Environmental impact assessment for the proposed coastal modifications Chaaya Lagoon Hakuraa Huraa

Abstract

This report addresses the environmental concerns of the proposed first phase of the coastal modifications including installation of groynes and sand pumping for beach nourishment on the western end of Chaaya Lagoon Hakuraa Huraa, Meemu Atoll. This project has been previously approved and due to delays in implementation, the project is further scrutinized including changes to the proposed shore protection structures and new EIA. Hakuraa Huraa, like several other resorts and inhabited islands across the Maldives, is subjected erosion and coastal protection structures have been constructed. These mainly include the groynes and seawall structures on the eastern side as well as temporary sandbag groynes and revetments on severely eroding areas on the proposed western end of the island. The southern side and the eastern and western ends are prone to severe erosion while the northern side has always had accretion. There had never been any beach nourishment despite having a groyne field on the southern side. Therefore, the effectiveness of the groyne field on the southern side has not been known. The southern side with a long stretch of shallow reef flat faces the atoll rim. Therefore, this side is constantly subjected to the swell-induced crossshore movement of sediment. Hence, groyne field on the southern side may not be effective. However, on the eastern and western ends of the island, there is a strong longshore current and groynes are expected to be quite suitable for these two ends of the island. Hence, a groyne field is proposed for the western side, which is being considered as a first phase of the shore protection project. The groynes will be constructed using rock boulders with a core enclosed by geotextile. A small volume of about 500tons of rock boulders is estimated for the proposed groyne field. In addition, the groyne field and part of the southeastern shoreline will be filled with sand pumped from a location on the southern side where there is ample sand. The location will be about 150m from the island’s shoreline, which is the most practicable distance for sand pumping using most of the sand pumps currently available in the Maldives. A sand pump is most suited due to its small size and dredgers would not be feasible due to the small volume, which is 5,500m3 of sand. The second phase will be implemented based on the success of the first phase and would most probably replicate the groyne field proposed in this phase. However, the second phase components are not considered within the scope of this EIA report. Sand pumping is necessary in order to fill eroded areas even if structural protection is provided. In most cases, regular beach nourishment by pumping sand would be required. However, in the proposed project, what is proposed is a one-off pumping and additional pumping requirements will be established based on findings of follow-up monitoring so that regular beach nourishment for the proposed area will be considered within the scope of the EIA for the second phase. The negative impacts to environment due to the construction of groynes and beach nourishment is mainly during the construction phase which include impacts due to mobilisation, construction noise and machinery movement. However, these are considered to be minor negative given the prevailing environmental conditions at Hakuraa Huraa. The negative impacts of sand pumping for both borrow and fill areas include loss of habitats for some bottom dwelling organisms in the nearshore environment (mud feeding, filter feeding and juvenile fish etc). However, this is not a significant ecosystem in the Maldives, especially in Hakuraa Huraa, where the reef extent is very large and the biodiversity of nearshore ecosystem is low. Therefore, the impact significance is almost negligible. Also, the impact from sedimentation and sediment re-suspension is low due to good flow of currents in the area. There will be no sedimentation impact on the reef. The positive impacts of shore protection and beach nourishment will be that it will help to protect coastal vegetation as well as coastal properties and other amenities, particularly on the south-western corner as well as the northwestern corner, where the coffee shop is under threat of erosion. There will also be socio-economic impacts including tax revenue and short-term employment. The overall environmental impacts of the project assessed using appropriate matrices, professional experience/judgement and the results of continuous environmental monitoring over the past few years indicated that the proposed project is expected to have net positive impacts compared to a few negative environmental impacts. There will be no irreplaceable damage to any of the environmental components. The resort has a comprehensive environmental monitoring plan in place and monitoring recommended under the proposed project will form an integral part of the current practice. Given that the project has several advantages or benefits compared to a few minor negative environmental impacts, it is recommended to allow the project to proceed as proposed.