Ahtanum Creek At Union Gap flow report
As of July 12, 2026, Ahtanum Creek At Union Gap is flowing at 11 cfs with a gage height of 2.92 ft, rising 22% over the past 24 hours. Source: USGS gauge #12502500, refreshed throughout the day.
Historical Data
Ahtanum Creek At Union Gap at a glance
How Ahtanum Creek At Union Gap is running right now, where it sits on the map, and the key gauge stats.
Ahtanum Creek At Union Gap is flowing at 11 cfs, with the water sitting 2.92 ft at the gage. Flow is up 22% since yesterday — a rising hydrograph.
This is USGS gauge #12502500 in Washington. Over the past 10 days the average has been 13 cfs, peaking at 17 cfs.
Over the next 5 days, Ahtanum Creek At Union Gap is expected to hold near today's 11 cfs, toward roughly 10 cfs by 2026-07-17 (likely range 6-20 cfs) -- running well below the seasonal normal.
For real-time updates and historical context, see the realtime view or the historical comparison. Browse other gauges in the Washington flow report.
Streamflow Forecast
Powered by PULSE — Snoflo’s Predictive Unified Learning & Simulation Engine, which learns from how this river has answered every past storm, snowmelt, and dry spell to forecast where it’s headed with a precision generic models can’t match.
How does this compare to past years?
Year-over-year overlay, annual peak discharge, the full distribution of daily flows on record, and the gauge's rating curve.
Weather Forecast
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day forecast
Daily temperatures, snow, and rain projected over the next two weeks.
Ahtanum Creek At Union Gap
The creek's flow is primarily influenced by snowmelt in the spring and summer rainfall. The Ahtanum Creek has several tributaries, including Dry Creek, Tampico Creek, and Cowiche Creek, which contribute to its flow. There are no major dams on the creek. Interestingly, the Ahtanum Creek is known for its trout fishing, and the area is popular with local anglers. Overall, the Ahtanum Creek is an important source of water for the Yakima River and provides critical habitat for fish and wildlife in the region.
Nearby streamflow levels
Cross-check Ahtanum Creek At Union Gap's discharge against nearby gauges to spot whether the change here is local or regional.
| Gauge | Streamflow |
|---|---|
| Ahtanum Creek At Union Gap | 11 cfs |
| Yakima River Above Ahtanum Creek At Union Gap | 2,680 cfs |
| Granger Drain At Granger | 46 cfs |
| Toppenish Creek Near Fort Simcoe | 7 cfs |
| Yakima River At Umtanum | 3,730 cfs |
| Columbia River Below Priest Rapids Dam | 115,000 cfs |
Nearby snowpack data
Snowpack at SNOTEL stations near Ahtanum Creek At Union Gap. Spring snowmelt is the dominant driver of streamflow in mountain basins -- a deep snowpack upstream means more runoff later in the season.
| SNOTEL station | Snowpack |
|---|---|
| Lost Horse | 0 in |
| Lost Horse | 0 in |
| Green Lake | 0 in |
| Satus Pass | 0 in |
| 20d01 - Satus Pass | 0 in |
| Indian Rock | 0 in |
Plan a trip
Reservoirs, boat launches, river runs, and fishing spots within driving distance of Ahtanum Creek At Union Gap.
Boat launches
See all →
River levels & flood safety
- Read the level before you go
- A river that's runnable at one flow can be deadly at another. Check current discharge and gage height — like the values shown above — against the flood-stage thresholds, and remember levels can spike fast after rain or a dam release.
- Respect cold water
- Snowmelt rivers run cold even in summer. Sudden immersion triggers cold-water shock and saps strength within minutes. Wear a PFD, dress for the water temperature (not the air), and never wade or paddle alone.
- Watch for swiftwater hazards
- Strainers (downed trees), undercut rocks, and low-head dams are the deadliest features on moving water. High, fast, muddy water hides them. If in doubt, scout from shore and portage.
- Mind flash floods & releases
- Narrow canyons can flood from a storm miles upstream, and dam-controlled reaches can rise without warning. Know the forecast, the release schedule, and your exit before you launch.
Track Ahtanum Creek At Union Gap in the Snoflo app
Save this gauge as a favorite, set push alerts when streamflow crosses a threshold (e.g. "alert me when Ahtanum Creek At Union Gap crosses 5,000 cfs"), and Snoflo's iOS app will push the moment USGS reports the crossing.
About Ahtanum Creek At Union Gap
Where does the streamflow data for Ahtanum Creek At Union Gap come from?
Discharge, gage height, and water temperature come directly from the USGS streamflow gauge 12502500. Snoflo refreshes the time series throughout the day. Forecasts come from the NOAA / yr.no feed Snoflo's iOS app uses.
How often is the report updated?
USGS gauges report continuously (typically every 15 minutes). Snoflo pulls fresh values throughout the day — look for the "as of" timestamp on the streamflow hero card.
What's the difference between discharge and gage height?
Discharge (cubic feet per second, or cfs) is the volume of water flowing past the gauge each second. Gage height is how high the water sits at the gauge (feet). They're related by a rating curve specific to each gauge — higher water means more flow, but the exact ratio depends on channel shape.
How is "percent of median" calculated?
Today's discharge is compared to the historical median discharge on this calendar day across the gauge's full record. 100% = right on median; 200% = a very high year; 30% = a drought-level low.
What are flood stages, and is this river safe right now?
Flood stages are NWS-defined gage-height thresholds — Action, Minor, Moderate, Major — marking when nearby roads or floodplains start to be affected. "Safe" depends on your activity and skill: a level that's a fun paddle for an expert can be lethal for a wader. Always check the current level against the thresholds above and the safety links, and when in doubt, stay off the water.
Can I get alerts when Ahtanum Creek At Union Gap rises?
Yes — flow alerts are managed in the Snoflo iOS app. Favorite this gauge, set a streamflow threshold (e.g. "alert me when discharge crosses 5,000 cfs"), and you'll get a push the moment USGS reports the crossing.
Access the free Ahtanum Creek At Union Gap report
Create your free account to track this river — and everything else you love on the water.
- Flow alerts — get pinged the moment this river hits your range
- Save favorites — every river, lake & snowpack in one place
- Full history & forecasts — plus the free iPhone app