Guanacaste is heading into another period of water uncertainty as Costa Rica’s long-promised PAACUME water project remains far behind schedule, four years after the country signed a $425 million loan agreement to finance the work.
The project, officially known as the Water Supply Project for the Middle Basin of the Tempisque River and Coastal Communities, was designed to move water from the Arenal reservoir system toward some of the driest and fastest-growing areas of the Chorotega region. But the project has reached only 20.8% completion, according to figures from Senara reported this week.
The delay comes as Costa Rica prepares for a possible El Niño-driven dry spell. NOAA said that El Niño is likely to emerge between May and July 2026, with an 82% probability, and continue through the Northern Hemisphere winter. For Guanacaste, where drought and pressure on aquifers have long shaped public policy, the timing is especially sensitive.
PAACUME is meant to take water from the Arenal reservoir and remaining flows from the Arenal-Tempisque Irrigation District, move it through existing canals to the Río Piedras reservoir, and then carry it to the right bank of the Tempisque River. From there, the system would serve roughly 18,639 hectares of farmland, hotel green areas from the Gulf of Papagayo to Pinilla, and drinking-water aqueducts in Carrillo, Santa Cruz and Nicoya.
The project is not only about agriculture. It sits at the center of Guanacaste’s long-running water debate, where tourism development, farming, population growth and rural communities all depend on a limited resource. Senara says the project would also reduce the use of groundwater and local surface sources by replacing part of that demand with water moved through the new infrastructure.
The $425 million loan agreement with the Central American Bank for Economic Integration was submitted to the Legislative Assembly in 2022 and formally listed as financing for PAACUME under loan contract No. 2220. The broader project cost has been estimated above that amount, with Costa Rica expected to provide additional counterpart funding.
The project received a public relaunch in July 2023, when the government announced the formal start of works in Guanacaste. At the time, BCIE said PAACUME would provide water for human consumption and irrigation to more than 700,000 people in the province.
Since then, progress has been uneven. Senara’s latest breakdown shows some parts moving faster than others: the access road is 57% complete, the storm relief canal is 89.3% complete, tunnel arch fabrication is 95% complete, and the electric distribution line is 77.3% complete. But other core components remain far behind, including water intake works at 4%, tunnel lining fabrication at 5%, conduction works at 18.6%, and the temporary irrigation canal at 19%.
The completion date has now slipped to 2029. Former President Rodrigo Chaves had previously acknowledged that the project would not be finished during his administration, after earlier government messaging suggested the works could move faster.
That leaves the new administration with a major infrastructure decision almost immediately: push PAACUME forward, redesign parts of it, or allow the project to keep moving at its current pace. Interview requests made to Agriculture and Livestock Minister Juan Gabriel Ramírez about the project’s future went unanswered, according to the report.
For Guanacaste, the stakes are practical. The province is one of Costa Rica’s main tourism and real estate growth areas, while still carrying a dry-season water burden that affects farmers, towns and coastal districts. PAACUME was built politically around the promise that the same water system could support food production, tourism, drinking-water supply and climate adaptation.
That promise remains mostly on paper. With El Niño now raising the risk of hotter and drier conditions, the question is no longer only when PAACUME will be finished. It is whether Guanacaste can afford to wait until 2029.
