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Reliable discharge monitoring of spilled flows

To meet regulatory requirements by implementing a monitoring system enabling reliable measurement of the spilled flow.

Fiabilisation autosurveillance

The josette

The josette is a weir with a rounded notch dimensioned on a case-by-case basis according to the expected flow range so as to minimise the measurement uncertainty without significantly impacting the rise in the upstream water level.

Réduction des déversements

Water level sensor control

Our device allows for easy verification of the water depth measurement, in accordance with regulatory requirements.

Reduction of spills

Our goal is to limit discharges from the sewerage network into the receiving environment via CSOs and optimise implementation costs for the project owner. To do so, we exploit the storage capacity of the network for normal rainfall while maintaining the network's evacuation capacity for intense rainfall.

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The StockO gate

The StockO is a tilting gate installed downstream of a sewer used for online storage. 

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The Deomatic gate

The Deomatic is a robust tilting gate that makes it possible to limit wastewater discharges from CSOs.

The Deomatic and StockO gates allow a dynamic management of the sewer network. The integration of this equipment in a network hydraulic model allows the storage capacity of the sewers to be evaluated without compromising the normal operation of the network. The operating laws of the gates can be customised using the tool available below.

Fighting deposits

Controlling sand deposits and limiting their re-suspension in the sewerage network in order to maintain the evacuation capacity and minimise the risks of malfunctions such as polluting spills, blockages, flooding, etc...


The bed load trap

The bed load trap makes it possible to trap and store sands while allowing most of the lighter organic matter to pass through.


The volume required is therefore lower than that of a conventional grit chamber. This also avoids bad smells for the local residents and creates a safer and more comfortable working environment. 

The installation of flush gates upstream enables the structure to be supplied while limiting deposits in the network.

The flush gate

The function of the flush gate is to create a water reserve upstream of the deposits and then release the stored volume of effluent abruptly. 

Water released under high flow and speed will re-suspend the deposited sands and carry them downstream.

Lutter conte les dépôts

For more information on HYDRASS - 3D WATER services 

Fighting floating debris

Fighting against floating debris in stormwater systems and in urban aquatic environments.

Lutter contre les macrodéchets
Cloison siphoîde flottante - HYDRASS 3D

The floating debris trap

The trap is used to retain floating debris upstream of a discharge point.

It consists of a floating siphon that follows the water surface in order to retain the debris upstream.

The know-how of the company

3D EAU and HYDRASS joined forces to offer comprehensive solutions (consultancy + equipment) combining the pragmatic and efficient approach of HYDRASS and the precise hydraulic approach of 3D EAU.

  • The Deomatic gate to limit and measure discharges.

  • The bed load trap  to force the settling of sands without retaining smell-generating organic matter.

  • The flush gate  to minimise workers intervention.

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