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T


he sophistication of land devel- opment is a far cry from the primitive methods of the past. In green building, terms some-


times get muddied. For example, in this ar- ticle we’ll discuss both sustainable develop- ment and Low Impact Development. First let’s clarify the defi nition of LID. LID focuses specifi cally on how water


enters, is stored on-site and leaves a site. LID practices, which continue to evolve, apply several methods to reduce resource waste, runoff and potential pollution. These include minimizing impervious surface, protecting and enhancing native vegeta- tion and soils, and managing stormwater at its source—not treating it as someone else’s problem. Low Impact Development has benefi ts


for every party involved, including the si- lent parties (wildlife). The more we learn about wetlands, the more critical we fi nd their role in the entire ecosystem to be. Protecting and even restoring them with LID helps to preserve wildlife habitat, and decrease stormwater runoff and erosion that can cripple or destroy aquatic systems. Using less water, energy and natural re- sources—and avoiding toxic chemicals— prevents pollution, reduces waste and decreases the strain that we place on the environment As the table on p. 50 shows, develop-


ment that incorporates LID minimizes im- pervious surfaces, protects and enhances native vegetation and soils, and manages stormwater at its source. These practices have evolved in the past two decades, to include carefully siting buildings, minimiz- ing impervious surfaces and infi ltrating runoff . And that evolution didn’t happen by accident.


Mistakes of the Past Low Impact Development requires smarter decisions during planning, design, permit- ting and construction, and these sometimes involve upfront investments. If they’re not already doing so, it’s likely that municipal and county planning offi cials in your re- gion will require the use of LID or environ- mental site design (ESD), in part because of mistakes of the past. In the late 1980s and booming 1990s, especially, poor handling of


storm runoff caused ever more damage to wetlands, channels and natural assets such as rivers. On a national scale, runoff -related events such as the oxygen-deprived “dead zone” in the Gulf of Mexico have given lo- calized stormwater control more urgency. Previously, developers would control


stormwater by building a pond or a deten- tion type system as a sort of “purgatory” to hold the estimated diff erence between pre- development runoff and post-development runoff . Then the developer (or whoever ended up in charge after construction was done), would release that stormwater over a longer period of time, to match the pre- development peak rate. This may sound rational, but that’s not


how nature works. In the natural environ- ment, there would be a momentary peak rate in the stream channel, not a sustained one. So, by releasing the retaining pond wa-


LOW IMPACT DEVELOPMENT ADVANTAGES


At every level, the use of LID stormwater strategies has several positive outcomes.


Developers > Reduces land clearing and grading costs > Reduces infrastructure costs (streets, curbs, gutters, sidewalk) > Reduces stormwater management costs > Increases lot yields and reduces impact fees > Increases lot and community marketability


Municipalities > Protects regional flora and fauna > Balances growth needs with environmental protection > Reduces municipal infrastructure and utility maintenance costs (streets, curbs, gutters, sidewalks, storm sewers) > Fosters public/private partnerships


Homebuyers > Protects site and regional water quality by reducing sediment, nutrient and toxic loads to waterbodies


> Preserves and protects amenities that can translate into more salable homes and communities


> Provides shading for homes and properly orients homes to help decrease monthly utility bills


Environment > Preserves integrity of ecological and biological systems > Protects site and regional water quality by reducing sediment, nutrient, and toxic loads to waterbodies


> Reduces impacts to local terrestrial and aquatic plants and animals


> Preserves trees and natural vegetation Source: “The Practice of Low Impact Development,” PATH


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