Check dam at Keishampat to purify Nambul water
Source: Chronicle News Service
Imphal, December 17 2022:
In a bid to make water of Nambul River clean, the department of environment and climate change is building a check dam at Keishampat as a bioengineering solution.
Foundation work for the check dam, which is being constructed on the northern end of Keishampat Bridge is nearing completion.
The check dam is being constructed under National River Conservation Plan.
Speaking to The People's Chronicle in this regard, environment and climate change director Dr T Brajakumar explained that the main reason behind drying up of rivers of the state is climate change and shorter rainfall season, which resulted in inability of the rivers to maintain natural flow.
Even though the water volume is high during rainy season, it recedes soon after the rainfall intensity decreases.
As a result, pollution load in rivers are high further leading to polluted water.
Microorganism and bacterial concentration in low water volume is high which further increases the Biological Oxygen Demand (BOD) of water.
On the other hand, high water volume decreases pollution load, microorganism and bacterial concentration as well as BOD while increasing dilution factors.
These scientific reasons were taken into account while formulating plan for the check dam, which is being taken up as a bioengineering solution pilot project, the director said.
The check dam will keep the water volume and dilution factors high.
Water passing over the check dam resembling a low height waterfall will provide aeration and will act as a natural water treatment plant.
These are the main factors behind the idea of the check dam, he said.
The check dam will not be solid concrete dam but will have multiple perforations to maintain porosity.
It is similar to the natural filtration mechanism provided by big boulders in the catchment areas of river sources.
Similarly, the department is planning to add some boulders to act as filtration mechanism.
Moreover, there are plans to add water plants for natural treatment of water, Dr Brajakumar informed.
There are also plans to build more check dams in Pishum, Mongsangei and Samurou area of Nam bul River as well as other major rivers like Imphal and Kongba rivers.
As for Imphal river, the directorate is planning to develop an artificial wetland, where the river water will be diverted for natural filtration before falling back again into the river, he confided.