Environmental impact assessment for the proposed shore protection project in Bilehffahi, Shaviyani Atoll

Abstract

The purpose of this document is to fulfil the requirements to get necessary environmental clearance from the Environmental Protection Agency to carry out the proposed harbour maintenance project in Bilehffahi, Shaviyani Atoll. The proponent of this project is Ministry of Environment & Energy. The main rationale for the project is to improve the access facilities of Bilehffahi Island to facilitate improvement in the social and economic condition of the island. The island has a harbour and a reef entrance, but the reef entrance has become shallow overtime and has become dangerous for navigation due to the narrow width. This project mainly involves widening the reef entrance, relocating a section on the breakwater and disposing the dredge waste in designated locations near the harbour. The development is designed based on environmental best practices suitable for marine construction in Maldives. The project involves constructing erosion mitigation measures in Bilehffahi Island on the northern and a section of the western beach. The proposed structures are nearshore breakwaters based using armour rock. All project activities will be in conformance to the laws and regulations of the Maldives, and relevant international conventions that Maldives is party to. The key laws and regulations applicable to this project are: Environmental Protection and Preservation Act, Dredging and Reclamation regulation and Environmental Impact Assessment Regulation 2012. Additional approvals are required for the following before commencement of project activities. Detailed drawings approval from the Ministry of Environment, Revision to the Dredging and Reclamation approval if the alternative site plan is chosen. At present the island is undergoing severe erosion on the north and western side. Analysis using long-term data shows that Bilehfahi is ranked among the islands with the largest changes to the shoreline in the last 50 years. The northern side has retreated alarmingly prior to 2004 but the southwestern side has also grown to an unprecedented rate. The proposed protection measures are warranted on the north as it displays a long term trend of island migration. However, the southern side erosion could be considered periodic and the deployment of erosion mitigation measures on a section of beach could have consequences for the stability of the rest of the island. The proposed project site is in the shallow reef flat. It does not contain any live corals and the neared live coral cover zone is far from the site. Moderate live coral cover was observed on the reef slope at the surveyed points. Significant impacts of this project during construction phase of the project are potential significant impacts on the marine environment due to excessive sedimentation, turbidity and direct excavation related to temporary sand bed construction. The specific impacts on the coral reef and lagoon environment are cumulative in nature and include loss of lagoon benthos organisms along the dredge site, temporary sedimentation in on the reef areas close to the northern tip of the island particularly with table corals, loss of coral life and temporary impacts on fish life. These impacts are likely to persist only in the short-term. There will positive and negative impacts on hydrodynamics and beach erosion. Changes to hydrodynamics are an intended objective of the project. The leeward side of the breakwater is expected to be calm, stabilising the beach behind it. Wave refraction around the corners of the breakwater is likely to cause focussed erosion on the corresponding beach areas. The orientation of the breakwater will have an effect on wave behaviour. During the operation phase the main concerns are the potential risks to health and safety. There is also the potential risk of erosion in unprotected sections of the beach. Most of these impacts can be minimized with proper mitigation measures recommended in the report. Key mitigation measures for the construction stage include working during calm conditions to minimise damage to the surrounding coral reefs. It has been recommended to consider alternative orientation for the northern breakwater to reduce the effects of wave refraction and costs. The southern breakwater is recommended to be redesigned to facilitate seasonal movement. Consultations were undertaken with the public, Island Council and Ministry of Environment. All persons consulted were in favour of reviewing the designs to propose designs that would have least impact on the environment and those that would allow to continue the activities undertaken on the beach such as boat maintenance and recreation. The alternatives evaluated for the project were the no project option, alternative erosion mitigation plan, alternative sediment containment measures and sand burrow areas. The no project option is viable on the island, particularly on the southern side, in geophysical terms as the island is undergoing substantial net accretion, at a scale which has not been observed anywhere else in the Maldives. The no project option is not viable socially as there will be significant public discontent if the project is stopped. It was recommend proceeding with modified design based on these conditions. Alternative erosion mitigation measures were anlaysed for both the northern and southern side and recommend over the existing site plan. The revised options are cheaper, more efficient and address public concerns as well. The monitoring plan has been designed with a focus to analyse the significant impacts over time, particularly the effect on water quality and the impacts on marine life A management framework has been proposed and it is essential that this framework be used in the construction stage of the project. The operation stage management can fall within the overall resort environmental management framework. In conclusion, project mainly has beneficial socio-economic impacts.