The Bílá Desná Reservoir - The Failed Dam

In the 19th century the power of the Desná and Kamenice rivers was harnessed by the developing textile and glass industries burgeoning on their banks. To prevent floods the “Water Board for the Construction of a Reservoir on the Black Desná” was established in 1903 in Dolní Porubná. In order to gain planning permission for the reservoir, a detailed analysis of the area was sought from Prof. Otto Intze. Towards the end of 1904 a lecture was held in Dolní Porubná, which was attended by industrialists from the surrounding area. The meeting resulted in an increase in Board membership, projects and name of the Board, “Water Board for Flow Regulation and Construction of a Reservoir on the Black Desná, White Desná and Kamenice in Dolní Porubná”.
Upon the death of Prof Intze (28.12.1904) the architect Wilhelm Plenker designed a series of dams in the Kamenice catchment area in 1906. After protracted negotiations just two of the reservoirs - on the Black and White Desná - were accepted. These were to be interconnected with an adit to channel off flood water. Both reservoirs were built simultaneously from 1911 – 1915.
A suitable location for the White Desná dam was found in the undeveloped White Desná valley. The earth-filled dam was 244m in length at its crest and 17.85m high above the foundations. In its day it was the tallest dam in the Czech lands.
The Prague firm Schon & Sons began construction of the dam and the connecting adits running beneath the mountain ridge to take flood water to the Souš and Black Desná reservoirs in October, 1911.To empty the reservoir a concrete adit was set into the valley floor, built on two concrete barriers set on wooden piles.

 Flood waters were to be carried over a precautionary spillway and drainage channel with cascades down to the valley, where they joined a 1105m long adit which took the water to the Souš storage reservoir in the neighbouring Black Desná valley. This part of the project was completed in September, 1915, and, together with Souš, was officially opened on the same day in November. On 18th September, 1916, ten months after opening, the 290 000m3 dam broke. The ensuing wall of water caused an unprecedented disaster in the villages along the White Desná, the Desná and Kamenice rivers, and 62 lives were lost. The list of destruction was appalling: 1020 people lost their livelihoods, countless domestic and wild animals were killed, 33 houses were destroyed and a further 69 damaged, and 309 people were made homeless. In the aftermath the army was called in to help clear up the destruction. Investigations into the cause of the tragedy took almost two years while criminal investigations dragged on for sixteen. The case was closed in 1932 and the defendants were acquitted. Professional witnesses ruled out any technical fault. The disaster brought into question the condition of other reservoirs, and from 1924 – 27 the reservoir at Souš was rebuilt.Today the remains of the earth-filled dam can be seen, together with the original inlet structure, connecting adits to Souš, drain adit, channel sliding gate, lateral spillway and cascade channel, all of which were declared national monuments in 1996.
Plans for the rebuilding of the reservoir were never realized. The failed dam and the original buildings remain as a memorial for later generations and are today an attractive tourist destination.

Edited by OHK v Jablonci nad Nisou
Translation: EDUCA – vzdělávací centrum, s.r.o., Jablonec nad Nisou


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