What Is LID?
Low Impact Development, or LID, is a new, comprehensive approach to managing stormwater. By using innovative site planning and design strategies and treatment practices, LID protects water quality and habitat from development impacts more effectively than traditional stormwater management techniques. Specifically, LID seeks to:
- avoid impacts by preserving and protecting as much of the natural site condition as possible,
- reduce impacts by minimizing the amount of impervious cover (paved surfaces) in order to lessen the amount of runoff being generated, and
- manage impacts by treating stormwater runoff as closely as possible to the point where runoff reaches the ground, rather than conveying and managing stormwater in large, costly drainage systems.
Types Of LID
LID site planning and design will typically utilize multiple, cost-effective treatment practices located throughout a development project or property to effectively manage stormwater, including:
- Site design-utilizes a variety of techniques, including conservation development, vegetated buffers,
- permeable pavement, and other innovative strategies to decrease impervious cover and maximize efficiency.
- Rain gardens and bioretention areas- shallow depressions that collect and filter stormwater through layers of mulch, soil and plants. Small rain gardens can be integrated onto residential lots, while larger bioretention systems are suitable for cul de sacs, roadsides or parking lot drainage.
- Bioswale- typically a long, narrow channel planted with grasses or other native vegetation that may convey stormwater to another LID practice or capture and treat stormwater directly.
- Cisterns and rain barrels- water collection techniques to capture runoff from rooftops and other paved surfaces for various non-potable water uses, such as lawn watering or fire control.
- Green roof- roof either partially or completely covered in vegetation to absorb and capture rainwater, reducing the amount of water available to runoff.
- Infiltration trenches and dry wells-a trench or chamber filled with crushed stone to capture and temporarily store stormwater before allowing it to infiltrate into the soil.
- Permeable pavement- method of paving that allows stormwater to seep into the ground through openings within the paving material.
LID In Rhode Island
LID is the new industry standard! Under the revised Rhode Island Department of Environmental Management (RIDEM) and Rhode Island Coastal Resources Management Council (CRMC) stormwater regulations enacted in 2011, LID techniques are thoroughly incorporated into the Rhode Island Stormwater Design and Installation Standards. Any new development or redevelopment projects are expected to utilize LID techniques to manage stormwater. Residential projects on single-family lots should refer to the guidance document Rhode Island Stormwater Management Guidance for Individual Single-Family Residential Lot Development for assistance in meeting LID requirements on any new rooftop 600 square feet or greater and for all new driveways and parking areas. For more information about managing stormwater at new development projects, visit the Rhode Island Department of Environmental Management Stormwater Program.
- Browse the LID Inventory to see examples of LID throughout Rhode Island.
- Introduce real estate developers to LID with a Low Impact Solutions for RI Land Developers factsheet.
- Introduce local businesses to LID with a LID Alternatives for RI Businesses factsheet.