Floods at Great Falls

Floods at Great Falls (HM2CLJ)

Location: McLean, VA 22102 Fairfax County
Buy Virginia State flags at Flagstore.com!
Country: United States of America
Buy United States of America flags at Flagstore.com!

N 38° 59.682', W 77° 15.204'

  • 0 likes
  • 0 check ins
  • 0 favorites
  • 408 views
Inscription

Great Falls Park

—National Park Service, U.S. Department of the Interior —

The high-water marks seem hard to believe, but powerful Potomac River waters sometimes cover this area. How can that happen? High water occurs at least once a year when all the rocks in the falls are covered. Floods occur about every 10 years after extremely heavy rainfall or a series of storms upstream in the Potomac River watershed. When the deluge reaches Mather Gorge, where the riverbed narrows from nearly 1,000 feet into a rocky, mile-long funnel 60 to 100 feet wide, the waters have no place to rise but upward. As high waters recede, they deposit organic matter, minerals, and seeds that help make this one of the nation's most biologically diverse areas.

Major Floods
1936 March 18-19
Highest Recorded flood after rapid melting of snow and ice and torrential rains


1937 April 26-27
Heavy rainfall


1942 October 15-17
After 10-19 inches of rain in parts of watershed


1972 June 24
Hurricane Agnes


1985 November 4-7
Tropical Storm Juan


1996 January 19-22
Blizzard followed by warming temperatures and rain


1996 September 6-8
Tropical Storm Fran floodwaters came up to the pole's base, unmarked.


(captions - clockwise from top)
The Potomac splits into two sections at Olmsted Island. Great Falls also can be viewed via a trail and bridge at the Chesapeake and Ohio Canal National Historical Park in Maryland.

Viewed



from upstream, the river flows into Great Falls toward Mather Gorge.

In 1966 a severe drought exposed the jagged rocks of the Great Falls of the Potomac.

Occasionally the Potomac River rises above its banks and floods park facilities as this 1996 photo shows.

This January 1996 flood crested in 48 hours, then receded over the next 24 hours. High wet marks on the post are splashes. The red tape shows the highest water level.
Details
HM NumberHM2CLJ
Tags
Placed ByNational Park Service, U.S. Department of the Interior
Marker ConditionNo reports yet
Date Added Monday, October 22nd, 2018 at 11:01pm PDT -07:00
Pictures
Sorry, but we don't have a picture of this historical marker yet. If you have a picture, please share it with us. It's simple to do. 1) Become a member. 2) Adopt this historical marker listing. 3) Upload the picture.
Locationbig map
UTM (WGS84 Datum)18S E 304849 N 4318603
Decimal Degrees38.99470000, -77.25340000
Degrees and Decimal MinutesN 38° 59.682', W 77° 15.204'
Degrees, Minutes and Seconds38° 59' 40.92" N, 77° 15' 12.24" W
Driving DirectionsGoogle Maps
Area Code(s)540, 703, 571, 202
Which side of the road?Marker is on the right when traveling North
Closest Postal AddressAt or near Old Carriage Rd, McLean VA 22102, US
Alternative Maps Google Maps, MapQuest, Bing Maps, Yahoo Maps, MSR Maps, OpenCycleMap, MyTopo Maps, OpenStreetMap

Is this marker missing? Are the coordinates wrong? Do you have additional information that you would like to share with us? If so, check in.

Nearby Markersshow on map
Check Ins  check in   |    all

Have you seen this marker? If so, check in and tell us about it.

Comments 0 comments

Maintenance Issues
  1. Is this marker part of a series?
  2. What historical period does the marker represent?
  3. What historical place does the marker represent?
  4. What type of marker is it?
  5. What class is the marker?
  6. What style is the marker?
  7. Does the marker have a number?
  8. What year was the marker erected?
  9. This marker needs at least one picture.
  10. Can this marker be seen from the road?
  11. Is the marker in the median?