Flood damage risk reduction – Is it possible?

Wednesday, 22 December 2010 00:01 -     - {{hitsCtrl.values.hits}}

This is the last in the three-part series on the impact of bad weather, floods, possible remedial measures and safeguards.

Our interest or continuing interest in this topic should not be in the naïve expectation of flood prevention, or the undoubtedly yet challenging task of restoring what is damaged ‘after the fact,’ but more importantly, in my view, in the flood damage risk reduction measures (if there are any) that other nations deploy.

Beyond damage assessment

Particularly while gaining insight into Pakistan’s tragedy and response, I wondered what safeguards are really being built for the future and even inquired of colleagues what concepts, designs or estimates are being developed of preventive or defensive infrastructure.

Apparently this was not clear; due perhaps to the costs associated with it or since their mandate or thinking did not extend beyond restoring what was damaged. I thought it only prudent that risk reduction strategies should be necessarily designed as part of the measures to protect the heavy investments being made in restoration. I trust several components to address this management of risk must be part of the designs – at least to a reasonable extent. I only hope so.

Quite by chance while overseas and waiting for the commencement of a meeting connected with an infrastructure project recently, I was glancing through an international civil engineering magazine and was awestruck by an analysis of the efforts of the city of New Orleans, pursuant to Hurricane Katrina – just five years ago. I thought that it was certainly of futuristic interest and deserved to be studied and shared.

Hurricane Katrina

Hurricane Katrina is regarded as the costliest natural disaster and one of the five deadliest hurricanes in US history since 1928. Over 1,800 people died in this 2005, hurricane itself and in the subsequent floods. Property damage was estimated at $81 billion.

The American Society of Civil Engineers refers to the flooding as the worst catastrophe in the history of the United States. Over 204,000 homes were damaged or destroyed and more than 800,000 citizens displaced — apparently the greatest displacement in the United States since the Dust Bowl of the 1930s.

Katrina had formed over The Bahamas, crossed southern Florida and caused severe destruction along the Gulf Coast from central Florida to Texas. The most severe damage was to New Orleans, Louisiana, as a result of the levee system (an embankment built to prevent the overflow of a river) failing.

80% of the city was flooded and the floodwaters remained for weeks. The worst property damage had occurred in coastal areas, in Mississippi beachfront towns, which became flooded over 90% within hours. Boats and casino barges rammed buildings, pushing cars and houses inland, with waters reaching 10-19 km from the beach.

Law suits and resignations

The hurricane protection failures in New Orleans led to a lawsuit against the US Army Corps of Engineers, who had built the levee system as mandated in the Flood Control Act of 1965. In January 2008, the Army Corps was cited as responsible for the failures and flooding. However, the federal agency could not be held financially liable due to sovereign immunity in the Flood Control Act of 1928.

Pursuant to investigation of the responses from federal, state and local governments, the Director of the Federal Emergency Management Agency (FEMA) and the Superintendent of the New Orleans Police Department (NOPD) resigned.

FEMA is an agency of the United States Department of Homeland Security, initially created by Presidential Order on 1 April 1979. The United States Department of Homeland Security is also a department whose strategy and structure are worthy of study in order to generate thoughts for Sri Lanka.

In contrast to the resignations, I mentioned, it must be said that the United States Coast Guard (USCG), the National Hurricane Centre (NHC) and National Weather Service (NWS) were commended for their actions, accurate forecasts and abundant lead time. Yet as of today, five years after the hurricane, thousands of displaced residents in Mississippi and Louisiana are still living in temporary accommodation.

Bars, cars and soggy trunks

Bars were apparently the first businesses to reopen while gas stations, supermarkets, appliance stores and restaurants followed. Businesses which did better after Katrina than before were new car dealers. An estimated 200,000 vehicles in Metro New Orleans were regarded as totally damaged.

Local reporters had found “a used car dealer selling partially cleaned up flooded cars with restored engines but still soggy trunks”. It is interesting that this happens even in the best of the West! But the state legislature had passed legislation mandating that cars declared ‘totalled’ must be dismantled, crushed or otherwise disposed of and could not be resold.

Even three months after the storm, restaurants were serving food and drink in disposable plates and cups because of the shortage of dishwashers. Many restaurants offered wages double pre-Katrina levels for dishwashers. There were few takers. It was found that the reason was that untrained labourers were able to make more money in industries related to demolition and reconstruction.

A futuristic response

Perhaps unknown to many who cite the US’s mismanagement of relief to those affected, as a defence to perpetuate weaknesses in our own nations, whether in Asia, Africa or South America (as is happening now), US engineers led by the Army Corps of Engineers are apparently in the final phase of extensive civil works to reduce the risk of storm damage to the city of New Orleans.

The response is very extensive, expensive and even a microcosm of this infrastructure is clearly beyond our reach. Hence, I will first share with readers a few personal memories of hurricanes in The Bahamas, which prompt simple ‘preparedness measures’. This will be the aperitif, appetiser, or hors d’œuvre for the description of what engineers are doing in New Orleans.

The Bahamas

Having lived in the Bahamas and been exposed each year to hurricane seasons which begin in late summer, many memories come to mind.  We learned to keep abreast of the way in which several US TV stations (given the very close proximity of The Bahamas to Miami Florida) tracked the movement of the ‘eye of the hurricane’.

Alerted by warnings, days ahead, we stocked canned foods and other items. Several homes with glass windows, which could shatter, installed wooden boards as defences.

Memories of how a few professional colleagues in Jamaica and Bermuda were affected by hurricanes and even hospitalised while we in the Bahamas were spared and also how insurance for our cars against hurricane or storm related damage – including something as rare as a falling tree – became routine also comes to mind.

Interestingly enough, in his first year in The Bahamas, an accountant who chose to avoid insuring these risks to reduce his premium found that a tree chose only his car to fall on! Insurance had refused to pay. Hearing this, I insured my new vehicle against hurricanes from day one. Given the many flood-damaged cars in the garages in Sri Lanka last month, I know this is not funny.

Risk reduction vs. prevention

At the outset, what I learned from the engineering analysis of Louisiana’s complex new defences is that the term ‘flood prevention’ is no longer used simply because you cannot prevent a flood.

The defensive mechanism or structure and systems being built are referred to as Hurricane and Storm Damage Risk Reduction System (HSDRRS), which engineers say will only reduce the risk of damage rather than protect against it.

The HSDRRS, the final phase of which is scheduled to be completed by 1 June 2011, is designed to reduce the risk of storm damage from a one-in-100 year event even though the city was struck by the one-in-400 year storm. Apparently insurance companies find this acceptable!

Engineers have however warned New Orleans residents that they will still have to flee the city in the event of another Hurricane Katrina despite the massive US$ 15 billion in investment in flood defences. I hope our politicians will not use this as a defence to do nothing about the recent floods, death and devastation and the near ‘temporary floating Parliament’.

The Coastal Protection Authority of Louisiana (perhaps a thought for us in Sri Lanka to increase the robustness of equivalent authorities in our country) is reported to have recently submitted a technical evaluation of risks of storms to Congress and the costly design, but apparently Congress has not been too interested in receiving recommendations for the review of standards.

Perhaps our legislators have greater motivation to study similar proposals, given our limited resources for restoration and the costs of defence, as well as at least to keep them afloat!

Levees and contra flows

The levees, which are being constructed, would not wash away as they did in Katrina and less water would get into the city. The HSDRRS has 218 kms of levees and floodwalls, 73 pumping stations, three canal closure structures and four gated outlets.

It is reported that most of the work is being completed at least three times faster than normal while some structures are speeding ahead at up to 15 times faster. While there is criticism that this pace would lead to mistakes, an extraordinary range of checks and balances is also said to be in place.

Pumping stations and surge barriers

A pumping station – considered to be the largest in the US – will evacuate storm water at a rate of 540 cubic meters per second. A surge barrier with around 1,300 vertical concrete piles and 645 steel-angled batter piles is being built. This barrier is about 13 kilometres away from the town.

Ground conditions for foundation work had been difficult since there was no bedrock anywhere, so all the piles are working in friction. The 1,300 precast concrete soldier piles of 1.7 m diameter are at depths of nearly 44 meters. The plan is to create flood defences along the Mississippi River and dredge several canals in order to increase storm water drainage capacity.

US Army Corp of Engineers

The annual budget for the US Army Corp of Engineers who are responsible for building the floodwalls and levees is US$ 4.5 billion. Those involved in the project say that the experiences following Katrina have been a wake-up call for flood risk assessment in the Netherlands, which is supposed to have robust and extensive flood defences.

The justification to invest US$ 15 billion in this flood defence project is that US$ 100 million worth of infrastructure in New Orleans is otherwise at risk. A novel project had been designed and a commitment to build it all in five years had been made.

Rather than execute contracts in the traditional manner, framework contracts were used in order to commence activity. The US Army Corp turned to private contractors – something not ordinarily done in its civil works history. Contractors were brought on board to start work while design continued.

Here again are possible thoughts to engage our Sri Lanka Army Corps of Engineers by providing them with wider scope and to conceptualise and implement private-public partnerships.

I have described the technicalities, very briefly, but have done so, so that civil and structural engineers could research this flood defence project even more in order to make recommendations to Government on flood defence or flood damage reduction systems, undoubtedly on a smaller, less complex scale, relevant for Sri Lanka.

Thoughts for Sri Lanka

It would be prudent to begin in earnest a programme to develop our defences. Here are a few thoughts to catalyse thinking:

•    Is there merit in the State Engineering Corporation taking the lead and together with all relevant Government institutions to conceptualise, design and build defensive infrastructure appropriate to the country and to address reasonable expectations of rain and floods? These need not necessarily be once-in-500 year systems.

•    Is there a role for our universities and graduate and postgraduate students in engineering to work alongside the SEC?

•    Are their multilateral and bilateral organisations which will finance research relevant to the Sri Lankan terrain, the costs of concept evaluation, design, prototype building, overseas exposure visits, etc., for our engineers and PhD students? USAID and bilateral organisations of the Government of Netherlands (a country which is said to have robust systems) are possible, prospective partners.

•    Is there an expanded role for the Sri Lanka Army Corp of Engineers?  Particularly since the ‘war’ as it were is over and Army personnel can be productively employed, thus justifying further their current payroll and related expenses.

•    Are there opportunities for private sector contractors?

There are and will be many more thoughts from many quarters, but I will pause here.

Stakeholder consultation

Apparently, immediately following Katrina, the US Army Corps of Engineers had lined up at the district’s emergency management office to volunteer to assist in the Corps’ recovery efforts.

What policy planners in Sri Lanka can also learn from is that the US Army Corps has welcomed public participation throughout the decision process, hosting more than 300 public meetings across greater New Orleans area to listen to stakeholders and to obtain public comment on the HSDRRS.

This concludes the three-part series. I hope that, in the larger interest of defending against the potential loss of life, economic loss and damage to, inter-alia, infrastructure and agriculture, this series, will have catalysed thinking and action.

(Together with the thoughts expressed throughout this year in other articles in the ‘The Thought Leadership Forum,’ these are dedicated to the memory of my father –Attorney-at-Law, the Late E.G. Wijesinha of Getamanna, in the District of Hambantota. This is also the last Thought Leadership Forum article for 2010, as we begin to enjoy a hopefully rain and flood free Christmas and the dawn of a New Year. I wish all readers and the Daily FT and its wonderful team the best of health and happiness at all times.)

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