Low Impact Development (LID) is touted as an innovative stormwater management approach with different principles, practices and processes for site design. LID techniques seek to control stormwater at the source. This is accomplished by using various strategies which aspire to create a hydrologically functional landscape that mimics a watershed's water budget for recharge, ground water storage, evapotranspiration and runoff volume/rate.
LID uses five basic management, planning and design principles:
- Conserve vital ecological/natural resources (trees streams, wetlands, drainage courses etc.).
- Minimize impacts at the site level to the extent practical by reducing imperviousness, conserving natural resources/ecosystems, maintaining natural drainage courses, reducing use of pipes and minimizing clearing and grading.
- Maintain predevelopment stormwater time of concentration by strategically routing flows to maintain travel time and control discharge.
- Provide runoff storage measures using small decentralized techniques dispersed throughout the landscape to detain, retain and filter runoff water.
- Implement public education and incentive programs to encourage property owners to use pollution prevention measures and maintain on lot landscape management practices.
LID, in principle, promotes the concept that a developed site can be designed to be a functional part of the watershed with comprehensive and appropriate use of LID practices and principles.
>> Low Impact Development Guidebook for North Carolina
Outer Banks Low Impact Development Feasibility Assessment
The UNC Coastal Studies Institute, in conjunction with the Outer Banks Hydrology Management Committee and the counties and towns of Dare and Currituck, have commisssioned the work for a coastal watershed and stormwater management assessment and feasbility study to effectively implement LID techniques on the Outer Banks of North Carolina. These groups also hosted a presentation of an assessment of the feasibility of implementing Low Impact Development (LID) methods as part of a regional integrated stormwater management program. Moffatt and Nichol, the engineering firm hired to perform the assessment, presented their findings at a public meeting at Jockey's Ridge State Park Auditorium in Nags head on June 22, 2006.
In 2005, the Outer Banks Hydrology Management Committee was convened to review issues related to flooding and stormwater problems facing Dare and Currituck counties. The committee identified problems linked to stormwater management in the outer banks including flooding, closing of shellfish beds, property damage and threatened water quality of the receiving waters. Based on stakeholder input, the committee outlined a number of action items to address stormwater and water quality issues on the Outer Banks.
A key recommendation of the committee was to remove barriers and develop incentives for the use of Low Impact Development (LID) on the Outer Banks. LID's goal is to mimic a site's prevelopment hydrology by using techniques that infiltrate filter, store, evaporate and detain runoff close to its source.
The study is a follow up to the efforts by the Outer Banks Hydrology Management Committee, conducted for UNC-CSI in partnership with Dare and Currituck counties. The LID study area encompasses all of the Outer Banks portions of Dare and Currituck counties
For a complete copy of the LID feasibilibity assessment report, please click here (PDF).
For a copy of the LID presentation from the public meeting on June 22, 2006, please click here (PDF).
For a copy of the Outer Banks Hydrology Management Committee report, please click here (PDF).