Salmon in Silicon Valley

“Salmon in Silicon Valley” by Greg Kerekez

Chinook Salmon Calabasas Creek Santa Clara
Chinook Salmon Calabasas Creek Santa Clara

Salmon in Silicon Valley? The Valley is not known for its salmon but they are here in very small numbers.  Each fall,  Chinook or King Salmon  swim from the Pacific Ocean past Great White Sharks, through the Golden Gate lined with hungry Sea Lions and Harbor Porpoises and into the San Francisco Bay. From there, they encounter a myriad of currents from watersheds all over the bay. Most follow the currents of the Feather, Sacramento, and American Rivers but some are drawn by the flow of the Guadalupe River, Coyote Creek, and many of the smaller creeks in Santa Clara County. Their numbers are so low, that most people don’t know they exist, and if river health and function are not drastically improved, we may loose these salmon for good.

Urban Wildlife Research Project of Silicon Valley has been monitoring salmon since 2011 along side other conservation groups Salmon and Stealhead Restoration Group, and Friends of Los Gatos Creek. Most years we’ve counted less than a dozen Salmon per year. However, so far 2016 has been our best year with 20** Salmon counted.

History of Salmon in the South Bay

The runs of salmonids(trout and salmon) in our area, historically, were much larger. Chinook, Coho, and Steelhead were once plentiful in our south bay watersheds. These fish were a mainstay in the diet of the indigenous Ohlone tribes. Historical accounts of the landscape from early explorers and scientists painted a picture of a wet, stream filled Silicon Valley. Famed Naturalist, John Muir, in 1868 wrote remarkably about his first sight of the Santa Clara Valley “…hundreds of crystal streams joined songs with the larks, filling all the valley with music like a sea, making it an Eden from end to end.”

Ads in the 1920s, for Redwood Estates in Santa Cruz Mountains, boasted easy trout fishing in Los Gatos Creek.  Besides Salmonids, other anadromous fish, which start their live’s in the river and make their way to the ocean and back again, were also regular sights in our watersheds. This included fish like the Pacific Lamprey and Green Sturgeon. All of these fish are now on some level of the Endangered Species List and all but one, the Coho, still spawn in our waters. A decline in these fish populations coincides with the growing urbanization in Silicon Valley but it started long before that.

The Guadalupe River is short but mighty. She flooded and destroyed the first two spanish missions built along her banks starting in 1777. Ever since there has been an effort to tame the Rio Guadalupe. Saratoga, San Thomas, and Calabasas Creeks once joined the Guadalupe River upstream of the salt marshes, but in the 1870s they were separated from the watershed and diverted on new, straight paths through the valley to the bay. In the 1930s the South Bay’s creeks were further damed, straightened, leveed, and paved to speed up the water’s exit to the bay, which prevented flooding of city streets and homes. This left spawning habitat for anadromous species just a fraction of what it was before the turn of the century, but floods persisted. Prior to the technology boom, no one would dream to do anything but farm on the lower floodplain of the Guadalupe River. In the 1980s corporations lobbied water companies to raise levees, eliminating the remaining floodplain and opening up large swaths of land for development. Thus it was the taming of our Lady Guadalupe and other waterways, that downloaded Silicon Valley over the previous version, Valley of the Heart’s Delight .

Citizen Scientists work to Save Salmon

In the 1990s, a man named Roger Castillo started the Salmon and Steelhead Restoration Group to monitor, protect, and restore the ancient salmon runs. His historic videos show a healthier run of Chinook in the 1990s, but by the end of the first decade of the new millennium, the runs had dwindled to a hand full of fish.  Roger documented flood prevention projects in the early 2000s along the Guadalupe River which replaced prime spawning habitat with concrete blocks, further channelized the once meandering river.

Other human impacts on Salmon, Castillo has documented, are pollution and poaching. Over 1 million people live in Silicon Valley,  which puts a strain on the health of our river ecosystems. Trash and chemicals wash from our city streets and rush to the waterways, each time it rains.  The homeless population in Santa Clara county is in the thousands, many of whom live along our streams. Nets, traps, and illegal fishing equipment can be found in the stream and stashed about encampments.

These fish are up against many challenges and to add just one more, is the mismanagement of the water supply. Roger Castillo has been following the in stream gauges, that monitor water flow and releases from reservoirs, storm drains, and at various points along the river. He watches, in real time, how our water is being managed. Then he’ll go out and film the effects of the operations. In November, Los Gatos Creek ran dry near Auzerais Avenue in San Jose, after water was diverted from a rubber dam down stream of Lark Avene, to fill ground water recharge ponds in Los Gatos and Campbell. Salmon who had already started their nests, referred to as a “Redd”, were stranded in shallow pools, some flopping on the stream bank, all of which Roger caught on video.

On December 14, 2016 Roger followed the flows as Almaden Lake released 200 cubic feet of water per second(CFS), thats about 12 shipping containers worth of water every minute. These flash flows move gravel and sediment which could disturb salmon redds downstream and hurt future salmon populations. Also at Almaden lake is a flash dam. Roger noted this dam is supposed to be removed before Salmon Spawning season, to lower the level of the lake. This makes it easier for the fish to find the flows of the river’s tributaries of Calero, Los Alamitos, and Guadalupe Creek, all of which have prime spawning habitat. “The near death salmon do not have energy to waste swimming around the lake looking for a stream to spawn in, and removal of the flash dam is supposed to prevent that” Roger Said.

There is one problem, as of 12/16/16 the flash dam is still up and residents using the trail near the lake reported people trying to catch a lost salmon, swimming in circles around the lake. Salmon have been in the watershed since early November. “Gradual water release from Almaden lake should have started months earlier to encourage better fish passage and stable habitat. This flash dam should have been removed in late October before the fall rain storms triggered the up migration of Salmon into our river.” explained Roger.

This is way citizen science is so important. With out members of the public checking balances who would know about these salmon’s plight. These citizen groups mentioned in the article have reported these issues to the CA Department of Fish and Wildlife, NOAA, and other regulatory agencies in hopes to achieve better operations for greater salmon populations.

These fish are not without controversy. Some of these salmon that swim up our streams are from hatcheries on the Feather or Sacramento Rivers, like they took a wrong turn some where and came up our rivers by mistake.  There has been debate in the past, wether or not the hatchery Salmon that stray to our rivers should receive protections or water allocation. After all, salmon are “supposed” to return to the stream they were born in, right? The Wild Salmon Center in Portland Oregon reports about 2-5% of salmon stray from their native stream and choose a brand new stream to repopulate. There is also data to suggest that hatchery fish stray more than wild born fish. Pete Rand of Wild Salmon Center says, “Straying is just as important as homing ability in salmon.  We think this straying is very important for fish to colonize (or re-colonize) suitable habitats.” It is evolutionarily savvy to not put all your eggs in one basket, or lay them all in one river. So to say a salmon always returns to the stream it was born in, is a misconception.

Salmon is in every grocery store and on most menus in the south bay. California Commercial and Recreational Salmon Economy in 2014 was $202 million.  We should be doing our part in Silicon Valley to enhance the chinook salmon population, wether or not it came from a distant hatchery. What do this Salmon need? What can we do to boost their populations. These fish need clean water, access to the habitat, and humans with compassion. They need less metal on concrete and more ripples on cobble stones. Fewer straight deep pools and more meandering streams, oh and Beavers! The groups mentioned in this article are advocating for better management of our fisheries. If you wish to help them enhance our fisheries for future generations, visit their websites and join the efforts to save our salmon.

Roger is about to conduct his own press release putting forth a solution to improve our salmon fisheries and provide fish clean cool water even during a drought. I won’t give it away, but let’s say it involves better water management. Not of the drinking water coming from the mountain reservoirs, but the free water that is bubbling up under our feet as we walk the Silicon Valley Streets. Follow or join his group at to be up to date on the “Free Water for Fish” release and help restore the fisheries of Silicon Valley.

Steve Holmes’ group South Bay Creeks Coalition is a major force in trash removal from our waterways. In 2015 he held XXX many cleanups and removed XXX tons of waste keeping that trash from entering the bay and ocean.

Rick Lanman of Friends of Adobe Creek in Los Altos says:xxx

Stephanie Moreno of Guadalupe Resource Conservation District says:xxx


The water that was sent to the percolation ponds, as they’re called, eventually was returned to the Guadalupe River in Downtown San Jose via pumping stations near the SJ International Airport designed to keep runways, freeways, and city skyscrapers basement dry.


The Economics of Salmon