What are stormwater detention vaults and what are they used for?

Stormwater detention vaults are man-made basins that are used to temporarily store large amounts of rainwater.

When it rains a lot, the runoff eventually exceeds the discharge capacity of the sewer system or sewage treatment plants, and this is when these basins come into play. The excess runoff is diverted into the stormwater detention vaults until the storm has passed and the water can be transported and treated. Detention basins can also be used to avoid direct discharges into rivers during heavy rainfall, reducing the pollution that is common in these circumstances.

In addition to other smaller basins, Madrid has four large stormwater detention vaults built at strategic locations in the city. One of these basins, with a total capacity of 358,919.50 m3, is the Butarque underground vault, which together with that of Arroyofresno (also in Madrid) is one of the largest in Europe. Madrid currently has 36 stormwater detention vaults with a total capacity of 1,410,100 m3. 

In the Butarque stormwater retention vaults, the original 20 series butterfly valves no longer functioned properly, which led to numerous problems. This is because these butterfly valves regulate the flow of recycled water, which is used to clean the vaults after rainfall. These butterfly valves are used about 50 times a year, so they must function properly.

The operators therefore opted for Hawle kife gate valves DN 200 with actuator, which are activated via a remote control. Hawle knife gate valves DN65-400 are also availiable with pneupatic actuators.