Picture offered by Retema (Environmental Technical Magazine - Spain)
The population from the metropolitan area of Bilbao, Spain, already counts on a reinforced drinking water distribution system, which now includes the water from the Nervión-Ibaizabal river, which allows to take advantage of the river's water resources in periods of drought or during shortage supply periods from Zadorra System.
The Etxebarri pumping station is the result of years of planning and environmental work. This project was only possible to be carried out after execution of several other projects, such as the wastewater treatment plants in Bilbao, the Venta Alta water treatment plant and the reservoirs of the Zadorra system.
The pumping system is equipped with six 1100kW, 6kV medium voltage WEG motors, from the W50 Line, for pump application, which are used to drive the Etxebarri pumping station to pump water from the Bilbao river (Nervión river and Ibaizabal river, after they join) up to the Venta Alta water treatment plant, where it is treated for potable water conditions and then pumped back (actually by gravity) to Bilbao metropolitan area.
This project became viable after the pollution levels of the Bilbao river were reduced, as a result of the installation of several wastewater plants in the city. Now the water of the main river can considered as drinkable and serve the population of the city.
The Etxebarri pumping station will only work when the Zadorra Reservoir System, which feeds the Venta Alta WTP, will have low water levels. The Zadorra System includes the Nervión River and many others, but now with the new system it can also count on the water from Ibaizabal River, taken just after Nervión meets Ibaizabal, then becoming the Bilbao River.
Etxebarri also has a hydroelectric plant installed nearby. When the Zadorra System is in a surplus period, producing more water than Bilbao is consuming, the same pipe that sends water to Venta Alta from the Bilbao river will now flow in the opposite direction, allowing excess untreated water from the Zadorra system going down to Bilbao. The water will generate electricity taking advantage of the hydraulic drop / jump (about 156 meters).
The hydroelectric plant project was designed assuming an operation of 42 days a year. It will operate only between December and April to prevent the transfer of an invasive species of mussels called Charru mussels (zebra mussels) to the lower channel of the Nervión river.
For WEG, this is another relevant reference among the major hydraulic works projects in Spain.