Water levels in Rock Creek and the Potomac River hit historic highs yesterday.
It rained yesterday. A lot. But how much, exactly?
According to a U.S. Geological Survey water monitoring station at Little Falls on the Potomac River, the volume of water moving past the station jumped to 87,500 cubic feet per second yesterday evening — a level not seen in 50 years.
If that doesn't mean much to you, consider this: The median flow is 11,000 cubic feet, and the max flow recorded came in 1964, when 86,200 cubic feet flowed per second. As high as yesterday's flow seems, though, it's nothing compared to the 484,000 cubic feet that flowed per second during storms in 1936 and 1889.
The same monitoring station also reported that the gage height — the height of the water in the river at that point — doubled during the day, climbing from four to eight feet.
Much the same could be seen in Rock Creek at Joyce Road, where gage height jumped from two to over nine feet. Discharge was also at historic levels: 1,810 cubic feet of water flowed at the storm's peak, far above the median of 41 cubic feet.