Is It Safe to Tube the San Marcos, Comal & Guadalupe Right Now?
Live 2026 river status with real USGS gauge data, safe flow ranges, and this week's float recommendation for Central Texas.
Current Status at a Glance
This page is refreshed weekly with the latest conditions on the three rivers most Austinites float: the San Marcos, the Comal, and the Guadalupe below Canyon Lake. Use it as your first stop before booking a shuttle or heading to an outfitter.
Canyon Lake: 58.4% of capacity. Release from the dam is about 61 cfs into the Guadalupe — well below the 250 cfs sweet spot for Guadalupe tubing.
Spring-fed rivers: The Comal and San Marcos are not flow-dependent. They run steady at 70-72°F year-round, drought or not, which is why they remain the safest bet all season.
Per-River Live Status (April 20, 2026)
San Marcos River — SAFE & OPEN
- Temperature: ~72°F (spring-fed, year-round)
- Flow: Healthy; Rio Vista section running clear
- Open? Yes, year-round. Lions Club Tube Rental (weekends only, Sat/Sun) and Texas State Tubes operate through summer.
- Heads up: New 2026 Rio Vista Park non-local fee ($5/day) on Memorial Day through Labor Day weekends and holidays.
Comal River — SAFE & OPEN
- Temperature: ~72°F (spring-fed from Comal Springs)
- Flow: Steady, unaffected by drought
- Open? Outfitters run 7 days a week once Memorial Day hits. Texas Tubes, Rockin' R, and Landa Falls are all operating.
- Rules reminder: Disposable container ban is in full effect — no cans, glass, styrofoam, or single-use zip bags. Violations are $500.
Guadalupe River — LOW FLOW, CAUTION
- Canyon Lake release: ~61 cfs (well below the 250 cfs optimum)
- Temperature: Cool near the dam, warmer downstream
- Open? Outfitters are running, but float times are long and gravel-bar walking is likely.
- Recommendation: Choose a 1-2 hour upper stretch, or wait for a larger release before committing to a full-day float.
Safe CFS Ranges Explained
CFS means cubic feet per second — the volume of water moving past a gauge each second. For recreational tubing, here is what the numbers actually mean on the water:
| Flow (CFS) | Rating | What to Expect |
|---|---|---|
| 250 - 350 | Optimal | Steady drift, clear channels, ideal family floats. |
| 150 - 250 | Low but doable | Slower pace, some shallow spots. Bring patience. |
| Below 150 | Walk sections | Expect to get out and drag your tube over gravel bars. |
| Over 550 | Unsafe | Fast water, strainers, and flip risk. Outfitters typically close. |
Important: CFS applies to the Guadalupe (which depends on Canyon Lake releases). The San Marcos and Comal are spring-fed and run steady regardless of drought.
Live USGS Gauge Links
Click any gauge below for real-time readings (updated every 15 minutes by the U.S. Geological Survey):
- Canyon Lake Outflow (08167800) — the release into the Guadalupe
- Comal River at New Braunfels (08169000) — primary Comal gauge
- San Marcos River at San Marcos (08170500) — primary San Marcos gauge
What "Unsafe" Actually Means
Unsafe is not just "fast water." Here are the specific conditions that should keep you off the river:
- High flow above 550 cfs on the Guadalupe: strainers, flip risk, and outfitter closures.
- Recent flood event (last 48 hours): debris, submerged hazards, and murky water hiding obstacles.
- Active bacterial advisory: check the Texas Commission on Environmental Quality (TCEQ) before floating after heavy rain.
- Water temperature below 60°F: hypothermia risk, mostly a winter concern on the Guadalupe.
- Outfitter closures: if Rockin' R, Texas Tubes, or Lions Club are closed, that is your signal.
- Thunderstorm in the forecast: Hill Country flash floods are fast and fatal.
This Week's Recommendation
Week of April 20, 2026:
- Best pick: Comal River, Prince Solms Park launch. 70-72°F, steady flow, outfitters fully open.
- Runner-up: San Marcos at Rio Vista. Clear water, family-friendly, no fee yet this week (fee kicks in Memorial Day weekend).
- Skip for now: Full Guadalupe day floats. Consider shorter upper stretches only.
Weather looks warm and dry heading into the weekend — perfect early-season floating conditions. Book shuttles 2-3 days out; it is not peak yet, but weekends still fill.
Frequently Asked Questions
Is the Guadalupe River safe to tube right now?
As of April 20, 2026, the Guadalupe below Canyon Lake is running low at about 61 cfs. It is safe from a flow-safety standpoint (no flash flood risk), but floats will be slow and you may need to walk shallow sections. Upper stretches or spring-fed alternatives are a better bet this week.
What CFS is safe for tubing?
250-350 cfs is optimal. 150-250 cfs is slow but floatable. Below 150 cfs you may walk sections. Above 550 cfs is unsafe.
Can you tube after it rains?
Wait 24-48 hours after heavy rain in the watershed. Flash floods, elevated bacteria, and floating debris make post-storm tubing dangerous.
Is the Comal River safe to tube year-round?
Yes. The Comal is spring-fed and holds 70-72°F with steady flow regardless of drought. It is the most reliably safe river in Central Texas.
How do I check current river flow?
Use USGS Water Data. Key gauges: Canyon Lake outflow (08167800), Comal at New Braunfels (08169000), San Marcos at San Marcos (08170500). Real-time CFS updates every 15 minutes.
What does unsafe flow mean for tubing?
Unsafe means flows above 550 cfs, recent flooding, active TCEQ bacterial advisories, water below 60°F, or outfitter closures. Any one is enough to postpone.
Is the San Marcos River safe right now?
Yes. As of April 20, 2026, the San Marcos is running clear at roughly 72°F with a healthy spring-fed flow. Rio Vista is open and safe for all skill levels.
Can kids tube the Guadalupe when it is low?
Technically yes, but not fun. At 61 cfs, shallow gravel bars mean lots of walking. For families during low flow, the Comal through Prince Solms Park and the upper San Marcos are far better.