Lake Ilsanjo
Lake Ilsanjo is a man-made lake located in Annadel State Park east of Santa Rosa in Sonoma County, California, United States. It is a place for fishing and swimming, especially in the summer months. Entrepreneur Joe Coney originally owned the land that is now Annadel State Park and named the lake after his wife Ilsa and himself. Thus it came to be called Lake Ilsanjo. It drains into Spring Creek.

The lake is formed by a dam constructed in the 1950s. Originally the overflow drained to a gully during the winter months, but in 2003, the state spent almost $400,000 building a spillway and release valve to reduce downstream erosion. During the winter of 2007–08, park officials accidentally left the release valve open, causing the lake level to drop far below normal, exposing mudflats that would normally be underwater.
Q23397
lake
Concept
Q4767772
Annadel State Park
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Santa Rosa
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Sonoma County, California
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Q30
United States
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Spring Creek
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state
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Q6476272
Lake Ilsanjo
LOC
Q6476272
Lake Ilsanjo
LOC
1950-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1950
DATE
2003-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
2003
DATE
2007-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
2007
DATE
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400,000
NUMBER
+08^^http://www.w3.org/2001/XMLSchema#decimal
08
NUMBER
instance of
location
country
inflows
located in the administrative territorial entity
located in the administrative territorial entity
country
located in the administrative territorial entity
country
country