The 1987 Corps of Engineers Wetlands Delineation Manual indicates that an area meets the wetland hydrology criterion if the area is inundated or saturated to the surface for at least 5% of the growing season in most years. The State of Michigan Technical Manual for Identifiying Wetlands provides a similar, but broader interpretation of wetland hydrology by indicating that an area exhibiting wetland hydrology, under normal circumstances, will be permanently or periodically saturated (at or near the surface) during the growing season. 

The following websites provide information on lake and stream hydrology that may be useful in making wetland delineations.

 USGS: Water

 Great Lakes Hydrology Outlooks

 Current Hydrologic Conditions