2001 MAL: Report on Integrated Water Resources Management and Sustainable Sanitation for Four Islands, Republic of Maldives
Author: Falkland, T. Ecowise Environmental
The Government of Maldives (GoM), with financial support from UNICEF, has sponsored the construction of sewerage systems on 7 islands. In recent years, there have been a number of reviews of the design, construction, operational performance and problems occurring with the GoM-sponsored sewerage schemes. It would be fair to conclude from the available reports of existing sewerage systems that there have been some successful elements of sewerage systems on some islands but that most systems have experienced problems of one form or another.
Purpose / Objective
Review and summarise all relevant works previously carried out regarding water and environmental sanitation (WES) in the islands -- in particular, small bore systems and rain water harvesting.
Analyse and interpret the data collected with regard to the water and sanitation situation of the four selected islands -- V. Keyodhoo, Adh. Dhagethi, Dh. Ribudhoo, M Muli -- carried out by MWSA under UNICEF programme of activities. With the aid of the above findings, together with the government health sector policy (2020 vision, National Development Plan etc.), prepare, analyse, assess and document the long-term WES requirements and community attitude for these islands.
Propose methods that can be applied to provide each island with integrated sustainable management of water resources and sanitation system, and recommend appropriate action for GoM/UNICEF collaboration. Suggest ways to encourage community participation, health education activities and social marketing strategies in these islands with regard to WES issues. Propose specific recommendations, feasible strategies and action for the island communities to successfully manage, operate and maintain water supply and sanitation infrastructure in a way that is affordable, sustainable and provides for or leads towards cost recovery.
Prepare funding proposal detailing the costs, financial and economic analysis regarding:
- Appropriate methods of sewage disposal and treatment in the four selected islands;
- Long-term water supply requirements for the selected islands and sustainable management of existing or available water resources; and
- Integrated management and development of water resources, and sustainable sanitation in the islands.
The relevant literature and reports on all previous water and sanitation work were reviewed. Data from surveys of four islands are reported in this evaluation; however, all survey results and methodology are not presented here. [See Small Bore Sewerage System Monitoring Rakheedhoo, Vaavu Atoll and Komandoo, Shaviyani Atoll.]
As part of the investigations, visits were made to all of the selected islands. Some additional islands, where sewerage systems have been installed, were also visited (K. Gulhi and V. Rakheedhoo). One other island where a sewerage system could be installed (Dh. Meedhoo) was also briefly visited due to its proximity to one of the selected islands (Dh. Ribudhoo).
Key Findings and Conclusions
There are significant problems with the present GoM-UNICEF funded sewerage systems installed on 7 islands. These problems vary from island to island. Groundwater quality was variable between these islands, but the highest groundwater pollution levels were generally associated with the most densely populated islands with a history of blockages in their sewerage systems (e.g. Kadholudhoo and Hinnavaru). The near-shore marine water quality around the islands with sewerage systems showed evidence of faecal and other pollution.
There is insufficient data to make definite conclusions about the impacts of the sewerage systems on the health of the island populations. The only island to report a significant change attributable to the sewerage system installation was Hinnavaru, where the health impacts were seen as negative. Outfalls discharging to the near-shore marine environments are a significant problem and future sewerage systems should avoid their use.
All islands suffer from a rainwater deficiency in dry periods, with Ribudhoo having the least capacity. There are many communal tanks with leaks. All islands have limited fresh groundwater resources, with Keyodhoo being the worst affected and Dhagethi the least affected. The best areas for fresh groundwater are most of Dhagethi, the northern and wider part of Muli and the central part of Ribudhoo.
There is a need to strengthen the capacity of MWSA in a number of key areas so that the proposed project and future situation analyses, including groundwater investigations, can be undertaken more successfully. Key areas identified for strengthening are:
- Monitoring and investigations: equipment, procedures and training
- Database for groundwater and other environmental data storage, retrieval and analysis
- Capacity to develop and deliver community education, awareness and information material related to water and sanitation
- Capacity building is required through additional equipment and training, and additional staff, where necessary
Development of the islands, particularly for housing, is done without prior detailed knowledge of groundwater conditions. This has the effect of (a) some house plots being located on very marginal groundwater where salinity is higher than acceptable limits, and (b) preventing some areas from being reserved as future groundwater protection zones, especially in the centre of islands where the lowest salinity groundwater is generally present.
A very high proportion of wells, including those used for drinking water, show evidence of faecal pollution. There are many factors that contribute to such contamination, but the most important is proximity to groundwater pollution from sanitation systems. Evidence suggests that wells in open areas (e.g. mosques) and wells into which rainwater is directed have lower bacteriological contamination and lower salinity than other wells. The injection of rainwater into the well has the effect of locally increasing the water level and preventing or slowing the migration of pollutants from nearby sources of pollution such as septic tanks.
Reclaimed land, either as separate islands or on the edge of current islands, will gradually enable the development or enlargement of fresh groundwater in the form of freshwater lenses. A number of years is required before such a freshwater lens would achieve relatively stable conditions. This fact should be taken into account in the land use planning process.
Specific technical recommendations are given in the report for: sanitation improvements (small-bore and treatment systems; septic tanks and de-sludging methods) and water supply improvements (rainwater harvesting; community groundwater pumping schemes; disinfection of potable water).
Comprehensive groundwater assessments should be conducted on populated islands, especially those that are planning to expand their urban areas, or where groundwater salinity problems are identified. This will require the purchase of appropriate geophysical equipment. In the future, GoM should also consider the purchase of a suitable drilling rig for groundwater investigations work.
Further investigations into the impact of pumping from wells should be undertaken. This will require the selection of wells, fitting and reading of flow meters, and assessment of salinity and water level using manual and automatic methods. The data should be analysed to quantitatively assess the impacts of pumping on groundwater salinity. Based on the findings, guidelines on pumping rates should be developed and distributed.
Community education and information about water and sanitation issues need to be enhanced using a range of methods including community discussions, workshops, radio programmes, brochures and lectures on specific topics.
Full report in PDF
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