Know Your Watersheds

What IS a Watershed?

A watershed is a land area that channels rainfall, snowmelt and springs (groundwater) to creeks, streams and rivers, which eventually connect with larger rivers, bays or the oceans.  Despite this simple definition, a watershed is actually a complex interaction between ground, water, vegetation, climate, people and animals.  Other elements such as nutrient rich agricultural, suburban and urban stormwater runoff, impervious surfaces, man-altered stormwater flows, and erosion are all detrimental to the health of watersheds.  

In our area, there is the Flint Creek Watershed, which winds all around the Barringtons, Lake Zurich, Hawthorne Woods, and Fox River Grove, eventually leading to the Fox River.  The Spring Creek Watershed includes parts of Hoffman Estates, East Dundee, Carpentersville, South Barrington, Barrington Hills and Fox River Grove, as it too, empties into the Fox River.

In the “big” picture, ours are two subwatersheds that are part of the Fox River Watershed.  The Fox empties into the Illinois River, which ultimately feeds the Mississippi River.

Illinois Map Showing Our Watersheds
Map of Flint Creek Watershed
Map of Spring Creek Watershed

Before the time of European settlements, the two watersheds were balanced ecosystems with a diversity of plants, wildlife and fish.  This was a mosaic of prairie, oak savanna, and wetlands, maintained by fires ignited both by lightning and the Native Americans in the area.  Herds of  bison and elk also helped maintain the landscape by their grazing.  Most of the water that fell as rain or snow was absorbed in the upland prairie and savannas or within the extensive wetlands that existed along the stream corridors.  Some percentage of the rain and snow in the western parts of the Spring Creek Watershed quickly – within hours, days or weeks – trickled down to the network of shallow aquifers that now provide our drinking water.  The western area is a “rapid recharge” area for our aquifers (more on this in the groundwater section).  Any additional waters slowly seeped into Spring Creek or Flint Creek.

Ecological conditions changed drastically and quickly following European settlement in the mid 1800’s.  Settlers removed most of the prairie and savanna and drain tiles were installed to drain the wetland areas for farming.  Buffalo and elk were hunted to extinction.  As the 1900’s dawned, residential and commercial development followed.

As people alter the landscape and it becomes more urbanized, streams suffer the side effects.  Urbanization creates hard, or impervious, surfaces such as roads, rooftops, sidewalks and parking lots, causing greater stormwater runoff.  Stormwater drains empty into area creeks.  As runoff velocity and volume increase, streambanks erode, water becomes cloudy with suspended soil particles, and sensitive habitats degrade.  Soon come invasive species, degraded in-stream habitat, phosphorus and nitrogen runoff from improper land management, and more sediment deposition.  These effects generally result in poor water quality.  That happened in Flint Creek. 

Example of extreme bank erosion.

This picture was taken along Flint Creek, and shows a severely degraded stream bank. Erosion sediments flow into the creek and are carried by the waters - adding to the cloudiness and the TSS - total suspended solids - that are a major concern in the Flint Creek Watershed.

Nowadays, as water shortages loom in the not-too-distant future for many areas, experts are beginning to look at alternative ways to work with nature – and restore some of the ecosystem services – clean air, clean water, healthy lands and life – that worked so well in the past.  For example, some engineers and planners are asking how we can keep waters out of stormwater pipes, so it can infiltrate back into the soils and the aquifers, rather than wash away to distant oceans.  This approach is called Green Infrastructure.

Although watersheds can cross municipal, county, township, and so forth,  boundaries, they provide a logical organizational context in which people can work together to effectively plan and manage land use and other activities that impact water resources.  Watershed planning helps address water quality problems in a comprehensive manner, rather than piecemeal.  

Watershed planning aims to help citizens address water quality prolems by assessing the  contributing causes and sources of pollution, and prioritizing restoration and protection strategies.  Many federal grant guidelines now require a watershed plan to quality for grants.   Both Flint Creek and Spring Creek have active Watershed Plans.  These are covered on their website pages.