Low Impact Development is an approach to environmentally friendly land use planning. 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 where it can recharge the local water table rather than being lost as surface runoff. An important LID principle includes the idea that stormwater is not merely a waste product to be disposed of, but rather that rainwater is a resource. 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 throughtout a subdivision cumulatively improve rainfall and run off management.

More info: http://www.lid-stormwater.net/intro/background.htm

How do LID costs compare to traditional storm water engineering techniques?

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.

More info: http://www.lid-stormwater.net/intro/sitemap.htm

Can LID be done in cold climates such as Massachusetts?

Actually LID is already being done in Littleton, Plymouth, and Walden Pond State Reservation in Concord.

Will LID techniques work in the winter?

Even when the vegetation is dormant, the chemicals in the soil and the bacteria in the ground filter the water. During the coldest months there is snow and not a lot of storm water, however when properly amended and planted the ground can still provide some infiltration during brief periods of freeze/thaw. The physical depressions and slopes designed with LID techniques still encourage retention and ultimately infiltration of water during the winter.

Are curbs necessary for snow plowing?

While it is true that care must be taken when plowing roads with no curbs, there is a maintenance cost associated with curbs and plows when curbs are used as a guide for snow plowing.

Are standard road widths and sidewalks necessary for public safety?

Alternative road designs which are crowned for runoff, curved for reducing speeds and narrower to reduce impervious area are already being used safely in Massachusetts. Sidewalks do not have to be located on both sides of the road and can be designed of gravel or porous pavers as opposed to asphalt or concrete.

More info: http://nemo.uconn.edu/publications/tech_papers/tech_paper_9.pdf

Will landscape features such as rain gardens increase mosquitoes?

Rain gardens and other LID landscape techniques actually encourage infiltration of stormwater. If designed properly, bioretention areas drain completely in ½ hour.

Will roof gardens put too much weight on buildings and cause the roof to collapse?

Green roofs vary in the amount of water they store. Most designs use vegetation for filtering water which is then stored or directed off the roof. Desing standards are available and the increased loads must be factored into the building construction in accordance with State Building Code.

More info:
http://www.greenroofs.com/resources.htm
http://peck.ca/grhcc/
http://www.lid-stormwater.net/greenroofs/greenroofs_specs.htm

Can porous pavements be sanded and plowed?

Porous pavements cannot be sanded but many can be plowed when installed correctly.

What type of plants should I use in my rain garden?

Plants should be chosen based on conditions such as amount of light and the amount and quality of the water the garden is designed to filter. Native plants do best as they thrive on Massachusetts' climate conditions. See the sample plant layouts in the Rain Gardens brochure (PDF).

More info on native plants: http://www.massnativeplants.org