The Arga is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 of Navarre

Navarre

Navarre , officially the Chartered Community of Navarre is an autonomous community in northern Spain, bordering the Basque Country, La Rioja, and Aragon in Spain and Aquitaine in France...

, in Spain

Spain

Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

 and is one of the tributaries of the river Ebro

Ebro

The Ebro or Ebre is one of the most important rivers in the Iberian Peninsula. It is the biggest river by discharge volume in Spain.The Ebro flows through the following cities:*Reinosa in Cantabria.*Miranda de Ebro in Castile and León....

. The Arga was known as the river Runa in antiquity. Situated in the north-east of Spain, the river stretches some 145 kilometres, and has a basin of 2,759 km², 2,652 km² of which is in Navarre and the remaining 107 km² is near Arakil

Arakil

Arakil is a town and municipality located in the province and autonomous community of Navarre, northern Spain.-External links:*...

. The source of the river is to the north of the village Esteríbar

Esteribar

Esteribar is a town and municipality located in the province and autonomous community of Navarre, northern Spain.-External links:*...

, near the border with France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, and it empties into the Aragón River

Aragón River

The River Aragón is one of the left-hand tributaries of the river Ebro. It starts at Astún , passes through Jaca and Sangüesa , and joins the Ebro at Milagro , near Tudela....

 near Funes

Funes, Navarra

Funes is a town and municipality located in the province and autonomous community of Navarre, northern Spain.-External links:*...

.

The river is dam

Dam

A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...

med in the Eugui reservoir

Reservoir

A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...

 near Esteríbar; the dam principally serves the needs of Pamplona

Pamplona

Pamplona is the historial capital city of Navarre, in Spain, and of the former kingdom of Navarre.The city is famous worldwide for the San Fermín festival, from July 6 to 14, in which the running of the bulls is one of the main attractions...

's metropolitan area

Metropolitan area

The term metropolitan area refers to a region consisting of a densely populated urban core and its less-populated surrounding territories, sharing industry, infrastructure, and housing. A metropolitan area usually encompasses multiple jurisdictions and municipalities: neighborhoods, townships,...

, the largest city on the Arga.

Vegetation

At the upper basin, the river is mainly surrounded by beech

Beech

Beech is a genus of ten species of deciduous trees in the family Fagaceae, native to temperate Europe, Asia and North America.-Habit:...

 trees and beneath these grow bilberries, cornish heath

Cornish heath

The Cornish heath is a species of heath that bears pink flowers and mid-green foliage. This is a shrub, reaching 0.75 m by 0.75 m. Its English name comes from the fact that, in Great Britain, it is only found on the Lizard peninsula in Cornwall, where the unusual geology gives rise to the alkaline...

, sedges

Cyperaceae

Cyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses or rushes. The family is large, with some 5,500 species described in about 109 genera. These species are widely distributed, with the centers of diversity for the group...

 and luzula

Luzula

Luzula is a genus of about 80 species of flowering plants the family Juncaceae, with a cosmopolitan distribution, the highest species diversity being in temperate Asia and Europe....

s. Additionally, a variety of shrubs can be found in the proximity of the Eugui reservoir, including; alder

Alder

Alder is the common name of a genus of flowering plants belonging to the birch family . The genus comprises about 30 species of monoecious trees and shrubs, few reaching large size, distributed throughout the North Temperate Zone and in the Americas along the Andes southwards to...

, ash, maple

Maple

Acer is a genus of trees or shrubs commonly known as maple.Maples are variously classified in a family of their own, the Aceraceae, or together with the Hippocastanaceae included in the family Sapindaceae. Modern classifications, including the Angiosperm Phylogeny Group system, favour inclusion in...

, common hazel

Common Hazel

Corylus avellana, the Common Hazel, is a species of hazel native to Europe and western Asia, from the British Isles south to Iberia, Greece, Turkey and Cyprus, north to central Scandinavia, and east to the central Ural Mountains, the Caucasus, and northwestern Iran. It is an important component of...

 and buckthorn

Buckthorn

The Buckthorns are a genus of about 100 species of shrubs or small trees from 1-10 m tall , in the buckthorn family Rhamnaceae...

. After the dam, the lower river is lined with oak

Oak

An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...

 and Scots Pine

Scots Pine

Pinus sylvestris, commonly known as the Scots Pine, is a species of pine native to Europe and Asia, ranging from Scotland, Ireland and Portugal in the west, east to eastern Siberia, south to the Caucasus Mountains, and as far north as well inside the Arctic Circle in Scandinavia...

 trees and boxwood

Buxus

Buxus is a genus of about 70 species in the family Buxaceae. Common names include box or boxwood ....

 shrubs.

At the point where the river passes Huarte/Uharte, crack willow

Crack Willow

Salix fragilis is a species of willow native to Europe and western Asia, usually growing beside rivers.It is a medium-sized to large deciduous tree, which grows rapidly to 10–20 m tall, with a trunk up to 1 m diameter and an irregular, often leaning crown. The bark is grey-brown, coarsely...

 appear. The shrubbery around the area of Belascoáin

Belascoáin

Belascoain is a town and municipality located in the province and autonomous community of Navarre, northern Spain.-External links:*...

 marks the change from Cantabria

Cantabria

Cantabria is a Spanish historical region and autonomous community with Santander as its capital city. It is bordered on the east by the Basque Autonomous Community , on the south by Castile and León , on the west by the Principality of Asturias, and on the north by the Cantabrian Sea.Cantabria...

n forest to more Mediterranean plant life; black poplar

Black Poplar

Populus nigra, the black poplar, is a species of cottonwood poplar, the type species of section Aigeiros of the genus Populus, native to Europe, southwest and central Asia, and northwest Africa....

 and white willow

White Willow

Salix alba is a species of willow native to Europe and western and central Asia. The name derives from the white tone to the undersides of the leaves....

are common in this region.