Investigation on the application of Floating Treatment Wetland modules in Kerala, India

Nanma Gireesh, Translational-Civil engineer (NestAbide)
Ben K. George, Translational-Electrical engineer (NestAbide)

Civilizations have flourished through the banks of water bodies, but the current scenario of expanding human population is disturbing the water quality and ecological balance. Floating Treatment Wetlands are proven eco-technological solution for declining water quality. An ecological habitat must be maintained in consideration with limnetic, littoral and upland zones of a water body. Importance of macrophytes and air intrusion in these zones for rejuvenating the water bodies are analyzed in this paper with three rejuvenation projects from Telangana and Kerala states of India. Neknampur Lake in Telangana contains India’s largest floating wetlands to improve the wastewater from the inlets flowing from nearby townships.

Considering it as a model, an analysis has been done regarding the functional effect of floating wetlands in Kerala state. Presently, two pond rejuvenation works in Kollam and Trivandrum districts of Kerala are completed using floating treatment wetlands eco-technology with due consideration to limnetic and littoral zones. Water quality data on Biological Oxygen Demand (BOD), Dissolved Oxygen (DO), Nitrates and Phosphates have been thoroughly examined with water samples taken. Reconnaissance surveys and investigations indicated the issues at the site. Floating Wetlands were designed for a) the area required to treat the water using the water quality parameters and b) the buoyant base structure which itself acts as a natural habitat for the aquatic life.

The paper includes the applications, construction materials used for the buoyant base structure/ buoyant platform, local vegetation species, mechanisms for pollutant removal and sustainable management strategies. The uncontrollable weed growth has been reduced after the introduction of floating treatment wetlands which indicates the reduction in nutrients, Biological Oxygen Demand and increase in Dissolved Oxygen. The buoyant platform is currently being redesigned as a pre-fabricated module to withhold the capacity of growing plants for a square meter of area.

Keywords – Floating Wetlands, Buoyant base, Rejuvenation, Kerala, India


Nanma Gireesh is a Civil engineer with post-graduation in Translational Engineering. She co-founded an interdisciplinary consultancy firm called NestAbide with the second author Ben Kappil George. NestAbide currently focuses on flood-resistant activities like water body rejuvenation and flood resilient structures like amphibious and floating buildings. Nanma was a TEDx speaker in 2019 and thereafter has addressed over 1000 students in one year through different platforms creating awareness about floating buildings and the importance of floating wetlands. She has been an active project engineer and consultant for various pond rejuvenation projects and a multi-crore lake rejuvenation project in Kerala, India. With the help of Government of Kerala, she is trying to build an Amphibious model building for the flood-affected people to witness and experience the working and help adapt.

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