Guadalupe River Flow Rate
Current flow information for the Guadalupe River
The speed of flow on the Guadalupe fluctuates with the release rate of water from Canyon dam turbines. Flows are usually between 100 and 300 cubic feet per second (cfs). Read below for more information.
Daily Flow Information
Canyon Dam Release Rate
Flows above 550 cfs may be unsafe for parts of the river. Consult an outfitter.
Flows between 350 to 550 cfs are above average, and should only be tubed by experienced people. Even then, great caution should be exercised at all rapid areas and you may need to walk around them. For these levels, we suggest you consult an outfitter for the area you'll be tubing.
Flows between 250 to 350 cfs are optimum. There will be fewer shallow rocks to hit your rear on, which is a major plus.
Flows from 150 to 250 are low, but you can still tube. Some parts of the lower Guadalupe may require getting out of the tube and walking across a shallow rock shelf, but the river is still fun. Though manly men generally refuse the "bottom tube", when the water gets below 200 CFS you may wish you'd considered it.
Below 150 cfs release rate, and you will have to walk short distances where the water gets too shallow.
Do the Flows Change Often?
Yes! The dam's main purpose is flood control, and therefore rain up river can mean fluctuating release rates. If there's been heavy rain recently, make sure you call ahead as the flow can change at any time.
Predicting the Flows
When the river is at conservation levels, it is under the control of the Guadalupe / Blanco River Authority. Above 909', it is in flood control level, and under the control of the US Army Corps of Engineers.
Therefore, noting the level of Canyon Lake itself is helpful in this exercise. When the lake is at 908.9 feet or less it is in conservation mode. Releases will be very low.
At the normal level of 909', expect a great tubing trip.
When the lake rises past 909', expect quick releases from the Army. These may happen with little notice, so consult an outfitter if recent up river rains have been heavy. Remember it's the rain *above* the dam that's relevant, where it will feed into the river.
The Army seeks to keep the lake around conservation levels, as is the mission of the Canyon Lake.
The other caveat to this is that the Corps of Engineers wants to work with the water sports industry, and therefore changes their normal flood control release procedure between April and August. So instead of releasing a torrent of water to keep the lake within a tight regulation, they release it slower so we can be tubing!
The Guadalupe River Trout Unlimited chapter reports that above 909' elevation, flow rates will generally be the greater of: The flow rate at Spring Branch gage; or 250 cfs.
Below 909.0, The Guadalupe-Blanco River Authority controls the flow. The minimum flow is 90 - 100 cfs, and can be lower during drought. The GRTU-GBRA Flow Agreement provides trout protective flows from May 1 to September 30 in non-drought years. These flows will average around 200 cfs for the time period.