Analysis of alternative approaches to stormwater management and prospects for their implementation in Ukraine

Abstract

Due to aging infrastructure, frequent wastewater network overflows, and potential charges for stormwater disposal, there is a need to find alternative approaches to stormwater management. Rain gardens and rainwater harvesting systems are widely used in local areas such as private homes, small businesses, and parking lots. Therefore, the aim of this study was to conduct an economic analysis of two alternative solutions – a storage tank with water reuse and a rain garden. The cost-benefit analysis was based on an evaluation of the effectiveness of each approach in reducing stormwater runoff volume and decreasing stormwater disposal fees in the wastewater network. The precipitation regime used for the calculations was selected based on data from 2014 to 2023 for the Kyiv. In the study, technical and economic aspects were considered as key factors in the decision-making process. The results of the economic sustainability analysis of both options using an example of an impermeable surface showed that both systems have an effective service life of approximately two years. The storage tank is an effective solution, reducing stormwater overflows and allowing the collected water to be reused for various purposes. However, the costs of construction and maintenance of the tank exceed the savings on stormwater disposal fees to the sewer system by almost twice, therefore the project is not economically viable in the initial period. The implementation of a rain garden design to reduce stormwater disposal fees to the wastewater network is the most cost-effective solution. Assuming that the effective use period of a rain garden design is 8-10 years, the accumulated savings on tariffs can range from €606.8 to €848.2. The introduction of financial incentives will help promote the implementation of alternative stormwater control solutions, leading to a range of environmental and economic benefits, such as reducing the impact of stormwater on the environment, protecting water resources, and potential savings in the construction and management of stormwater systems