Monthly Archives: April 2009

Stormwater is not something that has suddenly appeared in the world. It has been in existence since the first drop of water fell from the sky (an act of God, if you will). Originally associated with rainfall, it now, includes a myriad of human activities including, but not limited to: excessive watering of lawns and gardens, washing cars, paved roadways, concrete platforms, discharges from various types of plants, sewage, etc., etc., ad nauseum.

In the form of rainfall, where the surface upon which the rain falls is also in a natural state (dirt, stone, grass, woodlands, etc.) nature does some truly remarkable things to make good use of the rainfall while minimizing negative impacts. Humankind, however, does not seem to have the same type of understanding that nature does.

In recent decades, the philosophy seems to be build, build, and build more. Most often, this ‘building’ has occurred in such a manner as to be in direct defiance of all of those measures used by nature to effectively utilize stormwater. Where nature would have plants growing that were consistent with the rainfall patterns of a specific geographic area, human kind has planted vast ‘farms’ of asphalt. Where the leaves of trees would have helped slow and direct the flow of water, making sure that plenty of that water was available to nourish the roots of the tree, there are now houses stacked side by side. Of course, each of those houses usually wants to have a paved roadway to access it and a paved parking area, and for good measure, maybe a garage.

The grass, plants, shrubs, trees, and even rocks that nature used to make the flow of water a productive contributor to the environment have been supplanted by vast acres of impervious surface. All of the natural ways of handling stormwater are dwindling away into non-existence. Or, are they?

There is a new trend in land development called Low Impact Development (LID). The United States Environmental Protection Agency has a nice website where you can obtain more information on this idea. What seems to be the key component to this Low Impact Development is that it works in new developments and can be integrated into existing developments. It provides opportunities for the property owner and the developer to both play active parts in helping to minimize stormwater problems such as flooding, damage to homes, pollution, waterway degradation, loss of habitat for fish and wildlife..

Of course, there are a lot of things already being done to handle stormwater, very costly things. What nature managed to do for centuries for free, humankind has developed into a process that has become a ‘black hole’ for taxpayer money.

A recent study provided by the EPA, Reducing Stormwater Costs through Low Impact Development (LID) Strategies and Practices is available on the Internet. This document shows that the benefits of Low Impact Development are not restricted to simply the cost of handling stormwater.

While this study focuses on the cost reductions and cost savings that are achievable through the use of LID practices, it is also the case that communities can experience many amenities and associated economic benefits that go beyond cost savings. These include enhanced property values, improved habitat, aesthetic amenities, and improved quality of life. This study does not monetize and consider these values in performing the cost calculations, but these economic benefits are real and significant. For that reason, EPA has included a discussion of these economic benefits in this document and provided references for interested readers to learn more about them. (p.iii, Forward)

As noted on page 1, para.2 of this report: “Extensive development in the United States is a relatively recent phenomenon. for the past two decades, the rate of land development across the country has been twice the rate of population growth”. It is this very fact that makes it mandatory that RESPONSIBLE development must be required by local governments. Low Impact Development is one such approach to responsible development yet, it has many features that the average homeowner/renter can incorporate into existing landscapes to further reduce the negative impact on our natural resources.

The techniques discusses affect various areas of stormwater management (p.3-5)

1. Conservation designs

2. Infiltration practices

3. Runoff storage practices

4. Runoff conveyance practices

5. Filtration practices, and

6. Low impact landscaping

Each of these contain applications that mimic those stormwater management techniques used by nature for centuries. This is a significant change from the more recent historical approach to stormwater management that approaches it from an engineering perspective.. This approach has often created situations in which a solution generated different types of problems later in the process.

Some of the benefits of Low Impact Development (p.6) include:

1. Environmental Benefits

   1. Pollution abatement

   2. Protection of downstream water resources

   3. Ground water recharge

   4. Water quality improvements/reduced treatment costs

   5. Reduced incidence of CSO’s (sewage related)

   6. Habitat improvements

2. Land Value and Quality of Life Benefits

   1. Reduced downstream flooding and property damage

   2. Real estate value/property tax revenue

   3. Aesthetic value

   4. Public spaces/quality of life/public participation

3. Compliance Incentives

   1. Regulatory compliance credits

4. Cost Considerations

   1. Use of natural drainage rather than infrastructure (reduced infrastructure costs)

   2. Reduction in impervious surface (reduced construction cost)

   3. Incorporated into landscaping could yield room for additional housing units.

   4. Natural management methods require less maintenance

Of particular note is Table 2 (p.12) where the study evaluated 17 different projects and compared as to Conventional Development Cost and Low Impact Development Cost. In all but one of those, there was a significant savings. Only Kensington Estates reported that the LID cost was higher than the conventional development cost.. In part this was due to the choice of a semipervious material for paved areas.. Furthermore their design brought imprevious area from 30% down to 7%!!!

This study shows some of the potential benefits to Low Impact Development, and, at the least, warrants some attention by our local elected officials and planning departments. There is a lot more information readily available on the Internet and from other government resources that would provide local jurisdictions in Virginia more than enough information to begin incorporating some of these criteria into zoning and subdivision ordinances.

There is no need to do things the way they have been done for the last 30 years simply because it is the easy way out. After all, would you go to a doctor or dentist that still practiced based on how things were done 30 years ago?