Patapsco River near Elkridge below Patapsco Valley State Park
Highest listed crest 21.38 ftFlood stage 16.0 ft14 crests since 2011
The Patapsco River near Elkridge below Patapsco Valley State Park crested above flood stage 14 times among the 14 crests the National Weather Service lists from 2011 to 2025. The highest, 21.38 ft on August 4, 2018, was minor flooding, 5.38 feet above flood stage. 2 other gauges on the Patapsco River crested above flood stage within a week of it.
The gauge
- Highest listed crest
- 21.38 ft
- August 4, 2018
- Flood stage
- 16.0 ft
- No major stage set
- Crests at major
- 0
- 14 above flood stage
- Most recent flood crest
- July 13, 2025
- 18.85 ft, minor flooding
Flood stages
The thresholds the National Weather Service uses for this gauge today, and how many listed crests reached each.
| Action stage | 15.0 | 0 | — |
| Flood stage (minor) | 16.0 | 14 | Jul 13, 2025 |
Every listed crest
14 crests from 2011 to 2025. Filled: at or above flood stage. Hover a crest for its date and stage.
Crests at or above flood stage, by decade
- These are the crests the local National Weather Service office lists for the gauge: the highest on record and recent crests. Lesser floods between them may be missing, so counts by decade are a floor.
- Categories use today's flood stages. Levees, dams and channel changes since a crest can make old and new stages not directly comparable.
Highest crests
| 1 | Aug 4, 2018 | 21.38 | +5.38 | Minor |
| 2 | Sep 28, 2018 | 20.29 | +4.29 | Minor |
| 3 | Jul 26, 2018 | 19.69 | +3.69 | Minor |
| 4 | Sep 10, 2018 | 19.64 | +3.64 | Minor |
| 5 | Nov 25, 2018 | 19.35 | +3.35 | Minor |
| 6 | Nov 1, 2019 | 18.90 | +2.90 | Minor |
| 7 | Jul 13, 2025 | 18.85 | +2.85 | Minor |
| 8 | Sep 18, 2018 | 18.72 | +2.72 | Minor |
| 9 | Mar 10, 2011 | 17.95 | +1.95 | Minor |
| 10 | Apr 13, 2020 | 17.56 | +1.56 | Minor |
| 11 | Jul 22, 2018 | 17.43 | +1.43 | Minor |
| 12 | Jun 9, 2022 | 16.52 | +0.52 | Minor |
| 13 | Aug 22, 2018 | 16.23 | +0.23 | Minor |
| 14 | May 7, 2022 | 16.00 | 0.00 | Minor |
The worst floods along the Patapsco River
For this gauge's highest crests, the other gauges on the Patapsco River that crested above flood stage within a week.
August 4, 2018: 21.38 ft here, minor flooding
- CatonsvilleMD · Aug 4, 2018 · 22.17 ft · Minor
- Elkridge at Patapsco Valley State ParkMD · Aug 4, 2018 · 17.24 ft · Minor
July 26, 2018: 19.69 ft here, minor flooding
- CatonsvilleMD · Jul 24, 2018 · 21.20 ft · Minor
- Elkridge at Patapsco Valley State ParkMD · Jul 24, 2018 · 16.31 ft · Minor
September 10, 2018: 19.64 ft here, minor flooding
- CatonsvilleMD · Sep 10, 2018 · 20.39 ft · Minor
- Elkridge at Patapsco Valley State ParkMD · Sep 10, 2018 · 15.22 ft · Minor
Gauges on the Patapsco River
Flood gauges sharing the river's name, linked within 80 miles of one another.
| Ellicott City | MD | 124.78 ft, May 27, 2018 | 0 |
| Hollofield | MD | 31.30 ft, Jun 22, 1972 | 1 |
| Catonsville | MD | 27.15 ft, May 27, 2018 | 0 |
| Elkridge at Patapsco Valley State Park | MD | 24.76 ft, May 27, 2018 | 4 |
| Elkridge below Patapsco Valley State Park this gauge | MD | 21.38 ft, Aug 4, 2018 | 0 |
Other gauges in Howard County
| Rogers Avenue at Ellicott City | 261.06 ft, May 27, 2018 | 1 |
| Allview | 284.53 ft, May 28, 2018 | 1 |
| Lake Kittamaqundi | 303.76 ft, May 28, 2018 | 0 |
| Guilford | 18.38 ft, Jun 22, 1972 | 0 |
| Savage | 25.40 ft, Jun 22, 1972 | 1 |
| Elkridge at Patapsco Valley State Park | 24.76 ft, May 27, 2018 | 4 |
| Duckett Dam near Laurel | 25.00 ft, Jun 22, 1972 | 0 |
Howard County: every hazard · River floods across the country · Maryland
NOAA National Water Prediction Service, gauge ELKM2, retrieved October 30, 2026. Stages in feet on the gauge's own datum, not elevation. Crests are as the National Weather Service lists them; preliminary values may be revised.