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Geography, climate and population
Grenada is a tri-island state, located at longitude 61º4’W and latitude 12º4’N. It is situated 145 km north of Trinidad and Tobago and is the most southerly of the Windward Islands. The total area of the country is 340 km2. Grenada, which is 34 km long and 19 km wide, accounts for 89 percent of the area, and Carriacou and Petit Martinique account for 10 percent and 1 percent respectively. Grenada is mostly volcanic in origin, of steep rugged topography, with a main mountain chain running almost north-south in two main sections. The island is politically divided into six parishes, all of them on the island of Grenada (Saint Andrew, Saint David, Saint George, Saint John, Saint Mark and Saint Patrick), and 1 dependency (Carriacou and Petite Martinique together). The capital is Saint George’s.
The Draft Land Development Policy of the Ministry of Agriculture (1995) classifies 74.9 percent of the total land mass, or 25 500 ha, as being suitable for agriculture. In 2012, the total physical cultivated area was estimated at 10 000 ha, of which 70 percent (7 000 ha) consisted of permanent crops and 30 percent (3 000 ha) of temporary crops. Permanent meadows and pasture cover 1 000 ha, which brings to total agricultural area to 11 000 ha (Table 1).
The climate can be classified as semi-tropical with a marked dry season from January to May and a wet season running from June to December. Spatial variations in annual rainfall range from about 1 000 mm near the coast to more than 4 500 mm in the central mountains, with an average totaling 2 350 mm.
In 2013, the total population was about 106 000 inhabitants, of which around 60 percent was rural (Table 1). Population density is 312 inhabitants/km2. The average annual population growth rate in the 2003-2013 period has been estimated at 0.2 percent.
In 2012, 97 percent of the total population had access to improved water sources (99 and 95 percent in urban and rural areas respectively) and 98 percent of the total population had access to improved sanitation (both in urban and rural areas).
Economy, agriculture and food security
In 2013, the gross domestic product (GDP) was US$ 834 million. Agriculture accounted for 5 percent of GDP, while in 1992 it accounted for 11 percent. In 2013, total population economically active in agriculture is estimated at 9 000 inhabitants (20 percent of economically active population), of which 22 percent is female and 78 percent is male.
Surface water and groundwater resources
Grenada has an average annual precipitation of 2 350 mm, or 799 million m3 and renewable water resources are estimated at about 200 million m3/year (Table 2).
Water resources originate mainly from a system of permanent streams and rivers but there is some groundwater available from the limestone areas along the northwest coast. Most of the surface water originates from the high rainfall areas in the central mountain ranges of Grenada island. Overall, there are 71 river basins on the island, of which the eight largest are: Grand River (4 574 ha), Beausejour (3 793 ha), Pearls (1 500 ha), Saint Patricks (1 253 ha), Bailes Bacolet (1 233 ha), Antoine (1 102 ha), Saint Johns (1 208 ha) and Saint Marks (835 ha). All major rivers have perennial flows, though these are significantly reduced during the dry season.
Rainwater harvesting was used widely in earlier times but it has declined with the improvement of public water supply. However, in some remote high elevation areas, where the public water supply is inaccessible, rainwater harvesting is often the main source of potable water. Rainwater harvesting ponds are used in livestock production and, in a few cases, for the provision of water for intensive vegetable production (UNDESA, 2012).
In 2014, total produced municipal wastewater in Grenada was estimated at 11.4 million m3.
Lakes and dams
In 2014, total capacity of large dams (large dams in Grenada are those with a height of more than 4 m) was estimated at 22 000 m3. This capacity corresponds to the Annandale reservoir in the Beausejour river (5 000 m3), the Concord reservoir in the Black Bay river (4 000 m3), the Les Avocat reservoir in the Ballie's Bacolet river (6 000 m3), and the Mardi Gras reservoir in the St. Louis river (7 000 m3).
Grand Etang lake, with a surface area of about 8 ha, is within a basin of 86 ha of tropical rainforest. It is the only exploitable natural lake. Since the 1990s, during extreme dry seasons water from this lake has been used to supplement water supply.
Lake Antoine has a surface area of 6.5 ha. In the late 1990s, water from this lake was used for irrigation of organic bananas. The project was however unsuccessful due to the poor quality of the water, contaminated by agrochemical use.
Levera pond, with a surface area of 9.3 ha, is an ancient volcanic crater filled with a mixture of fresh and salt water. The pond is surrounded by red and white mangroves. Coconut palms, cactus and woody shrubs grow in the upland regions next to the pond. This lake holds no major importance for water supply, except for the occasional watering of livestock (UNDESA, 2012).
In 2014 total water withdrawal was estimated at 14.1 million m3 of which 12 million m3 (85 percent) for municipalities, and 2 million m3 (15 percent) for agriculture (Table 3 and Figure 1).
Surface water and groundwater withdrawal account for 13.1 and 1 million m3 respectively (Figure 2). Groundwater is used mainly during the dry season, since surface water yields can then drop by 25 percent (UNDESA, 2012).
Irrigation and drainage
Evolution of irrigation development
The irrigation potential has been quantified at 894 ha. The limiting factor to the development of irrigation is that in many cases suitable land is and available water resources are located in different places.
Between the 1950s and 1960s, irrigation practices increased particularly for banana growing. Sprinklers were widely used on estates such as Paradise, Grand Bras, River Antoine and Mt. Rueil where water was sourced through river diversion or pumped directly from the rivers. The decline of the plantation system during the 1970s reduced the irrigation areas. From 1979 to 1983, emphasis was placed on irrigation as a way of increasing productivity on the state farms using Eastern European and Cuban sprinkler irrigation systems. After 1983, many of the state farms were divided into small units and the government made efforts to improve irrigation technology including micro sprinklers and drip irrigation. Notwithstanding the availability of water, the success of the irrigation programme was low due to poor implementation (UNDESA, 2012).
In 1997, on the island of Grenada 219 ha was under irrigation, compared to 5 ha in 1973. Localized irrigation was used on more than 90 percent of the area, the remaining area being under sprinkler irrigation. Less than 1 percent of the irrigation area obtained water from river diversion, 6.5 percent from reservoirs and the remainder from direct pumping from rivers.
In 2008 the area equipped for irrigation was estimated at 365 ha, which represents 4 percent of the cultivated area (Table 4). Of the total area, 71 ha or 19 percent uses sprinkler irrigation and 294 ha or 81 percent localized irrigation (Figure 3).
Role of irrigation in agricultural production, economy and society
In 1997, crops grown under irrigation included mainly vegetables (90 percent), fruit trees and grapes (5 percent), cut flowers (2 percent) and maize, roots, tubers and pulses (3 percent).
In 2008, it is estimated that vegetables account for 100 percent of the total irrigated harvested area of 365 ha (Table 4).
In 2008, average costs for sprinkler and localized irrigation systems are US$3 684 and US$3 813 per ha respectively.
Women and irrigation
The Caribbean Policy Development Centre (CPDC), with the support of UN Women, has led a project focused on women agricultural producers’ role in sustainable development in Grenada that aims to reduce women’s lack of access to resources (UN Women, 2014).
Water management, policies and legislation related to water use in agriculture
The National Water and Sewerage Authority (NAWASA) is responsible for the development of drinking water supply as well as the sanitary disposal of sewage.
The Ministry of Agriculture’s Forestry Division is responsible for the protection of water catchments.
In Grenada the timing and duration of periods of high and low precipitation are not predictable particularly during the dry season and droughts. In the past water management has concentrated mainly on the supply of water for domestic uses. At present, there are growing concerns about the need to manage the water resources in an integrated manner (UNDESA, 2012). The conversation on integrated water resources management (IWRM) in the country is at an advanced stage.
The first significant plan for the whole island on potable water supply, ‘A plan for water development in Grenada 1965-1990’, was developed in the 1960s. As a result of the plan, a number of projects were implemented including treatment plants at Annandale, Peggy’s Whim, Douglaston and Petite Etang.
Policies and legislation
A recent draft water policy sets out a framework for the governance of the water sector and the allocation of duties, responsibilities and powers as well as the respective roles of the public and private sectors. The policy objectives include (UNDESA, 2012):
- The provision of a framework for integrated use, management and regulations of water resources and associated services
- The establishment of an institutional framework for IWRM
Environment and health
Very little data are available on the quality of the water resources in Grenada. There have been several reports about the washing of equipment laden with agricultural chemicals in rivers, which has resulted in frequent fish kills. In some cases, the use of chemicals and explosives to catch fish in the rivers in large quantities has been reported (UNDESA, 2012).
The impact of agriculture on water quality was evident in the production of bananas, which required intense applications of agrochemicals. Banana production also prompted deforestation and soil degradation as farmers moved to higher and higher forested areas in the watershed. These negative impacts were subsequently diminished after the collapse of the banana industry (UNDESA, 2012).
Prospects for agricultural water management
The demand for water is expected to increase in the near future due to an increase in the population and irrigation areas and the expansion of the tourism sector (UNDESA, 2012).
Constraints on sustainable water management, due to increased levels of pollutants and catchment degradation, water shortages during the dry season, lack of distribution infrastructure, inadequate financial and technological resources and poor human resources capacity, have to be considered for future water management plans.
Main sources of information
Ministry of Agriculture - Madramootoo, C. A. 2001. Hydrological analysis of potential irrigation Sites in Grenada. Ministry of Agriculture, Government of Grenada. Report funded by the United Nations Collaborating Centre for Water and the Environment.
CEHI, GEF/IWCAM Project. 2007. Road map toward integrated water resources management planning for Grenada. Caribbean Environmental Health Institute, GEF/IWCAM Project. Report funded by the United Nations Collaborating Centre for Water and the Environment.
Government of Grenada. 2007. Grenada water sector review. Report funded by FAO. Companion “Draft National Water Policy” endorsed by Cabinet of the GoG Nov. 2007 .
Gansu Research Institute for Water Conservancy, Ma Chengxiang, Zhou Luwen. 2008. Feasibility study on rainwater harvesting for agriculture in Grenada. Gansu Research Institute for Water Conservancy, China. Report funded by the Caribbean Development Bank.
Ministry of Agriculture, Puebla, J. H. 2008. Report on irrigation work May 2005-July 2008. Ministry of Agriculture, Government of Grenada.
UNDESA. 2012. Climate change adaptation in Grenada: Water resources, coastal ecosystems and renewable energy. United Nations Department of Economic and Social Affairs.
UN Women. 2014. Protecting their crops through green technologies, Caribbean women fend for themselves.