A programme for Promoting Rainwater Harvesting in the Caribbean

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Caribbean Rainwater Harvesting Programmeintake dams and damages to the distribution network disrupted the water supply onmainland Grenada, the individual household and communal cisterns of Carriacou and PetitMartinique provided a ready potable water supply during the immediate recovery period.In short, the extent of destruction caused by recent hurricanes has elucidated the heightenedneed for reducing human-induced influences in terms of vulnerability to natural disasters.Greater emphasis needs to be placed on coordinated and integrated land use planning,regularization of unplanned settlements, watershed resource conservation and rehabilitation,and integration of hurricane safety provisions in the rebuilding process.While the climate change scenario is expected to have a magnifying effect on the occurrenceand magnitude of hurricanes in the Caribbean region, it is anticipated that sea-level rise (SLR)and higher temperatures in general will have further negative effects on fresh water resourceavailability due to (Sweeney and Vermeiren, 2002):• Salt water intrusion of coastal aquifers;• Reduced rainfall producing less ground water recharge and surface water in streamsand rivers;• Higher temperatures increasing the rate of evaporation from surface water sourcesthereby reducing the amount of water available in reservoirs;• Greater overall demand from resource users to combat higher temperatures.3.4. Water governance and rainwater harvesting in the Caribbean –Select country reviewsThis section presents a brief synopsis of the water sector, challenges and the status of rainwaterharvesting in select countries of the Caribbean.Antigua and BarbudaAntigua and Barbuda have very limited water availability on account of the low rainfallregime. The country is almost devoid of perennial streams and consequently the country’swater supply is sustained by ground water extraction, man-made pond structures anddesalination. Antigua’s water demands ranges between 22,500 and 27,000 m 3 /day (5 to 6MGD) during non-drought periods and as much as 40,000 m 3 /day (9 MGD) in droughtperiods. The drought periods coincide with the high arrival rate of tourists to the country thusthe increase in demand in the drought periods.Antigua’s aquifers are subjected to some level of contamination from land-based activities,most notably farming. Irrigation back-wash contaminated with agro-chemicals often flushesinto these aquifers compromising water quality. Farmers are encouraged to engage in goodagricultural practices to reduce excessive chemical use and conserve water in irrigationapplication.A major 9,100 m 3 /day (2 MGD) Multi-Stage Flash Distillation (MSFD) desalination plantoperated by the Antigua Public Utilities Authority (APUA) is installed at Crabbs and supplieswater to 90% of Antigua. A number of reverse-osmosis (RO) plants operated by the APUA10
Caribbean Rainwater Harvesting Programmeaugment water from the main facility. The APUA has also installed a RO plant in the sisterisland of Barbuda. This plant was commissioned in March 2005 and has a capacity of 120m 3 /day (27,000 IGPD). Since its commissioning, the plant had to be taken out of service foroperational reasons (CEHI, 2006). A number of privately operated RO plants exist in Antiguaas well, including at St. James’ Club, Carlisle Bay Hotel, Rex Halcyon Resort and Jumby Bayresort (CEHI, 2006).To address water resource constraints, rainwater harvesting has been built into infrastructureand development policy. The Town and Country Planning Act requires that all dwellings mustbe built with facilities to store at least 3 to 4 days water requirements based on the house size;this approximates 18 m 3 (4,000 gallons) storage for every bedroom. In general for each gallonof storage, US$1.10 (EC$3.00) needs to be invested in cistern construction. Cisterns generally costabout 6% of the house construction cost. There has been public request for the Government toconsider providing incentives to offset some of the cost of cistern installation. (Source: APUA,2006)BahamasThe Bahamas are among the Caribbean’s most water-scarce countries. These islands do nothave surface rivers and have traditionally relied on ground water and rainwater harvesting.The groundwater reserves in the Bahamian islands lie at very shallow depths below the rocksurface and are inherently vulnerable to surface-based contamination sources. Additionally,the over-pumping of boreholes has led to intrusion of saline water compromising the utility ofthe water. This is particularly the case for New Providence (BWSC, on-line source). BahamasWater & Sewerage Corporation (BWSC) has invested in reverse osmosis as a principle strategyto process brackish and seawater to augment the country’s tremendous water demand. TheCorporation has a Marine Operations outfit which is responsible for the barging of some 19,300m 3 /day (4.25 MGD) of potable water per day (year 2000 figures) from the Andros Island wellfields (BWSC, on-line source). Some 88% of the population has access to pipe borne water. Itis estimated that there are over 200 RO plants currently operational in the Bahamasproducing more than 4.5 m 3 /day (1,000 GPD) each. Future plans anticipate termination ofthe system of barging water and the commissioning of new plants with near total dependenceon desalination for main supply (CEHI, 2006).Rainwater harvesting is a significant source of water for individual households on many islandsof Bahamas especially in the off-shore Abaco cays, Cat Island, and sections of Long Island,although desalination plants and piped distribution is forcing less reliance on RWH. Largeartificial catchments were operational in former US naval bases in Eleuthera and Mayaguana,and on Moores Island, Grand Cay, Mayaguana, and Green Turtle Cay community catchmentswere built however many have become defunct. Public institutions with rooftop systems arerelied on in some of the islands to serve communities. The island of Whale Cay has a pipeddistribution system that is supplied by rainwater. Industries, hotels and restaurants rely heavilyon RWH exclusively or as a back-up source (UNEP/OAS, 1997).BarbadosBarbados is a critically water-stressed country given its relatively small land area (430 km 2 or166 sq.mi.) and large population (estimated at 272,000 at 2005; UN-ECLAC, 2004), and thehigh level of commercial development. The country’s main water supply is from groundwateraquifer reserves (79% of the total fresh water resources), and 2005 estimates of production11
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A programme for Promoting Rainwater Harvesting in the Caribbean

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