San Carlos River Basin, northeastern Costa Rica

Water Use

The hydropower sector is the largest water user in the basin followed by agriculture, domestic water uses and tourism (Water direction, 2020). Today pineapple is the highest volume export crop in San Carlos with more than 10,448 hectares of plantations (Figure 5). This crop has a constant demand for water and soil, is in continued expansion, and exerts increasing pressures on the natural resources, particularly water, and poses a serious threat to water quality and quantity through fertilizer and pesticides and locally excessive extraction of groundwater (Rodriguez, nd). Figure 8 and 9 indicate that most hydropower projects directly use water that is generated from protected forested areas in the headwaters and that the more intense agriculture is located downstream of the hydropower generators. The latter downstream gradient of water users bears a certain potential for water resources conflicts.


Water (l/s)




4 004,29


590,76 (85% surface water)




Tourism increased since the late 1980s mainly in the district of La Fortuna with an ecotourism approach. Hydropower generation has also proliferated (Figure 9) with the first large scale Hydropower project that created the artificial Lake Arenal in the 1950s that exports water from the San Carlos basin now into the Pacific Bebedero river basin. Due to this water diversion, we excluded the Lake Arenal sub-catchment from the natural drainage system of the San Carlos River basin delineation.

Project name

Installed capacity (MW)

Aguas Zarcas


Balsa Inferior


Caño Grande




Daniel Guiterrez


La Esperanza




El Carmen – El Embalse


Pocosol – Agua Gata


Peñas Blancas


San Lorenzo


Figure 9. Hydropower projects in the San Carlos river basin.


Barrantes, V.J. (2019). Drought in the northern area goes beyond the El Niño phenomenon. CAMPUS Magazine, September 2019 edition, National University of Costa Rica (UNA). Recovered from:

Birkel, C. et al. (2020). Headwaters drive streamflow and lowland tracer export in a large-scale humid tropical catchment. University Space for Advanced Studies (UCREA), University of Costa Rica (UCR). Recovered from:

Correa, A. (2020) Blogs of the European Union of Geosciences, EGU Blogs. Featured catchment series: The San Carlos Catchment in northeast Costa Rica, a multi-scale hydrological observatory to leapfrog data scarcity in the tropics. Recovered from:

Water direction (2020). Public report: Flow assigned by use (total) per basin (San Carlos river basin). Ministry of Environment and Energy (MINAE). Recovered from:

Fick, S. & Hijmans, R. (2017). WorldClim 2: new 1km spatial resolution climate surfaces for global land areas. Recovered from:

National Forest Finance Fund, FONAFIFO (2012). Costa Rica Forest Coverage Study 2009-2010. Recovered from:

Costa Rican Electricity Institute, ICE (2017). Power generation expansion plan 2016 – 2035. Recovered from:

Instituto Metereologico Nacional, IMN (No date). Climate Atlas of Costa Rica. Recovered from:

National Institute of Statistics and Census, INEC (2014). VI National Agricultural Census. Recovered from:

Rojas, N. (2011). Study of Costa Rica's watersheds. Recovered from:

Rodríguez, F. (No date). The San Carlos river basin. Historical, economic, social and environmental characterization. Studies on the San Carlos River Basin, Costa Rican Institute of Technology. Recovered from:

United Nations Development Programme, PNUD (2018). Human Development Index (IDH). Recovered from:

National Territorial Information System, SNIT (2020). OGC Services. National Geographic Institute (IGN), Costa Rica. Recovered from:

FaLang translation system by Faboba