Lake Washington

Lake Washington is a big, beautiful freshwater lake next to the city of Seattle, in the state of Washington, United States. It is the biggest lake in King County and the second biggest natural lake in all of Washington, after Lake Chelan. The lake touches many cities, including Seattle on the west, Bellevue and Kirkland on the east, Renton on the south, and Kenmore on the north. It even surrounds Mercer Island.

Lake Washington is a fun place for boating and fishing. People can catch many kinds of fish there, such as sockeye salmon, coho salmon, Chinook salmon, rainbow trout, largemouth bass, smallmouth bass, yellow perch, and black crappie.

The lake also has two special places for seaplanes: Kenmore Air Harbor on the north end and Will Rogers – Wiley Post Memorial Seaplane Base on the south end, close to Renton Municipal Airport. These seaplane bases let people take exciting flights right on the water!

Name

Lake Washington has been called x̌ačuʔ ("lake" in Lushootseed) by the Duwamish and other Indigenous peoples for a long time. When European settlers arrived, the lake was recorded as At-sar-kal on a map by engineer Abiel W. Tinkham. It was also known as Hyas Chuck, meaning "great/large water" in Chinook Jargon. Later, it was named Lake Washington after George Washington, the first president of the United States, a suggestion made by Thomas Mercer. This happened when the area became the Washington Territory.

Geography

Lake Washington was formed long ago when big glaciers moved and changed the land. These glaciers carved out a big bowl shape in the ground. When the glaciers melted, water filled this bowl and made the lake.

At first, the lake was connected to the ocean, but over time, dirt and rocks built up and separated the lake. Now the lake has fresh water. There are also three places in the lake where forests sank underwater after an earthquake many years ago.

Creeks and rivers

The main rivers that flow into Lake Washington are the Sammamish and Cedar Rivers. The Cedar River gives the lake most of its water. The flow of the Sammamish River changes with the seasons, but a structure called a weir at the Lake Sammamish inlet helps control this.

Lake Washington’s water leaves through the Lake Washington Ship Canal.

Many small creeks and rivers also add water to the lake, such as:

• Coal Creek
• Denny Creek (O.O. Denny Park)
• Fairweather Creek
• Forbes Creek
• Juanita Creek
• Kelsey Creek
• Little Creek
• Lyon Creek
• Mapes Creek
• May Creek
• McAleer Creek
• Mercer Slough
• Ravenna Creek
• Taylor Creek
• Thornton Creek
• Yarrow Creek
• Yesler Creek

Long ago, building the Lake Washington Ship Canal changed how water moved in and out of the lake. Before 1916, Lake Washington’s water left through the Black River, which joined the Duwamish River and flowed into Elliott Bay. After the canal opened, the lake’s level dropped almost nine feet. The canal became the only way for water to leave the lake, and the Black River dried up. Before the canal, the Sammamish River was the main source of water for Lake Washington, and after the canal was built, the Cedar River became the lake’s main source.

Infrastructure

Canal

The Montlake Cut, part of the Lake Washington Ship Canal, connects the lake to Lake Union and then to Puget Sound.

Bridges

Three special floating bridges cross Lake Washington: the Evergreen Point Floating Bridge (SR 520), the Lacey V. Murrow Memorial Bridge (I-90 eastbound), and the Homer M. Hadley Memorial Bridge (I-90 westbound). These bridges float on the water because the lake is too deep and has a muddy bottom for regular bridge supports. The bridges have hollow parts that stay above the water, connected with cables to weights on the lake bottom. Roads sit on top of these floating parts.

The Evergreen Point Floating Bridge (officially the SR 520 Albert D. Rosellini Evergreen Point Floating Bridge) carries State Route 520 from Seattle's Montlake neighborhood to Medina. It opened in April 2016 and replaced an older bridge that opened in 1963. It is the longest floating bridge in the world.

The Lacey V. Murrow Memorial Bridge carries Interstate 90 eastbound from Seattle's Mount Baker neighborhood to Mercer Island. It originally opened in 1940 but had to be rebuilt and reopened in 1993 after part of it sank.

The Third Lake Washington Bridge (officially the Homer M. Hadley Memorial Bridge) carries the westbound lanes of Interstate 90 and two tracks of Sound Transit's 2 Line between Mercer Island and Seattle. It opened in June 1989 and is the fifth-longest floating bridge in the world.

Steamboats and ferries

Steamboats and ferries traveled on the lake from about 1875 to 1951. In 1892, John L. Anderson began ferrying people between Leschi Park and Newcastle on a boat named Winnifred. After Winnifred burned in 1894, Anderson used many other boats. In 1913, Seattle started its own steel-hulled ferry named Leschi, which made Anderson's business difficult, and he stopped in 1917. Public ferries kept running until 1950, about one year after tolls were removed from the Murrow bridge.

Shoreline cities and towns

The cities and towns around Lake Washington, going clockwise from the west, are Seattle, Lake Forest Park, Kenmore, Kirkland, Yarrow Point, Hunts Point, Medina, Bellevue, Beaux Arts Village, and Renton. Mercer Island is a city on an island in the middle of the lake.

Water purity

In the early 1900s, Seattle put waste into Lake Washington. By the 1940s and 1950s, many plants were putting treated water into the lake every day. This, along with new cleaning products, caused the lake to fill with harmful algae. The water looked bad and hurt fish. People called the lake "Lake Stinko."

People worked together to fix this. They started sending the waste to Puget Sound instead. By 1968, this plan began, and soon after, the algae decreased and the water became clear again. By 1975, the lake was fully recovered and is much clearer and healthier today.