The reservoirs will no longer be filled as before", explains Narcís Prat, professor emeritus of Ecology at the University of Barcelona. More desalination, reuse of regenerated waste flows and recycling of water used at home are some of their recipes to face future droughts.
The reservoirs in the Barcelona region are at 16% of their capacity, and the emergency is just around the corner. How we got here?
There are two factors. One is the climate, which has changed. For three years in a row we have suffered a drought with 300 millimeters of rain, as if we were in Almeria. The second factor is that at the time a series of investments should have been made, but due to political issues it was decided that they would not be made [period 2009-2017]. If the 2009 plan had been fulfilled, in which these investments were already included, we would already have them. And if we could have been three years without restrictions, with these investments we could have reached four years without problems.
At this point, will we be left with empty reservoirs?
The reservoirs will no longer be filled as before, due to several factors. The first is the weather. If it rains and snows less and the snow melts earlier, the water no longer accumulates in the reservoirs. Previously, the thaw began in May and the reservoirs were filled to be able to irrigate in the summer; but in the future it won't be like that. Irrigators will suffer greatly in the future. It was already seen last year, when the Rialb (Segre) reservoir was empty, a fact that seemed possible. There will be no choice but to reduce the number of irrigated hectares in the Ebro basins.
What other factors cause less water to flow into reservoirs?
The evapotranspiration of plants, which take water from the ground and which depends on the temperature. Before, from November to March, the plants practically did not transpire, because it was cold; what rained ran down the rivers into the reservoirs. But now, because it's hot, they sweat in the middle of winter and, therefore, start using up water much earlier. That's why it can rain 20 liters in an area and almost no water enters the reservoirs. In 2009 they warned that there would be a decline in snow resources in Catalonia.
You have criticized the lack of investment in hydraulic works by the Generalitat.
In the drought of 2008, the Catalan Water Agency (ACA) asked the Minister of Economy for 300 million euros to undertake emergency works due to the drought at the expense of the Generalitat's budget. The counselor didn't have them and told them to go into debt. When the drought ended, the counselor did not remember that he had promised them the money. Successive councilors continued with the emphasis that hydraulic works in Catalonia should be covered by the fee [which the user pays when receiving the water], but since this fee was insufficient, the ACA continued to take on debt. The debt grew so much that there was no money for investments. Paying back the debt was prioritized. Result: nine years without investment. The Generalitat has not allocated money from the ordinary budget to the water cycle, it allocates almost nothing, now. For years he has not put in the necessary money.
What should be a fair consumption of water?
A consumption of 40 liters per person per day should be the vital minimum. People who consume 40 to 100 liters a day show that they do their homework, because the person is already careful in their consumption and you can't ask for more. But spending 100 liters or more per day of individual consumption, and especially more than 150, should lead to a large increase in the price of water.
The Prat desalination plant and the reuse of regenerated Llobregat water have been key to tackling the drought.
Both the Prat desalination plant and the reuse are ideas from 2004-2008 and, to a large extent, the result of the consultation made by the then councilor Salvador Milà at the Fundació Nova Cultura de l'Aigua. Their principles were followed, that is, efficiency, and not depending on a single resource, that of reservoirs, but having several resources available at the same time: desalination, reuse, some reservoirs and others; it's about having multiple sources available, so that in the future you don't just rely on rain.
Where can we recover more resources?
With desalination and reuse of water we will have a permanent resource, although there will always be a little bit left; we cannot completely dispense with the water from the sky. On the other hand, the fact that there are municipalities with a supply network that loses more than 10% of the water means that they are doing it wrong, because they have not invested in maintenance. It cannot be that there are municipalities that lose 40% of their water. Going down by 10% is very difficult, because the economic investment is very large and the profit is very small. Public investments are required and not just paid by users in the tariff.
All over Spain we have pig macrofarms...
We have the problem when there is more slurry than expected in the fields and contamination of water reserves occurs due to excess nitrates. A very high percentage of pigs are raised here, they pollute the waters and then they are exported. Why does slurry pollute so much? Well, because they are not treated well. But there are technical solutions. The slurry accumulates in a digester on the farm. This way you get methane, with which you can make energy, water that you can recycle and a residual sludge that, once treated, can be applied to the field, since you no longer throw ammonia into it and do not pollute the atmosphere. The problem is, nobody wants to do it. This solves three problems. What's going on? That this is expensive. And there are lobbies that exert great pressure.
How can we improve or obtain more water resources?
The focus cannot be on the citizen who spends 100 liters a day or less. It is key to reuse the water used at home, in the kitchen, in the toilet or in the showers, which can go into the toilet tank. There are already systems of this type; but they are expensive. An incentive policy is needed, as it would save 20% of water.
More proposals?
All urbanizations in Catalonia should have a plan that incorporates the collection of rainwater. When it rained, a good amount of water could be collected, so that for two months it would serve to irrigate, make it potable and drink it. Urbanizations in Catalonia use a lot of water, deplete aquifers, dry up springs or take it from the river.
Would it be good for drinking water?
Yes, if you have a good tank, it is easy to make it drinkable. With a filter and disinfection with ultraviolet light, the water can be drunk. Making a collective deposit is fine, but making it individually helps to raise awareness of the person, who becomes responsible. This could provide 15% to 20% additional resources.
