Low Impact Development Design: Integrating Suitability Analysis and Site Planning for Reduction of Post-Development Stormwater Quantity

Abstract

"A land-suitability analysis (LSA) was integrated with open-space conservation principles, based on watershed physiographic and soil characteristics, to derive a low-impact development (LID) residential plan for a three hectare site in Coshocton OH, USA. The curve number method was used to estimate total runoff depths expected from different frequency storms for: (i) the pre-development condition, (ii) a conventional design, (iii) LID design based on the LSA of same building size; and (iv) LID design based on the LSA with reduced building footprints. Post-development runoff depths for the conventional design increased by 55 percent over those for the pre-development condition. Runoff depth for the same building size LSA-LID design was only 26 percent greater than that for the pre-development condition, and 17% for the design with reduced building sizes. Results suggest that prudent use of LSA may improve prospects and functionality of low-impact development, reduce stormwater flooding volumes and, hence, lower site-development costs."