Storm Water management

April Showers

 

Those April showers feed the flowers that bloom in May. They also flood basements, lawn areas, and perennial beds in properties with poorly conceived storm water runoff plans.

I was out for a walk this sunny Easter morning admiring the bulbs blossoming, shrubs and trees beginning to sprout, and lawns greening up. Repeatedly, I saw properties with ill conceived run off from their homes that were clearly causing less than ideal conditions for the lawn areas and other recipients of natures plenty.

The basic laws of water are very fundamental. Much like the behavior of my children when it’s time to do homework, water seeks its own (or the lowest) level. Unfortunately, this is often our basements which is the first thing we need to protect. Many folks do this by redirecting downspouts away from their homes. Though a good idea in principle, in practice, this often means the water pools in the middle of the lawn, creating a soggy area less than ideal for a healthy lawn. If this happens often enough, as the water table rises, water ends up penetrating basement walls anyway.

The laws of water management are simple: 1) store it and redistribute. 2) Direct to a river, stream, pond, or sewer. Of course option 2) is really a glorified version of option 1). When you redirect it, it moves on to a larger storage area (other than your basement). Many homes in hilly areas were originally built with drywells, or underground storage areas where water from the homes roof accumulated and seeped slowly back into the ground. These were large, and expensive and worked well until after 30-50 years of use they filled up with silt. The idea of the dry well is to store the water under gorund so that you have a nice dry lawn (and basement).

The more creative and less expensive approach today is to direct the water from your house to the street, or create a drybed above ground that may become a wet bed when it fills up, plant a greenroof, and/or lastly to plant a raingarden. Most municipalities really don’t like the street option since it means that their sewer systems get overworked and silted up. Check with your village, but Im pretty sure this is not so legal.

The drybed approach is very popular in Colorado for example. Under the eves of many homes are drainage beds filled with stone that take the water to streams, or to dedicated ponding areas that are filled with water or dry depending on the season. Water is directed to these areas and either assimilated into the streams or  slowly absorbed by the landscape (away from the basement). This is a pretty effective tool. When the beds are dry, the stones give the feeling of a river and pond, in heavy thaws or rain, they actually are.

Greenroofs are a thin layer of plants covering the roof. They absorb 80% of the water that landsc on the roof and double the life of the roof membrane. Yes, you can do this on a slanted roof by the way. If yo want to see one in action, there is a greenroof demonstration roof at the Greenburgh Nature Center our company built last year.

Raingardens are combinations of using plans that love water and drywells. Usually planted in the lowest area of the property, the idea is to dig out a water holding area, filled with gravel or even a small dry well, layer soil over this area, and plant above it with plants that love water and thrive on moisture. This way you get a place to put the water and a natural system of absorbing it and releasing it into the atmosphere. We will build a demonstration rain garden at the Greenburgh Nature Center next month.

Rain GaRain Gardenrden

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