A. VETIVER PLANTING TO REDUCE WATER POLLUTION: LOCAL COMMUNITY ENGAGEMENT AND ENVIRONMENTAL BENEFIT (03RD AUGUST, 2023)

Community-driven action by National Service Scheme (NSS) volunteers from B.S. Abdur Rahman Crescent Institute of Science & Technology, in collaboration with local authorities, targeted sewage-induced water pollution in the 27-foot-deep Urapakkam Kolatchiammal temple pond. The intervention focused on planting Vetiver grass along pond banks and upstream catchment areas to stabilize soil, reduce erosion, filter runoff, and enhance infiltration, thereby limiting pollutant transport to the pond. NSS volunteers from B.S. Abdur Rahman Crescent Institute of Science & Technology, alongside participants from SRM University, SRM Valliammai Engineering College, and Aadhi Engineering College, worked with local authorities to implement the plan. Vetiver’s deep, dense, fibrous root system is central to the approach, as it improves soil stability and infiltration, reduces surface runoff, and exhibits pollutant-retention properties. Expected outcomes include reduced sediment and nutrient loads entering the pond, improved groundwater recharge, and long-term soil rehabilitation around the watershed.

COMMUNITY AND GOVERNANCE FOCUS

The Urapakkam Kolatchiammal Temple pond faces long-standing sewage discharge from nearby residences, with unauthorized connections channeling wastewater into stormwater drains that should carry only rainwater. This situation contaminates the pond, accelerates sedimentation, risks eutrophication, and degrades water quality, potentially affecting local biodiversity and the pond’s cultural and community uses. The pollution also poses health risks to nearby residents and undermines the pond’s aesthetic and communal value. Addressing these issues requires a dual approach: managing soil erosion and runoff at the watershed level while simultaneously tackling sewage leakage through governance and infrastructure improvements.

EMPHASIS ON EDUCATION AND STEWARDSHIP

The primary objective is to reduce pollutant loads entering the pond by enhancing soil stability and filtering runoff at the source and along runoff pathways. A secondary aim is to improve soil health and infiltration around the pond to promote groundwater recharge and resilience against erosion. The intervention also seeks to foster collaborative learning and stewardship by involving NSS volunteers from multiple institutes and linking community action with local authorities, thereby building a model for cross-institutional watershed management and pollution prevention.

INTERVENTION DETAILS

Vetiver grass (Chrysopogon zizanioides) was introduced along the pond’s banks and in key erosion-prone zones within the upstream catchment. NSS volunteers from B.S. Abdur Rahman Crescent Institute of Science & Technology and partner institutions, under guidance from local authorities, participated in planting Vetiver. Vetiver was chosen for its deep, dense, and fibrous root system that stabilizes banks, reduces runoff velocity, and improves soil porosity and infiltration in compacted soils. Additionally, Vetiver can act as a biofilter, supporting microbial communities in the rhizosphere that aid in pollutant degradation and sequestration, including uptake of certain nutrients and heavy metals. Planting sites focused on the pond’s banks, upstream catchment areas, and zones most susceptible to runoff entry points.

MECHANISMS BY WHICH VETIVER REDUCES WATER POLLUTION

Vetiver reduces water pollution through several interrelated mechanisms. Its extensive root network anchors soil, significantly reducing bank instability and sediment entrainment during rainfall. Dense vegetative cover slows runoff, promotes infiltration, and lowers both the volume and velocity of runoff that would otherwise transport sediments and attached pollutants to the pond. As a biofilter, Vetiver’s root zone traps particulates and supports uptake of nutrients such as nitrogen and phosphorus, thereby reducing nutrient leakage to the water body. Improved soil structure from root penetration enhances infiltration rates, further diminishing surface runoff. Infiltration improvements also aid groundwater recharge, contributing to watershed resilience. Vetiver’s low-maintenance, drought-tolerant characteristics make it a robust, scalable solution for interfaces between rural and urban environments, supporting long-term sustainability.

EXPECTED ENVIRONMENTAL AND COMMUNITY BENEFITS

The initiative is anticipated to yield several benefits: improved pond water quality through reduced turbidity and nutrient loads; decreased sedimentation, which enhances the pond’s storage capacity and ecological health; strengthened ecosystem resilience with better habitat conditions around the pond; and empowered communities through NSS-led engagement that raises awareness about pollution sources and promotes responsible waste disposal. The approach also holds promise for informing local watershed management plans and anti-pollution strategies, particularly when integrated with proactive sewage management and enforcement of wastewater discharges.