Towards a water solution for all
“When one man drinks while another can only watch, Doomsday follows.” Turkish Proverb
It is obvious to anyone who pays attention to the media that something is seriously wrong with our water system – it’s an embarrassment. We don’t need to recap what is being reported but, put very simply, there’s not enough water to go around.
Two main reasons have been given for this situation. First, that we are still experiencing the effects of the 2015-16 drought conditions and that the recent rains have not yet had an impact. Second, the water supply system is breaking down so the water is not reaching the people. Clearly, this situation is unacceptable and more needs to be done. But we have to be careful not to act without thinking.
Water supply systems are expensive to build and run and they last a long time. How often have we been told that some of our system is over 100 years old? So, whatever we do must consider what the future might hold. And that means taking account of how climate change is going to impact us.
In our first article, we saw that in just over 30 years’ time, we expect the amount of water needed to increase by around 30%, to support a growing population, businesses and tourism. At the same time, we expect how much we can get from the groundwater to drop by around 50%. In other words, even with the present Spring Garden desalination plant, there will not be enough water to meet everyone’s demand.
If we do nothing, then by 2050 (just over 30 years from now), on average water demand would be equivalent to 60,000 gallons per person (that’s about four times as much water that you’d drink in a lifetime) whereas we would only be able to get 33,000 gallons per person from the desalination plant and the groundwater; a shortage over a year equivalent to 27,000 gallons for every person on the island. The implications are enormous.
There are two ways to bridge the gap. You increase the supply by finding more water or you decrease the amount of water being used. Either way, supply and demand have to be brought into balance. We could increase supply in three ways; by desalinating seawater – which is plentiful but costly, by importing water or, by rainwater harvesting. We could decrease demand by; asking people and businesses to use less, using technology to improve the way in which water is used or, by introducing economic incentives which reward good behaviour or punish waste.
The Barbados Water Authority has plans for two seawater desalination plants, provisionally with the same production capacity as the Spring Garden plant. Assuming that they could operate all year round, two such plants would add the equivalent of 20,000 gallons per person. We don’t know what the cost of building these two desal plants is going to be, how much they will cost to run or what their source of energy might be (fossil fuel maybe?).
But, if we base rough estimates on the cost of the existing plant and without operating costs, that is the equivalent of everyone having to pay at least an extra $100 every year. And it would not cover the demand.
The calculations of demand include the reduced level of leakage that the BWA hopes to reach through their current mains replacement programme. It is obvious, to us at least, that more needs to be done to reduce leakages. We estimate that reducing leakage to say just 15% from the current level of 43% of consumption would reduce demand by the equivalent of 17,600 gallons per person.
This is just less than the additional supplied by the desal option at broadly the same overall annual capital cost. The advantage would be, though, that there would be cost savings as operational costs would fall whereas with desal, they would increase. However, this still does not balance the books so other measures would have to be considered.
We need to get serious about this and realise that water is scarce and it’s going to get worse. People need to learn the value of water. We cannot have situations where people wait for the BWA tanks to be filled just so they can wash their cars. Perhaps we need to look at smarter water tariffs that encourage more efficient water use. Perhaps we need to incentivize the use of previously used (what we would normally call waste) water.
Reusing water could add the equivalent of 10,000 gallons per person to supply, though at what cost we are not sure. A mix of technological and economic measures that improve how water is used could reduce demand by anything up to 50%. Surely these are worth looking at. But time is running out and we need concerted action now. We have seen what the future looks like if we do nothing and it is not pretty.
The research that UWI is engaged in can contribute to better decision-making and the choice of options. But research alone is not enough, we all need to be more respectful of our water with people, professionals and politicians working together to secure a future where we all have access to water; children, senior citizens, working mothers and users all across the island, not just for the good of a few but for the many.
(Dr Adrian Cashman CEng, PhD, MCIWEM is Senior Lecturer in Water Resources Management and Director of the Centre for Resource Management and Environmental Studies based at the University of the West Indies, Cave Hill Campus)