Most of the rivers is on mountainous relief, this gives us as consequence navigable short and very few rivers. The rains so abundant feed the flows of the rivers, characteristic of a tropical region as ours. The presence of two stations a dry one and another rainy one affects the flow of the rivers and the systems orographics directly more or less continuous that cross our country; the mountain ranges of Guanacaste, Tilarán, Central and Talamanca, with direction northwest-easte. Due to these elevations, the fluvial waters of the territory run exclusively in two addresses toward the sea Caribbean or toward the ocean Pacific and it is for this reason you are distinguished two slopes: the slope of the Pacific and the slope of the Caribbean.
The pluvial regime of the country causes that a zone receives the rainwater all the year, whereas the other single zone receives partly from this period. This together with the climatic conditions of both zones determines that rivers present an abundant volume all the year, and the one of the others is much more irregular. In our country we can appreciate near 34 hydrographic river basins of considerable size and that, they are made up as well by smaller others. The terrain relief does not know limits nor political divisions; some of our river basins are only partially in the Costa Rican territory and they extend to the neighboring countries, like the Sixaola river it starts off of which it is in Panama and of some affluents of the San Juan river.
Vertiente del Pacífico
The rivers of this slope are originated in slopes of the mountain range of Guanacaste and of the Central mountain range, they are characterized by being short, accidents and deep, greatest they are navigable by small boats in a considerable section of its course.
From they run there to end at the Pacific Ocean, gulf of Nicoya and Dulce gulf. This slope covers near 55% percent with the national territory. There are 17 of the main hydrographic river basins of the country. Between that we have three greater of the country; the one of them Terraba river that have 5,077 Km2, the one that forms the rivers of the Peninsula of Nicoya and 4,202 North coast Km2 and the one of the 3,404 Tempisque Km2. Between the main rivers of this slope they are Tempisque, Tárcoles, Pirris or Parrita, Térraba and Coto Colorado. Less important they are the Bebedero, Aranjuez, Barranca and Jesús María.
Vertiente del Caribe
It covers near 45% of the national territory and it is divided in two subslopes; North Subslope and Subvertiente of the Caribbean.
It is located in the northwest region of the country and it includes 7 hydrographic river basins that end at the lake of Nicaragua and the San Juan river; of they go there towards the Caribbean Sea. The rivers of this subslope are born in the skirts of mountain ranges Central, Guanacaste and Tilarán. These rivers are similar to those of the slope of the Caribbean, because there are abundant rains and the land is more level than in the slope of the Pacific. The Sapoa river and the Frío river end at the lake of Nicaragua. The river San Carlos is he more mighty length and of the North subslope and is navigable, ends at the San Juan river. The Sarapiquí river is navigable partly of the course and also it ends at the San Juan river, just like the Chirripó river, last of the North subslope.
Subvertiente del Caribe
It is located to the southwest of the country: They compose 10 hydrographic river basins that end directly at the channel of the Tortuguero or at the Caribbean Sea. The rivers of this subslope are born in the skirts of the Mountain ranges Central and Talamanca; they are wider, caudalusos, longer and less deep than those of the Pacific. In this subslope several rivers through union arms intercommunicate, as in the case of the Chirripó and San Juan through the Colorado. The main rivers of this subslope are: San Juan, Colorado, Tortuguero, Parismina, Pacuare, Matina, Estrella and Sixaola.
The Sarapiquí River counts on a length of 85 kms and is born in the skirts of the north of the Central mountain range. In fact, the nascent of the Sarapiquí is in the old crater of Poás Volcano, transformed into a lagoon of cold and crystalline waters. That is to say that this river is the drain of this deposit. On the origin of the Sarapiquí word, we can indicate that formerly Siripiquí river was said to him.
The Sarapiquí River has been during all the colonial and republican history, one of which greater services have rendered to him to the country, since by means of their waters the inhabitants of the Central Valley, with thousand anguishes by the escarped thing of the route, could break through until the Atlantic, that is the Caribbean, in the mouth of the San Juan River.Actualmente una carretera va casi paralela al río, en cuyas inmediaciones encontramos los poblados de San Miguel, La Virgen, Puerto Viejo y otros menores.
Without place to doubt is the Sarapiquí a river of singular beauty; which gives great contribution to the whole region.
This he is one of the most important rivers of our country, with 152 kms of length. To the path of his waters the white man was based for the first time; in the borders of the Reventazón it lived, grew and suffered the indigenous population. It was by this river of impetuous volume by where he raised in the backs of a Indian, as he says the tradition, the Virgen del Rescate de Ujarraz.
The rivers Macho and Grande de Orosi form in the high part to the Reventazón. But also there is another affluent that is born in an old crater of Irazú Volcano, the Reventado one - probable origin of the Reventazón name -.
The most important river in the region guanacasteca is The Tempisque, having a longitude 144 kms. it picks up all the waters of what is known as Slope of the Gulf of Nicoya. It is born, the same as the Sapoá, in the skirts of the hill or volcano Orosi and it picks up the waters of flowing to end transformed into beautiful estuary in the Gulf of Nicoya.
Enormous amount of affluents has the Tempisque river, which is the main artery of the northern province; among others the Bebedero, the Salto, the Piedras, the Colorado, the Bolsón, etc. In short the Tempisque unites to the doubtless beauty that it gives to the landscape, its historical importance like main "highway" of guanacaste; but, in addition, its present value is incalculable, because their waters contribute to alleviate the shortages of agriculturists who need to irrigate their earth.
The Pacuare river, is born to about 2 thousands mts in the Mountain range of Talamanca and ends at the Atlantic Ocean. In addition to the natural wealth in flora and fauna, and its quality of hydrographic source, the Pacuare is one of great attractive the tourist ones of our country.
For that they prefer a calmer displacement through the river, this trip is ideal to rest, to take photographies and not to worry about much. It will enjoy special a wonderful landscape for the lovers of the nature.
Great amount of fauna glimpses while it is sailed to borders of the river, being able to take a lunch with time to give a stroll by the exotic tropical forest. In the city of Bebedero exists an excursion to the Palo Verde National Park (that counts with more than 300 species of birds), which can be taken by visitors when finalizing its trip.
At the moment the deposit for the more important hydroelectric project of the country, the Lake Arenal ground is a vast water body surrounded by waved hills that maintain grass and patches of forest. Excelling on the end of the side this, it is the conical figure of the Arenal Volcano ground, which regularly does eruption throwing streams of lava and great ash clouds. Although all those that handle around the lake make an impression with the landscape, Arenal ground is specially popular with the fishermen and "windsurfers". The fishermen with cane are attracted by guapote, or róbalo rainbow, a fish that blooms with force in waters of the lake. The "windsurfers" meets at the end of the side the west of the Lake Arenal ground, where the forts and consistent winds, do one of the best places in the world for the practice of this sport.
Caño Negro, a not very deep seasonal lake near the north frontier, is during second half of the year a paradise for the observers of birds, when great flocks of ducks, herons and other aquatic birds life there. Caño Negro has been designated a humid land of importance under convention RAMSAR. At the moment the representation of Caño Negro in most of the maps is deceptive, since it shows the extension of the lake in his maximum of the rainy season. Once the water goes away in December, the lake quickly minimizes, and around February it disappears completely, and most of the aquatic birds they are transferred to the Frío River -- the river in which Caño Negro empties. The trip by the Frío River, which is the way common to arrive at Caño Negro, is consequently frequently more interesting than to visit the own lake.
The passage by the aquatic route of low earth more popular is the Canales del Tortuguero (Caribbean), which run next to the Atlantic coast to the north of the port of Moín towards the communities of Parismina, Tortuguero, and Bar of the Colorado. Most of the travellers they go towards the National Park of Tortuguero, which protects an important beach for the egg-laying of the marine turtle and vast extensions of rainy forest of earth low and marshy lands. A trip by anyone of the extensions of the channels is a true adventure in the jungle, offering opportunity to see animals such as crocodiles, sluggish of three fingers, oropendo them and herons. Also one offers fishing of world-wide quality for tarpón and other species.
The Area of Arenal-Tempisque Conservation (IT ACCEPT) is one of
the 11 zones that conform the National System of Areas of Conservation (Sinac)
under the direction of the Ministry of the Enviroment and Energy (Minae); in him
are innumerable natural places of great beauty, between which it excels the
Celeste River, with waters of that tonality that are consequence of the sulfide
emanation and the precipitation of calcium carbonate.