Civil Engineering May 2021 | Vol 29 No 4

Civil Engineering May 2021 23 Seychelles, an archipelagic island country situated in the Indian Ocean near the equator, is known for its serene ocean landscapes and budding tourism industry. Despite its remote location, the island has a strong economy, boasting one of the highest nominal per capita GDPs among African nations. Key to the country’s economic prosperity is Port Victoria, Seychelles’ primary international sea-freight terminal. The existing spatial and infrastructural limitations of Port Victoria and its potential effect on Seychelles’ economy have made the expansion of the port a key priority. Port Victoria is located on Mahé, the island hub of Seychelles. The port is base to an industrial-scale fishery which generates a major part of the country’s revenue-earning exports of produce. It is also handles the bulk of the country’s imports, including fuel, cement and general cargo (mostly contain- erised). Cruise ships also call at the port. The port currently comprises two adjacent quays, namely the Halcrow and Norplan quays. Construction of these quays was completed in 1972 and 1985 respectively, providing a total quay length of approximately 370 m, presently referred to as the Mahé quay. The Halcrow quay is in a heavily deteriorated condition, while the Norplan quay is considered still to be in a fair condition. The quays were originally built to serve general cargo vessels equipped with their own lifting equipment and are therefore not equipped with quay cranes. Apart from the poor condition of the quays and the lack of handling equipment, the port’s terminal area is insufficient to accommodate the increasing container throughput demand. Furthermore, the berth area is about -12 m to chart datum, severely restricting access for Panamax- sized and larger container vessels. PROJECT DESCRIPTION As a result of the spatial and infrastruc- tural limitations of Port Victoria and its potential effect on Seychelles’ economy, the Seychelles Port Authority embarked on a journey to expand the port. The fea- sibility study, concluded in 2017, proposed to replace the existing quay with a 600 m long quay, reclaim land through a seaward offset of the cope line, and deepen and expand the port basin to accommodate container vessels and fuel tankers with static drafts of up to 14 m. In 2019, the detail design study needed to take this project forward to construction stage was awarded to Project Planning and Management (PPM). PPM appointed WSP to develop the container terminal operational layout, undertake ship nautical studies and provide the dredging design and management plan, while Zutari was appointed to undertake the design work for the quay wall and reclamation. This article focusses on the development of the basin area, as depicted in Figure 1, and the associated dredge management plan (DMP). Marthinus Retief Maritime Technical Director WSP Africa marthinus.retief@wsp.com Port Victoria expansion – port basin design Roy van Ballegooyen Maritime Associate WSP Africa roy.vanballegooyen@wsp.com Marius Rossouw Port & Coastal Engineer WSP Africa marius.rossouw@wsp.com Figure 1 The Port Victoria basin BASIN AREA PROPOSED NEWQUAY WALL Yasmin Kistner Port & Coastal Engineer WSP Africa yasmin.skibbe@wsp.com