Streamflows into the Chesapeake Bay surged at near-record levels for the third straight month in March, according to the U.S. Geological Survey.
In March, freshwater streamflow into the Bay averaged about 144 billion gallons per day, almost 1.5 times higher than the average flow for the month, according to the USGS. Streamflow in both January and February averaged more than twice the normal amount.
The USGS attributed the high streamflows to unusually warm temperatures and frequent, heavy rainfall. Water that would usually be on the ground in the form of snow - which typically melts more gradually - is running directly off the land and into rivers and streams.
As it runs off, the water carries sediment and nutrients collected along the way. As a result, the high flows experienced so far this year are expected to result in unusually large amounts of nutrients and sediment being delivered into the Chesapeake Bay.
Increased nutrients can trigger algae blooms which, along with sediment in the water, block sunlight from reaching important underwater grasses that provide important food and habitat for waterfowl, crabs, juvenile fish and other species. Also, when the algae die, they sink to the bottom and decompose in a process that depletes the water of oxygen critical for many aquatic species.
Flows this year have been particularly heavy in the Potomac. In March, flows near Washington, D.C. averaged about 31 billion gallons per day, twice the average for the month. Streamflow in the Potomac in January and February was three to four times the average for those months.
Ground water levels in the Bay watershed have also been above average for the third straight month, the USGS reported.