Low Impact Development
Low-impact development (LID) is an alternative approach to site planning, design and building that minimizes impacts to the landscape and preserves the natural hydrologic cycle. LID is accomplished as a two-step process: 1. better site planning and 2. incorporation of best management practices (BMPs). This approach results in reduced impervious surfaces, smaller lawns and more natural landscaping. Therefore it is commonly less costly to construct, lower maintenance and more attractive, adding to real estate values.
Thoughtful site planning begins with an approach that identifies critical site features such as wetlands, poor soils, or drinking water protection areas that should be set aside as protected open space. Natural features, such as vegetated buffers and view sheds, will also play an integral role in any LID planning exercise. After the critical open space areas are identified and set aside, sustainable development areas are then identified as "building envelopes."
Within the delineated building envelopes, a broad range of design techniques or best management practices (BMPs), such as shared driveways, permeable pavers, and bioretention are used to reduce the level of impervious cover and improve the quantity and quality of stormwater drainage. Other LID design techniques include green roofs, rain barrels, rain gardens, grassed swales, stormwater infiltration systems, and alternative landscaping. Through these techniques, natural drainage pathways are conserved, open space is preserved, and the overall impact from development is significantly reduced.
This fall Horsley Witten Group conducted 3 LID workshops. This hands-on, practical short course covered land planning principles, design criteria, permitting strategies and used real case studies.
Below is a selection of workshop slideshows.