 Upper Penitencia Creek remains a steelhead trout ("Oncorhynchus mykiss") stream and according to two reports may have supported coho salmon ("Oncorhynchus kisutch") historically, based on habitat suitability analysis.The Santa Clara Valley Urban Runoff Pollution Prevention Program (SCVURPPP) developed a workplan for watershed analysis in 2006 as the stream was deemed potentially impaired by sediment from anthropogenic activities, this Limiting Factor Analysis reported results from an extensive snorkel sampling effort during spring and fall 2005 which indicated that the watershed supported between 1,300 and 1,500 age 1+ and older steelhead, of which age 2+ and older fish comprised approximately 5 to 10%, from approximately 3.5 miles (5.6 kilometers) upstream of the confluence with Coyote Creek upstream to natural waterfall barriers in Upper Penitencia Creek and Arroyo Aguague.With the exception of the man-made, historic rock baths confining the stream in Alum Rock Park, significant barriers to spawning runs were not identified.