Prior to the construction of Chatfield Reservoir in the 1960s and 1970s, Plum Creek merged with the South Platte River in far northern Douglas County.

Now, however, it empties into the southern side of the reservoir itself, just west of Santa Fe Drive and within the boundaries of Chatfield State Park.

This higher reservoir level will cause the mouth of the creek to move about 7,000 feet further upstream.

Over 14 inches of rain fell in under four hours in a concentrated part of the Plum Creek watershed on 16 June.

Peak flows along Plum Creek and its two major tributaries, East and West Plum Creek" exceeded the "estimated 1965 flood peaks with the 100-year (1% annual chance) and 500-year (0.2% annual chance) published flow" by two to four times the 500-year predicted flood rate.