Aerial photograph of Milton, Delaware, showing the area of Savanna bay

The Bays and Basins of Delaware. Overlay map of ground water temperature in Savanna bay. Explanation, Observation well, with temperature of water measured in degrees Fahrenheit Air temperature, 70 to 72 degrees in shade. Contour interval one degree.; From Rasmussen, W., Geology and Hydrology of the Bays and Basins of Delaware, 1958 , Plate 6F.