The Des Plaines River -- Part One
Nature Bulletin No. 606 May 28, 1960
Forest Preserve District of Cook County
Daniel Ryan, President
Roberts Mann, Conservation Editor
David H. Thompson, Senior Naturalist
THE DES PLAINES RIVER -- PART ONE: DESCRIPTION
Chicago was incorporated as a village in 1833 and in less than 100
years it had become one of the world's great cities. Four unique natural
features have contributed to its phenomenal growth.
The first is Lake Michigan. Chicago is strategically located at the
south end of it, deep in the heart of the continent and the vast central
lowland -- bread-basket of our nation. The lake provides an
inexhaustible supply of fresh water and a highway for water-borne
commerce. Since the completion of the St. Lawrence Seaway, Chicago
has also become a port for ocean going ships.
The second is the broad, remarkably flat Chicago plain that,
originally, was the bed of Lake Chicago -- glacial ancestor of Lake
Michigan. When its swamps and wet prairies were properly drained
this plain became ideal for industrial, commercial and residential
The third is a low continental divide between the St. Lawrence and
Mississippi drainage systems. Northeast of Summit it is only 15 feet
above the level of Lake Michigan. Drainage of the Chicago Plain, and
an outlet other than Lake Michigan for the city's sewage, and a deep
waterway to the Illinois River, were all accomplished by constructing a
canal through that divide and utilizing another natural feature: the Des
The Des Plaines is a placid prairie stream that, from swampy sources
in Kenosha and Racine counties, Wisconsin, meanders southward
through a flat valley roughly parallel to the shore of Lake Michigan.
Its most important tributaries are Salt Creek and the Du Page River.
River Grove the Des Plaines flows southward -- except for two
hairpin bends at Riverside -- across the Chicago Plain until, near
Summit, it turns southwest into a deep valley. Mighty torrents from
Lake Chicago poured through that valley, and the Sag valley which
joins it at Sag Bridge, when the last glacier melted away. That is the
Chicago Outlet, one of five great "keys to the continent": the best
natural pass to the Mississippi valley.
U. S. 66 to Romeo the river flows in a diversion channel
constructed with a levee to keep it from overflowing into the Sanitary
and Ship Canal completed in 1900. From Romeo it flows south and
drops 80 feet until, near Joliet, it joins the canal. At Brandon Road
lock and dam, south of Joliet, the canal ends and the Des Plaines,
widened and deepened as part of the Illinois Deep Waterway,
continues southwest until it joins with the Kankakee to form the
Just below U. S. 66 the Des Plaines originally angled southeast. Near
Harlem Ave. south of Santa Fe railroad, instead of flowing eastward to
Lake Michigan it turned southwest into the Chicago Outlet valley.
That area has been designated a national historic site commemorating
The Chicago Portage.
East of Harlem Ave. there was a swamp called Mud Lake. That was
the Chicago Portage, a route followed by the Illinois and Michigan
Canal completed in 1848, by the Ogden-Wentworth Ditch draining
Mud Lake, and by two railroads. Occasionally, during floods, the Des
Plaines would pour eastward across the low continental divide,
through Mud Lake and the South Branch of the Chicago River, into
One of those floods in August, 1885, swept so much sewage out into
the lake that the city's water supply was terribly polluted and a great
many deaths resulted. Shortly after, the Sanitary District of Chicago
was established and, in 1892, construction began on the Sanitary and
Ship Canal from the South Branch, near Damen Avenue, to Lockport -
- 28 miles, much of it through solid rock.
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Update: June 2012