Geography and population
The twin island state of Antigua and Barbuda (17°03' North, 61°48 West) is situated in the northeastern part of the Leeward Islands of the Lesser Antilles. The islands are located between 17° 00' and 17° 35' N latitude and between 61° 40' and 61° 55' W longitude. Total land area is 440 km2, Antigua being the larger island with an area of 280 km2 and Barbuda having an area of 160 km2. Approximately 31% of the total land area (13,810 ha) is considered cultivable. Within this area, some 2,000 farmers are engaged in production on 1,863 ha. Eighty-seven percent of the cultivated area (1,618 ha) is under annual crops while the remaining 13% is under permanent crops.
There are three main agro-ecological zones in Antigua: the North-Eastern Limestone Formation, the Central Plains (mixed volcanic and sedimentary/mudstone together with alluvials area) and the Volcanic Region. The highest peak in Antigua is Boggy Park (403 m). Barbuda, by contrast, is coraline and flat. Its highest peak, Highlands, is only 38 m.
The total population of Antigua and Barbuda was estimated at 63,900 (1992), 62,600 in Antigua and 1,300 in Barbuda. Sixty-four percent of the total population of both islands is rural. The annual growth rate of the population was 0.63% between the period 1990 and 1997.
Over the past 15-20 years, agriculture recorded a steady decline in growth from 15% of gross domestic product (GDP) in 1980 to 4.5% of GDP in 1996. Agriculture is dominated by livestock. More than 75% of livestock production of Antigua is carried out in the Central Plains and the North-Eastern Limestone Formation. Barbuda is devoted entirely to livestock production with the exception of a few agricultural stations and fenced farming areas. Tourism is now the major foreign exchange earner, contributing 65% of GDP.
Climate and water resources
Antigua enjoys a semi-arid, tropical climate with an average annual rainfall range of 1,070 - 1,140 mm, unevenly distributed with peaks during the months of October to December and extended periods of drought during March to June. Barbuda is drier with average annual rainfall ranging between 760 - 990 mm.
Droughts occur every five to ten years. When several low-rainfall years occur consecutively, the country faces critical water shortages. In 1983-84 water had to be imported from other countries.
The total average rainfall for both islands is estimated at 453 million m3/year and internal renewable water resources (IRWR) about 52 million m3/year. There are no perennial water sources in the country. At present the country's agricultural and municipal (domestic and commercial) water demands are being met by two desalination plants (total capacity 3.3 million m3/year); three surface dams, numerous small ponds and 5 well fields (total capacity 2.8 millions of m3/year). Individual residences have cisterns which provide part or all of the household water needs. The amount of water collected through this method is not known.
Water for Barbuda is supplied from a single well that serves Codrington where most of the population lives. The groundwaters are generally saline with the notable exception of Palmetto Sands, a 600 ha area of beach sands on the southwestern shore.
Lakes and dams
Total dam capacity in Antigua was about 7 million m3 in 1992. It is estimated that there are over 500 ponds, each with capacity less than 1,000 m3. The small ponds are used primarily for agriculture and many of the reservoirs are used for both agricultural and municipal uses. During drier months irrigation is restricted to a very limited surface due to shortfall in surface and groundwater yields, and most surface water storage is diverted to municipal supply. On the other hand, Barbuda's topography and geology are not well suited to dam construction.
Annual water withdrawal in 1990 was about 5 million m3, of which the domestic sector accounts for 60%, while agriculture and industry account for 20% each.
The entire population, both rural and urban, has access to potable water. Most of the municipal water is treated at three main treatment plants.
Irrigation and drainage development
Owing to the low annual rainfall and high evapotranspiration, irrigation is a necessity for the successful cultivation of crops. Irrigation potential has been estimated at 319 ha. This estimate is based on developing surface water storage capacity in an economically rational manner. Proposed sites with favorable development potential have been selected on the basis of their topographic suitability, geological conditions and proximity to agricultural lands.
Approximately 7% (130 ha) of cultivated land is currently irrigated in Antigua and Barbuda. Sprinkler and micro-irrigation systems are mainly used on 19.0 and 78.6% of the irrigated area, respectively. The remaining 2.4% are equipped inland valley bottom land.
Surface supplies are the main source of irrigation water for agriculture, with occasional use of groundwater when municipal demands allow. Agriculture uses about 21% of the municipal water supplied, as priority is given to domestic and municipal uses. Many small dams have not been used efficiently and underutilization and lack of maintenance have resulted in the deterioration of these facilities.
An assessment of the natural resources of Antigua and Barbuda identified reclamation and recycling of treated sewage as a potential source of agricultural water supply. The report estimated that up to 4,550 m3/day could be collected from some 600 ha of urban area if adequate sewage system existed. Villages, hotels and the airport were also identified as potential sources of reclaimable waste suitable for tree crops and pasture irrigation. It was assessed that as much as 80% of non-agricultural water demands could be reclaimed for limited agricultural uses.
There are three main government-owned irrigation schemes in Antigua - the Sanderson, Bethesda and Potworks Irrigation Projects. The Sanderson Project is the smallest with a size of 8 ha. It is a micro-irrigation system which supplies 10 households. The second largest project is at Bethesda, a sprinkler irrigation system serving 10 households. The Potworks Project is the largest, extending some 50 ha, serving 15 households. Both sprinkler and micro-irrigation systems are used in this project. All three irrigation projects service farms which are 1 ha or less in size. There is no charge for the use of irrigation water obtained from surface dams or ponds. Where irrigation water is obtained from the municipal water supply, the user is charged.
About 120 ha of annual and 10 ha of permanent crops are irrigated. Primarily, vegetables such as tomatoes, onions, cucumbers, water melon and cabbage are irrigated.
The drained surface area is about 808 ha and is limited to on-farm drains constructed to dispose of excess rainfall and downhill runoff.
All water resources of Antigua and Barbuda are currently vested in the Antigua Public Utilities Authority (APUA). APUA operates a network of distribution pipes throughout the country to supply treated water to both domestic and commercial sectors. Agriculture is considered to be a commercial activity and irrigation generally does not enjoy any special preference in water allocation.
The Ministry of Agriculture, Lands, Fisheries and Housing (MALFH) is responsible for technical assistance to farmers on irrigation, drainage, soil and water conservation.
The Caribbean Agricultural Research and Development Institute (CARDI) provides technical assistance and training in soil and water conservation to the MALFH and farmers in collaboration with the Extension Division and under the Natural Resources Management Programme.
Private sector companies such as hotels and recreation facilities (golf courses) employ local and expatriate personnel for irrigation operation and maintenance.
Trends in water resources management
Freshwater is a scarce resource in Antigua and Barbuda. In the context of a growing tourist industry, demand for water is rising. The Antigua Public Utilities Authority has a long-term water development plan with emphasis on desalinization of seawater to eliminate the risk of drought and inadequate surface storage and groundwater facilities.
Currently there is no irrigation and agricultural water development policy in Antigua and Barbuda. Adhoc programmes and projects are generally used to satisfy the individual farmer's demand for small-scale irrigation infrastructure, such as small dams. An agricultural water resource development committee has been proposed in a recent seminar to formulate appropriate policy and projects to develop irrigation in Antigua and Barbuda.
CARDI has been promoting a dryland farming system among smallholder farmers by demonstrating drip irrigation, water harvesting, mulching, minimum tillage and drought tolerant crops for sustainable agricultural production in the Eastern Caribbean islands.
- Water profile of Antigua and Barbuda, Food and Agriculture Organization.
- World Factbook: Antigua and Barbuda, Central Intelligence Agency.
- Natural Resources Institute (NRI). 1996. Renewable Natural Resources Profile of the Eastern Caribbean. United Kingdom.
- FAO. 1996. Horizon 2010. Antigua and Barbuda. World Food Summit Follow-up. Draft Strategy for National Agricultural Development, Rome.
- Caribbean Conservation Association-Island Resources Foundation. 1990. Antigua and Barbuda. Environmental Profile. St. Michael, Barbados.
- FAO. 1989. A proposed watershed development programme for Antigua. TCP/ANT/8851. Rome.
- FAO. 1989. Strengthening small-scale irrigation and soil and water conservation programme. TCP/ANT/8851. Rome.
- Organization of American States (OAS). 1985. Evaluation of Agricultural Water Supplies in Antigua & Barbuda. Washington D.C.
- Atkins Land and Water Management.1983. Soil and Water Conservation, Winward & Leeward Islands. Reconnaissance Study. United Kingdom.
Disclaimer: This article is taken wholly from, or contains information that was originally published by, the Food and Agriculture Organization. Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the Food and Agriculture Organization should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.