Flood Dams, Klavže

Five hundred years of mining in the Idrija Mercury Mine required vast quantities of timber for the mine's architecture, supporting pillars, machines, smelting ore, as well as supplying the inhabitants of Idrija. The town lies in a hilly region surrounded by vast forests. Nearby forests had been cut early, so the most practical way was to transport timber on waterways from forests far away. Dams, called klavže were made on the rivers Zala, Belca, Idrijca, and Kanomljica for timber transport all the way to the town of Idrija.

Klavže ("flood dams") were made to dam lakes, timber was piled in the lake, which was later released and the accumulated water drove the timber downstream to Idrija on river rakes. On the Idrijca river the timber was caught and retrieved from the water for further use. Because of their huge stone structures and technical ingenuity klavže are praised also as the Slovene pyramids. Some of them were restored and are well worth a visit.

Origin of the word

Klavže is a plural noun meaning 'the gate'. It derives from Latin clausura (the closing). The Slovene term, however, was borrowed from the German die Klause meaning also 'the pass'. In any case, the term denotes something that has not been permanently closed but is of a transient nature. The main characteristic of klavže is namely the closing and opening mechanism for the regulation of the water accumulation. The name of the war fortress Kluže near Bovec has the same origin.

History

The first klavže were built out of wood in the 16th century on the Zala river, but were too dependent on rainfall and high waters. Around 1770 the monumental klavže were built out of brick, stone and mortar, with the ingenuously designed mechanisms that required only a pair of oxen to lift or close the dam barriers, also in extreme weather conditions. The most grandiose klavže were those of a local Master Mrak's (1709–1786), positioned where the river Idrijca formed an 800-metre-long lake that could drive some 10,000 m3 of timber at a time downstream to Idrija 20km away.

It has been calculated that the river Idrijca carried approximately 4,540,000 m3 of fuel wood and 375,000 m3 of pit wood and round timber. The transportation of timber via rivers ended in 1926, after catastrophic floods took away the rakes in Lenštat in the centre of Idrija. Being a klavžar ("dam operator") was a very responsible, but also highly valued, position among the people.

Visit

Klavže attracted the audience already at the time when they performed their duty. The opening of a dam and the noisy transportation of timber was an attractive performance of the engineering ingenuity. The models of klavže and Lenštat rakes made by Janko Trošt explain well the whole process and can be seen in the Idrija Municipal Museum. The visit to one of the preserved sites remains, however, a unique experience.

For a few decades the abandoned klavže were decaying and became hardly accessible due to the lack of road maintenance. In 1968 the Municipality of Idrija proclaimed them as a first class technical monument and from 2001 onwards the following klavže have been protected as a cultural monument on a state level: Belčne klavže, Putrihove klavže (both close to Idrijska Bela) - built from 1767 till 1769 according to the plans by Jožef Mrak, Idrijske klavže (Vojsko), and Kanomeljske klavže (Gorenja Kanomlja, called also Ovčjak klavže), built in 1813 and considered the most aesthetically appealing.

External links

Klavže - Slovenian Pyramids on the Idrija Tourism website
A richly illustrated book on the Master Jožef Mrak (1709–1786) by Janez Kavčič (in Slovenian)
Jožef Mrak on Wikipedija (in Slovenian)
Idrija Municipal Museum
Mercury Mine Idrija

Flood Dams, Klavže

Contents

Origin of the word

History

Visit

See also

External links

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