Low Impact Development
Prairie solar is one form of Low Impact Development, i.e. “green infrastructure.” Low Impact Development (LID) uses natural landscape features to manage storm water as close to the source as possible. LID strategies beneficially manage stormwater while delivering savings.
Low impact development manages stormwater runoff with practices that mimic natural processes of the water cycle that allow for infiltration to the ground and evapotranspiration to the air. The result is improved water quality and reduced flooding. Other approaches include rain gardens, green rooftops, rain barrels and permeable pavements.
Natural Processes, Revisited
In most natural environments when there is a large amount of rain, vegetation and soil will absorb much of the water. The plants and soil filter the water, and what once was stormwater eventually ends up as groundwater.
Large impervious surfaces, however, disrupt the natural water cycle. Stormwater runs across surfaces and collects and increases runoff flows. The stormwater can carry pollutants such as oil, bacteria, sediments, metals, hydrocarbons and nutrients into waterways. The sudden discharge contributes to flooding downstream.
Low impact development prevents this by using natural processes to return the water to the water cycle, making it an asset, instead of a detriment.
Advantages of Low Impact Development
Low impact development has several advantages in addition to preventing water pollution. LID can reduce flooding, reduce soil erosion and replenish groundwater. When deployed on a large scale, LID can also help mitigate urban heat island effect and climate change, save energy, reduce air pollution and increase property values.
Low impact development is also cheaper to install and maintain than traditional storm water management techniques. One EPA study found that compared to traditional storm water management techniques, LID had cost savings that ranged from 15 to 80 percent.
Low impact development can save money by reducing the amount of land that needs to be paved, reducing demand for pond dredging and reducing material costs for building and installing pipes. Land not used for water basins can be productive, e.g. by hosting solar panels.
Low impact development can also substantially increase property values nearby due to reduced flooding risk and increased aesthetic value. Additionally, LID can increase property values downstream by reducing the risk of flooding for the community downstream.
More on :
- EPA: Low Impact Development
- State of Massachusetts: LID case studies
- American Society for Landscape Architects: Designing sustainable landscapes
- Susdrain: Information and guidance around planning, designing, and maintaining sustainable drainage systems
- Department of Housing and Urban Development: Publication on the practice of LID
- Construction EcoServices: Why LID?