The Krka River
The beautiful karst Krka River springs near Knin, under the Topoljski slap waterfall, and after flowing 72.5 km, drains into the Adriatic Sea at Šibenik.
The Krka River flows through the Dalmatian region, in the area of Šibenik-Knin County, between the plateau of the Čikola River and the Dalmatian Zagora region.
The freshwater course of the Krka is fed by five tributaries: Krčić, Kosovčica, Orašnica, Butišnica and the Čikola with the Vrba River, while the submerged part of the mouth is fed by the Guduča River. Thanks to the constant process of travertine-building, the Krka River is a karst phenomenon that is nature’s priceless gift to man.
The maritime influence on the lower course of the Krka penetrates deep inland, and significantly influences the climatic conditions of the upper course and springs. The influence of the sea is weakened further inland.
The Krka River flows through the Dalmatian region, in the area of Čibenik-Knin County, between the plateau of the Čikola River and the Dalmatian Zagora region. The mountain massifs Velebit, Dinara, Svilaja and Mosor rise up to the west, north and east. The river is bounded by a triangle of cities Knin – Zadar – Split, and its backbone is along the line Knin – Drniš – Šibenik.
The relief around the Krka River is marked by the wall of mountains to the north, formed by the Dinara, Uilica and southern part of Velebit, as well as valleys (Kninsko Polje, Kosovo Polje and Petrovo Polje), limestone plateaus (northern Dalmatian, Kistanje and the plateau around the Krka and Čikola Rivers) and the canyons of the Krka, Krčić and Čikola Rivers. Mt. Promina separates the valleys and plateaus.
The Krka springs at the foot of Mt. Dinara, 3.5 km northeast of Knin, just under the 22 m tall Topoljski slap. The river flows 72.5 km to its mouth in the Adriatic Sea near Šibenik. The upper 49 km of the course is purely freshwater, while the lower 23.5 km course is brackish. The total slope is 224 m. The freshwater course of the river is fed by five tributaries: Krčić (10.5 km), Kosovčica (12.5 km), Orašnica (5.3 km), Butišnica (39 km) and the Čikola with the Vrba River (37.8 km), while the submerged part of the mouth is fed by the Guduča River (7 km). The hydrogeological basin of the Krka River covers an area from 2500 to 2650 km2. The mean annual flow of the Krka River over Skradinski buk is approximately 55 m3/s, while the daily flow varies from 5 to approximately 565 m3/s.
Geological properties and the morphogenesis of the Krka River
Thanks to the constant process of travertine-building, the Krka River is a karst phenomenon and natureâ€™s priceless gift to man.
The present day appearance of the Krka canyon is the result of tectonic movements and surface karst-building processes in the carbonate layers. Following the Würm period of deglaciation in the Pleistocene, the melting of the ice on Earth cause the sea level to rise, thereby submerging today’s Adriatic coast. At that time, the estuary of the Krka River, from Šibenik to Prukljan Lake, was formed.
With the formation of the travertine layers in the post-Würm period, the Skradinski buk, Roški slap and the remaining waterfalls began to rise along the river’s course, thus causing the formation of Visovac Lake and the remaining water accumulations in the canyon part of the present day river. The only man-made accumulation is Brljan Lake, which was created as a reservoir for the Miljacka hydroelectric plant
Source: Krka National Park
The seven waterfalls of the Krka River
With its seven travertine waterfalls: Bilušića buk, Brljan, Manojlovac slap, Rošnjak, Miljacka slap, Roški slap and Skradinski buk, the Krka River is a natural and karst phenomenon.
Travertine is a common feature of the surface waters of the Dinaric karst; only the most extraordinary travertine creates significant layers, which build the waterfalls seen on the Krka River. The travertine waterfalls of the Krka River are very fragile formations, and are sensitive to environmental change and all human activities.
Only through the constant growth of phytogenic travertine is it possible to ensure the continued survival of the waterfalls that create the hydrogeology and landscape of the park, and form the foundation for its great biodiversity. The development and growth of the waterfalls is the result of complex physical, chemical and biological processes. In order for travertine to grow, live and age, it is imperative that the natural balance of the ecosystem of the Krka and Čikola Rivers be preserved.
With its seven travertine waterfalls, Bilušića buk, Brljan, Manojlovac slap, Rošnjak, Miljacka slap, Roški slap and Skradinski buk, the Krka River is a natural and karst phenomenon.
Skradinski buk is the seventh, final and longest travertine barrier on the Krka River. It is one of the most unusual and beautiful landscapes in Krka National Park.
Skradinski buk is the seventh, final, and longest travertine barrier on the Krka River. It is located approximately 13 kilometres downstream from Roški slap and a total of 49 kilometres downstream from the source. The growth of travertine barriers at Skradinski buk was caused by the unification of the waters of Krka River with the three kilometre lower current of the Čikola River at Roški slap, creating one of the most unusual and beautiful landscapes of the Krka National Park.
The combined waters of the Krka and Čikola Rivers flow over the 17 steps at Skradinski buk, distributed along the 800 metres in length. The width of the cascades is between 200 and 400 metres with a total height difference of 45.7 metres. Travertine formations in the upper portion of the river include thresholds, travertine islands, draperies and barriers, while the lower portion has caves and tufts. A walking trail has been constructed over the river. The trail takes you on a 60 minute light walk through the deep shade of lush Mediterranean and sub-Mediterranean vegetation, which offers the exceptional possibility of direct contact with the unique microcosms of mystical sounds, lights, colours, the mysterious world of travertine mosses and numerous plant species of the travertine barriers and aquatic habitats. Lucky visitors will not miss the song of the nightingale, the splashing of the coot, the swimming of the Illyrian ide, fast movements of the European grass and dice snakes, the call of the green frog, the flight of the hawk and the playful ballet of emerald dragonflies and colourful butterflies.
On the left bank of the river, just under the waterfall, is the Miljacka hydroelectric plant, the largest on the Krka River. Its construction began in 1904 and, until 1910, it was the most powerful hydroelectric plant in Europe.
One kilometre downstream from Rošnjak, squeezed in the riverbed between tall cliffs overgrown with lush sub-Mediterranean vegetation, is the Miljacka slap cascade. It is made up of three larger and numerous smaller travertine steps with a total height of 23.8 metres.
The upper portion of Miljacka slap is characterized by tufts and small caves, while the lower portion has small thresholds. The Krka River, through the Miljacka source, is connected to the course of the Zrmanja River. This source represents a direct connection between the Zrmanja and Krka Rivers and is a unique hydrogeological phenomenon. In the dry period, the minimum flow rate is approximately 2 m3/s. At the base of the cascades, on the right bank of the river, there are several destroyed mills and the waterworks for Kistanje; on the left bank is the Miljacka hydroelectric plant. The Miljacka hydroelectric station is the largest such plant on the Krka River. The construction of this station began in 1904. The first aggregate began operation in April 1906, and operations in its final scope began in 1907. Until 1910, it was the most powerful hydroelectric power plant in Europe. About a hundred metres downstream from the waterfall, on the right bank of the river, is the Miljacka II cave, a habitat for numerous endemic and protected subterranean animals. Among these species, the most attractive are the olm, considered to be an exceptional species in Europe, and the long-fingered bat, with a colony of over 4,000 individuals, one of the largest colonies in Europe.
Once a visitor sees the tallest and, many say, loveliest waterfall in all of its glory, it will long remain engrained in the memory as one of the most impressive natural scenes. Half a kilometre downstream from Brljan, where the river makes a sharp turn, Manojlovac slap emerges. This waterfall is the largest and is considered by many to be the most beautiful waterfall of the Krka River.
The waterfall is made up of a series of travertine barriers with a total height of 59.6 metres; the largest barrier is 32.2 metres high. The cascades are approximately 500 metres in length, with a width of around 80 metres. Travertine formations on the waterfall are most represented by beard-like tufts and small caves. The canyon surrounding the waterfall is overgrown with sub-Mediterranean vegetation, and along the river's current there are small fields and pastures. At the foot of the waterfall are the ruins of abandoned mills that can be seen. This waterfall is similar to Brljan, in that during the warm season, the waterfall is dried out due to the redirection of water to supply the nearby Miljacka hydroelectric plant. In periods of high water, the waterfall crashes into the deep water with a deafening roar, surrounded by a veil of scattered rainbow coloured drops of water. Once a visitor sees the waterfall in its luxurious beauty, it will long remain engrained in the memory as one of the most impressive natural scenes.
The first of seven cascades along the course of the Krka River. Though damaged, this cascade today is still very noisy and attractive, as it is the only one not impacted by the utilization of the riverâ€™s water to produce energy.
The first of seven cascades on the course of the Krka River is Bilušića buk. The falls are found wedged in a canyon approximately 16 km downstream from the source, specifically 9 km downstream from Knin, at an altitude of 214 m above sea level. The appearance of the waterfall and current has been changed on four occasions, when dynamite was used to stop flooding in the Knin Field (in 1834, 1895, 1953 and 1954).
These operations lowered the water levels of the upstream current, which dried out Bobodol Lake. Though damaged, the waterfall today is still very loud and attractive as this is the only waterfall which has not been impacted by the utilization of the river's water for energy needs. Year round, the entire current of the Krka River flows over this cascade. It is made up of two main steps and several intermediate steps 300 metres in total length, with a total difference in altitude of 22.4 metres. The width of the waterfall is approximately 100 metres, but even during low water levels, the water flows through a cutting which is only thirty metres wide. Bilušića buk is formed by travertine formations such as tufts and small caves. There are numerous barriers downstream from the falls, with travertine thresholds and islands directly beneath the falls. Near today's riverbed, well-maintained and attractive “dead travertine” can be seen. Between the travertine steps, there are small lakes.
The six and second last waterfall, Roški slap, is exceptionally interesting due to its cascades, which the locals called the "necklace" due to the lush vegetation, mills and pillars, some of which have been restored, and much, much more.
Approximately 14 kilometres downstream from Miljacka slap is Roški slap, the sixth cascade on the Krka River. It was named after the Rog hill-fort (Rog = horn), whose ruins are barely visible today.
The canyon in this section widens into a funnel shape. The beginning of the travertine barriers is made up of a series of small cascades (called a “necklace” by the locals), while the middle portion is made up of numerous backwaters and islands. The length of the barrier is nearly 650 metres, at its widest is approximately 450 metres wide, with a total difference in altitude of 22.5 metres.
The main waterfall is found at the end of the barrier where the Krka River falls 15 metres into Visovac Lake. Travertine formations at the waterfall are made up of caves, tufts, thresholds, small barriers and tapers. The tapers appear at the base of the main waterfall and represent the specificity of the Roški slap cascades. In 1910, on the right bank of the river, the Roški slap hydroelectric plant was constructed. Over the waterfall, there is a road that dates back to Roman times.
Due to its primordial simplicity and mystical inaccessibility, the locals called it the â€œaltarâ€. Rošnjak is the smallest of the Krka waterfalls. One kilometre downstream from the Manojlovac slap, where the canyon is deeper and narrower, hidden in pristine nature, is the smallest waterfall on the Krka River: Rošnjak (Sondovjel or Šundovi).
It is made up of one step that is approximately 40 metres wide and only 8.4 metres high. The most common travertine formations here are tufts and small caves. The waterfall is found in a picturesque canyon squeezed between nearly 200 metre tall cliffs. It is the only waterfall where mills were never constructed, due to its inaccessibility. Despite the fact that Rošnjak has been untouched by human hands and is accessible only to the eye, it is vulnerable to drying out in the warm months, when the water is rerouted to the Miljacka hydroelectric plant. In periods of high water, the waterfall at the bottom of the canyon gleams in loud fog and through its simplicity shows its true beauty. The mystical sight and its inaccessibility are most likely the reasons that people called it the “altar”.
Loveliest in the spring with the new green leaves and the lush vegetation has not yet covered the travertine cascades. Two kilometres downstream from Bilušića buk, at the canyon’s exit, the Krka River widens into the 400 metre wide and 1300 metre long Ćorić Lake (Bjelober, Brljan Lake). The lake emerged, in part, from the growth of the travertine barriers at the Brljan barrier, and in large part from the construction of a concrete dam constructed at Brljan for the needs of the Miljacka hydroelectric plant.
The water in the lake flows over the Brljan waterfall only during high waters, as water is redirected from the river through a drilled tunnel to supply the hydroelectric plant. The travertine barriers at the Brljan cascades are approximately 300 metres long, 180 metres wide, with a total drop of 15.5 metres. Upstream there are smaller rivers, rapids and thresholds. The waterfall is surrounded by lush sub-Mediterranean vegetation and cultivated fields. It is most attractive in the spring when everything is green, and the vegetation does not yet cover the travertine cascades. There is a path on the Bukovac side, through the canyon and over the waterfall, where visitors can see the remnants of the Roman military camp Burnum. Over the travertine barriers, there is a path from Bukovac towards Promina. On the left side of the river, there are the remnants of various mills that can still be seen today. In the warm months, the waterfall is dry and lifeless, and the 500 metre long bed of the Krka River between Brljan and the Manojlovac slap waterfall dries out.
Source: Krka National Park
Travertine and travertine-builders
Travertine is the name for the calcium carbonate (limestone) that precipitates out of water in running streams and is deposited onto various substrates. Both algae and mosses play an important role in the formation of travertine.
Species that have the ability of encrusting calcite crystals are called travertine-builders. Algaes and mosses play an important role in the formation of travertine.
The formation of travertine begins at the rapids, at uneven places in the river bed, on submerged branches and the like. As the water splashes, the chemical balance of the water is disturbed and CO2 is released.
Source: Krka National Park
The fauna of Krka National Park
The fauna of Krka National Park is very rich and diverse, with many endemic, rare and threatened species. This puts the Krka River among the most valuable natural entities in both Croatia and Europe.
Have you ever heard of the endemic species that inhabit Krka National Park? There are many subterranean animals, including freshwater cave snails, cave pseudoscorpion, cave isopod, cave polychaete, olm, and cave cricket. There are ten fish species that are endemic to the Adriatic river basins: Adriatic salmon, huchen, Adriatic dace, Dalmatian rudd, Croatian dace, Dalmatian barbel gudgeon, Adriatic barbel, Illyric ide, Visovac goby and the Dalmatian minnow?
Did you know that four species on the European endangered species list can be found in Krka National Park: greater horseshoe bat, wolf, otter and wild cat?
Source: Krka National Park
The flora of Krka National Park
Thanks to geographic position and the large number of different habitat types, the plant life around the Krka River is exceptionally diverse and picturesque, with 1022 species recoreded to date. The course of the Krka River lies in the transition zone between the evergreen Mediterranean and deciduous sub-Mediterranean vegetation belts. The natural forest vegetation has been significantly altered due by anthropogenic activities. Nonetheless, the plant life around the Krka River is exceptionally diverse, with 1022 species recorded, thus attracting both scientists and visitors.
Geographic position and the large number of different habitat types (travertine barriers, aquatic habitats with flowing and standing waters, cliffs, rocky terrain, anthropogenic habitats), the plant life around the Krka River is exceptionally diverse and picturesque, with 1022 species recorded to date.
The Krka River basin is dominated by white hornbeam forests and thickets, macchia, garrigues, grasslands, rocky pastures, weedy and ruderal communities, and planted conifer stands. Even today, primary vegetation types can be seen along the Krka and Čikola Rivers, such as the flora of the aquatic and wetland habitats, and the canyon vegetation. The most abundant species are the Mediterranean and southern European plants, though there are also many central European, European, and Eurasian floral elements, in addition to American, subtropical and tropical species.
Source: Krka National Park
There are about a hundred caves and pits along the course of the Krka River, some 40 of which are within the boundaries of Krka National Park.
The largest number of cave structures has been recorded in the Promina deposits and Upper Cretaceous rudist limestone. These structures were created from tectonic fissures that expanded over time under the corrosion and erosion influences of water. Cave structures from the Quaternary also include travertine barriers and are typically of smaller dimension.
Source: Krka National Park
Fun fact: Skradinski buk, najduži slap na rijeci Krki
- Slap tvore sedrene barijere, otoci i jezera. Može ga se razgledati tijekom cijele godine zahvaljujući mreži staza i mostova, koji omogućuju ugodnu i sigurnu šetnju. Na Skradinskom buku nalaze se obnovljeni mlinovi, valjavice i stupe, koje stoljećima koriste snagu vodenog toka. Uz poštivanje tradicijske arhitektonske vrijednosti, pojedini mlinovi uređeni su kao suvenirnice, dok su drugi pretvoreni u izložbene prostore za etnografsku zbirku.
Source: Krka National Park