Seychelles: On the way to a better wastewater management
The Republic of Seychelles plans to improve its own sewage system. Strong rainfall and a high groundwater level often lead to floods. Dorsch International Consultants GmbH was commissioned with design and construction supervision by "Public Utilities Corporation of Seychelles (PUC)" in 2015. After the successful completion of the design phase, the construction supervision has started now; the project ends in autumn 2019.
Vacation paradise in the Indian Ocean
The island republic of the Seychelles is located East of the African continent and North of Madagascar in the Indian Ocean. In total, the republic consists of about 115 islands and atolls, of which about 35 are inhabited. They have always been a popular tourist destination, generating about 70% of the country's income. The islands of Mahé (145 km²), Praslin (38 km²), Silhouette (20 km²) and La Digue (10 km²) belong to the Seychelles. They are distributed over a sea area of about 390 000 km ², while the land area covers only 454 km ², which is about the size of Andorra (Europe). It is the most densely populated and therefore the most important archipelago in the country. The climate of the Seychelles is influenced by the monsoon, the humidity is more than 80 percent.
Step by step to a new sewage system
Due to the high groundwater level and the fact that there was no sewer system at altitudes above 200 meters, heavy monsoon rains often cause flooding. In addition, the population is growing and thus an extended sewage system was necessary. With the "Seychelles Water Development Plan 2008-2030", the Seychelles government presented a 20-years investment plan to meet water needs in the three main islands of Mahé, Praslin and La Digue by 2030. This overall project focuses on the design / repair of a wastewater treatment plant on the main island of Mahé and the construction of a new wastewater treatment plant on the neighbouring island of La Digue. Wastewater treatment protects the valuable ecosystem with its flora and fauna. Ground water resources can be used and the disease risk of the population is reduced.
The project is divided into two phases. Phase I is primarily about the design of sewer and sewage treatment plants. Phase II involves construction supervision within the new sewage system, including sewerage and sewage treatment plant for 5,000 population equivalents on the island of La Digue. In addition, the replacement of the main pressure line, the reconstruction of eight pumping stations and the treatment plant of Providence for Greater Victoria on the island of Mahé with 87,000 population equivalents. The so-called population equivalents represent an arithmetic variable for wastewater treatment.
The Dorsch project scope includes:
- Feasibility studies
- Detailed Design of a new sewage system for La Digue
- Detailed Design for the rehabilitation of the sewage system on the island of Mahé
- Preparation of tender documents
- Technical evaluation of offers by contractors
- Construction supervision and supervision in compliance with environmental, safety and health requirements
„Also because of the flourishing tourism in this region, it’s important providing a high quality and stable on-site sewer system; it’s essential to protect the ecosystem and biodiversity sustainably. The new sewage system is an environmental benefit for the people and for the region", stated Dr. Laure Nicolet-Misslbeck, Technical Manager within the department "International Cooperation" at Dorsch in Munich.
Press Release: Seychelles: On the way to a better wastewater management (pdf, 572 KB)