Water column profiles were conducted using a Seabird Electronics profiler at seven locations in the Providence River and one location in the Seekonk River on September 9, 2026. In the five days leading up to this, there were 0.06 inches of rain recorded at T.F. Green International Airport (Warwick, RI). The water column was weakly stratified at Phillipsdale Landing and well-mixed at all other profiling locations: Bullock reach, Conimicut Point, Edgewood Yacht Club, Pawtuxet Cove, Pomham Rocks, Point Street Bridge and India Point Park.
Dissolved oxygen conditions below the hypoxia threshold (2.9 mg/L) were observed in the lower part of the water column at Pawtuxet Cove, Pomham Rocks and Point Street Bridge. The entire water column at India Point Park and Phillipsdale Landing had dissolved oxygen concentrations below the hypoxia threshold. The highest fluorescence reading was observed 1.25 meters below the surface at Phillipsdale Landing.