April 25th, 2010
Water is the most precious resource on the planet. Water rationing and efficiency has been an important part of life since ancient civilizations. Even Romans used rain barrels, rationed, and charted their daily water use thousands of years ago. So why is it that we, as Americans, view water so differently? Cost. No where in the world is water as cheap as it is in the United States, and not surprisingly that leads us to be the largest consumer of water in the world. A significant part of green building, that is rarely associated with the term, is storm water runoff. Americans view storm water as waste, whereas the rest of the world views it as an opportunity to acquire a resource.
The way we currently deal with storm water runoff has many problems, for both our infrastructure and nature. Our current ways need to change, which can have a positive impact on the environment and your wallet. On the residential side, a 1″ rainfall on a home with a 3000 sq. ft. roof, 5000 sq. ft. lawn, and 2000 sq. ft driveway produces 3800 gallons of storm water runoff. Now think about all the other homes on your street doing the same thing. Do you know where that water goes? The average consumer has no idea where their water comes from or where the waste flows. Often both raw sewage and storm water end up at the same facility, which overtaxes the infrastructure. In the Chicagoland area there are over a million residences. Now add in the urban scenario: In a dense urban area, like Chicago, a 1″ rain event generates 17.4 billion gallons of storm water. That is enough to fill the Sears Tower (or the newly named Willis Tower) 43 times. Every other country in the world would love to have the ability to harvest that type of water.
So where does all this water go?
All of this water is fed through local streams, tributaries, and rivers until it hits the Mississippi River, where it eventually dumps into the Gulf of Mexico. What that water does along the way is just as devastating as what it does when it gets there. The speed at which storm water moves down streams and rivers strips the soil and native vegetation from the banks of the waterway. This ruins these waterways. Not only is the soil lost where it is needed by the vegetation, but also the sediment is carried into streams, polluting the water. These sediment eventually finds its way to the Gulf of Mexico which is causing even bigger problems there. It wreaks havoc on the wildlife and fishing industry in that area. It also costs millions of dollars to continuously pump out this sediment. 80% of oceanic pollution is from garbage that enters the ocean through storm water.
Back to the local area. One of the most biologically diverse ecosystems in the world is the first few feet up from the natural waterline of rivers. Aquatic species and other organisms that make this their habitat are dying off at rates more than 5 times that of land species, mostly due to storm water. Storm water changes the water level in rivers so much that a natural sustained water line is a thing of the past. It completely changes the entire watershed. Over the past few years, we have been experiencing an historic amount of floods, with no more rainfall than in the past. It is the mass entry of storm water into the system that is causing these floods, and it will only get worse until we change our ways.
Another problem is the replenishing of our aquifers naturally. Rainwater is supposed to hit the ground, percolate the soil, filter the water, and end up in underground aquifers. When we are redirecting billions and billions of water to the ocean from the Midwest, we are creating a huge problem. A prime example if the Ogallala Aquifer. This is the worlds largest aquifer, and stretched from South Dakota to Texas. Our countries expansion can be largely credited to this body of water, and is still currently heavily relied upon for many Americans. However, even the worlds largest aquifer stands no chance against our way of dealing with storm water. The water that is needed to naturally refill the body of water is redirected elsewhere. Only 20 years ago, this water could be tapped from 80′ below the surface. Now the water is 120′ below the surface, and decreasing at an increasing rate. Not only does this cost people more money to deepen their wells for their water supply, but poses an even bigger problem for an increasing population. The population is expected to double in the next 30 years, and an extreme water shortage is estimated by 2030.
What can we do to help?
The average American uses 160 gallons of water per day per person. Of this, 80 gallons per day per person are used for landscaping and irrigation. There are several options to reduce the amount of water that you let leave your property:
1. Install a rain barrel to capture rain water from your gutters. This captured water can be used to water your lawn, irrigate your garden, and water your indoor plants.
2. Install pervious surfaces to replace your driveways, patios, and walkways. Pervious surface solutions are previous concrete, brick pavers, natural stone, gravel, pervious blacktop, or gravel grass. This will allow the rain water to percolate into the soil, filter, and return to the aquifer.
3. Install a cistern to capture rain water. The water can be used to irrigate your lawn, or in some areas be used as the water for your toilet or laundry.
4. Install a rain garden. Rain gardens are excavated depressions that are vegetated with native plants. These plants help to capture the rain water with their extensive root systems, instead of letting the water runoff the site. Another great feature is that rain gardens, when planted with native (prairie) plants, help sequester carbon dioxide from the air. Dense prairie grasses can actually sequester just as much carbon dioxide as trees.
5. Install a green (living) roofing system. A green roof will help to retain some of the water in the roots and soil of the roof, instead of letting it all run down the gutters and off the site. Another benefit of a green roof is that it will help insulate your home better, lowering your energy costs. A green roof will also prolong the life of your roof because it is protecting the membrane from harmful UV radiation, which is a primary factor in roof degradation.
6. Install a bioswale. A bioswale is similar to a rain garden in that native species are planted in it to help filter the water. A bioswale is usually in an area that has a slope to it where water would typically runoff. A bioswale help decrease the velocity of that water, and the plants help to retain some of the water and allow it to percolate into the soil, thus refilling the aquifers.
All of these steps would greatly help reduce the storm water runoff issue. A home that installs a simple rain garden and rain barrel could decrease their runoff from 3800 gallons to only 430 gallons per 1″ rain event. That’s reducing the burden on storm sewers by 90%. A rain barrel can be purchased for $50.
How will taking some of these steps save you money?
1. You will be using rain as a resource instead of an engineering problem. Instead of sending that water away only to repurchase it for your irrigation needs, you will keep it on site for your free use.
2. It will help to lower the impact fees villages and cities pass on. The engineering nightmare of storm water runoff will be reduced, which is one of the biggest obstacles municipalities face and spend money engineering.
3. It will reduce the amount of water that will go through the sewage plants, thus decreasing the tax dollars needed to run those facilities.
4. It will save on the tax dollars used to dredge out river mouths and tributaries to allow ships and boats to navigate these waterways.
5. It will save money on having to constantly dig deeper wells for our drinking water.
6. It will decrease the number of floods, thus saving billions of dollars on disaster relief.
There are also many more benefits than just monetary ones. You will be helping to save habitats in biologically diverse and sensitive areas. You will decrease the amount of oceanic pollution (even from the Midwest!). You will help ensure that aquifers can replenish themselves the way nature intended, allowing future generations to have access to drinking water. It will decrease the amount of flooding. It will decrease the amount of fertile soil that is washed away. It will decrease the amount of chemicals and toxins that are washed into rivers and oceans from agriculture and industrial areas.
The benefits of simple steps you can take at home to decrease storm water runoff, has an exponential amount of good it can to for the planet and your wallet.