Saturday 18 November 2017

Waterworld: where will we be in 10 years?

Tough choices will have to be made to save homes from floods in an era of climate change - but not ­everywhere and everyone can be defended in the future.

Boat and boots: Daniel Downey helps his little neighbour Beau (2) through the flood waters outside their homes in Crossdoney, Co Cavan. Photo: Lorraine Teevan
Boat and boots: Daniel Downey helps his little neighbour Beau (2) through the flood waters outside their homes in Crossdoney, Co Cavan. Photo: Lorraine Teevan
Cover of water: Properties in Co Galway after the flooding this week. Photo: Defence Forces
How to prevent flooding in your home
Kim Bielenberg

Kim Bielenberg

For householders on the banks of the Shannon only inches stood between relative comfort by their firesides and disaster this week. By Wednesday in Athlone houses were below the level of the surging river.

Only leaky sandbags, pumps and the hard work of volunteers, council workers and the Defence Forces - working morning, noon and night - were preventing an absolute deluge that could have ruined entire estates.

The flood defences seemed desperately flimsy and primitive in an age when our European neighbours are sending men and women into space, but one can only imagine what would have happened without them.

Having been slow to react, the Government this week was keen to be seen to take action on flooding on the Shannon.

But there are two things that can be said of this crisis with absolute certainty: we have been here before many times; and we will be here again in the not too distant future.

Dr Kieran Hickey, a UCC geographer and author of Five Minutes to Midnight? Ireland and Climate Change, says: "The situation is only going to get worse as a result of climate change with more frequent and more intense storms.

"It is noticeable with the recent storms that some places are flooding that never flooded before."

Even Ireland's oldest pub, Sean's Bar in Athlone, could not escape the deluge. At one stage the water came up, and regulars had to walk through part of the lounge on palettes, but the beer kept flowing.

Cover of water: Properties in Co Galway after the flooding this week. Photo: Defence Forces
Cover of water: Properties in Co Galway after the flooding this week. Photo: Defence Forces

Owner Timmy Donovan says: "If I wanted to, I could get a boat from the back door of the pub all the way to my home in Barrymore (near Athlone)."

This week's resolution by the Government to do something about the Shannon is just the latest in a long line of initiatives going back decades.

Back in 1952, the Minister for Lands Thomas Derrig, was being asked in the Dáil to help farmers who were being constantly inundated by floods from the river.

The minister said: "It is hoped to initiate a survey of this area shortly with a view to ascertaining, in consultation with other departments, what can be done to ameliorate conditions."

How to prevent flooding in your home
How to prevent flooding in your home

Six decades on and conditions have hardly improved on the Shannon. The only thing that has changed is the growth in the number of state agencies involved with administering the waterway.

As well as 18 local authorities responsible for dealing with flooding along the river, there are reckoned to be at least 16 state agencies, including government departments and quangos, now involved.

No wonder Enda Kenny's gathering of state flooding bodies on Tuesday looked like a praesidium of the National Congress of the Chinese Communist Party, such were the numbers.

As he manned the pumps on the riverbank in Athlone, local councillor Kevin 'Boxer' Moran, who has fought day and night to keep the floods away, said: "There should be one single agency in charge of the Shannon. We have tried to get flood defences in Athlone, but we had to go through six different agencies - and if you have to go from Billy to Jack, it is very hard to get anything done."

So, if we look ahead 10 years, what could be done to alleviate flooding and where possible prevent it?

The Government has identified 300 areas around the country that are at risk of flooding including 66 trouble spots along the Shannon. After the election it will be a matter for a new government to decide which areas should be given flood relief schemes, and just as importantly, when these will be built.

The Government plans to spend €430m on flood defences in the coming five years. That is double what is being spent at the moment.

But Kieran Hickey of UCC estimates that even that amount is only 20pc of what is required to solve the problem in areas where that is possible.

"The Government will have to prioritise towns and cities of high population, where there is regular flooding, such as Bandon and Ballinasloe," he says.

Urban flood relief schemes are hugely expensive and typically cost €20m to €40m. On the positive side, they seem to have worked in towns such as Clonmel and Ennis.

In recent days, there have been many sad stories of rural families left stranded and in some cases flooded out of their homes.

When it comes to flood defences in the future, the authorities will have to make tough decisions.

Liam Prendiville, engineer with JB Barry consultants, a company that has worked on flood schemes, says: "There are very difficult choices that will have to be made.

"If you have a handful of houses in an area that is being flooded regularly - and they are worth a total of €1m, do you spend €10m on a flood relief scheme?"

Back in the 1950s when there were similar flooding problems on the Shannon, there were plans to resettle rural families. And the Taoiseach has talked of a similar scheme in recent days.

Kieran Hickey says: "Any resettlement scheme would be extremely hard in Ireland, because of our attachment to property."

Any plan to tackle this almost perennial problem would also have to tackle the controversial issue of agricultural land and the flood plain.

When flooding becomes a problem, farmers are inclined to drain their land, but is that creating problems elsewhere?

"In Germany they are now creating systems where farmers are encouraged to allow their land to flood in periods of high rainfall, and they get grants for it,'' says Kieran Hickey. "It's really flood farming."

The problem for farmers along the Shannon is that the flooding has become more frequent, and also now happens more regularly in the summer time.

Professor Michael Hartnett, an engineer at the Environmental Change Institute at NUI Galway, says the problem on the Shannon is that there are no easy solutions.

"If you come up with a solution at Point A, you have to check what the consequences are elsewhere."

Some flood solutions can make matters worse.

"The Mississippi is a classic example. Over the years they have put embankments and flood walls in to prevent certain towns and cities from being flooded, but it has pushed the problems elsewhere."

Radical alterations to a river's course can also have negative consequences.

"In southern Florida they did a lot of work straightening the Kissimmee River to convey water more efficiently, and over the past 10 years they have spent the guts of $1bn putting it back to the way it was," says Prof Hartnett. "They allow it to meander more again and allow the natural flood plain to be the receptor."

He believes draining the land around the Shannon would not be a solution.

"If you drain the land you are getting larger amounts of water dumped into the river system quicker. You can drain certain areas of the Shannon but that may have a significant consequence somewhere else, and it could be in Limerick City."

In Holland, where much of the land is below sea level, the government goes to great lengths to stop flooding, and they use a technique known as "room for the river".

The flood plains are widened and deepened to take more water at times of heavy rainfall, and secondary canals are built to take some of the excess rainwater and river flow.

In Ireland, dredging is a solution that is frequently touted after floods as a solution to local problems.

"It's certainly not a panacea, and I believe the effects would be quite localised," Prof Hartnett says. "On parts of the Shannon, the extent of flooding is so wide, dredging may not have a significant impact on the inundated areas overall."

Kieran Hickey is also sceptical of dredging as a solution.

"There may be some pinchpoints along rivers that need to be cleared, but it shouldn't be seen as a catch-all solution.

"It has to be done very carefully, because it can undermine riverside structures such as bridges."

Kieran Hickey said councils could do more to prevent localised flooding by clearing out drains and culverts, and this might have been affected by the decline in local authority staffing.

In a country of high rainfall and more intense storms, we will never be able to prevent floods completely, but we should be able to use a much more sophisticated warning system.

Michael Hartnett and a team from NUI Galway have devised a flood model so accurate that it can pinpoint how floodwaters will affect individual houses days in advance.

"We have developed a model where we take the Met Éireann's forecasts and make a scientific forecast of the water level rise, and the timing of flooding. We should be able to tell which areas will flood 48 hours, or even a few days, before it happens.

"This type of model could be rolled to any river catchment in the country."

This could help householders to prepare to protect their homes, remove carpets and furniture, and sandbag the doorways.

The latest storms may have been a wake-up call to those in authority, and that may be timely given that storms are likely to become more intense in the coming decades as a result of climate change. Winter rainfall is projected to increase by 10pc, with the largest winter increases expected to occur in the midlands.

The Government is going out of its way to mollify irate householders who have been inundated by the latest deluge.

But the real test will come when the rain stops, the flood waters recede and after the election posters come down. Politicians will never solve the problem of flooding completely, particularly on the Shannon, but they can protect greater numbers of people and their home by putting in flood defences in certain areas and by being much better prepared when the inevitable storms return.

Measures that can be taken to improve your home's flood defences

How to prevent flooding in your home

Despite promises to improve community flood ­defence schemes, many Irish homes are likely to remain vulnerable, and this may only get worse as a result of climate change.

Surprisingly, many householders who are at risk do not take basic precautions, and there may be a case for making changes to the property to limit the possible damage. It is impossible to completely flood-proof a property, but there are a number of measures to prevent water getting in. These tips are recommended by the Office of Public Works and the British Environment Agency.

As well as coming through doors and patios, water can find its way in through air bricks on exposed walls and through gaps in the floor.

There are a number of flood guards or flood boards that can be used to block doors and gates. Some removable modern flood barriers seal your doorway at times of risk with a neoprene rubber sleeve. Covers should also be placed over ventilation bricks.

Another way that water comes in is through drains and pipes as the pressure created by flooding can reverse the flow, causing water to back-up and enter a home through sinks, toilets, washing machines. Consider fitting "non-return" valves to drainpipes and other pipes that could allow water to back up.

The traditional methods of using sandbags can help, particularly when used with plastic sheeting. Keep a supply in storage.

In construction, consider using products such as liquid membranes, polymer/cement coatings, mastic asphalt or pre-formed sheet membranes.

To improve the flood resistance of windows and doors, ensure that the seal around the frames is intact. Treat any wooden frames with oil-based waterproof stains, paint or varnish.

Air conditioning, heating or gas units should be situated on the first floor or in the attic.

Make sure that any streams, rivers or lakes on your property are able to flow. Check for blockages in the stream and ensure that the banks have not eroded.

Raise electrical sockets, fuse boxes and wiring to at least 1.5m (5ft) above floor level or well above the level that homes have flooded historically. In kitchens and bathrooms, use water-resistant materials, such as stainless steel, plastic or solid wood rather than chipboard. Use tiled flooring with rugs, rather than fitted carpets.

Fix TVs and other electrical entertainment devices to the wall at least 1.5m off the floor. Put valuable or irreplaceable items on high-mounted shelves.

Wrapping is an advanced method of reducing the effects of floodwater by enclosing the bottom 600-900mm (2-3ft) of a property in plastic sheeting.

The process involves digging a trench in front of the wall you wish to protect. The plastic sheeting is attached to the wall above the expected height of the flood. It is run down the wall and placed over a drainpipe at the base, before being run through the trench and secured on the other side with weights or sandbags. Wrapping a building takes some DIY ability and needs to be started well before floodwater arrives.

In cases of severe flooding (where floodwater rises above 1m) keeping water out of your property can be more harmful than letting it in. The stress on the building caused by that can damage the structure and foundations of the building.

For more information:

Indo Review

Promoted Links

Today's news headlines, directly to your inbox every morning.

Promoted Links

Editor's Choice

Also in Irish News