New drinking water reservoir for the town of Senden

Footprint of the hole elevated tank in Witzighausen

Senden has 23,000 inhabitants, the town’s average yearly drinking water consumption is 1,300,000 m³. The daily consumption is at present approx. 3,500 m³ and is anticipated to soon rise to 5,700 m³.

By now the town’s demand could be satisfied by two reservoirs with 1,200 m³ capacity each and very good well capacities that have delivered the required quantity from excellent quality groundwater resources. In case of a well or line failure, however, only 800 m³ drinking water would be available for the consumers. The a. m. 1.200 m³ cover the required fire water supply of 400 m³. The town’s water demand could consequently not be guaranteed any more with the two old reservoirs.

That is why they decided to build a bigger reservoir in the district Witzighausen. The new elevated reservoir has been planned by the Swabian engineering office Jellen & Co. that won the tender.

The project volume includes earthworks of approx. 147,000 m³ and 1,100 m³ ferro-concrete C25/30xC 4 – C35/45 XF 3 will be built in. Also stainless steel pipelines DN 250 – DN 500 are required for the hydraulic installations. Construction started on 5 November 2007 and was scheduled to be completed on 31 December 2008.

The whole plant is about 51 x 48 m big and includes four individual water reservoirs, each of them with a capacity of 1.750 m³ and a diameter of 21 m. For the time being, only two of these reservoirs will be built. These will cover the demand of 3,500 m³ water. All four reservoirs together will offer a total capacity of 7,000 m³ drinking water. The maximum flow to the plant during the first stage of construction is 120 l/s, the maximum water withdrawal 240 l/s. With all four reservoirs together, the maximum total flow can in the future be increased to 160 l/s, the maximum withdrawal up to 350 l/s.

HUBER’s part in this project has been to supply and install the required stainless steel products, such as pressure doors, safety doors, access doors and manhole covers including ladders, platforms, etc. The customer also ordered HUBER railings to provide the required degree of safety within the structure.