Reliability and financial feasibility assessment of a community rainwater harvesting system considering precipitation variability due to climate change

Mohammad Maksimul Islam; Sadia Afrin; Mehedi Hasan Tarek; Md Mujibur Rahman

doi:10.1016/j.jenvman.2021.112507

Reliability and financial feasibility assessment of a community rainwater harvesting system considering precipitation variability due to climate change

J Environ Manage. 2021 Jul 1:289:112507. doi: 10.1016/j.jenvman.2021.112507. Epub 2021 Apr 8.

Authors

Mohammad Maksimul Islam¹, Sadia Afrin², Mehedi Hasan Tarek³, Md Mujibur Rahman⁴

Affiliations

¹ Department of Civil Engineering, Bangladesh University of Engineering and Technology, Dhaka, Bangladesh; Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, NC, USA.
² Department of Civil Engineering, Bangladesh University of Engineering and Technology, Dhaka, Bangladesh; Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, NC, USA. Electronic address: safrin@ncsu.edu.
³ Civil and Environmental Engineering Department, West Virginia University, Morgantown, WV, USA.
⁴ Department of Civil Engineering, Bangladesh University of Engineering and Technology, Dhaka, Bangladesh; Department of Civil Engineering, University of Asia Pacific, Dhaka, Bangladesh.

PMID: 33839610
DOI: 10.1016/j.jenvman.2021.112507

Abstract

This study proposes a community rainwater harvesting (RWH) system as an alternative water supply solution for Paikgacha, a water-scarce coastal urban area in Bangladesh. Although individual household-based RWH systems have been implemented in many areas in Bangladesh, to date, no study has been conducted designing a community RWH system and assessing its reliability and financial feasibility. This study employs historical observed and available climate model predicted future rainfall data into stormwater management model (SWMM) for rainfall-runoff simulation of the community RWH, and compares SWMM's performance with rational formula based estimation. We then calculate volumetric and time reliability of the proposed system and assess its financial viability. We observe good agreement in reliability curves generated by SWMM and rational formula-based model. Under the historical rainfall scenario, our proposed community RWH shows up to 99% reliability for 100 L per day household demand, given that proper community size and storage tank size are chosen. Predicted rainfall pattern of 2041-2070 period shows similar reliability-tank size relation to that of historical observed rainfall; however, predicted high precipitation intensity during 2021-2040 and 2071-2100 seem to assist the system in attaining higher reliability. Cost-benefit analysis indicates the financial viability of the proposed system. Finally, we develop a nomograph incorporating interactive factors of RWH, which would ease decision making by the policymakers regarding the implementation of community RWH.

Keywords: Climate change; Community rainwater harvesting; Financial feasibility; Reliability.

MeSH terms

Bangladesh
Climate Change*
Conservation of Natural Resources
Feasibility Studies
Rain*
Reproducibility of Results
Water Supply