Irrigation in the Dominican Republic (DR) has been an integral part of DR agricultural and economic development in the 20th century. Public investment in irrigation has been the main driver for irrigation infrastructural development in the country. Irrigation Management Transfer to Water Users Associations (WUAs), formally started in the mid-1980s, is still an ongoing process showing positive signs with irrigation systems in 127,749 ha (46% of total irrigated land in the country), being managed by 41,329 users (57% of all users). However, the transfer process and the performance of WUAs are still far from ideal. While WUAs show a significant increase in cost recovery, especially when compared to low values in areas under state management, a high subsidy from the government still contributes to cover operation and maintenance costs in their systems. Water demand for irrigation is 7,340.41 million m3/year which is 82% of the total demand (8,891,45 million m3/year). Irrigation demand is covered mostly by surface water, and partially (13%) by groundwater. About 76% of Dominican Republic's land area (8,900 km2) is dedicated to agriculture, 17% of which is irrigated. According to FAO, 270,000ha are equipped for irrigation. Most of the irrigated areas are located in the valleys between the mountain ranges, with a medium to low rainfall and few limitations on its soil such as slope, depth of soil, and in some cases, salinity problems associated with irrigation or the presence of saline groundwater. Annual government investment in water resources and irrigation infrastructure is in the order of US$100 million. Needs in the irrigation sector are related to improving efficiency, productivity and organizational aspects. According to the FAO, solutions should be sought in the use of better technology, efficient operation of irrigation systems and adequate means of financial support. Poor maintenance of existing infrastructure and irrational use of water are causes for the low (overall) irrigation efficiency.
History of the irrigation sector
According to the Food and Agriculture Organization (FAO), irrigation development in the Dominican Republic started in the late 19th century, with the construction of the Juan Caballero, Luis Bogart and Santana canals and the Manzanillo Project. In the 1920s, due mostly to government investment, irrigation development increased substantially. The area under irrigation continued increasing in the 1940s and 1950s, from 32,000ha in 1941 to 132,000 in 1954. During the 1960s hydraulic development shifted towards multi-purpose dams, returning to canal network development for the next 30 years and reaching the current 280,000ha equipped with irrigation infrastructure. The Irrigation Management Transfer Program (IMTP) started formally in the mid-1980s and continues until today. IMTP aims at decentralizing operation and maintenance, and fee collection responsibilities among others to the Juntas de Regantes (Water Users Irrigation Boards - WUB). To this date, 17 main WUBs have been formed and the operation of 11 systems has been formally transferred to them. WUBs have a total membership of about 30,000 users. According to the FAO, some of the achievements of IMTP includes: (i) reduced conflicts between the authority and water users, (ii) improved service, and (iii) higher fee collection (an increase from 20% of total charges, when managed by National Institute for Water Resources to almost 80% on their own). However, these results are far from ideal. For example, overall cost recovery continues to be low hence O&M costs still depend on government subsidies.
Irrigation infrastructure Gravity and surface irrigation are the predominant systems supplying water for irrigation to an area of 278,965 ha.(gross area). According to FAO, this is about half the land where irrigation is feasible (550,000 ha.). The existing infrastructure is composed of 1,836.4 km of main canals, 1,773.2 km of secondary canals, 1,200 km of drainage canals and 14 major dams. The total storage capacity is 1,450 million m3. Actual water delivery is approximately 4,600 million m3/year.
Environmental aspects
Linkages with water resources
According to FAO, DR receives a mean annual precipitation of about 1,500 mm; with arid zones receiving as less as 500 mm/year, and humid areas receiving an average of 2,500 mm/year. Evapotranspiration is over 2,000 mm/year. Total runoff is estimated at 21,000 Million m3/year. Water demand for irrigation is 7,340.41 million m3/year which is 82% of the total demand (8,891,45 million m3/year). Irrigation demand is covered mostly by surface irrigation, and partially (13%) by groundwater.
Environmental impacts of irrigation According to FAO, 125,000ha and 80,000ha are affected by drainage and salinity problems, respectively. The majority of which are located in the Valleys such as Cibao, Santiago Montecristi, Azua, San Juan de la Manguana, Neyba y Barahona as well as downstream Yuna and the eastern coastal area, in the provinces of Maria Trinidad Gracias y Altagracia respectively.
Anticipated climate change impacts on irrigated agriculture Global climate change is expected to induce permanent climate shocks to the Caribbean region including sea level rise, higher surface air and sea temperatures, extreme weather events (such as tropical storms and hurricanes), increased rainfall intensity (leading to more frequent and severe flooding) and more frequent and severe "El Niño-like" conditions. Demographic growth accelerated environmental degradation, deforestation, and lack of mitigation measures will intensify the impact of disasters in the future. There is currently no information available about the specific impacts of climate change on irrigated agriculture in the DR. Although there is some data in terms of Climate Change impacts on water resources in DR's First Communication to the UNFCCC. Indeed, it is expected a great decrease in spatial distribution of rainfall, and total runoff for the year 2100, demonstrating a structural change that intensifies the transition from the most humid zones to the driest and an expansion of the areas of the country that are historically the driest.
Legal and institutional framework
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