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Technical Report
Environmental impact assessment for the proposed agriculture project in Funadhoo, Gaafu Alifu Atoll
(2017-09) Musthafa, Amir; Wahhab, Mahfooz Abdul; Adam, Rashihu
The proposed project is to undertake an Agricultural Project located in the island of Funadhoo in North Huvadhoo Atoll at 0°33’42.85” N and 73°31’33.83”E. The nearest airport is Koodoo airport approximately 20km north of Funadhoo. This Environmental Impact Assessment (EIA) report has been prepared in order to meet the requirements of Clause 5 of the Environmental Protection and Preservation Act of the Maldives to assess the impacts of the proposed Agriculture Project in GA. Funadhoo. The main components of the project include: creating accessibility to the island, Vegetation clearance, setting up utilities, harvesting local produce, and livestock farming. Currently, about 90% of fruits and vegetables are imported from overseas to the Maldives. The majority of this food are transported to the tourist resorts and a major portion of the remainder is used by the people of Male’, Hulhumale’, Villingili and nearby islands. The quality of the fruits and vegetables which reaches the atolls is therefore, compromised and not adequate for the population in terms of quality and volume. Therefore, there has always been great need to improve on this condition. As such, one of the main objectives of this project is to meet the needs of the local communities. Interms of harvesting and growth, based on the available land, the growing area will be allocated in a manner which has minimal effects on the natural habitat and trees to effect minimum interruption. One hectare will be designed with net houses to grow most vegetables, such as cucumber, chili, tomato, capsicum and sweet melon. In addition to that, availability of affordable fruits and vegetables to the local communities in Huvadhoo Atoll will be a priority. Goods will be produced using locally available fertilizers in order to promote healthy vegetables and fruits. Another eight hectares will be used for open growing such as coconut trees, banana, papaya, pumpkin, and sweet potatoes. A two hectare area will be allocated for facility development as well as maintaining livestock. This will help to maintain a naturally fertile land and make fresh meat available in the local area. A 30kVA gensets will be established at the project site in the powerhouse, along with Two 5kVA gensets. A 10 ton RO plant will be placed in the island along with a 6 ton plant for back up. 3 septic tank systems will be put in place as sewerage system. A rainwater collection system for building roofs would be built to subsidize and support the water production facility. A micro sprinkler system will be laid along the farm for irrigation purposes. Disease control and quarantine facilities will be in place. The project is expected to be completed in 12 months. Regarding existing environment, there are no declared environmentally sensitive areas on Funadhoo island. 9 different types of vegetation species were found on Funadho during the survey. Majority of the mature trees in the island were Screw pines, typical coastal vegetation and coconut palms. It is expected that about 30 to 40 percentage of vegetation will be removed as part of the works. However, coastal vegetation will not be removed and a 20m buffer area will be maintained. The island undergoes erosion on the eastern oceanward side, although a substantial beach could be found on the western atollward side. Groundwater quality of the island was surprisingly poor, with large number of coliforms. Eastern lagoon was covered with seagrass beds, while the seagrass beds were present only near the coast on the Western side. It was observed that the Eastern lagoon was shallower compared to the Western side, having less than 1m at low tide. The results of the surveys show that 49.9% of the western reef was composed of rock with only 1.6% live corals, and limited number of target fish were observed. The legal framework for the project includes existing policy are regulation with respect to any development sensitive to the environment such as the EIA regulation, regulation on cutting and uprooting trees, Environment protection and preservation act, regulation on coral mining, waste management regulation, dredging and reclamation regulation, etc. In addition to these, there are agriculture specific regulation and guidelines, such as the Agriculture policy, general regulation for food establishment, etc. One of the most important set of guidelines with respect to the project is the Maldives Good Agriculture Standards, which has been recently formulated. While it is not mandatory to conform to the standards currently, the study strongly emphasises on its importance and recommends its incorporation to the project. Impact evaluation is undertaken by standard accepted methods. General impacts from development in uninhabited islands exists for the development such as those including vegetation removal and marine dredging, which has been noted among the more important ones. General mobilisation and setup impacts are also there, in addition to establishing and operating utilities in the island. Waste management in a secluded island such as this is important. More specific impacts occur due to handling and using chemicals and fertilizers, animal and pest control, and harvesting procedures. Mitigation measures are given for each impact. Vegetation removal is unavoidable. However, it is recommended to transplant larger trees as much as possible, and to utilise green waste as compost for the facility. Marine dredging impacts are likewise unavoidable. But the harbour is designed in such a way as to minimise the long term impacts. With regards to agricultural practices, it is strongly recommended to follow the Maldives Good Agricultural Practices. Alternatives for the project includes assessment of the no project option as per usual where the need for the project is discussed at length. It is concluded that the no project option is not viable at this stage. Other alternatives such as those for the project site, harbour area, water source, sewage options, and energy source has been discussed. The project has proposed the most simple and commonly used sources and it is recommended to proceed with these for the time being, while the harbour has been designed in the most environment friendly manner possible. Stakeholder consultations were carried out with different government authorities in addition to respective councils. The councils were generally supportive of the project. However, they all unanimously stated that they recommend more involvement of the island communities in development such as these. The government authorities expressed concern with respect to projects such as these and the agricultural industry of the Maldives in general. Monitoring program has been proposed as per usual. It is recommended to carry out annual monitoring even after the construction works have been completed. Important monitoring parameters include groundwater monitoring, marine water, marine life, shoreline, product water, general health and safety at site, etc. One of the key points with regards to impacts is, the scale/magnitude of works will be much less compared to other types of development which takes place in uninhabited islands such as airport developments or more typically, resort developments. The operation stage of the project will also be much more environment friendly than other developments. However, the main area of concern with regards to operation is apart from general good practices in maintenance and waste management, the use of fertilizers and chemicals. This can be regulated if it is ensured that the operation is in compliance with MGAP. In fact, the entire operation can be made sustainable once the operation fully conforms to the guidelines as provided by MGAP. Considering these factors and the great socio economic benefits the project will bring to the regional community, the project can be regarded to be environment friendly on a long term basis. With proper operating procedures as outlined in MGAP, mitigation measures as given in this study, and subsequent monitoring, it is recommended for the project to proceed as proposed.
Technical Report
Environmental impact assessment multi-storey building at H. Del Rio Malé City, Maldives
(2015-10) Sandcays
This report discusses the findings of an Environmental Impact Assessment (EIA) carried out for the proposed 11-storey building including an underground basement at H. Del Rio, Malé. The project is proposed by the land owner, Mohamed Shafiu of H. Del Rio. EIA is required for buildings with basements or foundations that are laid below 1.8m from the ground, as per the EIA Regulations of the Maldives and all amendments to it up to date. The main objective of the EIA is to identify potential impacts of excavation, construction of foundation and dewatering and consider mitigation measures that may be adopted. In addition, the EIA would also consider other construction phase and operational phase activities such as waste management, energy and water supply although they are not directly related to the scope of the EIA. Demolition of the existing single storey building has been completed, and demolition impacts have not been covered in the EIA in detail. The project is to commence as soon as the EIA is approved and the duration of the project will not be more than 24 months. Substructure works, which is considered to be the most sensitive component (socially and environmentally), is expected to be completed within two months. The critical elements of excavation and dewatering are expected to be completed within three to four weeks. Therefore, the project has a critical impact timeframe of less than 2 months. Environmental assessment for building construction in Malé City was enforced following incidents of cracks in neighbouring buildings and vibration and noise-related inconveniences which occurred when deep piling was undertaken for the construction of the 15-storey building in Athireege-aage. Based on this incident, deep piling is considered unsuitable for congested Malé. Therefore, the most commonly adopted method of raft foundation will be adopted in the construction of the proposed multi-storey building at H. Del Rio. This method distributes the load from a structure over a large area, minimizing the pressure on the base. This method of foundation is ideal for loose soils with low bearing capacity. However, since the soil of Malé with well-compacted heterogeneous material provides very good base for such foundations, there would be minimal disruption to adjoining structures. Since Del Rio is on the original land of Malé close to the original shoreline, therefore, the foundation will be the on the original seabed and the same conditions would prevail. The area is also of compact nature as this is close to the rim reef of the island and material is well compacted. The proposed depth of the foundation for H. Del Rio is at about 2.8m below the existing ground level or road level. This depth, which is greater than that of a typical building, is due to the basement. The basement space is proposed as office space in the initial design, however, may be used as parking space for the building in future. Parking is becoming an important requirement due to the parking difficulties in Malé. The main concern in excavating to this depth is the safety of the adjacent structures, most of which are old and do not have a proper sub-structure. Therefore, appropriate protection measures have been considered during the excavation, dewatering and foundation works. It is usual practice to provide a retention structure to prevent the foundation of other buildings from collapsing during excavation and the same methodology is proposed for this project. For dewatering, the current practice is for Malé Water and Sewerage Company (MWSC) to install a purpose built catchpit connecting to the main sewerage network and for the Contractor to pump effluent from the dewatering process into this catchpit using multiple pumps at designated locations. Since dewatering is required throughout the process of laying the foundation, it will be continuous and irrespective of tide. In fact, tidal influence on the groundwater table has been seen to be very little or negligible in most of the larger islands. Heavy machineries that will be used in the construction include excavator and lorry for demolition and excavation including demolition and excavation waste disposal and concrete machine and large crane for concrete works on top floors. During excavation, excavators and lorries will work inside Del Rio plot except for some minor works on the roadside. Soil that is well segregated and free from debris and contaminants will be used in backfilling. Demolition has been completed quite some time ago and is not within the scope of this EIA. The plot is empty and grass has grown at the back of the plot indicating that the plot has been vacant for quite some time. Cement dust during concrete works is expected to be less of an issue compared to demolition dust and dust during sanding of walls. All these dust-prone activities is expected to be carried out with caution to minimize dust levels in the area. During concrete works, concrete machine and mobile telescopic crane will work from the road and appropriate road blocks, safety and traffic diversion measures will be implemented according to the requirements/recommendations of Malé City Council and Traffic Police. Safety measures within and outside the premises will be ensured during demolition of existing building until the end of construction phase. The project location is congested with mainly single storey buildings and a few multi-storey buildings of less than 5 storeys. The previous building in Del Rio is a single storey residential building with a normal roof. There is a multi-storey building on the south of Del Rio, at the corner of the road. There are a couple of 6-storey buildings on the south of Del Rio but not adjacent to Del Rio. The rest are mainly single-storey houses and a few 2-3 storey buildings. There are a couple of 5 or more storey buildings in front of Del Rio. There is hardly any vegetation in the area except for a mango tree on the west of the plot and a couple of Burmese rosewood (ofi eley) on the road side southwards. Due to the congested nature of Malé and the area surrounding the project site, the condition of neighbouring houses were considered including condition of the structures, condition of groundwater (if groundwater is used) and living conditions to some extent. It has been identified that most of the buildings are old, single-storey or two-storey buildings and have several cracks due to ageing and settlement (mainly on the ground floor in high rise buildings) but could not have been subjected to vibration impacts in the past. There is little or no structural damage in the existing multi-storey buildings. Traffic in the area was considered important and was assessed to be similar to other areas of Malé. Traffic and pedestrian numbers increases in the evening after 1600hrs because people are usually out during the evening to cool off, especially for use of recreational facilities near Del Rio. The roads in the vicinity of the project area are one-way roads making traffic diversions during the construction phase easier. All parking spaces are nearly full throughout the day mostly with parked motor cycles. Private cars are becoming increasingly common in Malé today, therefore, getting parking space on the road is also becoming increasingly difficult. In terms of living conditions in the vicinity of the project site, most of the houses have congested living conditions except for some multi-storey buildings. Groundwater is still quite commonly used in households for washing, flushing and other non-potable uses. Noise levels in the area are much higher than expected and average noise levels during day time as well as night time surpasses acceptable international standards for residential areas. There are also constant noise sources in the vicinity such as the STELCO powerhouse which add to the background noise levels of the area. The primary objective of the development is to enhance the income of the plot owner while improving quality of housing provided in Malé and improve living conditions in Malé. The living environment in Malé is in grave condition with building after building without any space except public spaces and roads. Most of the single storey houses and some of the multistorey buildings have congested living spaces. With a population density of 18,000persons/square kilometer of land area, and thousands of vehicles, Malé needs vertical growth and with increasing land value multi-storey buildings with adequate parking spaces in the building is an important aspect of development in Malé. The overall environmental and social impacts of the projects have been assessed and impacts are considered to be low magnitude and of minor significance. The negative environmental and social impacts of the development are also mainly short-term while the positive socioeconomic impacts of the project are long-term. Therefore, the overall impact of the proposed projects is greatly positive resulting mainly from improved living spaces and economic benefits, both direct and indirect. There would also be direct and indirect employment opportunities in the planning/design phase, construction phase as well as operational phase of the project. The socio-economic benefits of the project can be considered to outweigh the negative impacts of the project. The main potential impact of the project is possible damage to neighbouring structures due to vibration and weakness to substructure caused by soil movement due to deep excavation and dewatering. Disturbances to neighbours is an inevitable impact that will have to be minimized by taking appropriate measures to minimize nuisances such as noise and controlling dust and taking safety precautions. The construction staff needs to know about the importance of minimizing noise and dust and neighbours shall be made aware of the nature of works and potential disturbances. A grievance redress mechanism would have to be in place and made known to neighbours. Such a mechanism has been proposed in the report. Protection to neighbouring structures is an aspect that needs to be carefully looked at. Details of such protection are discussed in the report. Boundary walls of neigbouring structures would have to be protected prior to excavation. Impacts due to dewatering may be felt on adjacent buildings as well as neighbouring wells. Impacts of excavation and dewatering include loosening of subsoil and reduction in bearing capacity of the soil. This would generally occur in loose soil but not in compact sandy soil, as found in the project site, which is part of the original island of Malé. Sand particles have irregular shapes and sizes, therefore, it is well locked in place giving it a good load bearing capacity. Since the excavation is not too deep (about 3m from the ground surface), excavation would not have major impacts on the adjoining structures/buildings. The drawdown caused by dewatering on the water table is not expected to cause any loosening of subsoil in the area, since dewatering occurs at a shallow depth from the water table. However, the superficial groundwater lens will become saline due to drawdown. The current practice of using several small pumps instead of small number of large pumps minimizes such drawdown and there would be minimal impact on neighbours’ use of groundwater. However, this has to be monitored for the adjoining wells and provisions made to compensate for any drawdown effects. There is a mango tree on the west of the plot, which may be adversely affected due to salinization of the water lens. Appropriate mitigation of the impact by watering the tree regularly during the course of the dewatering works has been recommended. Atmospheric pollution due to concrete mixing works on site, cutting tiles, grinding and sanding of walls and timber works are of concern. Often only interior walls undergo smoothing by sanding and this process occurs within confined space. Carpentry works on site would be limited. Yet, it is often the case in Malé that interior finishing works are undertaken at night and with current regulations allowing noisy operations until midnight, there are certain disturbances that has to be minimized, especially given that the project happens in a residential area. In addition to foundation protection measures, the main mitigation measures for the proposed project would be to design for maximum natural ventilation and light, design for optimal efficiency of building while minimizing on losses such as excess concrete as in some of the recent buildings, minimizing and taking care in dusty operations, taking heed of noise during school hours and prayer times as well as night time and keeping the work areas safe and clean. The overall impacts of the proposed project are largely positive with some minor negative impacts. Yet, environmental monitoring has been proposed in order to ensure the effectiveness of the proposed impact management and mitigation measures. The proposed monitoring programme considers engineering inspection during foundation works, groundwater quality changes and availability during dewatering, dust and noise during construction, complaints/grievances, waste management measures including removal of excavated sand and demolition debris, measures to minimize falling of objects/materials during demolition, provision of personal protective equipment and so on. In conclusion, it appears justified from a socio-economic and environmental point of view, to carry out the proposed project.
Technical Report
Environmental impact assessment for beach nourishment, Anantara Kihavah Villas, Baa Atoll, Maldives
(2013-05) Zahid; Musthafa, Amir
This report is based on the proposed beach nourishment works in Anantara Kihavah Villas, also known as Kihavah Huravalhi. The island is located in Baa atoll, 133 away from the Ibrahim Nasir International Airport in Hulhule’. Access to the island is mainly by sea planes. The operations of the resort island are under Anantara Hotels and Resorts, which is a renowned luxurious hotel group. An Environmental Impact Assessment was necessary for the works outlined in this report as they fall under the ‘Jadhuvalu R’ of the Environmental Impact Assessment Regulations 2012 of the Maldives. In addition to meeting the regulatory requirements, the report would further assist the proponent and important stakeholders to make decisions in an environmentally sound manner, thereby ensuring the environmental sustainability of the project. In order to ensure a uniform volume of beach is available all around the island for its guests throughout the year, the operators have started undertaking a biannual sand pumping operation in the island recently. Beach Nourishment works at Kihavah is carried out by pumping sand from the lagoon to replenish 250m length of the eroded shoreline on the SW side. The proposed program is a continuous process for Kihavah, in order to maintain beach area available throughout the year for its guests. The process is integral in maintaining guest satisfaction and the overall quality of the resort. Sand for the nourishment is obtained from the lagoon on the SW side of the island, 70m away from the shoreline. The borrow area is 100 – 150m away from the reef edge on the SW side of the island. Alternatives, including the no project option and alternatives for the project components have been given Alternative methods are proposed, such as use of Sand filled nylon bags laid side by side perpendicular to the shoreline in the form of temporary groynes. The groyne field is proposed to be relocated depending on the seasonal variation to the long shore sediment transport. Sand will be pumped to a small extent to fill the sand bags. Further alternatives such as the use of hard engineering structures are also given, such as, creations of near shore breakwaters, rock revetments and creating feeder headlands have been looked into, but not recommended to be implemented in this environment. The overall environmental impacts of the project have been assessed using frameworks found on literature and the results indicate that the proposed project has a net positive impact. However, there are some significant impacts on the environment during the construction phase of the project and these needs to be mitigated to avoid any significant damage to the environment. Significance of the impacts and mitigation measures has been provided based on previous similar projects undertaken in the Maldivian environment and based on literature. In general, soft engineering techniques, as used for this project are favourable to the environment and it is the wish of the operators that such techniques be employed as much as possible without resorting to hard engineering solutions. Furthermore, the minor negative impacts from the project will be localised to the small lagoon in which Kihavah is located. Since there are no other islands in the lagoon, there will be no impacts on any neighbouring communities. It is recommended to continue to monitor the impacts of the proposed project by regular monitoring of shorelines and near shore currents and the changing marine environment. A two stage monitoring plan is given, which recommends monthly monitoring during the 1st year and less frequent monitoring for the next 5 years. Undertaking the monitoring, along with the mitigation measures is necessary to ensure the sustainable development of the project with minimum harm to the environment. Beach nourishment is widely regarded as an environmentally friendly method to combat coastal erosion. It is thus recommended that given the positive socio economic and environmental impacts from the project far outweighs the few negative local impacts, and since the project has major socio-economic benefits, it is advisable to allow the project to proceed as proposed.
Technical Report
Environmental impact assessment for the sewerage facility in Hanimaadhoo, Haa Dhaalu Atoll, Maldives
(2013-11) Energy Consultancy
This report is based on the proposed Sewerage system in HDh. Hanimaadhoo. The island is located North of the Maldives, in Haa Dhaalu atoll. Access to the island is mainly through the recently built harbour and airport. The project is proposed by Noomadi Resorts and Residences, and construction works are undertaken by Wavelength Maldives Pvt. Ltd. This EIA study is carried out by the team at Energy Consultancy Pvt. Ltd. An Environmental Impact Assessment was necessary for the works outlined in this report as they fall under the ‘Jadhuvalu R’ of the Environmental Impact Assessment Regulations 2012 of the Maldives. In addition to meeting the regulatory requirements, the report would further assist the proponent and important stakeholders to make decisions in an environmentally sound manner. The study aims to assist in the sustainable development of the project. Considering other legislative issues, the client has obtained approval from the EPA for the preliminary design of the system, in addition to approval from the Land and Survey Authority and Maldives Energy Authority. The need for the project is borne out of the poor status of the current sewerage system in the island, consisting of decentralised septic tanks and soak pits. One of the main issues of the current system is the pollution of the groundwater aquifer due to the bacteria and other pollutants leaching out into the groundwater system. This is an issue faced by many islands in the Maldives, and therefore currently there is a lot of emphasis on developing centralised sewerage systems in all the islands. As part of the stakeholder consultation, discussion was held with the island council, NGOs and the local community, who all emphasised on the importance of implementing the project in the island as soon as possible. They further stated that they are willing to pay a monthly fee for the operation and maintenance of the pumps and the system in general. The overall environmental impacts of the project have been assessed using frameworks found on literature and the results indicate that the proposed project has minimum negative impact and thus have an overall net positive impact. The main positive impacts comes from the fact that the sewerage system will stop the pollution of the groundwater. However, alternatively, this system also leads to the salinization of the groundwater aquifer, since all the water in the sewage will be removed from the system. The solution to this issue is the implementation of a Sewage Treatment Plant. However, this is not feasible at this stage, due to the high capital costs incurred. More importantly, such a system will require rigorous monitoring and operation costs will be quite high. This would lead the system to be mismanaged, leading to a potential breakdown of the system. Therefore such an implementation is not recommended for this project. Considering other impacts to the vegetation and the marine environment, these are minor issues which can be effectively mitigated. Alternative options to the sewerage system are considered. As such the no project option is first discussed and discarded as a possible alternative. Given the dire state of the groundwater aquifer, it is recommended that the project takes place. The other option is on the Sewage Treatment Plant, which is also not feasible at this stage. The location of the pump stations and the sewage outfall is also considered, including changing the outfall into a more central area, in which removal of vegetation for pump station construction will be at a minimum. However, after considering the positives and negatives of each alternative, it is recommended that the proposed design and locations are considered. The methodology of construction as proposed by the contractor is recommended, since it has been successfully implemented in several other projects in the Maldives without significant detrimental impacts to the environment. It is recommended to continue to monitor the impacts of the proposed project by regular monitoring of ground water, marine water and marine environment. A 2 stage monitoring plan is given, which recommends quarterly monitoring during the 1st year and less frequent monitoring for the next 5 years. Undertaking the monitoring, along with the mitigation measures is necessary to ensure the sustainable development of the project with minimum harm to the environment. It is thus recommended that given the positive socio economic and environmental impacts from the project far outweighs the minor negative impacts, and since the project has major socio-economic benefits and environmental benefits, it is advisable to allow the project to proceed as proposed. It is also recommended that consideration is given to implement a Sewage Treatment Plant at a later stage as another project, when the council and community is able to properly carry out the operation and maintenance of the system.
Technical Report
Environmental impact assessment for the proposed integrated water resource management project HA. Ihavandhoo
(2012-11) Sandcays
This report discusses the findings of a social and environmental impact study under the proposed integrated water resource management project in Ihavandhoo, Haa Alifu Atoll. The project is proposed by United Nations Office for Project Services (UNOPS). The project is targeted at providing potable water to the community and improving rainwater recharge. Potable water is provided by a combination of rainwater and desalinated water, which is a new and unique project for the Maldives. The recharge well system is even more unique. Consequently, several discussions have been held with the Ministry of Environment (represented by EPA), Ministry of Housing and Infrastructure and UNOPS to discuss the several issues. The issues were re-visited during the scoping meeting, the main issues identified by the EPA being the size of the rainwater tanks and good management of the system to ensure that most of the rainwater is used and desalinated water is depended upon as a supplementary source. EPA also has issues with the proposed recharge wells with the main concern lying in the possibility that the recharge wells may help to cause flooding during storm water. However, the project engineer is quite certain that this was not likely and this was also backed by the EIA Consultant. At present Ihavandhoo does not have a piped water supply system and groundwater is used unanimously for all purposes with the exception of bottled water and rainwater for drinking. Several efforts have been made in the past including the construction of public rainwater tanks with public tapbays, which was later replaced by household rainwater tanks of 2500l at each household for easier access but with some compromise on water quality issues. Rainwater, however, could not be depended upon during long, dry periods during the northeast monsoon. With changing climatic patterns worldwide, rainwater can rarely be depended upon. With lack of space for appropriate rainwater collection facilities combined with groundwater contamination and salinization has been seen to cause various health and environmental problems including water-borne diseases. The dependence on groundwater and untreated rainwater is often a cause for concern. Therefore, an integrated water supply system with sustainable groundwater resource is an immediate need for the people of Ihavandhoo, which has a population of over 2750 people in September 2012. The proposed integrated water supply system is designed for maximal use of rainwater supplemented by desalinated water for an average water demand of 50-70 litres per person per day. Raw water is proposed to be drawn from a borehole with 8’’ casing and pumps to pump the raw water to the treatment plant. The treatment for the water is proposed by using Reverse Osmosis technique. The plant will be run by diesel engine and the possibility of alternative energy options such as solar and wind will be considered. The pure water after treatment is collected in glass or fibre-reinforced plastic tanks of adequate capacity determined for Ihavandhoo to be 1000m3 based on EPA guidelines. The water thus collected is introduced in the network so as to reach all the households, institutional and commercial areas with adequate residual pressure through HDPE pipes. The distribution network is designed for over 35 years while the water tank capacity has been based on 15 years as per Government requirements. The proposed IWRM project also comprises of a mechanism to recharge groundwater using a collection of recharge wells made of concrete that will run along the main roads as well as the island periphery. Direct recharge of groundwater is minimized due to urbanisation as permeability is reduced and infiltration surface is minimized. Therefore, this process is assisted by the use of recharge wells that will direct the excess rainwater from roofs to the groundwater lens. However, it must be noted that these recharge wells are not anticipated to cater for storm water drainage. The sole purpose of these wells is to assist groundwater recharge so that the groundwater lens may be sustainably managed. Environmental impacts were assessed for both the construction and operation phase of the project. Most of the environmental impacts of the project have been identified as positive resulting mainly from easy access to safe water supply, improvements to groundwater quality and resulting reduction in water-borne and water-related diseases and improved health of the population. The socio-economic benefits of the project may be considered to outweigh the negative impacts of the project. There are a few negative impacts of the project including the minor impacts of landuse related to the project and clearing of some mature trees that may be required. The impact of clearing would be compensated by replanting mature trees in other areas of the island and, if necessary, planting additional trees. The impact of brine discharge is also considered minor or negligible especially due to the fact that there is no coral cover in the proposed brine discharge location and good mixing will occur due to currents in the area. Since the pipeline is a pressure system, the pipes will be laid above the water table and no dewatering will be required. Hence, no effect on the groundwater lens. Other minor negative impacts include excavation to lay the water distribution network and brine discharge pipe. One of the impacts of the proposed recharge wells would be space constraints to services on the road and the impact would be mitigated by appropriate planning for locating recharge wells and sewerage manholes as well as other such services. The other impact of the proposed recharge wells would be that there may be clogging of the pipes and such clogging may lead to unnecessary flooding in some areas where clogging occurs, especially in areas easily prone to flooding following rain. However, clogging is expected to occur over the long-term, therefore, it is not possible to do field tests to verify this. It has also been seen that recharge is also not much of a use if pumps are used to draw water from the groundwater aquifer, which leads to rapid salinization of the water lens during the dry period. Recharge of groundwater lens also occurs over a large surface due to rainfall. If we consider the sustainable yield estimated for Ihavandhoo, it can be seen that no amount of recharge will help to overcome the problems related to salinization due to increasing use of pumps. In fact, the Maldives receives well over 2000mm of rainfall, which would be more than sufficient to recharge the aquifer. Yet, the aquifer, similar to a rainwater tank, has its maximum capacity limits and cannot overgrow the impact imposed by high rates of abstraction. Therefore, only sustainable rates of pumping can ensure sustainable management of the aquifer. It has been observed from studies carried out for Malé that freshwater exists in pockets. Where the drawn down effect is high, due to the size of pumps and rate of pumping, there is a tendency for the water lens to become more saline at the location where the drawdown is greater. This draw down or lowering of the water table at the point of abstraction, sometimes referred to as the “coning effect” for the freshwater lens, can only be avoided with the use of appropriate technology such as skimming wells and infiltration galleries. The main mitigation measure for the proposed project would be to identify measures to minimize drawdown on the aquifer including the introduction of skimming wells by improving existing wells and enhancing water conservation techniques. The proposed concept of recharge wells is still at a preliminary stage, therefore, it is proposed that the detailed design takes into consideration the findings of this Environmental Impact Assessment, and consultations with the community and relevant government agencies, especially the EPA. It is inevitable that there would be some negative environmental impacts. However, these are minor compared to the positive effects of the proposed system. Yet, monitoring to ensure the effectiveness of the proposed system would be necessary. Therefore, a monitoring component has been suggested which takes in to consideration, the most important elements that require regular checks. This monitoring component will be adhered to and will allow the assessment of changes due to construction and implementation of the proposed water supply system and aquifer recharge system. Monitoring is specifically focussed on water quality, to include feedwater from the borehole (or other source), collected rainwater, groundwater, product water at designated locations and seawater at brine discharge location (upstream and downstream). Reef or marine ecological monitoring may be considered if the proposed location of the brine discharge or intake is found to be of ecological significance. In conclusion, it appears justified from a technical and environmental point of view, to carry out the proposed project to install and operate a piped water supply scheme using rainwater supplemented by desalinated water. However, the recharge well scheme needs to be further evaluated and possibly replaced by or integrated with an alternative scheme such as converting existing household wells to skimming wells to minimize salinization of the groundwater lens. It is also further recommended to consider one of the three islands under this project as a pilot island for the recharge wells instead of all three islands and Ihavandhoo seems to be the most appropriate since the island is higher in elevation compared to the other two and there is a lesser chance of potential flooding, where there is a concern.
Technical Report
Environmental impact assessment for the proposed integrated water resource management project GDH. Gadhdhoo
(2012-12) Sandcays
This report discusses the findings of a social and environmental impact study under the proposed integrated water resource management project in Gadhdhoo, Gaafu Dhaalu Atoll. The project is proposed by United Nations Office for Project Services (UNOPS). The project is targeted at providing potable water to the community and improving the rainwater recharge. Potable water is provided by a combination of rainwater and desalinated water, which is a new and unique project for the Maldives. The recharge well system is even more unique. Consequently, several discussions have been held with the Ministry of Environment (represented by EPA), Ministry of Housing and Infrastructure and UNOPS to discuss the several issues. The issues were re-visited during the scoping meeting, the main issues identified by the EPA being the size of the rainwater tanks and good management of the system to ensure that most of the rainwater is used and desalinated water is depended upon as a supplementary source. EPA also has issues with the proposed recharge wells with the main concern lying in the possibility that the recharge wells may help to cause flooding during storm water. However, the project engineer is quite certain that this was not likely and this was also backed by the EIA Consultant. At present Gadhdhoo does not have a piped water supply system and groundwater is used unanimously for all purposes with the exception of bottled water and rainwater for drinking. Several efforts have been made in the past including the construction of public rainwater tanks with public tapbays, which was later replaced by household rainwater tanks of 2500l at each household for easier access but with some compromise on water quality issues. Rainwater, however, could not be depended upon during long, dry periods during the northeast monsoon. With changing climatic patterns worldwide, rainwater can rarely be depended upon. With lack of space for appropriate rainwater collection facilities combined with groundwater contamination and salinization has been seen to cause various health and environmental problems including water-borne diseases. The dependence on groundwater and untreated rainwater is often a cause for concern. Therefore, an integrated water supply system with sustainable groundwater resource is an immediate need for the people of Gadhdhoo, which has a population of over 2899 people in September 2012. The proposed integrated water supply system is designed for maximal use of rainwater supplemented by desalinated water for an average water demand of 50-70 litres per person per day. Raw water is proposed to be drawn from a borehole with 8’’ casing and pumps to pump the raw water to the treatment plant. The treatment for the water is proposed by using Reverse Osmosis technique. The plant will be run by diesel engine and the possibility of alternative energy options such as solar and wind will be considered. The pure water after treatment is collected in glass or fibre-reinforced plastic tanks of adequate capacity determined for Gadhdhoo to be 900m3 based on EPA guidelines. The water thus collected is introduced in the network so as to reach all the households, institutional and commercial areas with adequate residual pressure through HDPE pipes. The distribution network is designed for over 35 years while the water tank capacity has been based on 15 years as per Government requirements. The proposed IWRM project also comprises of a mechanism to recharge groundwater using a collection of recharge wells made of concrete that will run along the main roads as well as the island periphery. Direct recharge of groundwater is minimized due to urbanisation as permeability is reduced and infiltration surface is minimized. Therefore, this process is assisted by the use of recharge wells that will direct the excess rainwater from roofs to the groundwater lens. However, it must be noted that these recharge wells are not anticipated to cater for storm water drainage. The sole purpose of these wells is to assist groundwater recharge so that the groundwater lens may be sustainably managed. Environmental impacts were assessed for both the construction and operation phase of the project. Most of the environmental impacts of the project have been identified as positive resulting mainly from easy access to safe water supply, improvements to groundwater quality and resulting reduction in water-borne and water-related diseases and improved health of the population. The socio-economic benefits of the project may be considered to outweigh the negative impacts of the project. There are a few negative impacts of the project including the minor impacts of landuse related to the project, however, no clearing is envisaged. The impact of clearing, if any, would be compensated by replanting mature trees in other areas of the island and, if necessary, planting additional trees. The impact of brine discharge is also considered minor or negligible especially due to the fact that there is no coral cover in the proposed brine discharge location and good mixing will occur due to currents in the area. Since the pipeline is a pressure system, the pipes will be laid above the water table and no dewatering will be required. Hence, no effect on the groundwater lens. Other minor negative impacts include excavation to lay the water distribution network and brine discharge pipe. One of the impacts of the proposed recharge wells would be space constraints to services on the road and the impact would be mitigated by appropriate planning for locating recharge wells and sewerage manholes as well as other such services. The other impact of the proposed recharge wells would be that there may be clogging of the pipes and such clogging may lead to unnecessary flooding in some areas where clogging occurs, especially in areas easily prone to flooding following rain. However, clogging is expected to occur over the long-term, therefore, it is not possible to do field tests to verify this. It has also been seen that recharge is also not much of a use if pumps are used to draw water from the groundwater aquifer, which leads to rapid salinization of the water lens during the dry period. Recharge of groundwater lens also occurs over a large surface due to rainfall. If we consider the sustainable yield estimated for Gadhdhoo, it can be seen that no amount of recharge will help to overcome the problems related to salinization due to increasing use of pumps. In fact, the Maldives receives well over 2000mm of rainfall, which would be more than sufficient to recharge the aquifer. Yet, the aquifer, similar to a rainwater tank, has its maximum capacity limits and cannot overgrow the impact imposed by high rates of abstraction. Therefore, only sustainable rates of pumping can ensure sustainable management of the aquifer. It has been observed from studies carried out for Malé that freshwater exists in pockets. Where the drawn down effect is high, due to the size of pumps and rate of pumping, there is a tendency for the water lens to become more saline at the location where the drawdown is greater. This draw down or lowering of the water table at the point of abstraction, sometimes referred to as the “coning effect” for the freshwater lens, can only be avoided with the use of appropriate technology such as skimming wells and infiltration galleries. The main mitigation measure for the proposed project would be to identify measures to minimize drawdown on the aquifer including the introduction of skimming wells by improving existing wells and enhancing water conservation techniques. The proposed concept of recharge wells is still at a preliminary stage, therefore, it is proposed that the detailed design takes into consideration the findings of this Environmental Impact Assessment, and consultations with the community and relevant government agencies, especially the EPA. After discussions with the engineers, it is believed that the system will retain water and about 500m3 of rain will be retained to slowly recharge the aquifer during the dry period or periods with prolonged duration without rain. However, the main problem with the salinization of the aquifer and the making full use of the sustainable yield of the island’s small aquifer lies with the fact that drawdown and coning effect due to the use of pumps in household wells and not with recharge. Also, the potential impact of recharge wells contributing to flooding in a floodprone island like Gadhdhoo is of significance, such a system is not recommended. It is inevitable that there would be some negative environmental impacts. However, most of the impacts of the proposed water supply system are minor compared to the positive effects of the proposed system. Yet, monitoring to ensure the effectiveness of the proposed system would be necessary. Therefore, a monitoring component has been suggested which takes in to consideration, the most important elements that require regular checks. This monitoring component will be adhered to and will allow the assessment of changes due to construction and implementation of the proposed water supply system and aquifer recharge system. Monitoring is specifically focussed on water quality, to include feedwater from the borehole (or other source), collected rainwater, groundwater, product water at designated locations and seawater at brine discharge location (upstream and downstream). Reef or marine ecological monitoring may be considered if the proposed location of the brine discharge or intake is found to be of ecological significance. In conclusion, it appears justified from a technical and environmental point of view, to carry out the proposed project to install and operate a piped water supply scheme using rainwater supplemented by desalinated water. However, the recharge well scheme needs to be further evaluated and possibly replaced by or integrated with an alternative scheme such as converting existing household wells to skimming wells to minimize salinization of the groundwater lens.
Technical Report
Environmental impact assessment for the proposed integrated water resource management project ADH. Mahibadhoo
(2012-12) Sandcays
This report discusses the findings of a social and environmental impact study under the proposed integrated water resource management project in Mahibadhoo, Alifu Dhaal Atoll. The project is proposed by United Nations Office for Project Services (UNOPS). The project is targeted at providing potable water to the community and improving the rainwater recharge. Potable water is provided by a combination of rainwater and desalinated water, which is a new and unique project for the Maldives. The recharge well system is even more unique. Consequently, several discussions have been held with the Ministry of Environment (represented by EPA), Ministry of Housing and Infrastructure and UNOPS to discuss the several issues. The issues were re-visited during the scoping meeting, the main issues identified by the EPA being the size of the rainwater tanks and good management of the system to ensure that most of the rainwater is used and desalinated water is depended upon as a supplementary source. EPA also has issues with the proposed recharge wells with the main concern lying in the possibility that the recharge wells may help to cause flooding during storm water. However, the project engineer is quite certain that this was not likely and this was also backed by the EIA Consultant given that there is overflow from one well to the other, especially in flood prone areas. At present Mahibadhoo does not have a piped water supply system and groundwater is used unanimously for all purposes with the exception of bottled water and rainwater for drinking. Several efforts have been made in the past including the construction of public rainwater tanks with public tapbays, which was later replaced by household rainwater tanks of 2500l at each household for easier access but with some compromise on water quality issues. Rainwater, however, could not be depended upon during long, dry periods during the northeast monsoon. With changing climatic patterns worldwide, rainwater can rarely be depended upon. With lack of space for appropriate rainwater collection facilities combined with groundwater contamination and salinisation has been seen to cause various health and environmental problems including water-borne diseases. The dependence on groundwater and untreated rainwater is often a cause for concern. Therefore, an integrated water supply system with sustainable groundwater resource is an immediate need for the people of Mahibadhoo, which has a population of over 2100 people in mid-2012. The proposed integrated water supply system is designed for maximal use of rainwater supplemented by desalinated water for an average water demand of 50-70 litres per person per day. Raw water is proposed to be drawn from a borehole with 8’’ casing and pumps to pump the raw water to the treatment plant. The treatment for the water is proposed by using Reverse Osmosis technique. The plant will be run by diesel engine and the possibility of alternative energy options such as solar and wind will be considered. The pure water after treatment is collected in glass or fibre-reinforced plastic tanks of adequate capacity determined for Mahibadhoo to be 700m3 based on EPA guidelines. The water thus collected is introduced in the network so as to reach all the households, institutional and commercial areas with adequate residual pressure through HDPE pipes. The distribution network is designed for over 35 years while the water tank capacity has been based on 15 years as per Government requirements. The proposed IWRM project also comprises of a mechanism to recharge groundwater using a collection of recharge wells made of concrete that will run along the main roads as well as the island periphery. Direct recharge of groundwater is minimized due to urbanisation as permeability is reduced and infiltration surface is minimized. Therefore, this process is assisted by the use of recharge wells that will direct the excess rainwater from roofs to the groundwater lens. However, it must be noted that these recharge wells are not anticipated to cater for storm water drainage. The sole purpose of these wells is to assist groundwater recharge so that the groundwater lens may be sustainably managed. Environmental impacts were assessed for both the construction and operation phase of the project. Most of the environmental impacts of the project have been identified as positive resulting mainly from easy access to safe water supply, improvements to groundwater quality and resulting reduction in water-borne and water-related diseases and improved health of the population. The socio-economic benefits of the project may be considered to outweigh the negative impacts of the project. The main negative impact of the project is the diesel-based power and resultant emissions, which has minor to moderate negative cumulative impacts. However, since rainwater is the primary source and desalination is supplementary to the proposed rainwater system, the power requirement is expected to be much lower than depending on RO desalination technology alone. There are a few negative impacts of the project including the minor impacts of landuse. The impact of brine discharge is also considered minor or negligible especially due to the fact that there is no coral cover in the proposed brine discharge location and good mixing will occur due to currents in the area. Since the pipeline is a pressure system, the pipes will be laid above the water table and no dewatering will be required. Hence, no effect on the groundwater lens. Other minor negative impacts include excavation to lay the water distribution network and brine discharge pipe. One of the impacts of the proposed recharge wells would be space constraints to services on the road and the impact would be mitigated by appropriate planning for locating recharge wells and sewerage manholes as well as other such services. The other impact of the proposed recharge wells would be that there may be clogging of the pipes and such clogging may lead to unnecessary flooding in some areas where clogging occurs, especially in areas easily prone to flooding following rain. However, clogging is expected to occur over the long-term, therefore, it is not possible to do field tests to verify this. It has also been seen that recharge is also not much of a use if pumps are used to draw water from the groundwater aquifer, which leads to rapid salinization of the water lens during the dry period. Recharge of groundwater lens also occurs over a large surface due to rainfall. If we consider the sustainable yield estimated for Mahibadhoo, it can be seen that no amount of recharge will help to overcome the problems related to salinization due to increasing use of pumps. In fact, the Maldives receives well over 2000mm of rainfall, which would be more than sufficient to recharge the aquifer. Yet, the aquifer, similar to a rainwater tank, has its maximum capacity limits and cannot overgrow the impact imposed by high rates of abstraction. Therefore, only sustainable rates of pumping can ensure sustainable management of the aquifer. It has been observed from studies carried out for Malé that freshwater exists in pockets. Where the drawn down effect is high, due to the size of pumps and rate of pumping, there is a tendency for the water lens to become more saline at the location where the drawdown is greater. This draw down or lowering of the water table at the point of abstraction, sometimes referred to as the “coning effect” for the freshwater lens, can only be avoided with the use of appropriate technology such as skimming wells and infiltration galleries. The main mitigation measure for the proposed project would be to identify measures to minimize drawdown on the aquifer including the introduction of skimming wells by improving existing wells and enhancing water conservation techniques. The proposed concept of recharge wells is still at a preliminary stage, therefore, it is proposed that the detailed design takes into consideration the findings of this Environmental Impact Assessment, and consultations with the community and relevant government agencies, especially the EPA. It is inevitable that there would be some negative environmental impacts. However, these are minor compared to the positive effects of the proposed system. Yet, monitoring to ensure the effectiveness of the proposed system would be necessary. Therefore, a monitoring component has been suggested which takes in to consideration, the most important elements that require regular checks. This monitoring component will be adhered to and will allow the assessment of changes due to construction and implementation of the proposed water supply system and aquifer recharge system. Monitoring is specifically focussed on water quality, to include feedwater from the borehole (or other source), collected rainwater, groundwater, product water at designated locations and seawater at brine discharge location (upstream and downstream). Reef or marine ecological monitoring may be considered if the proposed location of the brine discharge or intake is found to be of ecological significance. In conclusion, it appears justified from a technical and environmental point of view, to carry out the proposed project to install and operate a piped water supply scheme using rainwater supplemented by desalinated water. However, the recharge well scheme needs to be further evaluated and possibly replaced by or integrated with an alternative scheme such as converting existing household wells to skimming wells to minimize salinization of the groundwater lens.
Technical Report
Environmental impact assessment report for playground reclamation project GA. Dhandhoo
(2013-02) Energy Consultancy
Dhaandhoo is located on the eastern rim of G.A Atoll, approximately at 0° 37’ 15.88’’ N and 73° 27’ 43.78’’ E. Dhaandhoo has a population of 1949 and all areas of the island is populated. The island teams host their practice in a nearby island Nilandhoo. Since for each practice of the football team, the local players have to take a sea transport to Nilandhoo, the practicing is very inconvenient. The proposal to reclamation for the development of a football ground was proposed due to difficulties on land allocation. From the survey conducted to examine existing environment, the coastal environment shows well developed natural beach associated with beach erosion is some places along the west side of the island. In some places the beach rock can be seen. The mean coastal current was found to be 7.9cm/s. In the marine environment the coral cover found to be 16.3 percent and at the time of the survey, some fishes were observed in the vicinity. It is expected that the project will be completed within 150 days. The main components in this project include mobilization, dredging, construction of breakwater and quay wall and demobilization. The proposed area to be reclaimed is 0.72 ha. A total of 18000 m3 of sand needed to be mined from the borrow area, which is located Northwest of the existing harbor. The land reclamation would take place in the Southwest of the existing harbor. The most suitable alternative location for the borrowing area would be the existing harbor. However from the dredging of the existing harbor might not accumulate enough volume of sand to reclaim 0.72 hectors of land area required for the football field. An alternative location for the football field is the site that has been proposed for the land reclamation located at the Northwest of the harbor. However from the community consultation it was found the proposed dredging site is to be used as a commercial harbor in future. The main impact from this project to the environment was identified to be sedimentation and loss of some marine habitat. The main mitigation measures are carrying out the project during low tide and complete the project in a shorter period of the time.
Technical Report
Environmental impact assessment for the proposed integrated water resource management project HA. Ihavandhoo
(2012-11) Sandcays
This report discusses the findings of a social and environmental impact study under the proposed integrated water resource management project in Ihavandhoo, Haa Alifu Atoll. The project is proposed by United Nations Office for Project Services (UNOPS). The project is targeted at providing potable water to the community and improving rainwater recharge. Potable water is provided by a combination of rainwater and desalinated water, which is a new and unique project for the Maldives. The recharge well system is even more unique. Consequently, several discussions have been held with the Ministry of Environment (represented by EPA), Ministry of Housing and Infrastructure and UNOPS to discuss the several issues. The issues were re-visited during the scoping meeting, the main issues identified by the EPA being the size of the rainwater tanks and good management of the system to ensure that most of the rainwater is used and desalinated water is depended upon as a supplementary source. EPA also has issues with the proposed recharge wells with the main concern lying in the possibility that the recharge wells may help to cause flooding during storm water. However, the project engineer is quite certain that this was not likely and this was also backed by the EIA Consultant. At present Ihavandhoo does not have a piped water supply system and groundwater is used unanimously for all purposes with the exception of bottled water and rainwater for drinking. Several efforts have been made in the past including the construction of public rainwater tanks with public tapbays, which was later replaced by household rainwater tanks of 2500l at each household for easier access but with some compromise on water quality issues. Rainwater, however, could not be depended upon during long, dry periods during the northeast monsoon. With changing climatic patterns worldwide, rainwater can rarely be depended upon. With lack of space for appropriate rainwater collection facilities combined with groundwater contamination and salinization has been seen to cause various health and environmental problems including water-borne diseases. The dependence on groundwater and untreated rainwater is often a cause for concern. Therefore, an integrated water supply system with sustainable groundwater resource is an immediate need for the people of Ihavandhoo, which has a population of over 2750 people in September 2012. The proposed integrated water supply system is designed for maximal use of rainwater supplemented by desalinated water for an average water demand of 50-70 litres per person per day. Raw water is proposed to be drawn from a borehole with 8’’ casing and pumps to pump the raw water to the treatment plant. The treatment for the water is proposed by using Reverse Osmosis technique. The plant will be run by diesel engine and the possibility of alternative energy options such as solar and wind will be considered. The pure water after treatment is collected in glass or fibre-reinforced plastic tanks of adequate capacity determined for Ihavandhoo to be 1000m3 based on EPA guidelines. The water thus collected is introduced in the network so as to reach all the households, institutional and commercial areas with adequate residual pressure through HDPE pipes. The distribution network is designed for over 35 years while the water tank capacity has been based on 15 years as per Government requirements. The proposed IWRM project also comprises of a mechanism to recharge groundwater using a collection of recharge wells made of concrete that will run along the main roads as well as the island periphery. Direct recharge of groundwater is minimized due to urbanisation as permeability is reduced and infiltration surface is minimized. Therefore, this process is assisted by the use of recharge wells that will direct the excess rainwater from roofs to the groundwater lens. However, it must be noted that these recharge wells are not anticipated to cater for storm water drainage. The sole purpose of these wells is to assist groundwater recharge so that the groundwater lens may be sustainably managed. Environmental impacts were assessed for both the construction and operation phase of the project. Most of the environmental impacts of the project have been identified as positive resulting mainly from easy access to safe water supply, improvements to groundwater quality and resulting reduction in water-borne and water-related diseases and improved health of the population. The socio-economic benefits of the project may be considered to outweigh the negative impacts of the project. There are a few negative impacts of the project including the minor impacts of landuse related to the project and clearing of some mature trees that may be required. The impact of clearing would be compensated by replanting mature trees in other areas of the island and, if necessary, planting additional trees. The impact of brine discharge is also considered minor or negligible especially due to the fact that there is no coral cover in the proposed brine discharge location and good mixing will occur due to currents in the area. Since the pipeline is a pressure system, the pipes will be laid above the water table and no dewatering will be required. Hence, no effect on the groundwater lens. Other minor negative impacts include excavation to lay the water distribution network and brine discharge pipe. One of the impacts of the proposed recharge wells would be space constraints to services on the road and the impact would be mitigated by appropriate planning for locating recharge wells and sewerage manholes as well as other such services. The other impact of the proposed recharge wells would be that there may be clogging of the pipes and such clogging may lead to unnecessary flooding in some areas where clogging occurs, especially in areas easily prone to flooding following rain. However, clogging is expected to occur over the long-term, therefore, it is not possible to do field tests to verify this. It has also been seen that recharge is also not much of a use if pumps are used to draw water from the groundwater aquifer, which leads to rapid salinization of the water lens during the dry period. Recharge of groundwater lens also occurs over a large surface due to rainfall. If we consider the sustainable yield estimated for Ihavandhoo, it can be seen that no amount of recharge will help to overcome the problems related to salinization due to increasing use of pumps. In fact, the Maldives receives well over 2000mm of rainfall, which would be more than sufficient to recharge the aquifer. Yet, the aquifer, similar to a rainwater tank, has its maximum capacity limits and cannot overgrow the impact imposed by high rates of abstraction. Therefore, only sustainable rates of pumping can ensure sustainable management of the aquifer. It has been observed from studies carried out for Malé that freshwater exists in pockets. Where the drawn down effect is high, due to the size of pumps and rate of pumping, there is a tendency for the water lens to become more saline at the location where the drawdown is greater. This draw down or lowering of the water table at the point of abstraction, sometimes referred to as the “coning effect” for the freshwater lens, can only be avoided with the use of appropriate technology such as skimming wells and infiltration galleries. The main mitigation measure for the proposed project would be to identify measures to minimize drawdown on the aquifer including the introduction of skimming wells by improving existing wells and enhancing water conservation techniques. The proposed concept of recharge wells is still at a preliminary stage, therefore, it is proposed that the detailed design takes into consideration the findings of this Environmental Impact Assessment, and consultations with the community and relevant government agencies, especially the EPA. It is inevitable that there would be some negative environmental impacts. However, these are minor compared to the positive effects of the proposed system. Yet, monitoring to ensure the effectiveness of the proposed system would be necessary. Therefore, a monitoring component has been suggested which takes in to consideration, the most important elements that require regular checks. This monitoring component will be adhered to and will allow the assessment of changes due to construction and implementation of the proposed water supply system and aquifer recharge system. Monitoring is specifically focussed on water quality, to include feedwater from the borehole (or other source), collected rainwater, groundwater, product water at designated locations and seawater at brine discharge location (upstream and downstream). Reef or marine ecological monitoring may be considered if the proposed location of the brine discharge or intake is found to be of ecological significance. In conclusion, it appears justified from a technical and environmental point of view, to carry out the proposed project to install and operate a piped water supply scheme using rainwater supplemented by desalinated water. However, the recharge well scheme needs to be further evaluated and possibly replaced by or integrated with an alternative scheme such as converting existing household wells to skimming wells to minimize salinization of the groundwater lens. It is also further recommended to consider one of the three islands under this project as a pilot island for the recharge wells instead of all three islands and Ihavandhoo seems to be the most appropriate since the island is higher in elevation compared to the other two and there is a lesser chance of potential flooding, where there is a concern.
Technical Report
Environmental impact assessment for the proposed integrated water resource management project Gdh.Gadhdhoo
(2012-12) Sandcays
This report discusses the findings of a social and environmental impact study under the proposed integrated water resource management project in Gadhdhoo, Gaafu Dhaalu Atoll. The project is proposed by United Nations Office for Project Services (UNOPS). The project is targeted at providing potable water to the community and improving the rainwater recharge. Potable water is provided by a combination of rainwater and desalinated water, which is a new and unique project for the Maldives. The recharge well system is even more unique. Consequently, several discussions have been held with the Ministry of Environment (represented by EPA), Ministry of Housing and Infrastructure and UNOPS to discuss the several issues. The issues were re-visited during the scoping meeting, the main issues identified by the EPA being the size of the rainwater tanks and good management of the system to ensure that most of the rainwater is used and desalinated water is depended upon as a supplementary source. EPA also has issues with the proposed recharge wells with the main concern lying in the possibility that the recharge wells may help to cause flooding during storm water. However, the project engineer is quite certain that this was not likely and this was also backed by the EIA Consultant. At present Gadhdhoo does not have a piped water supply system and groundwater is used unanimously for all purposes with the exception of bottled water and rainwater for drinking. Several efforts have been made in the past including the construction of public rainwater tanks with public tapbays, which was later replaced by household rainwater tanks of 2500l at each household for easier access but with some compromise on water quality issues. Rainwater, however, could not be depended upon during long, dry periods during the northeast monsoon. With changing climatic patterns worldwide, rainwater can rarely be depended upon. With lack of space for appropriate rainwater collection facilities combined with groundwater contamination and salinization has been seen to cause various health and environmental problems including water-borne diseases. The dependence on groundwater and untreated rainwater is often a cause for concern. Therefore, an integrated water supply system with sustainable groundwater resource is an immediate need for the people of Gadhdhoo, which has a population of over 2899 people in September 2012. The proposed integrated water supply system is designed for maximal use of rainwater supplemented by desalinated water for an average water demand of 50-70 litres per person per day. Raw water is proposed to be drawn from a borehole with 8’’ casing and pumps to pump the raw water to the treatment plant. The treatment for the water is proposed by using Reverse Osmosis technique. The plant will be run by diesel engine and the possibility of alternative energy options such as solar and wind will be considered. The pure water after treatment is collected in glass or fibre-reinforced plastic tanks of adequate capacity determined for Gadhdhoo to be 900m3 based on EPA guidelines. The water thus collected is introduced in the network so as to reach all the households, institutional and commercial areas with adequate residual pressure through HDPE pipes. The distribution network is designed for over 35 years while the water tank capacity has been based on 15 years as per Government requirements. The proposed IWRM project also comprises of a mechanism to recharge groundwater using a collection of recharge wells made of concrete that will run along the main roads as well as the island periphery. Direct recharge of groundwater is minimized due to urbanisation as permeability is reduced and infiltration surface is minimized. Therefore, this process is assisted by the use of recharge wells that will direct the excess rainwater from roofs to the groundwater lens. However, it must be noted that these recharge wells are not anticipated to cater for storm water drainage. The sole purpose of these wells is to assist groundwater recharge so that the groundwater lens may be sustainably managed. Environmental impacts were assessed for both the construction and operation phase of the project. Most of the environmental impacts of the project have been identified as positive resulting mainly from easy access to safe water supply, improvements to groundwater quality and resulting reduction in water-borne and water-related diseases and improved health of the population. The socio-economic benefits of the project may be considered to outweigh the negative impacts of the project. There are a few negative impacts of the project including the minor impacts of landuse related to the project, however, no clearing is envisaged. The impact of clearing, if any, would be compensated by replanting mature trees in other areas of the island and, if necessary, planting additional trees. The impact of brine discharge is also considered minor or negligible especially due to the fact that there is no coral cover in the proposed brine discharge location and good mixing will occur due to currents in the area. Since the pipeline is a pressure system, the pipes will be laid above the water table and no dewatering will be required. Hence, no effect on the groundwater lens. Other minor negative impacts include excavation to lay the water distribution network and brine discharge pipe. One of the impacts of the proposed recharge wells would be space constraints to services on the road and the impact would be mitigated by appropriate planning for locating recharge wells and sewerage manholes as well as other such services. The other impact of the proposed recharge wells would be that there may be clogging of the pipes and such clogging may lead to unnecessary flooding in some areas where clogging occurs, especially in areas easily prone to flooding following rain. However, clogging is expected to occur over the long-term, therefore, it is not possible to do field tests to verify this. It has also been seen that recharge is also not much of a use if pumps are used to draw water from the groundwater aquifer, which leads to rapid salinization of the water lens during the dry period. Recharge of groundwater lens also occurs over a large surface due to rainfall. If we consider the sustainable yield estimated for Gadhdhoo, it can be seen that no amount of recharge will help to overcome the problems related to salinization due to increasing use of pumps. In fact, the Maldives receives well over 2000mm of rainfall, which would be more than sufficient to recharge the aquifer. Yet, the aquifer, similar to a rainwater tank, has its maximum capacity limits and cannot overgrow the impact imposed by high rates of abstraction. Therefore, only sustainable rates of pumping can ensure sustainable management of the aquifer. It has been observed from studies carried out for Malé that freshwater exists in pockets. Where the drawn down effect is high, due to the size of pumps and rate of pumping, there is a tendency for the water lens to become more saline at the location where the drawdown is greater. This draw down or lowering of the water table at the point of abstraction, sometimes referred to as the “coning effect” for the freshwater lens, can only be avoided with the use of appropriate technology such as skimming wells and infiltration galleries. The main mitigation measure for the proposed project would be to identify measures to minimize drawdown on the aquifer including the introduction of skimming wells by improving existing wells and enhancing water conservation techniques. The proposed concept of recharge wells is still at a preliminary stage, therefore, it is proposed that the detailed design takes into consideration the findings of this Environmental Impact Assessment, and consultations with the community and relevant government agencies, especially the EPA. After discussions with the engineers, it is believed that the system will retain water and about 500m3 of rain will be retained to slowly recharge the aquifer during the dry period or periods with prolonged duration without rain. However, the main problem with the salinization of the aquifer and the making full use of the sustainable yield of the island’s small aquifer lies with the fact that drawdown and coning effect due to the use of pumps in household wells and not with recharge. Also, the potential impact of recharge wells contributing to flooding in a floodprone island like Gadhdhoo is of significance, such a system is not recommended. It is inevitable that there would be some negative environmental impacts. However, most of the impacts of the proposed water supply system are minor compared to the positive effects of the proposed system. Yet, monitoring to ensure the effectiveness of the proposed system would be necessary. Therefore, a monitoring component has been suggested which takes in to consideration, the most important elements that require regular checks. This monitoring component will be adhered to and will allow the assessment of changes due to construction and implementation of the proposed water supply system and aquifer recharge system. Monitoring is specifically focussed on water quality, to include feedwater from the borehole (or other source), collected rainwater, groundwater, product water at designated locations and seawater at brine discharge location (upstream and downstream). Reef or marine ecological monitoring may be considered if the proposed location of the brine discharge or intake is found to be of ecological significance. In conclusion, it appears justified from a technical and environmental point of view, to carry out the proposed project to install and operate a piped water supply scheme using rainwater supplemented by desalinated water. However, the recharge well scheme needs to be further evaluated and possibly replaced by or integrated with an alternative scheme such as converting existing household wells to skimming wells to minimize salinization of the groundwater lens.

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