Our Watershed

The Southern end of the Nicoya Peninsula is comprised of 3 districts, Lepanto, Paquera and Cóbano, part of the Province of Puntarenas. The district of Cóbano, where most of our actions are implemented, has an extension of 316.61 km2 with a total population of 7.494 inhabitants. Cóbano is bordered by the Pacific Ocean to the south, east and west, its northern border is the Bongo and Juan de Leon Rivers, separating it from the Districts of Lepanto and Paquera. In the inland mountains of this area lie most of the Peninsula de Nicoya’s most important headwaters that are linked by many rivers all the way to the Pacific Ocean.

Nicoya Peninsula map

Nicoya Peninsula Waterkeeper®’s area of jurisdiction extends from the Cabo Blanco Absolute Nature Reserve covering all the coastal streams and marine waters up to the Caletas-Ario National Wildlife Refuge.


Traditionally, this area had been characterized by an agrarian lifestyle, secluded and relatively isolated from the rest of the Peninsula. The Bongo and the Ario rivers were the main transportation routes for people and goods, coming down in small boats traditionally known as “bongos” down the rivers and by small ferry boats from the coast to the port of Puntarenas. The Pacific side of the Nicoya Peninsula was colonized in the 1940’s by subsistence slash and burn agriculture primarily of beans and corn and extraction of lumber which prompted a strong deforestation process of the land. Due to limited resources, difficult access to the area and “middle men” which controlled the market for goods, many farmers began to lose their lands due to accumulated debts and by the late 1960’s there was an outmigration by small subsistence farmers to farming areas on the gulf side of the Peninsula with easier access to Puntarenas. Gradually, these middle men amassed larger farms and shifted land uses to cattle ranching farms which spread based on national bank system incentives and credits. This continued a strong deforestation process inland on steeper slopes and provided limited employment opportunities for locals who were forced to migrate out or dedicate themselves to new activities such as artisanal fishing and offering of daily work.

In the mid-1970s, a Government agrarian development expropriated a large cattle ranch and redistributed it to low income families which prompted recolonization of the coastal area from Manzanillo to Mal País. Unfortunately, this area had limited water supply and poor soils which led to a new shift in the direction of the region.

Starting in the late 1990s, a new wave of migration has hit the area, this time driven by the tourism industry. Land owners lured by booming land prices offered by foreigners began to sell off their lands mostly to foreigners who developed tourism-based businesses.

This migration has had significant impact in the towns of Manzanillo, Hermosa, Santa Teresa, Carmen and Mal País, where sun, sand, waves and nature have been the magnet for tourists from all over the world. The growth of touristic activity has been uncontrolled as has been the management and use of water. Some restaurants, hotels and houses along these touristic towns recurrently discharge their grey and black waters directly in the small streams along the coastline.

Marine Environments

The ocean bottom in from of this coast is characterized by rocky reefs which serve as home, breeding grounds and/or nurseries for a number of species including conchs, lobster and shrimp. There have not been any major studies of these environments, with the exception of conch studies conducted inside of the Cabo Blanco Absolute Nature Reserve. Marine environments suffer from inadequate grey and black water management deriving from the tourism and residential sectors, silt from erosion of soil due to unsustainable land management. These environments also suffer from inappropriate fishing and agricultural practices.

Intervention area map

Area description

There is one main river in the area, the Ario, as well as numerous streams and seasonal waterways. The Ario joins the Bongo river approximately 1.2km before flowing into the Pacific Ocean. The Ario River, born inland in the northern most part of the Cóbano District, has been identified by GRUAS II (Proposed Zoning for Biodiversity Conservation in Costa Rica) as one of the major gaps in ecosystem representation and has proposed this watershed as a protected area of 10.023,23 ha.

Higher Ario Watershed

The Higher Ario Watershed is characterized by broken terrain part of the central peninsular mountain chain which currently forms part of an important regional biological corridor. The grazing pastures give way to less altered environments such as gallery forests. A more thorough recognition of this area needs to be done in order to assess its main problems/opportunities comprising the communities that have a strong relation with the river.

The Lower Ario Watershed comprises tributaries (Caño Seco, Ceritral, Negro and Seco rivers) as well as the surrounding land from Cerro Villalta downwards. The lower watershed of the Ario is a mixture of riparian areas, gallery forests, agricultural land, pastures for cattle grazing and small rural towns. Near the coast, approximately 1.2 km inland, Ario joins with the Bongo River forming an estuary of environmental relevance currently protected through the Caletas Ario National Wildlife Refuge. Artisanal fishing and recreational activities such as bathing and camping also occur along this river.

Caletas-Ario National Wildlife Refuge

The Caletas-Ario National Wildlife Refuge is located along the coast of Ario and Caletas, with a total of 9.36km of coast. The Refuge’s total area is 20.179 hectares, of which 332 ha. terrestrial and 19.846 ha. marine. This Refuge includes areas such as mangroves, marshes, rivers, estuaries, marine rocky reefs, and beaches that serve as nesting grounds for 4 different species of marine turtles. The Caletas wetland is an area that has been severely affected by the creation of illegal rice fields, causing great environmental damage. Regrettably, this wetland received the 2010 Grey Globe Award, given by the World Wetland Network for inadequate management of wetlands.

Bajos de Ario

The Bajos de Ario community is located just before the junction of the Ario and Bongo and in the outskirts of the Caletas-Ario National Wildlife Refuge. The people of this community work mainly in the cattle and agricultural sectors with a minority traveling to the neighboring tourism communities to work. The lack of job availability in the community is forcing the locals to move elsewhere. Bajos de Ario relies on private water wells for their water supply.

Bello Horizonte

Bello Horizonte is a small town 2kms inland from Manzanillo. The area is home to many locals whose primary source of employment is tourism and construction in the neighboring towns of Hermosa and Santa Teresa. The majority of the area is owned primarily by local Costarican families in small cattle farms. Many of these farms are slowly being broken down into smaller parcels and sold off to either foreigners or to Costaricans from other areas of the country.

Manzanillo, Hermosa, Santa Teresa, Carmen and Mal País

Manzanillo, Hermosa, Santa Teresa, Carmen and Mal País communities are very renowned touristic destinations in Costa Rica. Having a very distinct high and low tourism seasons, the population of these communities doubles at the peak of the high season (December through April). The majority of the accommodations are small hotels or bed and breakfasts that cater all types of tourism, from adventure, sports, surf and environmental-driven tourism to leisure, relaxation and yoga. There are a few high-end resorts in the area which maintain a small number of rooms.

The maritime-terrestrial zones in these communities are managed as state concessions and are controlled by a land use regulation plan. Land use outside the maritime-terrestrial zones is not yet regulated.

These communities will benefit significantly from an aqueduct project which will be constructed shortly by the AyA (Costarican Institute of Aqueducts and Sewage Systems) feeding from the Ario aquifer and solving their serious water shortages.

Cabo Blanco Absolute Nature Reserve

The Cabo Blanco Absolute Nature Reserve was Costa Rica’s first protected national park and was the first conservation area with a management category and that included a marine component in all of the Central American Region. This Natural Reserve serves as a shelter for marine flora and fauna and its surrounding unprotected waters have seen an increase of biodiversity that has benefitted the marine health as well as the income for small artisanal fishers of Cabuya and Mal País.