MODULE-6 Smart Growth Opportunities

Introduction
Transfer of Development Rights (TDR)
Brownfields Redevelopment
Overlay Protection Areas
Low-Impact Development (LID)
Open Space Residential Design (OSRD)

Conventional development principles do not consider the short and long-term hydrological impacts of unplanned sprawling growth. These impacts often include the construction of large impervious areas, loss of natural communities and recharge areas, loss of community centers, and pollution of our drinking water supply. As Washington's population continues to grow, communities need to plan development in a way that protects and conserves our drinking water resources to achieve a more sustainable growth pattern.

Example of a green road design.

Low Impact Development (LID) is a comprehensive approach to site planning and design. It applies a variety of landscaping and design techniques to achieve an environmentally sustainable development that works with the landscape's natural hydrology to manage stormwater runoff. LID techniques capture water on site, filter it through vegetation, and let it infiltrate into the ground where it can recharge the local water table rather than being lost as surface runoff. LID's guiding principle is the idea of stormwater as a resource rather than a waste product to be disposed of. Properly planned LID projects can match pre- and post-development hydrology, maintaining natural groundwater recharge rates and peak stormwater runoff rates.

Alternative landscape design.

Implementing LID

LID is implemented through a site planning process that first identifies critical natural resources, and then determines appropriate building envelopes. LID also incorporates a range of best management practices (BMPs) to maintain and work with the natural hydrology of the land. BMPs include the use of "green roads", shared driveways, alternative landscaping, stormwater planters, use of permeable pavers, rain gardens, and bioretention to reduce the level of impervious surfaces and improve the quantity and quality of stormwater drainage. These features capture, treat, re-use, and recharge stormwater at numerous locations throughout the development and, in many cases, significantly reduce or eliminate the need for large, unsightly drainage structures such as detention basins.

Raingardens.

Stormwater planters.

Other LID design techniques include green roofs, rain barrels, bioretention cells, rain gardens, grassed swales, stormwater infiltration systems, and ecological landscaping. By applying all or some of these techniques, natural drainage is maintained and enhanced, water demands are reduced, open space is preserved, and the overall impact from development is significantly reduced.

Rain barrels and cisterns.

Low-Impact Development (LID) Case Study

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