Maryland River Levels & Streamflow
As of Sep 5, 2026, Maryland rivers are running at 156% of normal across 92 USGS gauges — the highest is 11,900 cfs on the Susquehanna River At Conowingo. Live discharge, gauge height, and percent-of-normal for every USGS streamgauge in Maryland.
Streamflow levels across Maryland are currently 156% of normal, with the Susquehanna River At Conowingo reporting the highest discharge in the state at 11,900 cfs and a gauge stage of 10.67 ft.
Meanwhile, the St Marys River At Great Mills is seeing a spike today — up 13465% since yesterday and currently running near peak.
Tap any gauge below for the full hydrograph, paired weather forecast, and historical context. Use the rivers panel to jump into Maryland's named rivers.
Active weather warnings for Maryland
Maryland residents should remain alert for one more round of severe storms expected before the weekend, potentially impacting major population centers including Baltimore County, Montgomery County, and the greater DC metropolitan area. After this system passes, conditions are expected to improve significantly, with few showers anticipated Saturday followed by dry weather through Sunday and Labor Day Monday. Residents are advised to monitor local weather updates and stay weather-aware through the weekend. Montgomery County residents can access emergency alerts through the county's newly launched translation service for non-English speakers. No active warnings are currently in effect for Maryland at this time.
State-wide streamflow overview
The Maryland flow picture in four data points -- where the state sits versus historical norms, what's flowing hardest, and what's spiking fastest.
Percent of normal
100% is the historical norm. Below 70% indicates drought; above 130% can flag elevated flood risk.
Highest discharge
Gauge stage 10.67 ft
Biggest 24h spike
Now 468 cfs
Network coverage
USGS gauges feeding 0 named rivers in Maryland.
Where every gauge actually sits
One dot per Maryland streamgauge, placed by its own percent of normal. The state average is a single line through all of it.
Percent of normal compares today's discharge with the historical average for this calendar day. Tap any dot to open that gauge.
Maryland streamflow, three water years
Statewide percent of normal, every day since Sep 2023. The dotted line is normal.
799 daily readings from 92 reporting gauges. Percent of normal is today's statewide discharge against the historical average for the same calendar day — 100% is normal, not "good". The axis tops out at 250%: 35 readings above that — including the 454% peak in Apr 2024 — are drawn along the top edge, so a few flood days cannot flatten three years of everything else. The line breaks in 2 places where the record skips more than five days — those are gaps in reporting, not readings of zero.
Maryland USGS streamgauges
Every USGS gauge Snoflo tracks in Maryland. Sortable, quickly filterable. Numeric columns heat-mapped from light to deep. Tap any gauge for its full hydrograph and forecast.
| Streamgage | Streamflow | Gage height | Water temp | Air temp | Elevation | Watershed |
|---|---|---|---|---|---|---|
|
Susquehanna River At Conowingo, Md
17 hours ago · USGS 01578310 |
42,800 cfs | 13.81 ft | · | 80°F | 21 ft | Lower Susquehanna |
|
Potomac River Near Wash, Md
16 hours ago · USGS 01646500 |
2,260 cfs | 2.88 ft | 45°F | 83°F | 43 ft | Middle Potomac-Catoctin |
|
Potomac River At Point Of Rocks, Md
16 hours ago · USGS 01638500 |
2,210 cfs | 1.50 ft | 82°F | 70°F | 192 ft | Middle Potomac-Catoctin |
|
Potomac River At Paw Paw, Md
17 hours ago · USGS 01610000 |
972 cfs | 4.31 ft | · | 69°F | 501 ft | Cacapon-Town |
|
Potomac River At Hancock, Md
17 hours ago · USGS 01613000 |
963 cfs | 3.25 ft | · | 69°F | 396 ft | Conococheague-Opequon |
|
North Branch Potomac River Near Cumberland, Md
17 hours ago · USGS 01603000 |
547 cfs | 2.74 ft | · | 69°F | 589 ft | North Branch Potomac |
|
Youghiogheny River At Friendsville, Md
17 hours ago · USGS 03076500 |
343 cfs | 2.79 ft | 71°F | 68°F | 1,555 ft | Youghiogheny |
|
Conococheague Creek At Fairview, Md
17 hours ago · USGS 01614500 |
255 cfs | 2.00 ft | · | 80°F | 438 ft | Conococheague-Opequon |
|
Youghiogheny River Near Oakland, Md
17 hours ago · USGS 03075500 |
249 cfs | 2.79 ft | · | 64°F | 2,370 ft | Youghiogheny |
|
Monocacy River At Jug Bridge Near Frederick, Md
17 hours ago · USGS 01643000 |
243 cfs | 2.13 ft | · | 81°F | 231 ft | Monocacy |
|
North Branch Potomac River At Kitzmiller, Md
17 hours ago · USGS 01595500 |
208 cfs | 2.60 ft | · | 68°F | 1,575 ft | North Branch Potomac |
|
Monocacy River At Monocacy Blvd At Frederick, Md
17 hours ago · USGS 01642190 |
167 cfs | 1.99 ft | · | 81°F | 259 ft | Monocacy |
|
Casselman River At Grantsville, Md
17 hours ago · USGS 03078000 |
159 cfs | 1.69 ft | · | 66°F | 2,135 ft | Youghiogheny |
|
Antietam Creek Near Sharpsburg, Md
17 hours ago · USGS 01619500 |
154 cfs | 2.53 ft | · | 69°F | 367 ft | Conococheague-Opequon |
|
Bear Creek At Friendsville, Md
17 hours ago · USGS 03076600 |
146 cfs | 2.40 ft | · | 68°F | 1,640 ft | Youghiogheny |
|
Gunpowder Falls At Glencoe, Md
17 hours ago · USGS 01582500 |
143 cfs | 1.34 ft | · | 81°F | 247 ft | Gunpowder-Patapsco |
|
Patuxent River Near Bowie, Md
17 hours ago · USGS 01594440 |
132 cfs | 4.31 ft | · | 82°F | 20 ft | Patuxent |
|
Wills Creek Near Cumberland, Md
17 hours ago · USGS 01601500 |
118 cfs | 2.42 ft | · | 68°F | 703 ft | North Branch Potomac |
|
Mattawoman Creek Near Pomonkey, Md
16 hours ago · USGS 01658000 |
118 cfs | 3.89 ft | 73°F | 83°F | 46 ft | Lower Potomac |
|
Gunpowder Falls Near Parkton, Md
17 hours ago · USGS 01581920 |
115 cfs | 2.01 ft | 63°F | 80°F | 352 ft | Gunpowder-Patapsco |
|
North Branch Potomac River At Steyer, Md
17 hours ago · USGS 01595000 |
112 cfs | 2.60 ft | · | 64°F | 2,276 ft | North Branch Potomac |
|
Seneca Creek At Dawsonville, Md
16 hours ago · USGS 01645000 |
96 cfs | 2.19 ft | · | 82°F | 216 ft | Middle Potomac-Catoctin |
|
Deer Creek Near Darlington, Md
17 hours ago · USGS 01580520 |
84 cfs | 1.29 ft | · | 80°F | 49 ft | Lower Susquehanna |
|
Big Elk Creek At Elk Mills, Md
17 hours ago · USGS 01495000 |
80 cfs | 3.62 ft | · | 81°F | 70 ft | Chester-Sassafras |
|
Patapsco River At Hollofield, Md
17 hours ago · USGS 01589000 |
78 cfs | 1.66 ft | · | 81°F | 190 ft | Gunpowder-Patapsco |
|
Nassawango Creek Near Snow Hill, Md
17 hours ago · USGS 01485500 |
64 cfs | 3.36 ft | · | 84°F | 21 ft | Pocomoke |
|
St Marys River At Great Mills, Md
17 hours ago · USGS 01661500 |
62 cfs | 2.17 ft | · | 83°F | 13 ft | Lower Potomac |
|
Savage Riv Bl Savage Riv Dam Near Bloomington, Md
17 hours ago · USGS 01597500 |
61 cfs | · | 59°F | 67°F | 1,382 ft | North Branch Potomac |
|
Deer Creek At Rocks, Md
17 hours ago · USGS 01580000 |
49 cfs | 2.08 ft | · | 80°F | 262 ft | Lower Susquehanna |
|
Zekiah Swamp Run Near Newtown, Md
17 hours ago · USGS 01660920 |
46 cfs | 1.43 ft | · | 82°F | 37 ft | Lower Potomac |
|
Western Branch At Upper Marlboro, Md
17 hours ago · USGS 01594526 |
46 cfs | 2.15 ft | · | 82°F | 9 ft | Patuxent |
|
Little Patuxent River At Savage, Md
17 hours ago · USGS 01594000 |
37 cfs | 3.07 ft | · | 82°F | 126 ft | Patuxent |
|
Antietam Creek Near Waynesboro, Md
17 hours ago · USGS 01619000 |
34 cfs | 2.24 ft | · | 80°F | 547 ft | Conococheague-Opequon |
|
Gwynns Falls At Washington Blvd At Baltimore, Md
17 hours ago · USGS 01589352 |
30 cfs | 2.44 ft | · | 83°F | 18 ft | Gunpowder-Patapsco |
|
Piscataway Creek At Piscataway, Md
17 hours ago · USGS 01653600 |
27 cfs | 2.81 ft | · | 83°F | 16 ft | Middle Potomac-Anacostia-Occoquan |
|
Patuxent River Below Brighton Dam Near Brighton, Md
17 hours ago · USGS 01591610 |
26 cfs | 1.47 ft | 70°F | 81°F | 310 ft | Patuxent |
|
Tuckahoe Creek Near Ruthsburg, Md
17 hours ago · USGS 01491500 |
26 cfs | · | · | 83°F | 14 ft | Choptank |
|
Little Falls At Blue Mount, Md
17 hours ago · USGS 01582000 |
26 cfs | · | · | 80°F | 306 ft | Gunpowder-Patapsco |
|
Monocacy River At Bridgeport, Md
17 hours ago · USGS 01639000 |
25 cfs | 2.49 ft | · | 80°F | 332 ft | Monocacy |
|
Catoctin Creek Near Middletown, Md
17 hours ago · USGS 01637500 |
24 cfs | 1.74 ft | · | 69°F | 436 ft | Middle Potomac-Catoctin |
|
Big Pipe Creek At Bruceville, Md
17 hours ago · USGS 01639500 |
23 cfs | · | · | 80°F | 370 ft | Monocacy |
|
Savage River Near Barton, Md
17 hours ago · USGS 01596500 |
21 cfs | 1.16 ft | 67°F | 67°F | 1,659 ft | North Branch Potomac |
|
Little Patuxent River At Guilford, Md
16 hours ago · USGS 01593500 |
20 cfs | 2.11 ft | · | 82°F | 267 ft | Patuxent |
|
Georges Creek At Franklin, Md
17 hours ago · USGS 01599000 |
20 cfs | 2.07 ft | · | 68°F | 975 ft | North Branch Potomac |
|
Patuxent Riv Near Laurel, Md
17 hours ago · USGS 01592500 |
19 cfs | 4.32 ft | · | 82°F | 160 ft | Patuxent |
|
Bennett Creek At Park Mills, Md
17 hours ago · USGS 01643500 |
19 cfs | 1.53 ft | · | 70°F | 304 ft | Monocacy |
|
St Clement Creek Near Clements, Md
17 hours ago · USGS 01661050 |
19 cfs | · | · | 83°F | 11 ft | Lower Potomac |
|
Town Creek Near Oldtown, Md
17 hours ago · USGS 01609000 |
19 cfs | 2.01 ft | · | 69°F | 567 ft | Cacapon-Town |
|
Choptank River Near Greensboro, Md
17 hours ago · USGS 01491000 |
17 cfs | 2.26 ft | 79°F | 83°F | 5 ft | Choptank |
|
Western Run At Western Run, Md
17 hours ago · USGS 01583500 |
16 cfs | · | · | 81°F | 265 ft | Gunpowder-Patapsco |
|
Winters Run Near Benson, Md
17 hours ago · USGS 01581700 |
15 cfs | 1.27 ft | · | 81°F | 190 ft | Gunpowder-Patapsco |
|
Little Gunpowder Falls At Laurel Brook, Md
1 day ago · USGS 01584500 |
14 cfs | 1.03 ft | · | 81°F | 260 ft | Gunpowder-Patapsco |
|
North Branch Patapsco River At Cedarhurst, Md
17 hours ago · USGS 01586000 |
14 cfs | 1.28 ft | · | 80°F | 423 ft | Gunpowder-Patapsco |
|
Patuxent River Near Unity, Md
16 hours ago · USGS 01591000 |
14 cfs | 2.03 ft | · | 80°F | 383 ft | Patuxent |
|
Unicorn Branch Near Millington, Md
17 hours ago · USGS 01493000 |
14 cfs | 1.70 ft | · | 83°F | 8 ft | Chester-Sassafras |
|
Gwynns Falls At Villa Nova, Md
17 hours ago · USGS 01589300 |
13 cfs | · | · | 81°F | 367 ft | Gunpowder-Patapsco |
|
Cattail Creek Near Glenwood, Md
17 hours ago · USGS 01591400 |
11 cfs | · | · | 80°F | 382 ft | Patuxent |
|
North East Branch Anacostia River At Riverdale, Md
17 hours ago · USGS 01649500 |
10 cfs | · | 78°F | 83°F | 14 ft | Middle Potomac-Anacostia-Occoquan |
|
Hawlings River Near Sandy Spring, Md
17 hours ago · USGS 01591700 |
10 cfs | · | · | 81°F | 307 ft | Patuxent |
|
Beaverdam Run At Cockeysville, Md
17 hours ago · USGS 01583600 |
9 cfs | 2.10 ft | · | 81°F | 245 ft | Gunpowder-Patapsco |
|
Gunpowder Falls At Hoffmanville, Md
17 hours ago · USGS 01581810 |
9 cfs | 1.06 ft | · | 79°F | 550 ft | Gunpowder-Patapsco |
|
Morgan Run Near Louisville, Md
17 hours ago · USGS 01586610 |
7 cfs | 1.31 ft | · | 79°F | 430 ft | Gunpowder-Patapsco |
|
Pocomoke River Near Willards, Md
17 hours ago · USGS 01485000 |
7 cfs | 4.63 ft | · | 82°F | 22 ft | Pocomoke |
|
Jones Falls At Sorrento, Md
17 hours ago · USGS 01589440 |
7 cfs | 7.78 ft | · | 82°F | 236 ft | Gunpowder-Patapsco |
|
Morgan Creek Near Kennedyville, Md
17 hours ago · USGS 01493500 |
7 cfs | 1.36 ft | · | 84°F | 4 ft | Chester-Sassafras |
|
Marsh Run At Grimes, Md
17 hours ago · USGS 01617800 |
7 cfs | 1.08 ft | · | 70°F | 405 ft | Conococheague-Opequon |
|
Chicamacomico River Near Salem, Md
17 hours ago · USGS 01490000 |
5 cfs | · | · | 84°F | 2 ft | Blackwater-Wicomico |
|
Beetree Run At Bentley Springs, Md
17 hours ago · USGS 01581960 |
5 cfs | · | · | 80°F | 491 ft | Gunpowder-Patapsco |
|
Bynum Run At Bel Air, Md
17 hours ago · USGS 01581500 |
4 cfs | · | · | 81°F | 260 ft | Gunpowder-Patapsco |
|
Georges Run Near Beckleysville, Md
17 hours ago · USGS 01581870 |
4 cfs | · | · | 80°F | 521 ft | Gunpowder-Patapsco |
|
Beaver Run Near Finksburg, Md
17 hours ago · USGS 01586210 |
3 cfs | · | · | 80°F | 431 ft | Gunpowder-Patapsco |
|
Piney Run At Dover, Md
17 hours ago · USGS 01583100 |
3 cfs | 1.37 ft | · | 80°F | 380 ft | Gunpowder-Patapsco |
|
Sawmill Creek At Glen Burnie, Md
17 hours ago · USGS 01589500 |
3 cfs | 1.87 ft | · | 83°F | 34 ft | Gunpowder-Patapsco |
|
Grave Run Near Beckleysville, Md
16 hours ago · USGS 01581830 |
3 cfs | · | · | 80°F | 560 ft | Gunpowder-Patapsco |
|
Long Green Creek At Glen Arm, Md
17 hours ago · USGS 01584050 |
2 cfs | · | · | 81°F | 290 ft | Gunpowder-Patapsco |
|
Sallie Harris Creek Near Carmichael, Md
17 hours ago · USGS 01492500 |
2 cfs | · | · | 83°F | 14 ft | Chester-Sassafras |
|
Gwynns Falls Near Delight, Md
16 hours ago · USGS 01589197 |
2 cfs | · | · | 80°F | 536 ft | Gunpowder-Patapsco |
|
Sideling Hill Creek Near Bellegrove, Md
17 hours ago · USGS 01610155 |
2 cfs | · | · | 69°F | 482 ft | Cacapon-Town |
|
Plumtree Run Near Bel Air, Md
17 hours ago · USGS 01581752 |
2 cfs | 1.12 ft | 73°F | 81°F | 187 ft | Gunpowder-Patapsco |
|
Manokin Branch Near Princess Anne, Md
17 hours ago · USGS 01486000 |
2 cfs | 1.58 ft | · | 84°F | 14 ft | Pocomoke |
|
Whitemarsh Run At White Marsh, Md
17 hours ago · USGS 01585100 |
2 cfs | 2.99 ft | · | 82°F | 42 ft | Gunpowder-Patapsco |
|
Dead Run At Franklintown, Md
17 hours ago · USGS 01589330 |
2 cfs | · | · | 81°F | 313 ft | Gunpowder-Patapsco |
|
Nw Branch Anacostia River Near Colesville, Md
17 hours ago · USGS 01650500 |
1 cfs | 1.29 ft | · | 82°F | 271 ft | Middle Potomac-Anacostia-Occoquan |
|
Birch Branch At Showell, Md
17 hours ago · USGS 0148471320 |
1 cfs | 3.13 ft | · | 83°F | 6 ft | Chincoteague |
|
Cranberry Branch Near Westminster, Md
17 hours ago · USGS 01585500 |
1 cfs | 1.30 ft | · | 80°F | 672 ft | Gunpowder-Patapsco |
|
Whitemarsh Run Near Fullerton, Md
16 hours ago · USGS 01585090 |
1 cfs | 1.08 ft | · | 82°F | 138 ft | Gunpowder-Patapsco |
|
Honeygo Run Near White Marsh, Md
16 hours ago · USGS 01585104 |
1 cfs | · | · | 82°F | 25 ft | Gunpowder-Patapsco |
|
East Branch Herbert Run At Arbutus, Md
17 hours ago · USGS 01589100 |
1 cfs | · | · | 82°F | 49 ft | Gunpowder-Patapsco |
|
West Branch Herring Run At Idlewylde, Md
17 hours ago · USGS 01585200 |
0 cfs | · | · | 81°F | 286 ft | Gunpowder-Patapsco |
|
Baisman Run At Broadmoor, Md
17 hours ago · USGS 01583580 |
0 cfs | 1.07 ft | · | 80°F | 333 ft | Gunpowder-Patapsco |
|
Minebank Run Near Glen Arm, Md
16 hours ago · USGS 0158397967 |
0 cfs | 4.04 ft | · | 81°F | 225 ft | Gunpowder-Patapsco |
|
South Fork Jabez Branch At Millersville, Md
16 hours ago · USGS 01589795 |
0 cfs | 3.21 ft | · | 82°F | 60 ft | Severn |
See every Maryland gauge ranked against normal.
- Percentile rank & % of median for all 92 gauges
- 15-day PULSE forecast on every gauge
- Custom flow alerts & full daily history
About Maryland streamflow
What are river levels like in Maryland right now?
As of September 5, 2026, Maryland rivers are running at 156% of normal across 92 USGS streamgauges, and the Susquehanna River At Conowingo is reporting the highest discharge at 11,900 cfs. The full sortable gauge table is below.
Which Maryland river is running highest right now?
As of September 5, 2026, the highest discharge in Maryland is 11,900 cfs on the Susquehanna River At Conowingo. See the sortable gauge table for the full statewide ranking.
Are Maryland rivers high or low right now?
Compare the statewide percent-of-normal on this page: above 100% means Maryland rivers are running higher than the seasonal average for the date, below 100% means lower (a dry spell or drought). Each gauge also shows its own percent of median.
Where does the Maryland streamflow data come from?
The U.S. Geological Survey National Water Information System. USGS streamgauges report continuously (every 15 minutes) and the data is the canonical real-time record for U.S. rivers. Snoflo pulls the latest readings and joins them to a 7-day NOAA weather forecast for each station.
What is cfs?
Cubic feet per second — the standard unit for streamflow. One cfs is about 7.5 gallons per second. Small creeks run at single-digit cfs; the Mississippi at hundreds of thousands.
What does Gauge Height mean?
The water level at the gauge in feet above the reference datum. Used together with discharge to track river state. Flood stage and runnable levels are typically expressed in gauge height (e.g., "flood at 16 ft").
How fresh is the Maryland data?
USGS streamgauges report every 15 minutes; Snoflo re-pulls throughout the day. The AI briefing regenerates daily.
Can I get a flow alert for a Maryland gauge?
Yes. Save any USGS gauge as a favorite in the Snoflo iOS app, set a discharge or stage threshold (e.g. "alert me when discharge crosses 2,000 cfs"), and you'll get a push the moment it crosses.
Is this a substitute for an NWS flood warning?
No. Snoflo is informational. For flood life-safety decisions always follow guidance from your local NWS forecast office and state emergency management. Snoflo data is one input among several.
Streamflow in every state
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