High winds over the weekend helped drop the water level of the Delaware River to the lowest point in almost 22 years, the National Weather Service said.
The big drop was recorded on Sunday. The National Weather Service released a graph showing that day's water level in comparison to the average.
"The river level fell to -3.4 feet mean lower low water (as shown by the red arrow on the graph). The last time the river level was that low at Philadelphia was on March 15, 1993," a spokesperson for the Weather Service wrote. "The red line on the graph indicates the actual water level, the blue line is what the water level should be based on the normal tidal fluctuations and the green line is the departure or difference between the two."
The spokesperson says the low water levels were caused by strong northwest winds that pushed ocean water away from the New Jersey and Delaware coasts, drawing water out of Delaware Bay and the tidal portion of the Delaware River.