What is LID?
Low Impact Development (LID) is an approach to environmentally friendly land use development. It includes a suite of landscaping and design techniques that attempt to maintain the natural, pre-developed ability of a site to manage rainfall. LID techniques capture water on site, filter it through vegetation, and let it soak into the ground.
The LID approach is different from conventional development which often clears trees along with valuable topsoil from a site and re-grades it so that all water ends up in a large detention basin. Resulting problems include loss of recharge, increased water temperature, decreased water quality, and higher run-off volumes.
LID can save money over conventional approaches through reduced infrastructure and site preparation work including reductions in clearing, grading, pipes, ponds, inlets, curbs, and paving. In addition, long term maintenance costs involve landscaping which is less expensive than infrastructure repair.
- LID Module: Massachusetts Smart Growth / Smart Energy Toolkit
- Frequently asked questions about LID (LID Urban Design Tools website)
Where should LID be used?
LID can be applied to new development, urban retrofits, and redevelopment / revitalization projects at many scales. At a small scale, LID techniques can be used to better handle rainfall for a single family lot through rain barrels and rain gardens. At a larger scale, proper site design in combination with many landscaping and infiltration techniques distributed throughout a subdivision cumulatively improve rainfall and stormwater run-off management. Even in the coldest months, LID techniques still encourage retention and, ultimately, infiltration.
- Case Studies: Plymouth, Lincoln, Cambridge, Acton, and Boston (Smart Growth / Smart Energy Toolkit)
- Case Studies: Tyngsborough, Boston, Cohasset, and Franklin (Coastal Smart Growth - MA Coastal Zone Management)
- Ipswich River Watershed: EPA Targeted Watershed Grant (Department of Conservation and Recreation)
The LID Approach
- Planning: preserve the site's natural features such as wetlands, native vegetation, flood plains, woodlands and soils to the greatest extent possible;
- Landscaping: plant native vegetation in buffer strips and in rain gardens (small planted depressions that can trap and filter runoff);
- Prevention: use vegetated areas to slow down runoff; maximizing infiltration and reducing contact with paved surfaces;
- Innovating: reduce impervious surfaces wherever possible through alternative street design, such as omission of curbs and use of narrower streets, and through use of shared parking areas.
LID Techniques including Green Roofs and Green Buildings
- Green Buildings Overview (Massachusetts Technology Collaborative)
- Matrix of LID Techniques : This table includes specifics and general descriptions of many techniques for implementing LID in a variety of environments.
- The Greenroofs Directory (Greenroofs.com, the green roof industry resource portal)
- Greenroof Specifications (LID Urban Design Tools website)
LID Information and Resources
Low Impact Development (LID) Working Group - a network of practitioners, policy-makers, and local officials that share resources, information, and experience with LID issues. For more information, contact Eric Hove.
Other resources include the following:
- LID Links (MA Smart Growth / Smart Energy Toolkit)
- LID Toolkit (Metropolitan Area Planning Council)
- Low Impact Development (U.S. EPA)
- Low Impact Development (Low Impact Development Center, Inc.)
- "The Practice of Low Impact Development", (July 2003, U.S. HUD)
- Roads raingarden.pdf file size 1MB , (Technical Paper #9 - Nonpoint Education for Municipal Officials NEMO)
- "Builder's Guide to Low Impact Development" brochure, published by the National Association of Home Builders (NAHB) Research Center, provides a good summary of LID including the why's and costs for developers and builders.
- "Rain Gardens in Connecticut, A Design Guide for Homeowners" raingarden.pdf file size 1MB (University of Connecticut)
- raingarden.pdf file size 1MB , a brochure published by GeoSyntec Consultants, gives a good overview of LID and sample plans for sunny or shady raingardens homeowners could construct.
This information is provided by the Executive Office of Energy and Environmental Affairs, Office of Water Policy.