The York River drainage basin is rural, with an economy based on farming, logging, fishing and recreation. Water quality conditions are generally good, with low chlorophyll and nutrients and low fecal coliform counts. Dissolved oxygen concentrations are high except for periodic deoxygenation of the water deeper than 8 m in the reach extending 10 km upstream of the mouth.
A quasi-three dimensional tidal average model was constructed and calibrated using intensive field data collected in June and July, 1976 and verified using slack water run data from September, 1976. The model components are: salinity, fecal coliform, chlorophyll, CBOD, dissolved oxygen, organic nitrogen, ammonia, nitrate plus nitrite, organic phosphorus and inorganic. phosphorus.
Model runs revealed that the deep-water deoxygenation is a natural condition little influenced by human activity and that the York is insensitive to point source loadings, owing to its enormous volume
