THIRUVANANTHAPURAM: Even as Kuttanad gears up to celebrate Onam with what little the local residents have been able to salvage after battling past yet another flood, a detailed study — carried out by IIT Madras and Centre for Water Resources Development and Management (CWRDM) — that identified structural measures to mitigate flooding has remained largely unimplemented three years after it was submitted to the government.
Commissioned by the irrigation department and submitted in 2023, the report proposed giving floodwater “more room” through additional channels, besides strengthening bunds and deploying regulators strategically. Its recommendations have gained renewed relevance after the recent floods inundated large parts of Kuttanad and Upper Kuttanad.
Experts are questioning the need for repeated studies when concrete solutions are already available. “We talk about more and more studies and technology while the real hard solutions are well laid out in this report,” a source said.
The report — titled ‘Hydrodynamic Study for the Scheme-Kuttanad Package-Flood Management Programme-Development of the Thottappally Leading Channel’ — makes it clear that Kuttanad’s flood problem cannot be addressed merely through evacuation and disaster response.
“Only with very hard engineering solutions can this be resolved to some extent. Otherwise, if we tell people to run away, the problem of floods won’t end,” the source said.
The study examined flood events with return periods of five to 100 years and found that conventional measures such as simply dredging or widening existing channels may not be sufficient. Its key recommendation was a new channel parallel to Korankuzhy Thodu, described as a ‘practically viable and superior option’ to divert floodwater towards the Thottappally Spillway with comparatively less disruption to habitation.
A second proposal — a channel linking the Pampa near Veeyapuram with the Thottappally Spillway — was found capable of reducing overtopping in Pullangady and Thakazhy, but ranked lower because of greater habitat disturbance and the need for four regulators. The report also called for raising and strengthening bunds around vulnerable areas such as Kavalam and Kidangara.
Regulators at locations, including Kuthiyathodu, were found capable of reducing downstream water levels, though the report warned of possible upstream rises.
The expert, however, flagged what he considers an important gap in the study — a detailed assessment of the carrying capacity of Vembanad lake and the water-holding capacity of Kuttanad’s polder lands.
“We know that the carrying capacity of the lake has reduced. We should increase the carrying capacity as well as implement the recommendations they have proposed,” he said.
The expert also stressed the need to clear the Thottappally sandbar, which the report identified as crucial for ensuring a proper flow of floodwater.
“There is no point in studying this again and again. We gave suggestions after running precise simulations. The 2023 study demonstrated through simulations that specific interventions could reduce flood levels, though Kuttanad could never be made completely flood-free. We can reduce the impact further,” the official said.
The official said that one of the 2023 proposals involved controlling and diverting water in one branch of the Pampa using a hydraulic structure. Simulations showed that diverting the flow could substantially reduce flooding downstream, though with some rise in upstream water levels.
Former water resources minister Roshy Augustine said a separate DPR (detailed project report) covering the Pampa, Manimala and Achankovil rivers based on a study report had been submitted to the Union government but was still awaiting approval.
He said the project was intended to improve the rivers’ capacity to carry flood discharge and to remove obstructions.
“We haven’t got the approval from the Centre,” Roshy said.
Key details
The study examined flood events with return periods of five to 100 years
Conventional measures may not be sufficient, it found
Its key recommendation was a new channel parallel to Korankuzhy thodu
