The 2002 Flood
The flood beginning July 4, 2002 was the first time that floodwaters flowed over the Emergency Spillway since the Reservoir was completed in 1964.
The upper part of the Guadalupe River Watershed officially received 34 inches of rain in approximately one week. (see the Canyon Lake tab for more info)
All lakeside and River Road campers were evacuated and parks closed.
When the floodwater was at peak flow, it was moving at about 67,000 cfs* approximately 7 feet above the Spillway. Normal flow from the reservoir is 350 cfs with a maximum release of 5000 cfs.
Just under 1-1/2 times the amount of water stored in the lake (at normal level) went over the Spillway during the flood event.
Water continued to flow over the Spillway for approximately 6 weeks. Rocks, trees, logs, and other flood debris piled up in the Guadalupe River and created a huge blockage. Flooding continued from the dam to the Gulf Coast.
* cfs = cubic feet per second
The Guadalupe River Basin is a part of "Flash Flood Alley" and is one of the most Flash Flood prone river basins in the world.
In 1998, the Guadalupe River Basin DOWNSTREAM of the Dam and Reservoir experienced the most significant flooding in recorded history.