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.
Guadalupe: Flow has rebounded to roughly 236 cfs — right in the 250-350 cfs sweet spot for tubing, a big improvement from the low-flow drought conditions earlier in 2026.
Comal: Running "High and Fast" at roughly 192 cfs. Still floatable, but faster-paced than its usual lazy-river reputation — check the gauge before bringing first-timers or young kids.
San Marcos: "Very Good" at roughly 96 cfs, clear and steady — the most forgiving pick for families this week.
Per-River Live Status (August 10, 2026)
Guadalupe River — PERFECT
- Flow: ~236 cfs — squarely in the 250-350 cfs ideal range
- Temperature: Comfortable summer water temps
- Open? Yes, outfitters fully open with standard summer hours.
- Heads up: This is a sharp rebound from the spring drought-driven low flow — conditions can shift, so recheck the gauge before you drive out.
San Marcos River — VERY GOOD
- Flow: ~96 cfs, rated "Very Good"
- Temperature: ~72°F (spring-fed, year-round)
- Open? Yes, year-round. Texas State Tubes and other outfitters running full summer hours.
- Heads up: Rio Vista Park non-local fee ($5/day) applies weekends & holidays through Labor Day.
Comal River — HIGH & FAST, CAUTION
- Flow: ~192 cfs, rated "High and Fast — caution advised"
- Temperature: ~72°F (spring-fed from Comal Springs)
- Open? Yes, outfitters running 7 days a week, but pace is quicker than typical.
- Recommendation: Fine for confident swimmers and older kids; check the gauge morning-of if bringing first-timers or young children. Disposable container ban remains in full effect — fines up to $500.
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: This CFS table is calibrated primarily for the Guadalupe (which depends on Canyon Lake releases). The Comal and San Marcos are smaller, spring-fed rivers where a lower absolute cfs reading can still mean a full, healthy float — and conditions can shift quickly after upstream rain, as this week's Comal reading shows. Always weigh the qualitative rating (Perfect / Very Good / Caution) alongside the raw number.
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 August 10, 2026:
- Best pick: Guadalupe River. ~236 cfs, right in the ideal range, healthy current without being pushy.
- Runner-up: San Marcos at Rio Vista. Clear water, family-friendly, the most forgiving pace this week.
- Check first: Comal River. Still a great float, but confirm the gauge morning-of — running quicker than usual.
Peak-summer heat continues through August — launch by 9-10am to be off the water before the worst 1-4pm heat window. Book shuttles at least a week out; late-summer weekends still fill fast heading into Labor Day.
Frequently Asked Questions
Is the Guadalupe River safe to tube right now?
As of August 10, 2026, the Guadalupe below Canyon Lake is running at roughly 236 cfs, rated "Perfect" for tubing — right in the ideal 250-350 cfs range. This is a big improvement from the low-flow conditions earlier in the year. Always confirm the live gauge the morning of your float.
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 right now?
It is floatable but running "High and Fast" as of August 10, 2026 at roughly 192 cfs, so caution is advised. Flow can spike after upstream rain even on this normally steady, spring-fed river. Check the gauge before bringing first-timers or young kids this week.
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 August 10, 2026, the San Marcos is running "Very Good" at roughly 96 cfs and a healthy spring-fed 72°F. Rio Vista is open and safe for all skill levels.
Which river is best for kids right now?
The San Marcos is the safest default for families this week. The Guadalupe at "Perfect" flow is also a strong family pick. Hold off on the Comal for young kids until its "High and Fast" flag clears.