Storm Water Management

With the ever increasing amount of pavement in our watershed, it has become increasingly important to reduce the quantity and speed at which rain and snowmelt enters our rivers. 

Nature's Run-off Management

When it rains, water may 1) be intercepted by plants, 2) infiltrate into the soil, 3) evaporate, or 4) run-off.  Under natural conditions, approximately 15% is intercepted, 25% infiltrates, 40% evaporates, and 10% becomes run-off.

Impervious Surfaces

Roads, parking lots, roof tops, etc. are all impervious surfaces.  As the percent of impervious surfaces increases, the percent of rain intercepted, infiltrated, and evaporated decreases.  Run-off increases dramatically.  In the average urban area, 55% becomes run-off.  

Not only does the amount of run-off increase, but the speed at which the water flows into the streams also increases.  This creates a "peak discharge" immediately after a storm event (as depicted by the green line in the hydrograph to the left).  These peaks are

responsible for extensive erosion along rivers and streams, as well as increases in the occurrence and magnitude of floods.  Impervious surfaces also increase the amount of sediment and pollutants carried by run-off and limit groundwater recharge.

What Can I Do?

As a landowner, you can reduce the impacts of impervious surfaces.

1)  Direct your roof drains into your yard or landscaping rather then onto the driveway.  This allows rain to percolate into the soil, as well as water your garden!

2)  Take advantage of natural low areas on your property by planting a rain garden.  A rain garden requires a pervious substrate (such as small stones or sand) and plants.  Use native, water-tolerant plants and allow mother-nature to do your storm water control for you!

3)  If you have a drainage way or stream on your property, plant trees along it.  Trees are amazingly efficient at absorbing water and releasing it back into the atmosphere (they also help prevent stream bank erosion).

Contact your County Soil and Water Conservation District to learn more!