Why We Must Protect Lake Sammamish
As residents of Sammamish, we are fortunate to live by Lake Sammamish's sparkling waters and enjoy its endless recreational opportunities. But did you know that Lake Sammamish is one of Washington state's rarest and most fragile ecosystems, home to a species of salmon unique to Lake Sammamish?
This is a call to all residents: stand as the lake’s protectors. Because right now, as the Town Center development takes shape, our "little red fish,” which once nearly disappeared forever, is again fighting for survival.
A lake like no other
What many Sammamish residents don't realize is that Lake Sammamish is home to a unique species, the kokanee. The kokanee salmon evolved over 11,000 years when the lake was covered with ice and sockeye salmon became landlocked. Nicknamed "little red fish" by the Snoqualmie Indian Tribe for their brilliant spawning colors, the kokanee were once abundant enough to serve as the tribe’s primary winter food source.
The kokanee population crashed to a catastrophic low of just 19 fish returning to spawn in 2017-18, putting the species on the brink of extinction. But thanks to intensive recovery efforts, more than 8,300 adult kokanee salmon returned to spawn during the 2024-25 season — the second-highest return since King County began monitoring in 1996. While this recovery offers hope, the kokanee remain extremely vulnerable to habitat destruction associated with urbanization and the introduction of predator fish species into the lake.
The stakes couldn't be higher. Fortunately, the Kokanee Work Group was formed in 2007 with “the goal to prevent the extinction and improve the health of the native kokanee population so it is viable, self-sustaining, and eventually supports fishery opportunities.”
The stormwater threat: from forest floor to parking lot
Historically, the Pacific Northwest's heavy rainfall wasn't a problem for Lake Sammamish. Why? Because of Sammamish’s tree canopy. Runoff from the high precipitation in the lake's watershed (nearly twice the 35 inches that Seattle gets each year) was absorbed by the surrounding forest’s loose and sponge-like soils together with transpiration from the forest canopy.
What is runoff? Runoff is rainwater that flows over the ground instead of soaking into it. When we replace forests with concrete, asphalt, and rooftops, watershed “runs off” – picking up oil, chemicals, and pollutants as it drains toward the nearest stream or storm drain.
Urbanization has fundamentally altered this natural cycle of rainwater. Per King County, “The conversion of forests to impervious surfaces, like roads and buildings, reduces the soil’s ability to store water, increasing runoff rates. This leads to higher wet weather flows, causing more erosion and sediment transport into the lake, while reducing summer low flows and harming in-stream habitats. Lake Sammamish experiences the cumulative impacts of these land use changes on its water quality.”
The consequences for salmon are devastating. Research shows that coho salmon died within hours of exposure to stormwater runoff, as heavy metals and toxins, particularly from tire residues in the stormwater, poison the fish and make it difficult for them to breathe. For kokanee specifically, summer lake conditions have become increasingly challenging as the lake stratifies during hot weather, leaving only a narrow band where the temperature-sensitive kokanee can survive. Stormwater runoff can also negatively impact a fish’s sensory system.
The Town Center: A perfect storm for runoff
This brings us to the Sammamish Town Center—a 240-acre development being built at one of the highest points, and in the middle of Sammamish. Currently planned for 600,000 square feet of retail and 2,000 housing units, the Sammamish City Council is now considering whether to allow the Town Center developer to expand to up to 4,000 units (you can read more about that here).
Development is inevitable, and any development will have an impact on our natural environment. Critics of the Town Center believe it is improperly sized for the environment where it is situated. Any development of this magnitude will inevitably mean significant tree canopy loss and a dramatic increase in impervious surfaces, creating more poisonous runoff. Sammamish's municipal code includes tree retention requirements, but it also allows for exceptions when "strict compliance with the provisions of this code would prevent reasonable use of the property."
Tree canopy is clear-cut to make room for buildings, roads, parking lots, and other hard surfaces. The code acknowledges this reality: "When forests are replaced by development, rainfall becomes stormwater runoff. Development clears forests and natural open spaces, and buildings, roads, parking areas, and lawns dominate the landscape. Much less stormwater soaks into the ground (infiltrates), and much more stormwater becomes surface runoff, carrying pollutants to nearby waters."
During heavy Pacific Northwest storms, this concentration of hard surfaces will channel significantly more contaminated runoff toward Lake Sammamish's tributaries and eventually the lake itself.
A voice of warning
Wally Pereyra, a longtime environmental advocate with a PhD in Fisheries and 25 acres downstream from the Town Center watershed, didn't mince words when asked about the Town Center's location: "The Town Center is being built in the wrong place.”
Pereyra, who moved to the area in 1973, has witnessed firsthand how development impacts the lake’s delicate ecosystem. He notes that while the original Town Center plan would have been less detrimental, even that version posed risks. With the Sammamish City Council now considering doubling the housing units to 4,000, he warns that more concrete and fewer trees will inevitably mean more runoff flowing into two of the major kokanee spawning creeks: Ebright Creek and George Davis Creek.
His concerns reflect decades of hands-on conservation work. Pereyra personally funded environmental impact studies, and has collaborated with the Snoqualmie Indian Tribe on restoration projects for Ebright and Zackuse Creeks.
Reflecting on past efforts to control runoff impacts from development on Sammamish streams, Pereyra pointed out the negative changes visible to the Ebright Creek wetland along 212th. The trees are all dead. Despite adherence to development guidelines, previous development accelerated runoff, causing floods in the winter and drought in the summer which killed the trees.
The Snoqualmie Indian Tribe: Guardians of an ancient legacy
For the Snoqualmie Indian Tribe, the kokanee crisis represents more than environmental loss. Lake Sammamish Kokanee Salmon are historically and culturally important to the Tribe, who has been an active partner and leader in the kokanee’s recovery effort.
The Tribe has been in this area for time immemorial and remain true stewards of Lake Sammamish’s ecosystem. Their environmental staff actively monitors adult salmon populations and leads restoration projects like the Remote Stream Incubator program on Zackuse Creek, which aims to "jump start" self-sustaining kokanee runs in restored habitat.
The Tribe's approach offers a model for balancing development with environmental protection. When it comes to the Zackuse Creek Fish Passage & Creek Restoration Project, Tribal staff began working closely with Pereyra to build a relationship founded in environmental conservation, proving that collaboration can achieve remarkable results.
Our shared responsibility as the lake’s stewards
As residents of Sammamish, we have both the privilege of living in this precious natural setting and the responsibility to protect it. The kokanee salmon's plight serves as a warning: development decisions have profound consequences for wildlife.
Of course we can’t stop development. The question is how we move forward as responsible stewards of Lake Sammamish's ecosystem.
What can we do?
Support green infrastructure/low-impact development techniques that mimic predevelopment forested conditions and reduce the volume of stormwater runoff
Advocate for stronger environmental protections in all development projects, present and future
Participate in the Kokanee Work Group and related conservation efforts
Practice low-impact landscaping on our own properties
A Lake Worth Fighting For
Lake Sammamish isn’t just beautiful—it is irreplaceable. As the sixth largest lake in Washington, it is designated as a natural resource of statewide importance under the Shoreline Management Act. The kokanee salmon represent millions of years of evolution and thousands of years of cultural significance to the Snoqualmie Indian Tribe.
The Town Center development puts Sammamish at a critical crossroad. We can either accept this crisis as an inevitable consequence of growth, or raise our voices as responsible stewards of our unique ecosystem. We can demand that the size of the Town Center be limited so as not to further endanger our iconic Lake Sammamish kokanee salmon.
The time for action is now—while there are still kokanee salmon to save. Once our “little red fish” are gone, they are gone forever.
Make your voice heard by the City Council as they prepare to vote on whether to double the housing units in the Town Center from 2,000 to 4,000. You can submit your comment on the Town Center Plan and Code Amendment Project here by July 9, 2025, 5pm. The City Council will take a vote at its July 15, 2025 regular meeting.
