The Neretva (), also known as Narenta, is one of the largest rivers of the eastern part of the Adriatic basin. Four hydroelectric power plants with large dams (higher than 15 metres) provide flood protection, electricity and water storage. The Neretva is recognized for its natural environment and diverse landscapes.
Freshwater ecosystems have suffered from an increasing population and the associated development pressures. One of the most valuable natural resources of Bosnia and Herzegovina and Croatia is its freshwater resource, contained by an abundant wellspring and clear rivers. Situated between the major regional rivers (Drina river on the east, Una river on the west and the Sava river) the Neretva basin contains the most significant source of drinking water.
The Neretva is notable among rivers of the Dinaric Alps region, especially regarding its diverse ecosystems and habitats, flora and fauna, cultural and historic heritage.
Its name has been suggested to come from the Indo-European root *ner, meaning "to dive". The same root is seen in the Bosnian root "roniti".
Geography and hydrology The Neretva flows through Bosnia and Herzegovina and Croatia before reaching the Adriatic Sea. It is the largest karst river in the Dinaric Alps in the eastern part of the Adriatic basin/watershed. Its total length is , of which are in Bosnia and Herzegovina, while the final are in the Dubrovnik-Neretva County of Croatia.
The Neretva watershed is in total; in Bosnia and Herzegovina with the addition of the Trebišnjica river watershed and in Croatia, . The average discharge at profile Žitomislići in Bosnia and Herzegovina is and at the mouth in Croatia is in addition to the Trebišnjica River's . The Trebišnjica River basin is included in the Neretva watershed due to a physical link of the two basins by the porous karst terrain.
The hydrological parameters of Neretva are regularly monitored in Croatia at Metković.
Sections
Geographically and hydrologically the Neretva is divided into three sections.
Its source and headwaters gorge are situated deep in the Dinaric Alps at the base of the Zelengora and Lebršnik mountains, specifically under the Gredelj saddle. The river source is at 1,227 meters above sea level and consists of five small and distinct wellsprings. On its 90 kilometers course through the first section the Neretva cuts two distinct deep and narrow canyons and two distinct wide and fertile valleys, around Ulog and then Župa Komska, wider area around Glavatičevo, before it reaches the town of Konjic. This section is also better known as the Upper Neretva (), and here the river flows generally from east-southeast to north-northwest as do most rivers in Bosnia and Herzegovina belonging to the Danube watershed, and covers some with an average elevation of 1.2%. Right below Konjic, the Neretva again expands into a third and largest valley which provided fertile agricultural land before it was flooded by large artificial reservoir, Jablaničko Lake, formed after construction of a Jablanica Dam near town of Jablanica.
The second section begins from the confluence of the Neretva and the Rama between Konjic and Jablanica where the Neretva suddenly takes 180-degree turn toward east-southeast and flows a short stretch before it reaches the town of Jablanica, from which point turns again toward south. From Jablanica, the Neretva enters third and the largest canyon on its course, running through the steep slopes of the mountains of Prenj, Čvrsnica and Čabulja reaching in depth. Three hydroelectric dams operate between Jablanica and Mostar.
When the Neretva expands for the second and final time, it reaches its third section. This area is often colloquially called the "Bosnian and Herzegovinian California". The last of its course forms wide alluvial delta, before the river empties into the Adriatic Sea.
Tributaries The right tributaries of the Neretva are: Tatinac (also known as the Jezernica), the Gornji Krupac and Donji Krupac, Ljuta (also known as the Dindolka), Jesenica, Bjelimićka Rijeka, Slatinica, Račica, Rakitnica, Ljuta (Konjička), Trešanica, Neretvica, Rama, Doljanka, Drežanka, Grabovica, Radobolja, and the Trebižat. From the left the Neretva receives Jezernica, Živanjski Potok (also known as the Živašnica), Lađanica, Krupac, Bukovica, Šištica with its Šištica Waterfall, Bijela, Baščica (also known as Idbarčica and Idbar), Glogošnica, the Mostarska Bijela, Buna, Bregava, and the Krupa.
Towns and villages Towns and villages on the Neretva include Ulog, Glavatičevo, Konjic, Čelebići, Ostrožac, Jablanica, Grabovica, Drežnica, Bijelo polje, Vrapčići, Mostar, Buna village, the historical town of Blagaj, Žitomislići, the historical village of Počitelj, Tasovčići, Čapljina, and Gabela in Bosnia and Herzegovina; and Metković, Opuzen, Komin, Rogotin, and Ploče in Croatia. The biggest town on the Neretva River is Mostar in Bosnia and Herzegovina.
Upper Neretva
The upper course of the Neretva river is simply called the Upper Neretva (). It includes numerous streams and well-springs, three major glacial lakes near the river and more lakes scattered across the mountains of Treskavica and Zelengora in the wider area, mountains, peaks and forests, flora and fauna of the area. The Upper Neretva has water of Class I purity. Rising from the base of the Zelengora and Lebršnik Mountain, Neretva headwaters run in undisturbed rapids and waterfalls, carving steep gorges reaching in depth.
Rakitnica River
The Rakitnica is the main tributary of the first section (). The Rakitnica River forms a long canyon, out of its length, that stretches between Bjelašnica and Visočica to the southeast from Sarajevo.
Middle Neretva
Hydrographically the Middle Neretva section begins from the town of Konjic, but after the construction of Jablanica Hydroelectric Power Station and flooding of the large fertile valley between Konjic and Jablanica, known simply as "Neretva" since Middle Ages. The new point for hydrographical division became the dam of the Jablanica HPP where there also is a place of confluence of the rivers Neretva and Rama. Here the Neretva river suddenly takes an almost 180° turn towards the east-southeast and flows for a short leg before it reaches the town of Jablanica. From this point it turns again towards the south and enters the third and largest canyon on its course, running through the steep slopes of the mountains of Prenj, Čvrsnica, and Čabulja, reaching between in depth. This section is characterized by a steep and relatively narrow canyon, and rugged karstic geology and hydrology.
Four enormous vale-size rifts appear in the mountainsides forming canyon walls, two from each side of the river, intersecting with the main canyon almost perpendicularly. The Neretva receives only four small streams in this section, all running through these side vales, which are relatively short. Going downstream from Jablanica, the first two from each side are the Glogošnica stream, its eponymous canyon and small village on the left, and the Grabovica stream with its eponymous canyon and historical village, from the right side. Further downstream two much larger vales appear again on each side, first on the right the stream of Drežanka and its large and steep valley, with two eponymous villages, Donja (Lower) and Gornja (Upper) Drežnica, and than Mostarska Bijela, as one of the most pristine vales in Bosnia and Herzegovina, with its eponymous uniquely characteristic subterranean stream, embedded deep into the Prenj mountain, on the left.
Even when these streams are of low outflow, there are also numerous wellsprings rising on both sides of the canyon at the river banks, with high-capacity discharge. Three large hydroelectric power stations operate in this section of the Neretva, between Jablanica and Mostar, namely Grabovica HPP, Salakovac HPP and Mostar HPP.
Lakes
Jablanica lake is a large artificial lake on the Neretva river, right below Konjic where the Neretva expands into a wide valley. The river provided fertile, agricultural land before the lake flooded most of it. The lake was created in 1953 after construction of a large gravitational hydroelectric dam near Jablanica in central Bosnia and Herzegovina. The lake has an irregular, elongated shape, and its width varies along its length. The lake is a popular vacation destination.
Lower Neretva Downstream from the confluence of its tributaries, the Trebižat and Bregava Rivers, the valley spreads into an alluvial fan covering . The upper valley, the 7,411 hectares in Bosnia and Herzegovina, is called Hutovo Blato.
Hutovo Blato wetlands
The Neretva Delta has been recognised as a Ramsar site since 1992, and Hutovo Blato since 2001. Both areas form one integrated Ramsar site that is a natural entity divided by the state border. The Important Bird Areas programme, conducted by Birdlife International, covers protected areas in Croatia and Bosnia and Herzegovina.
Since 1995, Hutovo Blato has been protected as Hutovo Blato Nature ParkHutovo Blato Nature Park and managed by a public authority. The whole zone is protected from human impact and provides habitat for many plants and animals. The historical site Old Fortress Hutovo Blato is in the Nature Park.
Gornje Blato-Deransko Lake is supplied by the karstic water sources of the Trebišnjica River, emerging from bordering hills. It is hydro-geologically connected to the Neretva River through its effluent, the Krupa River, formed out of five lakes (Škrka, Deranja, Jelim, Orah, Drijen). Large portions are permanently flooded and isolated by wide groves of reedbebds and trees. It represents a more interesting preserved area.
Krupa River
The Krupa River is a Neretva left tributary and the main water current of Hutovo Blato, which carries the waters from Gornje Blato and Svitavsko Lake into the Neretva River. The length of Krupa is with an average depth of . The Krupa does not have a specific source, but is an arm of Deransko Lake. Also, the Krupa is a unique river in Europe, because it flows both ways. It flows both towards and back from its mouth. This happens when a high water level causes Neretva to push Krupa in the opposite direction.
Neretva Delta wetlands
Passing towns and villages in Bosnia and Herzegovina, the Neretva spills out into the Adriatic Sea, building a wetland delta that is listed under the Ramsar Convention as internationally important.
In this lower alluvial valley in Croatia, the Neretva River splinters into multiple courses, creating a delta covering approximately 12,000 hectares. The delta in Croatia has been reduced by extensive land reclamation projects, reducing the river flows to just three branches from the original twelve. The marshes, lagoons and lakes that once dotted this plain have disappeared and only fragments of the old Mediterranean wetlands survive. Wetlands, marshes and lagoons, lakes, beaches, rivers, hummocks (limestone hills) and mountains compose the delta, with five protected areas with a total area of 1,620 ha. These are ornithological, ichthyologic and landscape reserves.
Endemic and endangered species
Dinaric karst water systems support 25% of the total of 546 fish species in Europe, many endemic. The Neretva River, together with four other areas in the Mediterranean, has the largest number of threatened freshwater fish species. The degree of endemism in the karst ecoregion is greater than 10%. Multiple fish species have small habitats and are vulnerable, so they are included on the Red List of endangered fish . The Adriatic basin has 88 species of fish, of which 44 are Mediterranean endemic species, and 41 are Adriatic endemic species. More than half of the Adriatic river basin species of fish inhabit the Neretva, the Ombla, the Trebišnjica, the Morača Rivers and their tributaries, and more than 30 are endemic.
Invasive species