| Abstract: | Kulhudhuffitshi Island with a population of over 8900 people is the most populated island in the northern region of the country and is considered to be the third largest population in the Maldives. The island is currently the hub of all commercial activities in the north. Physical and infrastructure developments have although brought socio-economic improvements to the resident community it has also come at an environmental cost. Among the environmental issues faced to the island, stormwater flooding has been considered having impacts on the people in many different ways. Land reclamation, reclamation of the wetland, destruction of the coastal vegetation belt and increased use of vehicles on sandy roads without an engineered drainage system have all contributed to the occurrences of stormwater flooding in the island.
In an attempt to address the issue of stormwater in Kulhudhuffushi, the Integrating Climate Change Risks into Resilient Island Planning Project (ICCRRIP) commissioned Male Water Supply and Sewerage Company (MWSC) and Engineering Consultant PVT. Ltd to undertake a study to identify technical options available to solve the flooding problem. Subsequently a report on the findings was submitted to ICCRRIP in 2013.
The study proposed a number of options for stormwater management in the island. The recommended method being that stormwater from the gutters and soak pits be connected to a pipeline terminating into underground storage tanks consisting of blocks of AquaCell which has an extensive range of modular cell products and are known to provide an efficient and sustainable method of storing large volumes of run-off for water attenuation or soakaway applications. These underground water tanks would hold the water and release into the ground slow enough for the ground to be able to absorb water and ultimately re-charging the groundwater lens. The report divides the island catchment areas into four zones and recommends two flood prone areas in the northern and the southern part of the island for piloting flood control by this method. However, due to the limited financing available for the
piloting flood control by this method. However, due to the limited financing available for the project, it has been decided to pilot the drainage activities in the north eastern region of the island only. This would involve diversion of storm water from six roads namely, Marukazu Magu, Miskiy Magu, Soafiya Higun, Madharusaa Magu, Dhanbu Magu and Orchid Magu. Approved project cost is MVR 16 million.
Maldives Road Development Corporation (MRDC) has been selected as the contractor for the project while MWSC will supervise their work. MRDC intends to merge pilot project activities with the on-going road construction works. The project planning, design and surveying began in July 2014 and is entire project is expected to completed and handed over by the contractor during the first half of November. The site clearance and the earthworks is expected to start as soon as EIA clearance is sought and have been planned to be completed within about 30 days.
hi order to proceed with the proposed drainage works and installation of the stormwater infiltration galleries and EIA was commissioned to obtain environmental clearance and the EIA was conducted based on the Terms of Reference agreed between the Consultant and the EPA.
The EIA recognizes the importance and urgency of addressing the heavy rain associated flooding in Kulhudhuffushi based on the field investigations backed by Detailed Island Risk Assessment in Maldives (2007) and Detailed Island Risk and Vulnerability Assessment (2013). The impact analysis show no significant negative impact expected to be arising out of any activity associated with the project. Project involves minor excavations, potential dewatering, filling back and operation of vehicles and temporary enclosure of the project sites. These may have minor and temporary negative impacts to the scenic view and vista.
Potential post-project negative enviromnental impact could arise out of breeding of mosquitos and pests in the tanks, in the pipeline and soakpits due to standing water. Through proper maintenance of the system the problem could be largely avoided.
Potential socio-cultural impacts associated with the pilot project include, disruption to services, and temporary obstacles to right of way.
Minor negative socio-cultural and environmental impacts associated with the project are temporary and reversible in nature. These further could be mitigated through appropriate mitigation measures.
The most expected positive impact expected from the project will be improvement to the drainage. With the project the project is expected to alleviate drainage issue from an area measuring 175,000m2 of urban land with better drainage, and as indirect positive impacts, the project is expected to further improve groundwater, reduce potential contaminants reaching the marine environment, leading to improved public health and quality of life through reduced risk of waterborne and water-related diseases and increased public satisfaction with the urban environment. The project is expected to bring some minor positive impacts to the local economy during the three phases of the project as a results of temporary opportunities created during the works.
Several major realistic and practical alternatives have been assessed including the 'no project alternative'. Without the project, the funds allocated for the project could be saved but may run the risk of losing it since the project may not have adequate time left before closure. Since, detailed designs, engineering drawings and contractor for the project has already been selected it would be completely unrealistic and wasteful to even consider utilizing the funds for a different activity. Considering meeting the objectives of the project, environmental and economical superiority of the alternatives evaluated, undertaking a pilot project in one of the flood prone area using underground tanks in empty available space for drainage has been found to the best practical option. The Council expressed their wish implement the project in the Zone A (the south east region) as opposed to Zone B (north east region). They were of the view that Zone A floods more severely compared to Zone B and therefore, the project would have greater impact by this shift. Considering that the detailed design has already been done for this zone, it is recommended to change the project location as suggested by the Council in order to increase public acceptability of the project.
The intended positive impacts of the project can only be accurately determined by the post-project monitoring scheme. In order to ensure effectiveness of underground stomi water collection tanks in mitigating against flooding it is essential to monitor, collect information, evaluate the information collected and disseminated.
With the following recommendations duly considered or addressed appropriately, the ETA found that the positive aspects of the project far outweigh its negative impacts.
■ Bank of Maldives Branch at Kulhudhuffushi have not been consulted during the design phase on the possible installation of an underground tank within their compound. ETA suggests that prior to the onset of ground work that the Bank be consulted for their consent.
■ Location identified for the tank at the football ground need to be relocated from the southwest corner to the northwest corner in order to reduce the pipeline length as well as the associated costs.
■ Capacity of the underwater tank proposed for Bank of Maldives' compound seem to be of inadequate capacity since it the region covers 53% of the total pilot project area.
■ It is not clear how the existing design will address the over-flow should such a situation arise. This issue need to be resolved prior to the construction.
■ Post project maintenance and management shall be discussed and agreed with the island council in order to avoid potential mosquito and other pest issues as a result of the project.
If the pilot project is successful in managing storm water in the piloted area, the system will be expended to other regions of Kulhudhuffushi Island and similar systems it could be replicated elsewhere in the Maldives. |
