Environmental impact assessment for the rehabilitation pf the harbor, Maavah Island, Laamu Atoll, Maldives

Abstract

This report discusses the findings of a social and environmental impact study undertaken by Water Solutions Pvt. Ltd. at the request of Ministry of Housing and Infrastructure for the proposed harbour rehabilitation project at L. Maavah. L. Maavah is located on the western rim of Laamu Atoll and has a population of 1800. The island economy depends mainly on fisheries which involve boating activities. The existing harbour at the island was constructed in 80’s. The quay wall and the breakwater was constructed using corals. The seawall had been badly damaged and the harbour has become too small to cater the large and deep draft vessels which call to the harbour. Hence the proposed project is to rehabilitee the existing harbour which can cater the growing demand for the vessels which will be using the islands for the next 15 years. The rehabilitation of the harbour includes, construction of 339 m of quay on western and southern side of the harbour using L blocks, deepening the harbour basin to – 3 at mean sea level. As part of the project, the harbour basin would be made 64 m long and 15 m wide. The existing breakwater on eastern side of the harbour would be rehabilitated as part of the project. The breakwater would be rehabilitated using existing materials at the breakwater and the materials recovered from the demolition of the existing quay wall at the island. It is estimated that 129 m of the rehabilitated breakwater would be made using reused corals. Additional 70m of the breakwater would be constructed using sand cement bags. The total length of the rehabilitated breakwater is 199 m. The rehabilitation of the harbour basin would generate around 28,665m3. This material would be disposed to the area north of the harbour. This area is presently eroding. It is estimated that the dredged material could be used to replenish 21,000 m2. Additionally the project would construct 91 m of sea wall using sand cement bags on northern side of the island and 15 m long revetment north of the harbour to protect it from erosion.. 4 marker lights would be place on 4 corners of the harbour entrance channel. Environmental and socioeconomic impacts of the project was assessed. The impacts of the project result mainly from excavation of the harbour basin and entrance channel and disposal of excavated materials. The impact of excavation would be that of sedimentation. This impact is considered to be minor and short-term. Re-excavation of the entrance channel and harbour basin would have irreversible impacts. The project would help to address the current erosion problem by replenishing the eroding beach with the materials borrowed from the harbour basin. The socio-economic benefits of the project may be considered to outweigh the negative impacts of the project on the physical environment of the island especially increasing the usable space on the quay wall, mooring area at the island’s harbour and additional land that would be available to develop fish processing industry. The proposed project conforms to prevalent environmental legislation and thrives to achieve its objectives in a environmentally friendly manner. Mitigation measures for these anticipated impacts have been identified and outlined in detail, including sedimentation and stagnation control methods and measures for minimizing negative effects demolition of the quay wall and the generation of construction waste. These mitigation measures need to be followed in order to minimize environmental damage. The details of the project have been established after considering the needs and requirements of the community by assessing and incorporating the outcomes from the community consultations held during the data collection stage. The EIA also allowed to explore the best possible alternatives for the proposed development and identified key mitigation strategies.Alternative locations and alternative designs have been investigated for the different components of the project. However, the present project design seems to be a feasible option in terms of costs, durability and safety. An environmental management plan with environmental monitoring plan has been developed including important elements that require regular checks. This monitoring component will be adhered to and will allow the assessment of changes due to construction of the harbour. Although the project involves inevitable negative environmental impacts, such impacts are not severe as to not undertake the project. The project is justifiable in light of the socioeconomic conditions and anticipated benefits resulting from the project, which seem to outweigh the negative environmental impacts.