La Gogue Dam at 71% in spite of drought: |26 September 2016

PUC wants to avoid water restrictions

Despite the ongoing drought which is normal for this period of the year, water level in the La Gogue dam has remained stable.

Seychelles’ largest water reservoir is at the moment 71% full even if recorded rainfall has been very low for the past three months. Rochon dam, which serves as a feeder reservoir to La Gogue, is even in a better situation, at 82% capacity.

Maintaining high water level in its main reservoirs has permitted PUC to up to now avoid imposing water restrictions or distribution by bowser. The sight of pick-up trucks loaded with tanks bringing water to long queues of waiting families up to the late hours of the night seems in fact to belong to the past, as confirms Public Utilities Corporation’s (PUC) managing director Philip Morin.

“The level is under control as we continue to closely follow the water situation on a daily basis. Our aim is to go through the dry season without restrictions,” he commented.

PUC’s capacity to maintain the high water level and prevent water shortage during the dry season is due to what it calls a “security of supply strategy” composed of five main elements:  A prudent management of the entire water collection, storage and distribution system; maintaining sufficient reserves in the dams; extracting more water from rivers and transferring it to more needy areas including across the island of Mahé; ensuring the full working capacity of the desalination plants while rivers go dryer; and reducing non-revenue water or water which goes to waste.

This last component which has included detecting leakage, preventing illegal extractions and removing non-working or ‘pirate’ metres has permitted water loss to drop to 38% from 55% previously. As examples, water loss has been reduced by two million litres in a single day in north Mahé alone and the recent detection of a leak at Roche Caïman permitted to save 4,500 litres of water a day.

In spite of the savings, Mr Morin insists that “there is still a lot to do in order to improve the situation”.

PUC’s efficient management of water distribution has also included the supply of a combination of rain and desalinated water. However, even if the company says its desalination plants are operating at a very efficient rate, the water they provide represents only 46% of daily consumption. In the case of Mahé for example, out of 39,000 cubic metres consumed every day, only 18,000 come from desalination plants. At the same time, the company wishes to reassure the public which is at times doubtful of the quality of water pumped from the sea that it is of very good quality.

“The water produced is the best that we can offer as we ensure the proper mix,” its managing director has ensured even if he insists that a sufficient level of water must be kept in the dams, in case there is a problem with the desalination plants.

“If we empty the dams we will have to rely entirely on the desalination plants. If then there is a breakdown or other problem we will be in serious trouble,” he added.

Mr Morin has taken the opportunity to justify the investment government has made in favour of desalination plants, saying that they are cheaper than building dams and are at the same time more reliable, even if they require strict maintenance. He gave the example of one billion rupees now needed for the building of a new dam at Grand Anse Mahé, while only about 18 million would suffice for a new desalination plant and of which capacity could be built gradually compared to a downright investment for a dam.

He added that PUC does not have the money now and that even if sufficient funds were available, construction would take two to three years while in the meantime water demand would increase.

He also added that a dam at Grand Anse would provide water to only the south west part of Mahé, while asking “what do we do for the rest of the island?” As for other islands like La Digue, the PUC boss reminds that there are no realistic locations to build dams, while he again emphasises that “water produced there is of better quality than from wells to the point that Diguois sometimes think they are drinking well water”.

He said that desalination plants are more environmentally friendly as they eliminate risks such as pollution.

“The use of desalination plants rather than dams puts us in a comfortable solution and ensures continuity of supply as we look for money to build dams. But we do not rely on them every day even if dams are in the long-term more expensive. The plants have avoided disruption in supply and have saved us so much trouble during the last years. For this reason, dams cannot substitute desalination plants. The decision to invest in them was a good one even if we continue to find other solutions. So we are not saying that we are putting more emphasis on desalination. It is a back-up and provides good water security. It is part of the solution,” Mr Morin explained.

He has however warned that even if deep into the dry season we are still enjoying a comfortable water situation, the current reserve in the dams represents only two weeks of consumption.

If we do not get sufficient rainfall by then, PUC says that it will have no other choice than to impose restrictions.