned five @-@ story high copra crane , used to transport large amount of copras from ships to the plant as late as 1974 , still remains on the creek bank preserved as a historic landmark . In the 1950s , Islais Creek was home to the largest sardine canning industry in the world . The deteriorated condition of the creek gradually improved after the construction of a water treatment plant in 1970 . Today , the majority of the creek is covered and transformed into a culvert with its remnants flowing at Glen Canyon and near the bay . 
 Many local community organizations were set up to improve the condition of the creek and nearby areas . Friends of Islais Creek , established back in 1984 , and David Erickson , a local community figure , were committed to build a waterfront park in Islais Creek . The initial plan for a park was finally launched in 1988 with a $ 50 @,@ 000 grant from the State Department of Water Resources as well as community groups in The Bayview . With an additional of $ 100 @,@ 000 federal and local grants as well as supports from non @-@ profit organizations and governmental agencies , namely the Sierra Club , San Francisco Municipal Railway ( Muni ) , Department of Public Works , Public Utilities Commission , Port of San Francisco , and Caltrans , the park was finished in 1998 . Located adjacent to Pier 80 on the shores of the creek , the Muwekma Ohlone Park or the Muwekma Ohlone Sanctuary is named after the native inhabitants and has since became an important habitat for a wide array of wildlife , including the Pacific Chorus Frog and Mission blue butterfly . 
 On November 19 , 2001 , construction crews , while preparing to drill an electrical conduit ( consisting of six large 115kV electrical cables ) across the creek for the Muni Metro T Third Street light rail line , cracked the concrete sewer underground which carries more than 80 million gallons of sewage a day . The incident flooded the creek and its adjacent Muwekma Ohlone Park with sewage . The park had to be excavated to make way for the repairing of the sewer pipe . It was estimated that it would take more than $ 101 @,@ 660 to repair and $ 65 @,@ 000 for wildlife habitat restoration . 
 
 = = = Health hazard = = = 
 
 Since Islais Creek is a culvert that carries storm water , domestic sewage , and industrial wastewater , it is possible for the sewage to overflow . Such overflow can cause a public health hazard as Islais Creek displays higher level of heavy metals , PCBs , bacteria , as well as organochlorines than other parts of the San Francisco Bay . 
 
 = = Transportation = = 
 
 The Third Street Bridge is the major crossing of the creek , carrying T Third Street light rail line and Third Street . It is a bascule @-@ type drawbridge . The Port of San Francisco extended Illinois Street across Islais Creek in 2006 to relieve traffic for Third Street . This crossing also uses a bascule bridge . 
 
 