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Preparing for 'trigger points' key to resilience

Climate change means drought and flood risks now exist everywhere in the world and preparing for "trigger points" is key to resilience, Jacobs Vice-President Bryan Harvey told the World Water-Tech Innovation Summit in London.

Drought and flood pose are a danger to countries throughout the world.Drought and flood pose are a danger to countries throughout the world.

Delegates at the summit in London, which took place on 20 and 21 February, heard from an array of global speakers on the subject of crisis and weather extremes. Referring to the current drought crisis in Cape Town in South Africa, Mark Lane, UK Water Partnership Director, said: "Cape Town is something that is very much in our minds given the news over the last few weeks, but it's much bigger than that, and the flooding side is no less serious."

Lane highlighted London's appearance on the BBC's recent list of the 11 cities most likely to follow Cape Town in potentially running out of drinking water, and Harvey said it was unfortunate that the UK capital had been located "in an estuary environment that's prone to drought and flood".

He said it illustrated an issue in many conurbations globally, adding: "More and more people are moving to the cities and the majority of the water is somewhere else. There's going to be a drought at some point in time and we need to prepare for that moment."

Harvey, who has been working in resilience for over a quarter of a century and operates in numerous countries around the globe, said he has seen indications that the world is waking up to the challenges ahead.

"There's no question that the risks associated with droughts and floods exist everywhere on the planet," he said. "From my experience, the long-term master-planning is definitely picking up pace around the world.

"There's been a real push in many cities to look 50 or even 100 years ahead to see what's going to happen in the future. The challenge is the trigger points. We can invest now to eliminate the risks, but that would be perceived as a waste of money, or we can wait until it's too late.

"What we're seeing in some places now is that they are looking at these leading indications of change which can start the trigger points for investment. We're not sure how much the rainfall is going to increase – the trigger point could happen in 20 years, 50 years or 100 years. We don't know. The important thing is that we know that at some point in time the trigger point is going to be reached which is going to require a new level of investment. That's the thing people are starting to buy into now – you can't prepare exactly but you need to prepare for that future point.

"With that comes that increased level of flexibility in planning, with recycling, desalination, water transfers, surface water issues for droughts, and similarly for floods with spatial and planning systems. I think there's a recognition now that most communities could be affected by flooding at some point, so why not build that into the planning process now?"

Other speakers at the conference spoke about how they are contending with the climate challenges they face.

Dwr Cymru Welsh Water Chief Operating Officer Peter Perry said: "We are seeing today rainfall events that we have not seen previously. If you go back to last summer, we had a month's rainfall in North Wales in an hour-and-a-half. 

"We are in unchartered territory, but I think this is about planning for the long-term. The reality is that doing what we've done in the past just isn't going to be good enough. We're not going to be able to rely on the conventional 'build the walls higher' methods. We have to think differently.

"The biggest improvement we're making is in sustainable drainage, where we're getting water out of our combined sewerage system. We're engaging with communities who are actually building better environments."

Perry stressed the importance of the Welsh Water 2050 programme and in securing customer support for programmes.

Discussing the challenges of retrofitting sustainable drainage systems, he said: "You're going into a street and saying: 'You're no longer able to park your car outside your house because we're going to have some form of natural flood defence there'. It's about engagement and involvement – if you can enhance the environment, you can get people on board.

"We're engaging with local community groups and we've been pretty innovative around this. We're actually paying people who live in streets to maintain those assets for us, or we're working with local authorities to employ people to set up their own landscaping businesses. You will not fix this through traditional methods."

The Netherlands also faces a significant threat from flooding, and Joke Cuperus, CEO at North Holland-based PWN, told the conference about the country's Delta Programme, which has much in common with the Welsh Water plan, with both looking ahead to 2050 and including the widening of rivers and promotion of green gardens.

The viability of alternative water sources to cope with drought was another major topic at the summit.

Anthony Tanti, Executive Director of Malta's Water Service Corporation, and Denis Bilodeau, President of Orange County Water District, both spoke about water reuse as a means of tackling scarcity.

Malta began investing in desalination plants in the 1980s and they contribute 60% of the country's water, but Tanti said groundwater had come under significant stress from agriculture, so they began using treated sewage effluent (TSE) for farming.

Orange County, California, has gone a step further to contend with what one speaker described as a "perpetual drought" in the area.

"In 1976, my district initially started reusing wastewater, taking partially treated sewage to drinking water standards," Bilodeau said. "We injected that water into the ground to create a seawater intrusion barrier to the Pacific Ocean so our aquifer would not be overdrawn. More recently we have constructed a groundwater replenishment system, which is the largest indirect global water reuse project in the world, and we currently make up to 100 million gallons a day of purified water from treated sewage.

"We take half of that water and put it in our seawater intrusion barrier and take the other 50 million gallons and pump it uphill to our service reservoirs that we use for our water replenishment that percolates in the ground."

Orange County Water District uses a three-step process of microfiltration, reverse osmosis and UV with hydrogen peroxide. Reuse is not a cheap process, with 16 megawatts of power used 24/7 and a $1M monthly bill, but Bilodeau said it "compares very favourably to the cost of imported water".

Bilodeau acknowledged that there is a substantial psychological hurdle to offering up purified drinking water from wastewater.

"We had a tremendous barrier to overcome in terms of the 'yuk' factor," he added. "We spent $1M before we built our plant on focus groups and we still run 4,000 people a year through our plant, with tours every day. A big part of our tour is to explain the need for a recycling plant. That's a big thing because the public needs to understand that there's an actual need for what you're doing and that you're not taking the easy way out.

"We get a lot of questions: 'Why are we drinking recycled sewage? The ocean's just there – why don't we just desalt the ocean? Isn't that cheaper?' We go about educating them that desalination is much more expensive and has its own environmental issues.

"We find that we need to continuously educate our consumers. We serve 2.5 million people and today we virtually have no opposition to our organisation, which is a very good thing."

In Iran, though, desalination is the method of choice. 

Mohammed Bagher Kiaei, Vice-Chairman of Energy & Water Resources at Rah Shahr International Group, said his country can no longer rely on available natural water resources and that the national policy is now to supply industrial and potable water in the coastal areas by seawater desalination as well as water reuse.

More than 10 million inhabitants will be settled in 'coastal new towns' in Iran, while private investment is funding the drive towards desalination, with over €370M spent on 64 projects, resulting in a production capacity of over 373,000 m3 per day.

However, even with the plentiful supply of oil and gas to assist with the power challenge, he said around $15BN is still required to meet the wastewater infrastructure challenges in Iran.

Author: Robin Hackett, Deputy Editor, WWT and WET News
Topic: Innovation , Water Resource Management , Flooding & Urban Drainage
Tags: drought , flooding , drinking water

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