Slow filters and treatment of water taken from the river

In the 19th century water supply in Wrocław had been taking water from Odra and had to be treated before it could be fed into the city’s network. This was done using slow filters, i.e. pools filled with sand and gravel. The river water poured into them was purified, seeping slowly through the gravel bed.

In the picture

Water supply complex seen from the perspective of the current footbridge on ul. Szybka over Oława (first decade of the 20th century)

1890-1892 First reservoir closed

There were four slow filters operating in the waterworks facility “Na Grobli”, but in 1890-1892 another one was built. Filter No. V - as opposed to previously built open pools (not covered with a roof) - was designed as a closed reservoir. A reservoir of 4600 m2 was hidden under the earth embankment. However, relatively quickly its original function became obsolete.

In the picture

Sand deposit replacement in an open slow filter (1920s)

1920s - moving away from river water to groundwater

At the beginning of the 20th century, Wrocław's waterworks stopped taking river water. It was replaced with groundwater. Filter No. V became unnecessary. It turned out that although the groundwater is clean and free of bacteria, it contains too much iron and is not suitable for direct consumption. The old facility "Na Grobli" had to be adapted to process this raw water into drinking water, and a separate reservoir was needed for its storage. The decision was made to use for this purpose the not used slow filter No. V.

In the picture

Fragment of the western elevation of the slow filter No. V (1920s)

1905 - Water tower and main drinking water reservoir instead of the former river water filter

After removing thousands of tons of sand and gravel, in 1905 the former filter became a huge reservoir with the capacity of 12 million litres of drinking water. Now it was the main water reservoir for the city - "reservoir no. 1". Water was first sent to the water tower. It was pressed by a large steam generator. However, in 1919, it underwent a breakdown, which stopped the water supply. This had to be quickly remedied, so in just five months the building of the emergency pumping station stood by the clean water reservoir.

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The inside of the clean water reservoir (years 1920-1930)

1919 - Emergency pumping station

Modern, electric rotodynamic water pumps have been installed in the emergency pumping station building. They sent water directly to the tank in the tower. The modest building did not match the magnificent architecture of the reservoir and was soon rebuilt for purely aesthetic reasons. In 1924, a new building was erected in its place, maintained in the style of modernism fashionable at the time. In the 1930s the appearance of the front elevation was further improved.

In the picture

6 Emergency pumping station for clean water in the 1920s (today's Cafe Arkadia)

The clean water reservoir and World War II

The clean water reservoir operated continuously until 1945. During fights for Wrocław its ceiling was perforated by Russian bombs and bullets. Shortly after the end of the war, the necessary repairs were made and the reservoir collected water for the city again. It was operated for over 50 years, without any repairs or cleaning. This was caused by a permanent shortage of drinking water in Wrocław, which made it impossible to even temporarily shut down the reservoir.

In the picture

Clean water reservoir - a fragment of the eastern elevation (1930s)

1997 - Central European flood hits the main drinking water reservoir

On 12 July 1997, the water works facility "Na Grobli" was unexpectedly hit by a flood wave. Buildings and equipment were flooded at a rapid pace. Reservoir No. 1 was under water. The flood of 1997 was the biggest disaster in the post-war history of Wrocław. Drinking water production stopped. In order for it to flow to the taps again, the tank had to be cleaned.

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8 The effects of the so-called Central European flood (1997)

2002-2015 - Modernisation of the water works facility "Na Grobli" and creation of Hydropolis

In the picture

9 Hydropolis copper facade shortly before opening (October 2015)