National IWRM Diagnostic Report Samoa


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National IWRM Diagnostic Report Samoa

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Diagnostic Report


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Sustainable development necessitates a balance be maintained between the needs of economic development, public health and environmental protection. Inevitably these three pillars of sustainability create competing and sometimes opposing pressures and demands upon the limited land and water resources of countries. In Small Island Developing States (SIDS) in particular, with limited land mass and even more limited natural water resources, these pressures are a present day reality.

Whilst many SIDS have made great progress to realising sustainable development and achieving the Millennium Development Goals and targets, such endeavour has been generally made through sectoral approaches. In doing so the competitive demands of different sectors are difficult to manage, and the result is a continued increase in population growth, land use and water usage. For some SIDS this demand is now close to exceeding the natural carrying capacity of the islands and watersheds, especially those hosting the country capital.

Samoa is no different to many other Pacific SIDS in having to address these challenges at this time, whilst recognising that it, like other SIDS, has limited human and financial resources, and does not have the benefits of the economies of scale that larger countries can utilise. Samoa consists of two main islands and seven islets. It is rugged and mountainous, with about 40 percent of Upolu and 50 percent of Savaii characterized by steep slopes descending from volcanic crests. The interior of both main islands is still covered with montane forests, and in the case of the highest altitudes on Savaii, cloud forest. These areas also contain volcanic peaks with the Upolu crestal ridge rising to 1,100 m. Savaii has more and younger volcanic cones with the highest peak reaching 1,848 m at Mt. Silisili. West Savaii and north-west Upolu are almost devoid of surface streams and their associated incised river channels, with uniform terrain and gentler slopes, allowing rapid rainfall infiltration and the development of fresh groundwater lenses.

Of the population of 180,000 people, approximately two thirds live on Upolu, and of them approximately 40,000 live in the capital Apia. The country as a whole has a population density of 63.5 persons/square kilometre, whereas that of Apia has a population density of 570 persons/square kilometre. Not surprisingly the land use in and around Apia is greatly modified from its natural state, with urban development in the coastal plain and low foothills, and periurban development and commercial agriculture in the watersheds.

Water supply in northern, eastern and southern Upolu and eastern Savaii is from surface water intakes, where as that for western Upolu and rest of Savaii is from groundwater. Water shortages are reported during the dry season, especially during extended dry periodsassociated with the ENSO, in the Apia area on Upolu (served by surface water intakes) and in the Falealupo Peninsula on Savaii (where groundwater is often brackish saline and the population relies upon rainwater harvesting). The Vaisagano Catchment behind Apia provides water for 3 of the 5 hydropower plants in the country.

The lack of natural water storage results in these catchments reaching low flow levels within several weeks. Conversely the lack of storage also results in rapid flooding events, with times to peak estimated at less than 3 hours for cyclone and tropical storm associated rainfall events. Flooding in Apia is a recurrent problem.

Water and energy demand is increasing with population wealth, and despite considerable effort in water demand management measures, including metering, leakage detection and repair, tariff incentives and conservation awareness campaigns, per capita consumption of water and power are predicted to rise.

With increasing population and landuse pressures, especially around the capital area, land degradation in the catchments is a concern. Inadequate wastewater management and solid waste management in the lower catchments, and increasing vegetation clearance due to urban expansion and cash cropping in the upper catchments not only reduces low flows and increases flash run-off, but also is resulting in perceived increases in erosion, sediment loading and nutrient enrichment of the water courses.

In Savaii logging and forestry are common economic activities in the uplands, whilst in Upolu the northern slopes are continuing to serve the economic expansion of Apia, whilst the southern coastal area is enjoying an expansion of the tourism industry.

Collectively these increasing pressures are perceived to be impacting upon public water quality, public health and causing degradation of environmental habitat. Samoa therefore recognises the benefits to be gained by adopting more integrated water resources management approaches. Many of the programmes currently being undertaken demonstrate a commitment to the fundamental IWRM principles.

This diagnostic report has allowed a more systematic analysis of the water sector and its linkages to the environment, health, land use, industry and other sectors to be undertaken. The diagnostic outcomes include areas identified requiring institutional strengthening, and a proposed coherent IWRM approach to plan the implementation of these tasks. The ethos of this approach is to build on the activities undertaken to date but to improve the coordinated and integrated planning and management of these activities, moving away from sectoral and institutional delivery, to more effective and efficient collaborative implementation.


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