State minister: Plant afoot to construct mega dam along coast

[Homo Sapiens]

State minister: Plant afoot to construct mega dam along coast
Tribune Desk

• Published at 09:27 pm November 12th, 2019

The government has a plan to build 300,000 disaster-resilient houses, he said

State Minister for Disaster Management and Relief Dr Md Enamur Rahman has said the government is planning to construct a mega embankment along the coast in order to protect people from natural calamities.

He made the remark at a roundtable conference titled "Grisly November 12: Sustainable Coastal Thinking," jointly arranged by Coast Foundation and Edu Aid at Dhaka's National Press Club on Tuesday.

He said: "We have devised a plan to cover our 710km coastal area with RCC moldings. If we can do this, it will protect our coastal belt from cyclones as well as rise in sea level."

The minister said the government has constructed 11,604 disaster-resilient houses for the homeless people, and the construction of 23,000 more is underway.

“We have a plan to build 300,000 disaster-resilient houses,” Dr Enamur added.

He furthered that 2,108,758 coastal residents had been evacuated to some 5,788 cyclone shelters before cyclonic storm Bulbul lashed Bangladesh early Sunday.

"In the country's history, we gave shelter to the highest number of people this time," the minister said.

He further said the government has planned to construct climate-resilient structures with its own funds, like the Padma Bridge.

Dr Enamur said the Disaster Management and Relief Ministry does not want to keep its activities limited to relief distribution. "We want to create a disaster-tolerant state in order to minimize the deaths caused by natural calamities."

https://www.dhakatribune.com/bangla...plant-afoot-to-construct-mega-dam-along-coast

 

[Homo Sapiens]

He said: "We have devised a plan to cover our 710km coastal area with RCC moldings. If we can do this, it will protect our coastal belt from cyclones as well as rise in sea level."

The minister said the government has constructed 11,604 disaster-resilient houses for the homeless people, and the construction of 23,000 more is underway.

“We have a plan to build 300,000 disaster-resilient houses,” Dr Enamur added.

This is one of the best decision so far. Actually not all the 710 km coast line need dam. A 15 meter elevated 4 lane coastal highway 300 km long extending from Mirsarai to Teknaf is under implementation to protect the entire coastline of Chatogram-Cox's Bazar region, it will also serves as the main transportation artery in those economically vital areas. Noakhali-Barishal-Khulna coastal region will only need such planned dam. This Noakhali-Barishal-Khulna region is also the main areas where most of the cyclone strike. So a 400-450 km long coastal dam will serve the purpose.

 

[bluesky]

This is one of the best decision so far. Actually not all the 710 km coast line need dam. A 15 meter elevated 4 lane coastal highway 300 km long extending from Mirsarai to Teknaf is under implementation to protect the entire coastline of Chatogram-Cox's Bazar region, it will also serves as the main transportation artery in those economically vital areas. Noakhali-Barishal-Khulna coastal region will only need such planned dam. This Noakhali-Barishal-Khulna region is also the main areas where most of the cyclone strike. So a 400-450 km long coastal dam will serve the purpose.

Bold part: Everything OK in your post except that DAM is not an appropriate word for coast protection structures. The news reporter also did the same mistake and I have found similar mistakes in other news reports as well.

The term for coast may be embankment, dike or dyke, but not dam or barrage by definition. While a dam is higher than a barrage and a barrage is higher than a dike. A dike can be built of compacted earth/soil and its slope being protected by concrete blocks which are kept in place segment by segment with wire nets that are anchored with the anchor bolts in the RCC grade beams all around a segment.

I do not understand why our benevolent minister is talking about the RCC structure. Does he mean RCC retaining wall? However, it is certain that a retaining wall cannot be made 15m tall. It will be prohibitively expensive because of a very wide footing to be supported by battered piles. So, I wonder what kind of structure he is talking about? Do you have any idea?

 

[Homo Sapiens]

Bold part: Everything OK in your post except that DAM is not an appropriate word for coast protection structures. The news reporter also did the same mistake and I have found similar mistakes in other news reports as well.

The term for coast may be embankment, dike or dyke, but not dam or barrage by definition. While a dam is higher than a barrage and a barrage is higher than a dike. A dike can be built of compacted earth/soil and its slope being protected by concrete blocks which are kept in place segment by segment with wire nets that are anchored with the anchor bolts in the RCC grade beams all around a segment.

I do not understand why our benevolent minister is talking about the RCC structure. Does he mean RCC retaining wall? However, it is certain that a retaining wall cannot be made 15m tall. It will be prohibitively expensive because of a very wide footing to be supported by battered piles. So, I wonder what kind of structure he is talking about? Do you have any idea?

Yes, it would be dyke. I am already aware about dyke is needed in such cases instead of dam. I only said dam because the minister said so.

I do not think the dyke would be 15 meters tall. This 15 meters height is for 4 lane coastal highway in Chattogram-Cox's Bazar region. Currently Patenga to fauzdarhat coastal 4 lane highway nearing completion and it is 30 feet high. This portion will extend north up to Mirsarai and in south towards cox's Bazar . This 4 lane highway will act both as a protective wall as well as a vital transportation artery.

While the dyke in Noakhali-Barishal-Khulna region would be 6 meters tall which I have read in one report. There are already 139 earthen polders in those districts protecting against cyclone and saline water intrusion. Six meters tall dyke would be more than enough to protect the coastline against any possible sea level rise and cyclone.

 

[bluesky]

Six meters tall dyke would be more than enough to protect the coastline against any possible sea level rise and cyclone.

As I said in my previous post that dikes need protection measures from the strong onslaught of seawater surge at the behest of a strong cyclone.

I have seen a few river dikes in BD, the slopes are too steep and are not protected with concrete blocks and wire nets. The slope should also be like a stair: slope, then horizontal (say, 2m), then again slope. No slope height should exceed 4m. Without these measures, the dike slope will break and be washed away by the sea waves in the cyclone times.