Efficient Ways to Deal with Storm Water Runoff
For those of you who are not familiar with the term, storm water runoff is the amount of rain water that cannot be absorbed into the ground. Besides industrial pollution, it is one of the greatest pollutants of drinking water resources. It runs off the streets, yards and other surfaces into the sewers or directly into the waterways, carrying pollutants and sediments that reduce the water quality and damage aquatic ecosystems.
Storm water runoff is particularly present in urban areas, where flat, paved, and concrete surfaces prevent natural drainage into the ground. Moreover, as less water is naturally filtered through the soil and restored to the aquifers, those areas often have a constant problem with water supply. Although it is a global problem, everyone can take several easy steps to reduce storm water runoff on their property.
Reducing Impervious Surfaces
Urban environment is characterized by abundance of impervious surfaces, which unlike soil and vegetation cannot absorb storm water. By minimizing the impervious surfaces and “opening up” more free soil, you can reduce the amount of runoff. For example, you can replace concrete or asphalt slabs with pavers or bricks that allow water to seep in between the spaces. Modify your driveway so that you only leave two strips for your car tires.
Using Gravel Strips for Borders
Your driveways, patios and sidewalks should have a gravel lining. Dig a shallow trench on both sides of an impervious strip and fill it with gravel. This small modification will slow the storm water and allow more of it to be soaked into the ground. If gravel doesn’t resonate with your garden décor, or you don’t want to plant any bordering vegetation, you can use mulch or wood chips instead. When it dries and hardens, bare soil can be almost impervious as concrete.
Valuable Roof Water
It is calculated that a 1,000 square foot roof produces over 600 gallons of runoff for every inch of rain that falls on it. Disconnect your downspouts from the storm drain and direct them into a rain barrel where you can collect the runoff water. In a recent chat with reputed Sydney-based plumbing professionals, I learned that this modification can significantly reduce the water bill, as less of tap water is used for outdoor purposes.
Native Species Instead of Lawns
With their thick structure, lawns are not among the best absorbing surfaces, especially during heavy downpours. That aside, they require a lot of irrigation, that can possibly cause even more runoff. On the other hand, native plants like shrubs and wildflowers develop extensive root systems that help with water absorption and retention. In addition, they need much less maintenance than a lawn.
A fully developed tree has apowerful root system that absorbs water over a large area. Also, the canopy slows the downpour so that larger amounts of water can be soaked into the ground. Native trees are the best, as well as those which can take a lot of water. If you are building a new home construction or extending the existing one, take care to leave the trees in place, or plant a few new ones for each one you remove.
Designing a Rain Garden
Rain gardens are often planted at the base of slopes, in slight depressions and even at the downspout outlets. The idea is to direct the runoff towards the garden where it will be retained until it gradually percolates into the soil. To improve the ground permeability, enrich the soil with compost and top it with a layer of mulch. Water-loving plants like canna or Siberian iris will help the garden to absorb large amounts of water in a matter of hours.
If left untended, water runoff can pose a threat not only to general water quality but also your basements and house foundation. Luckily, these measures are easy to apply and require minimal investment.