Is Rain a Friend Or Foe?
April showers bring May flowers is an old adage used to explain or justify a wet and rainy spring. Spring rains are thought to be slow steady drizzles lasting all day. Since the rain is falling slowly, the ground and your flower beds can absorb the water. As the water is absorbed, the soils or plants provide a method of treatment for many of the chemicals picked up during the storm. However, during thunderstorms more rain falls than can be absorbed into the ground and runoff occurs.
What is RUNOFF and how is it caused?
Runoff occurs when there is more water than the land, plants, or ground cover can absorb. This excess water flows across the surface of the land and into nearby creeks, streams, ponds or low points on roads or yards.
Surface runoff may be caused by the imperviousness of the land, or because the underlying ground is already saturated.
Why is RUNOFF bad for people and their environment?
Runoff erodes streams, kills fish, pollutes swimming beaches, floods homes, and causes many other problems. In addition, runoff collects an often-toxic mix of pollutants both solid and dissolved including Trash, Excess Fertilizer, Waste Oil, Other Pesticides, Soil, and other Sediments which causes the pollution of surface waters. The pollution of surface waters is a violation of the CLEAN WATER ACT.
Uncontrolled runoff also has a cumulative impact on people and the environment including Flooding – which causes damage to public and private property, and sometimes the death of people and/or livestock and wildlife. Eroded Streambanks – which causes sediment to clog waterways or pipe systems, fills lakes and reservoirs reducing their storage capacity during future storms, kills fish and aquatic animals. Widened stream channels –which leads to a loss or the destruction of valuable property.
How can you reduce the negative impacts of RUNOFF?
Since Runoff can’t be eliminated, we can discuss two Green Infrastructure stormwater engineering methods to control and/or reduce runoff impacts.
Rain Gardens and Bioretention swales
A rain garden or bioretention swale is a low area in the landscape that runoff is directed to from yards, roofs, driveways, or streets. The runoff is contained within the low area until the ground can absorb it. Planted with grasses and flowering perennials, rain gardens can be a cost effective and beautiful way to reduce runoff from your property. Rain gardens assist in filtering out pollutants in runoff. The more complex areas with drainage systems and amended soils are often referred to as bioretention swales.
Permeable Pavement
The typical road, parking lot, or home patio will encourage 100% of any rain that falls on it to flow off. The rainfall then becomes runoff. Permeable types of pavements are designed to permit infiltration of precipitation through the surface, thereby reducing stormwater runoff from a site and providing pollution reduction as it passes through the underlaying soils.
The top layer of a permeable pavement, made of a special type of asphalt or concrete, is typically placed on an open graded bedding course. The openings between the stones in the bedding course provide storage for the infiltrated water until it is absorbed into the underlying soil.
So, is rain a friend or a foe? Like most things, rain can be a friend and a foe depending on the circumstances.
HERE TO HELP
To learn more about LKB or to speak with an Environmental Engineering Expert, call 516.938.0600, or submit an inquiry here.
Want to Learn More?
Below are projects where Green Infrastructure stormwater engineering practices were used by LKB.
