Assessing the Applicability of Low Impact Development Techniques in Arid and Semi-arid Regions

Abstract

Low impact development (LID) techniques are increasingly used as a stormwater management strategy to maintain the hydrological conditions of developed areas and mitigate the negative consequences of stormwater runoff and nonpoint source pollution. Although LID techniques have been commonly used in moderate to humid areas, further information is needed on their effectiveness in semi-arid and arid regions. This study aims to examine and compare the effectiveness of LID techniques in arid and semi-arid climate conditions. First, a comprehensive study was conducted to rank LID techniques based on literature reviews while also incorporating different stakeholder priorities. Then, the city of Varamin, Tehran, Iran, was chosen as a low slope arid and semi-arid study region to assess the applicability of the best three high-ranked LID techniques using the storm water management model (SWMM). The results indicated that rainwater harvesting is the most effective technique in terms of stormwater quality and quantity management. The implementation of the rainwater harvesting technique across the case study is likely to decrease the average discharge, peak discharge, total volume, total runoff, and total suspended solids (TSS) by respectively 31.2%, 12.7%, 40.71%, 40.77% and 37.91%. Besides, rainwater tanks were projected to provide the water demands of home gardens during the five dry months, in addition to other domestic needs for water conservation objectives. The application of LID techniques in such water-limited regions can be useful for both stormwater management and water conservation.