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 section below 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 cubic feet per second (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.
The dam was built for two reasons:
1) to control flood events that originated in the watershed of the Guadalupe River in the Texas Hill Country.
2) for GBRA to have a stored supply of water available for citizens in the Guadalupe River Basin during times of drought.
Built in the early 1960's, the dam is constructed of rolled, compacted earth. The Reservoir took three years to fill to its optimal level.
Visit the Corps of Engineers website for more info about Canyon Lake and current lake levels.
Also visit the GBRA website to learn more about their vital role in protecting not only Canyon Lake, but all the water resources in it's 10-county statutory district, which begins near the headwaters of the Guadalupe and Blanco rivers, and ends at San Antonio Bay.
Surface area of 8,230 acres at normal level (909 msl*) and can store approximate 378,852 acre-feet** of water.
When over 909 msl, the Corps regulates how much water is released back into the Guadalupe River from the lake.
When 909 msl or below, GBRA regulates the discharge.
The dam is 224' high and 6,830' long. The top of the dam is at 974 msl.
The top of the emergency spillway is 943 msl.
Various parks are located around the reservoir and are operated by the Corps.
Headwaters of the Guadalupe River are north of Kerrville and runs approximately 420 miles to the San Antonio Bay in the Gulf of Mexico.
* msl = mean sea level / feet above sea level
** acre-feet (a/f) = one acre at one foot of water
Canyon Lake/Sattler OFFICE / Mailing Address
2075 FM 2673, Suite D
Canyon Lake, TX 78133
Office Hours: Monday-Friday 9am-5pm
N 29.86304 W 098.18750
© 2009 - 2019 Gorge Preservation Society