The Sacramento River Flood Control Project was authorized by the federal government in 1917.
While it intended to contain minor floods in the river banks by strengthening the existing levee system, the main feature was a series of bypasses, or sections of the valley intentionally designed to flood during high water.
Weirs placed at strategic points along the Sacramento River release water into the bypasses when the river reaches a certain stage, relieving the pressure of floodwaters on the main channel.
The bypasses are then allowed to drain slowly once flood crests have passed.
For most of the year, the bypasses remain dry and are used for annual crops such as rice.
Some of the principal features are the Butte Basin, Colusa Basin, Sutter Bypass and the Yolo Bypass.
The Butte Basin is a large lowland area on the east side of the river between Hamilton City and Colusa; the geographically similar Colusa Basin is located to the west.
The Sutter Bypass begins at Colusa and runs parallel to the east side of the Sacramento River until reaching the confluence with the Feather River.
The Yolo Bypass, located on the west side of the river, starts at the confluence of the Feather and rejoins the Sacramento in the Delta.
Although termed "bypasses", the system essentially reconnects the Sacramento with a portion of its historic flood plain, which it would have naturally flooded had the levee system not been in place.
The Sacramento River Flood Control Project was authorized by the federal government in 1917. While it intended to contain minor floods in the river banks by strengthening the existing levee system, the main feature was a series of bypasses, or sections of the valley intentionally designed to flood during high water. Weirs placed at strategic points along the Sacramento River release water into the bypasses when the river reaches a certain stage, relieving the pressure of floodwaters on the main channel. The bypasses are then allowed to drain slowly once flood crests have passed. For most of the year, the bypasses remain dry and are used for annual crops such as rice. Some of the principal features are the Butte Basin, Colusa Basin, Sutter Bypass and the Yolo Bypass. The Butte Basin is a large lowland area on the east side of the river between Hamilton City and Colusa; the geographically similar Colusa Basin is located to the west. The Sutter Bypass begins at Colusa and runs parallel to the east side of the Sacramento River until reaching the confluence with the Feather River. The Yolo Bypass, located on the west side of the river, starts at the confluence of the Feather and rejoins the Sacramento in the Delta. Although termed "bypasses", the system essentially reconnects the Sacramento with a portion of its historic flood plain, which it would have naturally flooded had the levee system not been in place.
Sacramento River