Lake Washington Summary Hydrograph
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Lake Washington Basin Lake Washington Summary Hydrograph |
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Notes:
1. Summary hydrographs are a family of graphs which show, for each day of
the calendar year, the maximum, minimum, and average water surface
elevation over the period of record.
2. Lake Washington water surface data were collected at eight am each
day.
3. The Lake Washington Ship Canal is operated primarily as a navigation
facility connecting Puget Sound and Lakes Union and Washington. Project
authorization documents state that under normal operation the Lake
Washington Ship Canal should be maintained within a 2-foot range between
20.0 feet and 22.0 feet (Corps of Engineers Datum), respectively. The
minimum elevation is maintained during the winter months to allow for
annual maintenance on docks, walls, etc., by businesses and lakeside
residents, minimize wave and erosion damage during winter storms and
provide storage space for high inflow. The storage between 20 and 22
feet is used to augment Lake Washington Ship Canal inflows for use in
operating the locks, the saltwater return system, the smolt passage
flume, and the fish ladder facility.
4. The locks and spillway dam regulate the elevation of Salmon Bay, Lake
Union, Lake Washington and the Lake Washington Ship Canal. The level of
Lake Washington was lowered about 8 feet by the construction of the Lake
Washington Ship Canal, but it is still the second largest natural lake in
the state, with a surface area of 22,138 acres and shoreline of about 91
miles at elevation 22 feet.
