Thursday, October 2, 2008

Low Impact Development

Low Impact Development (LID) is all about protecting rivers and lakes. The whole idea is to encourage the natural cycle of water - so rainwater soaks into the ground to be filtered by the soil and used by the plants rather than running over the ground as it runs down hill to the river and lake. As storm water runs across the ground, it also picks up debris, silt, chemicals and other pollutants and carries them directly to lakes and rivers. Silt and sediment are some of the biggest polluters because they choke streams, fish and aquatic life. Encouraging the natural cycle keeps silt and also pollution out of the water and promotes a healthy water environment for fish and humans. In our own area, fish have disappeared from a mile long stretch of Mill Creek in Izard County because the stream bank was cleared without erosion control measures and silt clogged the creek bed.

Another benefit is that not all the rainfall reaches the river in a short period of time. This means that the river doesn’t rise as much or so fast which means there is less bank erosion. It also means the groundwater reaches the river slowly so there is more “recharge”. The river is replenished by ground water even when there is no rainfall because it takes a while for the water to move through the soil and rock.

Development refers to anything people do that impacts the environment. Any time land is paved or a building built, less water can get into the ground. That means more run off. According to the Environmental Protection Agency (EPA), a typical city block generates five times more run off than a wooded area of the same size because there are so many hard surfaces that block water from soaking into the ground.

“What I do doesn’t make much difference”

Well, yes it does. There are many small ways we all contribute to environmental degradation, but there are many easy things we can do to encourage the natural water cycle that all together make a big difference. Rain barrels catch rain water from roofs that can be used later to water landscaping. Rain gardens are landscaped areas that are slightly depressed so rain water pools so it can be used by the plants or soak into the ground. If properly done, the water soaks is gone before mosquitoes can breed.

Improving landscaping can make a big difference. Trees and shrubs catch and absorb more rain water than grass. Grass absorbs more than bare dirt or rock. Another thing we can do is find ways to slow water down as it travels across the ground. Taking some of the energy out of the flow will decrease the amount of dirt carried away – and in our rocky area, we need all the soil we can get. Don’t over water and use pesticides and herbicides sparingly. Dispose of litter, household and yard waste, and hazardous materials properly.

Another LID strategy is to make sure our septic tanks are inspected and pumped regularly to ensure it is functioning properly. Just because the toilet flushes doesn’t mean that the sewerage is being properly treated. The state of Missouri estimates that 70% of the state’s septic tanks don’t function properly. That’s scary. The Bull Shoals area and northern Arkansas has the same kind of rocky “karst” ground as much of Missouri. In many places, traditional septic tanks can’t work. However, new septic tank technology that works much better is available.

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