GUWAHATI, Aug 8 - Adoption of a multi-disciplinary watershed approach, including ecological management practices (EMPs), holds the key to mitigating the problem of artificial floods and waterlogging in Guwahati.
Advocating this, a group of technical experts have made several recommendations for tackling the worsening situation vis-a-vis artificial floods and waterlogging, keeping in mind the city’s topography, which is surrounded by hills.
In their concept report, the experts called for implementing a project under the ‘Ridge-to-Valley’ concept, in which every waterway coming down from the upper ridges to the valley were to be thoroughly surveyed for adoption of suitable engineering and vegetative measures to convert the erosive velocity to non-erosive velocity, thereby arresting the silt generated at source.
The expert panel comprises Dr SV Ngachan, Director, ICAR, Barapani (Shillong); Dr RK Singh, Chief Scientist, ICAR; Dr Arup Sharma, Professor, Civil Engineering., IIT Guwahati; Dr HJ Barua, retd Director, Horticulture Dept, Assam; Dr Prasanta Bordoloi, former Director, NERIWALM, Tezpur; JN Khataniar, consultant engineer; Jayanta Barkataky, retd CMD, NEEPCO, Shillong; Indrajit Barua, structural engineer; Tarun Barua, retired District Soil Conservation Officer, Assam; Keshab Saikia, retd executive engineer, Agriculture, Assam; and Dip Barua, president, Nabin Nagar Welfare Society.
“Individual plans from the upper ridges to the lower valley area are to be designed. For preparation of this plan, each and every hillside needs to be visited and a socio-economic survey to be done and the stakeholders consulted for suggestions on a roadmap and alignment of waterways for guiding the same to a safe low-lying area for conservation of water in the form of water harvesting ponds,” Keshab Saikia, member of the expert panel told, The Assam Tribune.
The exercise will also entail identification of the locations for EMP and use of vegetative barriers (such as vetiver, citronella, etc) along the waterways and gullies, and across the hill slopes, to minimise the flow velocity and erosion.
“A terrace system with plantation should also be developed where scope is available. The creation of water harvesting ponds/structures in low-lying areas will serve a number of purposes, including rainwater retention at the hill slopes prior to reaching the city, acting as a silt detention structure, recharge of ground water, use of water by the residents in and around the hills, pisciculture development, etc.”
An added benefit will be the creation of horticulture orchards of papaya, banana, lemon, guava, etc, around the water harvesting ponds, which will ensure an income-generating source for the local inhabitants.
The water areas will also be developed as recreation and tourist spots, adding to the city’s aesthetic appeal.
Other measures suggested by the experts include construction of retaining walls in the areas having steep slopes to prevent soil erosion, and erecting fences on both sides of the Bharalu river to prevent disposal of garbage by households and others.
“This calls for initiatives and programmes on a large scale and on a priority basis with participation from the local committees for creating public awareness on the proposed objective of the flood control measures,” he said.
Advanced technologies like geo-net with EMP are also to be adopted to control landslides.
Another imperative, according to the experts, is to initiate inter-State discussions between Assam and Meghalaya for formulation of strategies to control the flow of rainwater through the Bahini and Basistha rivers.
The Kamrup (Metro) Deputy Commissioner had a meeting with his Ri-bhoi counterpart last month over the worsening waterlogging problem in Jorabat area. For the chronic flood-affected areas, underground pipe drainage is to be adopted along with silt detention structures.
Another measure involves construction of covered diversion drains with slabs to divert a portion of rainwater flowing through rivers Bahini and Basistha along the NH-37 to the Deepor Beel.
“Special attention has to be given to river Bharalu to make it silt-free, garbage-free, and to beautify and develop it as a tourist spot. Then, all the water bodies in and around the city are to be properly maintained for water conservation as well as beautification and recreational purposes,” Saikia said.
Referring to the IIT Guwahati’s report for mitigating the city’s flood hazard though ecological management practices, the expert panel called for implementation of the measures under the supervision of IIT Guwahati and the panel.
“IIT Guwahati should be entrusted for preparation of DPR for 20 hillocks comprising 105 micro-watersheds,” he added.