|by Joel Greenberg
Hickory Creek was born in the time of the last
glacier, which disappeared about 13,800 years
ago. Small lakes formed on plains nestled
between glacial ice and moraines, the ridges of
crushed earth deposited by the sheets of ice.
(Harlan Bretz described these water-bodies as
"huge mud puddles, unattractive to anyone but a
geologist.") One such lake was known as Lake
Tinley, which had an outlet flowing west towards
the Des Plaines River valley. That channel
became Hickory Creek, the source of whose
headwaters is the lowland that replaced the lake
when the ice melted.
Hickory Creek runs for 27 miles from its origins
in southwest Cook County to its confluence with
the Des Plaines River at Joliet. Twenty-five
tributaries enter the main stem, of which Spring
Creek, Marley Creek, and Union Ditch are the
largest. The total area drained by these streams
is about 107 square miles. This watershed was a
microcosm of the entire region. There was rich
prairie on the extensive plains, fecund marsh in
the low lands, barrens and savannas on rolling
moraines, and even stately forests in ravines
and west side of streams.
From their headwaters to mouth, streams are not
uniform but vary significantly in character.
Most of the upper portion of Hickory Creek is
flat, creating a low-gradient stream that gently
meanders towards its mouth. But then as it
approaches the steeper lower valley, the water
picks up speed. Water moving over a hard bottom
and fed by springs gains oxygen, attains greater
clarity, and creates a substrate of various size
rocks free of sediment. The more variation there
is in the creek, the greater the range of
organisms that can find suitable habitat. And,
in particular, these conditions are essential to
many of the more disturbance-sensitive animals
like darters and stoneflies.
Most of the streams of the Chicago region,
including the larger rivers, held little water
during the dry months of summer or early fall.
Hickory Creek, however, was different, as this
description from the 1830s attests: "Hickory
Creek was a well behaved stream which never
failed to furnish abundant water for cattle
farmers and the mills, some of which operated
year round. It was a well defined body of water
lasting the whole year. It was well stocked with
fish of the pickerel and pike species, with
bullhead and catfish."
Joel Greenberg 3926 N. Washington Westmont, IL