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<Sourcebook of Alternative Technologies for Freshwater Augumentation
in Small Island Developing States>



The Source Book is in three major parts:

- Part A provides an introduction to freshwater augmentation: what it is and why it is necessary. Part A also outlines the purpose of the Source Book; reviews the methodology used in this Source Book for the classification of "small islands"; and, presents an overview of how to use the Source Book.
- Part B briefly describes a series of alternative technologies available and used in Small Island Developing States (SIDS), and presents a consistent and comparable set of data about the technologies which can be used to compare their relative advantages for maximizing water-use efficiency and augmenting existing water supplies in small island states. The objective of these technology profiles is to provide a reasonably comprehensive inventory, summarised in Table 1, that water resources professionals can use when planning water development projects on SIDS.
- Part C comprises case studies that highlight specific technologies that have been adopted in the region, and summarizes the experiences gained from their implementation.

For the purpose of this Source Book, the technologies applicable to Small Island Developing States, discussed in Part B, are divided into four subsections:

- The first subsection reviews those technologies that are generally applicable to small islands regardless of their geological and topographical configuration. These include technologies such as alternative (dry) sanitation, water quality improvement, irrigation systems, and water conservation and groundwater assessment technologies.
- The second subsection reviews those technologies applicable to very small, low coral islands. These include technologies such as rainwater harvesting and groundwater abstraction techniques such as dug wells and infiltration galleries, as these islands are not likely to have surface water resources and moderate to low availability of groundwater resources.
- The third subsection reviews those technologies applicable to small, high volcanic islands which are likely to have greater options for water resources development. These include technologies for the development of rainwater, surface water and groundwater resources.
- The fourth subsection covers islands where specific problems or circumstances make it necessary to pursue alternative (and not so commonly used) technologies. These include technologies such as desalination, dual water distribution systems, importation, and wastewater reuse.


Summary of Freshwater Augmentation Technologies Applicable to Small Island Developing States.


Figure 1

Figure 1. Possible applications of water supply technologies for small high islands.

Figure 2

Figure 2. Possible applications of water supply technologies for small low-lying islands.

It should be noted that there are no fundamentally new technologies available to resolve the difficulties imposed on SIDS by their limited water resources. For very small, coral islands, either rainwater or groundwater is available. Most SIDS cannot afford desalination as an option, and importation of water by barge or submarine pipeline, similarly, is not often feasible. Small volcanic islands often have surface water as a third option, together with rainwater and groundwater. However, desalination and importation, likewise, are rarely used and only where there is no other feasible alternative and consumers can afford to pay for it. For these reasons, emphasis is placed on conserving and protecting the quality of the existing water resources. Pollution of groundwater and surface water resources is increasing due to untreated human waste discharges from individual households, hotels and industries, and urgent steps need to be taken to halt or minimise pollution of these water resources. Similarly, the water that is supplied to consumers is often wasted, and/or lost through delivery system leaks and illegal connections, and improved management of water resources and supply systems is needed. Often water is supplied without charge, even though costs are incurred in providing and maintaining the supply service. The technologies described in Part B address many of these issues.

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