• HydroStyx Discharge Brake
HydroStyx® Discharge Brake

Delays discharge and activates unused sewer volume

The Challenge

Measures to protect waters are necessary but often expensive. Legislation demands storage basins for the protection of receiving waters such as streams, rivers and lakes.
Because of the huge investment costs involved, local councils are often unable to realise such construction measures. Action is also called for when old sewers in an established urban area are overburdened by connection to new development areas. The removal of sealed surfaces for seepage is never really sufficient so that either buffer basins have to be built or whole sewer sections replaced
to secure the older parts of the urban area.

The Solution 

A sewer system usually has large amounts of unused
storage capacity since it was designed to cope with
maximum loads. The HydroStyx® discharge brake allows this hidden capital to be utilized. During heavy rain, the HydroStyx® discharge brake allows the free canal volume to be used as storage. The discharge is braked. HydroStyx® discharge brakes are installed from the initial position over stretches and in cascade formation. They are designed for use in existing shafts. A calculated discharge is passed on to the following position through the bottom outlet. When stormwater increases a build-up occurs in front of the discharge brakes. The particles in the water sink and are transported to the treatment plant. In the case of heavy stormwater, the combined water flows over the crest of the brakes and the canal regains full capacity. The discharge water contains fewer pollutants, the discharge hydrograph will show fewer peaks, is flat and elongated. Overcharged pipes can now carry away the delayed water volume. Replacement of sewer pipes is no longer necessary and volumes for new tanks can be reduced.

The design of the HydroStyx® discharge brake requires qualified engineering calculations of the canal network. We can recommend useful software and supply you with competent personnel.


  • saves on construction and investment by activating available storage volume in sewer channels
  • replacement of sewers no longer necessary
  • fewer basins required
  • maintenance-free

The Advantages

  • discharge peaks are evened out
  • discharge flows are decelerated
  • overflows are reduced
  • treatment plant operation is optimised
  • effective use of sewer network volume
  • hydraulic and ecological stresses are avoided
  • no electricity required – external energy-free
  • robust, stainless steel construction
  • retrofit in any shaft possible
  • adjustable to changed parameters
Steinhardt HydroStyx