Detention cistern for rainwater detention and sewer relief

  • A detention cistern retains the rainwater and drains it into the sewer at a delayed speed.
  • GRAF cistern for rainwater detention and sewer relief.
  • To guarantee retention of rainwater, a delayed drain is fitted in the sewer with a delay of 0.05 to 16 l/sec. depending on the customer’s specifications.
  • In the event of heavy rainfall, the water level in the cistern rises above this level and is drained into the sewer at a delayed speed using a floating drain choke. This relieves the sewer and the treatment works. The water level can rise to the emergency overflow and sink slowly back down again after the rain.
  • Sizes between 1,500 – 7,500 l with corresponding retention volumes are possible. 
  • We also construct and supply individual, special solutions.

Advantages

Thought-out in every detail

Low installation depth
Low installation depth
Low installation depth

The minimal installation depth saves you time and money during installation.

Low weight
Low weight
Low weight

Tank installation made easy! The significantly lower weight of GRAF products compared to steel or concrete cisterns makes transport and installation easier.

Low installation depth

The minimal installation depth saves you time and money during installation.

Low weight

Tank installation made easy! The significantly lower weight of GRAF products compared to steel or concrete cisterns makes transport and installation easier.

Sizing

Volume [l]Length [mm]Width [mm]Height [mm]Weight [kg]Retention volume [l]order no.add to enquiry
75003600225015653607500390305
50002890230013152405000390302
30002450210010501703000390301
1500210012501015801500390300

calculated size Request for information

Technical details

Accessibility

Earth covering with loading capacity [mm] 700 - 1000
max. axle load [t] 2.2
max. vehicle weight [t] 3.5
max. vehicle weight with reinforced concrete slab [t] 60

Groundwater installation

Earth covering with groundwater installation [mm] 700 - 1200

Installation

max. earth covering [mm] (without groundwater, vehicle loading) 1200

Accessory