The Oneida Reservation is drained by four major streams. Duck Creek and its tributaries (Oneida Creek, Fish Creek, Silver Creek, and Trout Creek) drain nearly 70 percent of the Reservation. Dutchman Creek drains 20 percent, and Lancaster Brook, with the headwaters of Ashwaubenon Creek and the South Branch of the Suamico River drain the rest of the land (USGS Report 00-4179).
At this time, the main sources of impairment are sedimentation (agricultural and residential construction) and nutrients (agriculture, suburban lawns, golf courses). Loss of hydrologic function from tiling and ditching has resulted in reduced flows in Reservation streams.
Several programs within the EH&S Division work in partnership to ensure the integrity of the surface waters of the Reservation by managing the quantity and quality of storm water runoff; defining, restoring, and enhancing the functions of the watershed/sub-watershed system of the Reservation, including wetlands; and, restoring and protecting aquatic habitats in the waters of the Reservation.