Rainwater Harvesting as a Stormwater Best Management Practice

Lesikar, B.

As a result of population and economic development, Texas, as most other states in the U.S continues to experience high escalation in urban growth. With urban growth, impervious land coverage usually increases due to the growth in the number of rooftops, parking lots, roads, and sidewalks and can be the cause of drastic effects on water quality and watershed ecosystems. As a result, infiltration and base flows will be reduced and urban runoff, the frequency of flooding and peak runoff flow rates will increase. The consequences of urbanization will be reflected not only on the hydrological cycle and infrastructures, but also on human health. Urban runoff has a significant role in transporting pollutants such as chemicals, sediments, pesticides, fertilizers, and oils, then depositing it in water bodies, where they harmfully affect water quality. Best management practices (BMPs) aim at negating the effect of urbanization on stormwater by reducing the runoff volume and peak flows as well as improving the water quality. BMPs can be costly and form a burden for municipalities and states. Thus, selecting a proper, cost effective solution is crucial. While rain water harvesting (RWH) has been extensively used as an alternative source of water, it has not been studied as a stormwater BMP. RWH can reduce stormwater runoff volumes, and delay and decrease peak runoff flow rates. Collected water can be used later for irrigation systems or filtered and reused for household activities such as toilet flushing. This research aims to demonstrate the effectiveness of RWH as a stormwater BMP in urban areas, specifically in Dallas, Texas. Different irrigation management methods combined with RWH and a control site without RWH are going to setup to determine the effect of RWH as a BMP on a singlefamily housing scale. The effects of each irrigation method on peak runoff rates and volumes as well as water quality are going to be compared. Results of this study will provide information on the required tank sizing, and water use method that will improve the performance of RWH as a stormwater BMP.