The sandstone-pavement pine barrens of northeastern New York are open-canopy woodlands on shallow soils over nearly horizontally bedded sandstone bedrock. Altona Flat Rock is the largest of the sandstone pavements and comprises approximately 30% of the upper Little Chazy River watershed. The thin soils require that the pine barrens communities maintain a delicate balance with existing hydrogeological and climatological conditions. Runoff from the sandstone pavement plays an important role in the hydrology of the Little Chazy River and in the vitality of the pine barrens ecosystem.

Storm runoff was monitored at a thin-plate V-notch weir at the outflow of a small (0.28 hectares), low-relief (4 meters) watershed on Altona Flat Rock in the summer of 2001. Soil moisture and meteorological data were also collected from lysimeters and weather stations within 1 kilometer of the watershed. The depth of the thin organic soil in the study watershed ranges from 0 to approximately 0.2 meters with the thickest soils associated with shallow, moss-covered depressions along the base of low-relief (<2 meters) bedding plane risers. Hydrographs from for three isolated runoff events between 16 June and 14 July indicate that most overland flow dissipated within 30 to 40 hours from the end of rainfall. Measurable amounts of stormflow, however, continued for more than 4 days after the storm event. The persistent stormflow runoff is attributed to saturated throughflow in the thin organic soil and subsurface flow through shallow fractures in the Potsdam Sandstone. This study was funded by the National Science Foundation Research Experiences for Undergraduates Program.