Washington
The nation's capital, at the head of the tidal Potomac.
- Population
- 689,545 (2020 census)
- Founded
- July 16, 1790
- Rivers
- Potomac and Anacostia
- Tides
- Two highs, two lows a day
Then
- Before 1600s
The Nacotchtank keep settlements along the Anacostia.
- 1749–1751
The river ports of Alexandria (1749) and Georgetown (1751) are founded. Both are later included in the new federal district.
- 1790
The Residence Act, signed July 16, creates the capital on the Potomac.
- 1814
On August 24, after the Battle of Bladensburg, British troops burn the federal buildings. A storm drives them out a day later.
- 1846
Congress returns Alexandria and the land south of the river to Virginia.
Now
Washington sits on the northeast bank of the Potomac, where Little Falls marks the fall line and the end of the tide. The Navy Yard lines the Anacostia, and the Tidal Basin sits beside the National Mall.
High tides combined with storm surge and runoff regularly flood Georgetown's waterfront. Alexandria, Bladensburg and Kenilworth Aquatic Gardens share this stretch of river.
On the water
From NOAA's predictions for WASHINGTON, Washington Channel, D.C., DC over the next 365 days. Heights are in feet above mean lower low water (MLLW).
- Pattern
- Two highs and two lows a day, close in size
- Typical daily range
- 2.8 ft
- Biggest swing
- 3.6 ft on Sep 30
- Smallest swing
- 2.0 ft on Oct 20
- Highest high
- 3.7 ft, Sep 30 at 8:59 PM
- Lowest low
- −0.7 ft, Jan 24 at 4:16 PM
9 tide stations around Washington
- WASHINGTON, Washington Channel, D.C.1.7 mi
- Washington Naval Yard2.8 mi
- Kingman Lake3.7 mi
- Kenilworth Aquatic Garden4.5 mi
- Bellevue, D.C.4.8 mi
- Bladensburg, Md.5.9 mi
- Alexandria, Va.6.2 mi
- Marshall Hall, Md.14.8 mi
- Indian Head, Md.21.8 mi