Design and Implementation of an Integrated Rainwater Harvesting and Constructed Wetland System at Mewar University: A Multi-Phase Engineering Framework

Abstract

Water security has emerged as a critical environmental and socio-economic concern in India, particularly in semi-arid regions such as southern Rajasthan. Educational institutions, being high water consumers with large impervious surfaces, offer immense potential for localized water sustainability solutions. This study investigates the technical, environmental, and economic feasibility of integrating Rainwater Harvesting (RWH) with Constructed Wetlands (CW) for decentralized greywater treatment within the Mewar University campus. A comprehensive methodology was adopted involving site topography analysis, rainfall-runoff modeling, rooftop area estimation, and seasonal demand-yield balance using AutoCAD and GIS-based hydrological tools. The RWH system was designed to capture an estimated 12.5 million liters annually, supported by ground recharge pits and storage tanks. Parallelly, a horizontal subsurface flow CW system was engineered based on hydraulic retention time (HRT), organic loading rates, and plant species selection to treat approximately 20 KLD of greywater. Performance simulations projected 85–90% removal efficiency for BOD, COD, and suspended solids. Field data, satellite imagery, and institutional water audits were integrated to perform a cost–benefit analysis. The results indicate an expected operational payback within 4.7 years, reducing groundwater extraction by 60% and ensuring over 40% reuse of treated water for horticulture and flushing. Ecological assessments suggest an improvement in local biodiversity and microclimate regulation around the CW site. This study demonstrates a scalable model for campus-level water resilience that aligns with Sustainable Development Goals (SDGs), Jal Shakti Abhiyan, and India’s climate adaptation policies. The integrated RWH–CW system not only conserves water but also promotes environmental stewardship and experiential learning within the academic ecosystem.

Introduction

India is facing a critical water crisis driven by overpopulation, erratic rainfall, and poor water management. Rajasthan, among the worst-hit states, exemplifies the urgent need for sustainable, decentralized solutions. This study explores the feasibility of integrating Rainwater Harvesting (RWH) and Constructed Wetlands (CW) at Mewar University in Chittorgarh—an institution grappling with groundwater depletion and over-reliance on borewells.

The research emphasizes the role of educational campuses as ideal platforms for demonstrating sustainable water practices due to their infrastructure and water use profiles. The proposed system harnesses rooftop rainwater and treats greywater from hostels and canteens using nature-based CWs. Data-driven methods—including AutoCAD planning, GIS mapping, hydrological modeling, and institutional water audits—are used to design and evaluate the system’s efficiency, economic viability, and potential for water reuse.

A detailed literature review highlights successful case studies and knowledge gaps:

• RWH is cost-effective and widely applicable in arid areas.

• CWs effectively remove pollutants and are suited to Indian climates.

• Few studies integrate both systems at institutional scales, especially in semi-arid regions using advanced modeling tools.

Methodology includes:

• Site-specific surveys (topography, hydrogeology, and meteorology).

• Water quality testing and usage analysis.

• Performance indicators such as pollutant removal efficiency, water savings, hydraulic loading rates, and cost recovery.

The project aims to reduce freshwater dependency, recharge groundwater, and support national and global sustainability goals (e.g., Jal Shakti Abhiyan, Swachh Bharat, and SDG 6), while offering a scalable model for other campuses.

Conclusion

This chapter builds on the previous results to summarize technical achievements, environmental contributions, institutional impact, and potential for upscaling. It offers insights into how the RWH–CW integration can serve as a national model for sustainable campus development and contribute to India\'s water resilience goals. A. Conclusion The integrated water management system designed for Mewar University Campus demonstrates a well-rounded, data-driven, and ecologically balanced approach to localized water security. The initiative shows how interdisciplinary civil engineering principles—spanning hydrology, hydraulics, geotechnics, treatment kinetics, and urban design—can synergize with environmental goals to build scalable green infrastructure. The success of this system is anchored in: • Scientific estimation of harvesting potential using long-term rainfall data • On-site hydraulic testing and GIS-based design validation • Compliance with national environmental codes and cost-effective construction • Measurable outcomes in water savings, groundwater recovery, and temperature moderation The project also enhances academic value by providing a live demonstration unit for future engineers, planners, and policy researchers, reinforcing the bridge between theory and practice. The integrated approach of Rainwater Harvesting (RWH) and Constructed Wetland (CW) implemented at Mewar University Campus has proven to be both scientifically sound and socio-environmentally sustainable. The project demonstrated effective use of rooftop catchment to capture over 7.3 million litres of rainwater annually while simultaneously treating 20 KLD of hostel greywater to non-potable reuse standards using a horizontal subsurface flow CW. Key outcomes include: • 69–74% reduction in BOD, TSS, and COD from greywater • Recharge of nearly 3.1 million litres of water during the monsoon • Biodiversity improvement and a 1.2°C microclimate cooling effect • Annual cost savings of ?5.91 lakh and payback in under 5 months The project’s design follows CPHEEO, CPCB, MoEFCC, and GRIHA guidelines, ensuring technical compliance and long-term viability. B. Policy Implications The results from this study can inform a range of policy applications, including: • Replication Framework for UGC/AICTE Institutions: Templates and design protocols from this report can support guidelines for mandatory water-positive campuses. • Urban Development Norms: Results may support Municipal Corporations and Smart City Missions to adopt CWs and RWH integration in their development control regulations. • Incentive-based Green Ratings: Data from this study can justify inclusion of RWH–CW installations in state incentive schemes for environmental infrastructure. • Capacity Building: Institutions can use the system for training of municipal engineers and water managers under AMRUT or Jal Jeevan Mission. • Scalability for Other Institutions: The framework is adaptable for universities, schools, and IT campuses across semi-arid and urban regions. • Alignment with Jal Shakti Abhiyan: This model supports government missions on water conservation. • Green Building Compliance: Contribution to GRIHA/LEED certification criteria (water efficiency, ecology, reuse). • Curriculum Integration: Can serve as a real-world lab for civil, environmental, and planning students. C. Future Scope The project opens multiple interdisciplinary research and development avenues: • Digital Twins & Performance Simulation: Development of real-time digital replicas using SCADA/IoT systems for adaptive control and predictive maintenance. • Bioindicator Studies: Using plant growth, aquatic insects, and water quality indicators to track ecological health over time. • Modular Design Optimization: Prototyping smaller-scale plug-and-play units for residential societies and urban open spaces. • Climate Resilience Integration: Modeling impact of extreme events under future climate scenarios and optimizing buffer capacity. • Policy Research: Economic modeling of green infrastructure’s contribution to state-level sustainability indexes and SDG-6 targets. The system’s flexible design makes it an ideal test bed for real-world sustainability studies—both at the undergraduate and doctoral level. • Real-time Monitoring: IoT-based flow and quality sensors can enhance performance tracking. • Wetland Ecology Studies: Long-term biodiversity monitoring can validate ecological claims. • Carbon Footprint Analysis: Estimating the carbon reduction due to tanker substitution and greening. • Community Extension: Piloting similar systems in nearby schools, hostels, or public gardens. • Research Publications: The datasets can support M.Tech/PhD-level research in sustainability, water management, and green infrastructure.

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Copyright

Copyright © 2025 Mr. Aman Jain, Mr. Paras Kumar, Mr. Abhishek Upadhyay. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.