Urgent desilting works under way ahead of heavy rain |24 December 2022

Desilting work under way at Cascade (left) and ex-Onezime Estate

Due to the heavy rainfall last weekend which caused flooding in some areas on Mahé, the department of Climate Change within the Ministry of Agriculture, Climate Change and Environment, in collaboration with the Seychelles Infrastructure Agency (SIA), is implementing urgent flood mitigation projects in the districts mostly affected, namely Anse Aux Pins, Pointe Larue and Cascade.

Speaking at the ex-Onezime Estate, Anse Aux Pins, where desilting and clearing works are being carried out at the mouth connecting the Kapisen, Gran Basen and Kayol rivers, Jitesh Shah, the chief executive of SIA, said that before the country experiences the next heavy rain, they are trying, with urgency, to do as much as possible to desilt rivers in critical areas that have been affected by flooding.

Desilting works in the marsh at the mouth connecting the three above-mentioned rivers at Ex –Onezime Estate (stretching 500 metres) to increase the capacity of the rivers to take up the volume of water including the accumulation of sediment during heavy rainfall, is being undertaken by Monaco Builders at a cost of R2 million.

It has been many years since desiltation has been done in the area. The desilting and clearing work is for four weeks. Funds will also be made available next year to rock armor the embankments that will be affected by the velocity of the water, hence impacting on properties and houses along the area.

“As we do the desilting, the velocity is going to increase in terms of the flow of the rivers which will put the embankments more at risks, and the plan is early next year to come and do some rock armoring in localised areas where we feel the risk of an embankment collapse is high,” Mr Shah said.

As to how regularly desilting  works will take place in the rivers, Mr Shah said it will be difficult to have an exact figure on how frequently desilting will take place given that sediment build-up in the rivers depend on a lot of factors. He added that nonetheless, they are working on measures to desilt the rivers before they get piled up with sediment beyond the acceptable level.

“So what we are planning to do is to put some markers in the rivers, which are clearly visible, where we can see when the silt is building up to a level which is going beyond the acceptable limit where we know that it’s going to start impacting on the rivers and where will make provision for the following year for us to make the budget available to come and do these desilting exercises as opposed to just doing ad-hoc work when we get a flooding event,” Mr Shah explained.

Desilting work taking place in the marsh at lower Pointe Larue, opposite the SACOS apartments, is being done by Esparon Enterprise at a cost of R700,000 while that taking place in the small river next to the St Andre village, leading to the lagoon at Cascade, is being undertaken by All Weather Builders at a cost of R64,000. Depending on their quality, the gravel and silt are being stockedpiled at Ile Perseverance to be used in construction projects and at the landfill for compacting purposes.

 The desilting works form part of the flood mitigation measures as instructed by the High Level Committee for the Flood Free Seychelles, headed by President Wavel Ramkalawan.

Patrick Joubert