Lake Washington
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Lake Washington is the second largest natural lake in Washington State, USA, after Lake Chelan, and the largest lake in King County. It is situated between Seattle to the west, Bellevue and Kirkland to the east, Renton to the south, and Kenmore to the north, and surrounds Mercer Island. It is fed by the Sammamish River at its north end and the Cedar River at its south, as well as a number of creeks, including Ravenna Creek along the Union Bay Natural Area and Thornton Creek on the west; and Kelsey Creek, Juanita Creek, and Coal Creek on the east.
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[edit] Canals and bridges
Before construction of the Lake Washington Ship Canal in 1916, Lake Washington's outlet was the Black River, which joined the Duwamish River and emptied into Elliott Bay. When the canal was opened, the level of the lake dropped nearly nine feet (3 m). The canal to Puget Sound became the lake's sole outlet, causing the Black River to dry up and disappear, as a few years earlier, the Cedar River had been diverted to empty into Lake Washington instead of the Black.
Four bridges cross Lake Washington. The Evergreen Point Floating Bridge (officially the Governor Albert D. Rosellini Bridge--Evergreen Point) carries Washington State Route 520 from Seattle's Montlake neighborhood to Medina. The Lacey V. Murrow Memorial Bridge and the Third Lake Washington Bridge (officially the Homer M. Hadley Memorial Bridge) carry Interstate 90 from Seattle's Mount Baker neighborhood to Mercer Island. The East Channel Bridge carries Interstate 90 from Mercer Island to Bellevue. The Evergreen Point, Lacey V. Murrow, and Third Lake Washington bridges are the longest, second longest, and fifth longest floating bridges in the world, respectively.
Concrete Floating Bridges were employed to span the lake because Lake Washington's depth and muddy bottom prevented the emplacement of the pilings or towers necessary for the construction of a causeway or suspension bridge, respectively. Though many questioned the wisdom of concrete floating bridge technology after the sinking of one of the Interstate 90 bridges in the early 1990s, it was later found that that incident was caused by improper handling of wastewater from a hydrodemolition process being employed to remove the sidewalks from the bridge and widen its roadway to the standards necessitated by the Interstate Highway System. This undercut the basic principle by which the bridges float - namely, that concrete can be made to float if it is fashoned so as to have a series of hollow air-filled chambers. When these air-filled chambers filled up with water from the hydrodemolition process, and a subsequent storm, the bridge sank. Nonetheless, the concrete floating bridge concept was vindicated when a Washington State Department of Transportation (WSDOT) investigation revealed that it was the improper handling of hydrodemolition water which was to blame, and not the design of the bridge. As long as excess water is kept out of the hollow chambers inside the pontoons of the bridges, they are a safe and structurally sound design concept. Hence, the concrete floating bridge continues to remain a viable means for the conveyence of traffic over Lake Washington.
1950, a year or so after the tolls came off the Murrow bridge, the inland ferry system on the lake came to an end, having operated since the 1880s.
[edit] Shoreline cities and towns
Cities and towns clockwise around the lake are Seattle, Lake Forest Park, Kenmore, Kirkland, Yarrow Point, Clyde Hill, Hunts Point, Medina, Bellevue, Beaux Arts Village, Newcastle, Renton. The City of Mercer Island occupies Mercer Island, in the southern part of the lake.
The area of Lake Washington boasts several areas of high affluence. Bill Gates's mansion is situated along its Medina waterfront, while Paul Allen lives on Mercer Island.
Kenmore Air operates passenger seaplane service at Kenmore Air Harbor at the northern end of the lake.
[edit] Statistics
| Area of lake | 21,500 acres | 87.6 km² |
|---|---|---|
| Area of drainage basin | 300,000 acres | 1,274 km² |
| Volume | 2,350,000 acre-feet | 2.9 km³ |
| Depth (mean) | 108 ft | 32.9 m |
| Depth (max) | 214 ft | 65.2 m |
| Length | 22 miles | 35 km |
| Height* | 20.6 ft | 6.3 m |
* Above Puget Sound mean lower low tide
[edit] References
[edit] Bibliography
