Storm events generate precipitation in many forms – rain, sleet, snow or hail. As rain reaches the ground surface, or other forms of precipitation melts, the water can either infiltrate into the ground or becomes stormwater runoff. The stormwater runoff is the water that does not soak into the ground due to impervious surfaces. An impervious surface is any area within a parcel which prevents or significantly impedes the infiltration of stormwater into the soil, such as; Parking lots, Roofs, Driveways, Patios, Sidewalks, Swimming Pools, Gravel and stone areas.

As pervious areas (natural soil) become "paved", increased amounts of stormwater runoff are generated, placing an increased demand on the stormwater drainage system.

Each and every precipitation event generates stormwater runoff. The amount of stormwater runoff generated from a storm or from melting snow and ice depends on many factors, including the quantity of rainfall, the duration of the storm, and the condition of the ground.

The condition of the ground impacts how much precipitation can infiltrate.  This is an important factor because any water that can’t infiltrate into the ground will become stormwater runoff.  Ground condition is dependent on several factors:

• Surface material – Some materials, such as grass, allow water to infiltrate, while others, such as asphalt pavement, do not.
• Land slope – Water travels more quickly over ground with a steeper slope, allowing less time to infiltrate.  The longer water is able to pond in an area, the more time it will have to infiltrate into the ground.
• Underlying soil – Some soils, such as sand or gravel, have more space to hold water and are therefore better for infiltration than others, such as clay.
• Moisture – Soils have a finite space in which to hold water.  As water infiltrates the ground, it becomes saturated and no additional water is able to infiltrate.
• Temperature – Water cannot infiltrate into frozen ground as well as it can into non-frozen ground.

Stormwater runoff either flows directly into surface waterways or is channeled into storm sewer conveyance system compromised of storm sewer pipes, swales, ditch, and detention basins; which, eventually discharge into local bodies of water.

The stormwater drainage system within the Village of Bensenville is divided into three different watersheds. Village of Bensenville Watershed Map

• Willow Creek North & South- drains approximately 1,050 acres in the northerly areas of town
• Silver Creek (commonly known as Bensenville Ditch)- drains approximately 700 acres in the central areas of town
• Addison Creek (Tributaries 1-4)- drains approximately 1,250 acres in the southerly areas of town

Willow Creek North and South as well as Silver Creek are tributary to Des Plaines River whereas, Addison Creek is tributary to Salt Creek. The Village’s storm sewer conveyance system drains to these creeks.

Frequently Asked Questions (FAQs)

Why does stormwater have to be managed?
Without proper stormwater management, rain events may result in flooding on roads and properties throughout the Village, leading to property damage and dangerous road conditions. Stormwater run-off must be channeled through a system of pipes, ditches, catch basins and storm drains before being safely discharged into local streams and rivers. Even if a specific property has never flooded, the stormwater that flows from the property still contributes to the overall flow and must be managed so that it does not cause flooding downstream on property or roads.

Why should I care about stormwater?
Any property is likely to generate run-off in a severe rain storm, even if the ground is able to absorb water in a normal rain event.  Everyone in the community benefits from adequate, properly functioning drainage and flood control systems, which decrease the likelihood of flooding, erosion, and the amount of pollutants discharged in surface and stormwater run-off.  

How is stormwater regulated?
The Village stormwater system is regulated by local, county, state and federal entities. The Village is required to manage the stormwater system at a level that ensures compliance with the federal Clean Water Act and in accordance with DuPage County Stormwater and Floodplain Ordinance.

What is the Village doing to address stormwater?
In addition to routine maintenance operations such as street sweeping, inspecting and cleaning stormwater inlets as well as the repair and replacement of storm sewer, the Village has constructed several capital projects in recent years to improve the stormwater conveyance in certain areas of town. The Village is actively seeking to improve the overall stormwater drainage system.

How can I manage stormwater runoff at home?

Use a Rain Barrel

A rain barrel is a water tank used to collect and store rainwater at the end of your downspout, which you can then use to water plants, wash your car and reduce your water bill. They are a simple, efficient, low-cost method for homeowners to collect and recycle water. The Conservation Foundation offers rain barrels for sale, as well as local retailers. 

Install a Rain Garden

A rain garden can soak up to 30% more water than a typical patch of grass before it lets the water slowly infiltrate into the ground. Please see the Rain Garden Manual: How to Guide for Homeowners for more information.