DENR Officially Announces Low Impact Development (LID) Program

NCDENR’s Division of Energy, Mineral and Land Resources (DEMLR) has formally noticed its new voluntary Low Impact Development (LID) program. The LID program is the product of a cooperative effort between engineering consultants, NC State University, the University of North Carolina, local governments, and the NC Coastal Federation.

For the first time in North Carolina, there is a quantifiable definition of LID. A development is considered LID when the volume of runoff leaving the site after development matches the volume of runoff before development. In addition, an LID project should maintain adequate flows to the streams and wetlands on the site rather than piping stormwater to a single low point. Storm-EZ is a spreadsheet based on the SCS Discrete Curve Number Method and current research findings on BMPs. Designers enter data on the site development plan and the BMPs that will be used. Then, Storm-EZ reports how closely the project matches the pre-development runoff volumes. Storm-EZ can also be used to judge compliance with conventional “pipe and treat” approach to stormwater (or a hybrid approach of some LID practices used with some end-of-pipe stormwater treatment).

DEMLR is public noticing the following items:

The LID & Storm-EZ Fact Sheet
The New Storm-EZ Permitting Tool
The New Disconnected Impervious Surfaces Chapter of the BMP Manual
The New Rainwater Harvesting Systems Chapter of the BMP Manual