Development of A Smart Rainwater Harvesting System with Automated Real-Time Water Quality Monitoring

Mohamad Faizal Abdul Halik¹, M. Sugirtharan², and G. Niroash³

¹ Research Scholar, Department of Agricultural Engineering, Faculty of Agriculture, Eastern University, Sri Lanka.

² Professor, Department of Agricultural Engineering, Faculty of Agriculture, Eastern University, Sri Lanka.

³ Lecturer, Department of Agricultural Engineering, Faculty of Agriculture, Eastern University, Sri Lanka.   

Abstract

Water scarcity in Sri Lanka is becoming an increasingly significant challenge due to irregular rainfall patterns and growing domestic water consumption. Increased household activities have raised water demand, while farmers, particularly in rural areas, often face difficulties in obtaining adequate quantities of clean water for agricultural purposes. Furthermore, atmospheric pollutants contribute to acid rain formation, which can negatively affect the quality of harvested rainwater. Conventional rainwater harvesting systems are generally designed for water collection and storage only, without evaluating water quality, which may result in the storage and use of contaminated water that is unsuitable for irrigation. Therefore, this study aimed to develop a smart automated rainwater harvesting system integrated with real-time water quality monitoring and sensor-based storage control to ensure the availability of safe and reliable irrigation water. The system was developed using an ESP32 microcontroller connected to pH, turbidity, and total dissolved solids (TDS) sensors. A two-tank configuration was employed, consisting of a primary assessment tank with a conical bottom for water quality evaluation and a secondary storage tank for retaining acceptable water. Sensor readings were transmitted and visualized through the Blynk IoT platform, while programmed automation logic-controlled solenoid valves to either transfer suitable water for storage or divert poor-quality water to drainage. Water was automatically rejected when the pH value was below 5.5 or above 7.5, or when turbidity exceeded the acceptable level. The results demonstrated that water stored in the secondary tank exhibited significantly improved quality compared with direct rooftop runoff and drainage discharge. Overall, the developed system provided effective automation, enhanced harvested water quality, and improved water management efficiency, offering a sustainable and practical solution for irrigation in both urban and rural environments.     

Keywords: Automatic water control, Clean water storage, IoT system, Smart rainwater harvesting, Two-tank design, Water quality monitoring

References

1. Abdulla, F.A. and Al-Shareef, A.W. (2009) ‘Roof rainwater harvesting systems for household water supply in Jordan’, Desalination, 243(1-3), pp. 195-207. https://doi.org/10.1016/j.desal.2008.05.013
2. Adebowale, I.J., Moses, P. and Abalist, R.O. (2026) ‘Organic contamination in water and sediment of Opokuma Community, Kolokuma/Opokuma Local Government Area, Bayelsa State, Niger Delta, Nigeria’, International Journal of Technology, Health and Sustainability, 2(1), pp. 333-339. https://ijths.com/wp-content/uploads/IJTHS-020192.pdf
3. APHA (2017) Standard Methods for the Examination of Water and Wastewater. 23^rd edn. Washington, DC: American Public Health Association.
4. Ariyabandu, R. de S. (1999) ‘Development of rainwater harvesting for domestic water use in rural Sri Lanka’, Asia-Pacific Journal of Rural Development, 9(1), pp. 1-14. https://doi.org/10.1177/1018529119990101
5. Balasuriya, B.M.C.M. and Arachchige, U.S.P.R. (2021) ‘Rainwater harvesting for drinking purposes in Sri Lanka’, Journal of Research in Technology and Engineering, 2(3), pp. 37-46. https://www.jrte.org
6. Banna, M.H., Najjaran, H., Sadiq, R., et al. (2014) ‘Miniaturized water quality monitoring pH and conductivity sensors’, Sensors and Actuators B: Chemical, 193, pp. 434-444. https://doi.org/10.1016/j.snb.2013.12.002
7. Blynk Inc. (2023) Blynk IoT Platform Documentation. Available at: https://docs.blynk.io/  (Accessed: 15 June 2025).
8. Boers, Th.M. and Ben-Asher, J. (1982) ‘A review of rainwater harvesting’, Agricultural Water Management, 5(2), pp. 145-158. https://doi.org/10.1016/0378-3774(82)90004-X
9. Campisano, A., Butler, D., Ward, S., et al. (2017) ‘Urban rainwater harvesting systems: Research, implementation and future perspectives’, Water Research, 115, pp. 195-209. https://doi.org/10.1016/j.watres.2017.02.056
10. Choong, J.J. and Chia, K.S. (2026) ‘IoT-based industrial wastewater monitoring system using ESP32 and Blynk’, Journal of Engineering Technology and Applied Physics, 8(1), pp. 106-114. https://doi.org/10.33093/jetap.2026.8.1.15 
11. Deswal, S. and Deswal, A. (2017) A Basic Course in Environmental Studies. 3^rd ed. New Delhi: Dhanpat Rai & Co. (P) Ltd.
12. El Mezouari, A., El Fazziki, A. and Sadgal, M. (2022) ‘Hadoop–Spark framework for machine learning-based smart irrigation planning’, SN Computer Science, 3(1), 10. https://doi.org/10.1007/s42979-021-00915-y
13. ESP32 DT (2023) ESP32 Arduino Core Documentation. ESP32 Development Team Available at: https://docs.espressif.com/projects/arduino-esp32/ (Accessed: 15 June 2025).
14. García, L., Parra, L., Jimenez, J.M., et al. (2020) ‘IoT-based smart irrigation systems: An overview on the recent trends on sensors and IoT systems for irrigation in precision agriculture’, Sensors, 20(4), 1042. Available at: https://doi.org/10.3390/s20041042
15. Meera, V. and Ahammed, M.M. (2006) ‘Water quality of rooftop rainwater harvesting systems: A review’, Journal of Water Supply: Research and Technology-Aqua, 55(4), pp. 257-268. https://doi.org/10.2166/aqua.2006.0010
16. Muktiningsih, S.D. and Putri, D.M.A.R.M.S. (2021) ‘Study of the potential use of rainwater as clean water with simple media gravity filters: A review’, Earth Environ. Sci., 733, 012147. https://iopscience.iop.org/article/10.1088/1755-1315/733/1/012147 
17. Nwamekwe, C.O., Uchenna, P.C. and Onyedik, S.C. (2026) ‘Leveraging emerging technologies to enhance business processes in blue economy sectors: A case study of Anambra State’s industrial landscape’, International Journal of Technology, Health and Sustainability, 2(2), pp. 559-572. https://ijths.com/wp-content/uploads/IJTHS-0202024.pdf
18. Obaideen, K., Yousef, B.A.A., AlMallahi, M.N., et al. (2022) ‘An overview of smart irrigation systems using IoT’, Energy Nexus, 7, Article 100124. https://doi.org/10.1016/j.nexus.2022.100124
19. Roman, D.C., Braga, A.M., Shetty, N.H., et al. (2017) ‘Design and modeling of an adaptively controlled rainwater harvesting system’, Water, 9(12), 974. https://doi.org/10.3390/w9120974
20. Shaheed, R., Mohtar, W.H.M.W., and El-Shafie, A. (2017) ‘Ensuring water security by utilizing roof-harvested rainwater and lake water treated with a low-cost integrated adsorption-filtration system, Water Science and Engineering, 10(2), pp. 115-124. https://doi.org/10.1016/j.wse.2017.05.002
21. Shetty, N.H., Wang, M., Elliott, R., et al. (2022) ‘Examining how a smart rainwater harvesting system connected to a green roof can improve urban stormwater management’, Water, 14(14), https://doi.org/10.3390/w14142216
22. Singh, A. and Agrawal, M. (2008) ‘Acid rain and its ecological consequences’, Journal of Environmental Biology, 29(1), pp. 15-24. https://www.jeb.co.in
23. Singh, A. and Deswal, S. (2025) ‘Groundwater quality assessment and thematic spatial mapping of Hisar district in Haryana (India)’, International Journal of Technology, Health and Sustainability, 1(1), pp. 37-45. https://ijths.com/wp-content/uploads/2025/12/IJTHS-010120.pdf
24. Sirisha, V., Sai, R., Yasodha, G., et al. (2026) ‘IoT-based real-time water quality monitoring and predictive alert system using ESP32’, American Journal of AI Cyber Computing Management, 6(1), pp. 340-346.
25. WHO (2022) Guidelines for drinking-water quality: Incorporating the first and second addenda. 4^th edn. Geneva: World Health Organization. Available at: https://www.who.int/publications/i/item/9789240045064 (Accessed: 15 June 2025).
26. Zhang, Y., Li, J., Tan, J., et al. (2023) An overview of the direct and indirect effects of acid rain on plants: Relationships among acid rain, soil, microorganisms, and plants’, Science of The Total Environment, 873, 162388. https://doi.org/10.1016/j.scitotenv.2023.162388