Water intakes and outfalls

Ensuring optimal conditions for supplying water to a process and releasing effluent into the environment.

Physical phenomena modelled

Water intake in a vortex shaft | Artelia Hydraulics
Water intake in a vortex drop shaft (Scale 1:20)

Whether in a marine or river environment, on an urban or industrial site, the design of a water intake for a process (hydropower, irrigation, drinking water, industrial use, cooling, etc.) or an outfall discharging effluent into the environment raises issues that are often examined using physical modelling.

Water intake structures must comply with a certain number of hydraulic design criteria, such as:

  • uniform intake velocity
  • absence of vortices
  • limitation of head losses
  • low sensitivity to floating debris
  • fish-friendliness
  • etc.

Similarly, to minimise environmental impacts, effluent discharged from the outfall must be well diluted in the receiving environment. The energy from the flow must be dissipated efficiently in order to limit risks of scour.

Water intakes at the Cordemais EDF power plant | Artelia Hydraulics
Water intakes at the Cordemais EDF power plant (France) - Scale: 1:35

Upstream water intakes of the Venda Nova III (pumped storage) hydropower scheme (Portugal) | Artelia Hydraulics
Upstream water intakes of the Venda Nova III (pumped storage) hydropower scheme (Portugal) - Scale: 1:33.33

Wave propagation on the outfall structure of the Safi thermal power plant (Morocco) - Scale: 1:68 | Artelia Hydraulics
Wave propagation on the outfall structure of the Safi thermal power plant (Morocco) - Scale: 1:68
The structural stability of intake and outfall structures exposed to hydrodynamic stresses from their environment must also be checked.

Physical modelling is a powerful tool that can be used at the end of the design phase to check that all the design criteria have been met and thus guarantee the long-term structural soundness of the structures and ensure that they will function efficiently from the hydraulic standpoint, whatever the conditions (tides, floods, screens blocked by waste, etc.).

What we do

Artelia’s laboratory performs the following assignments in the field of water intakes and outfalls:

  • dimensional design and hydraulic optimisation of intake and outfall structures
  • checking of different operating configurations and identification of operating limits (flow rate, water level, obstruction, head loss)
  • characterisation of hydraulic behaviour, velocity field and risk of air entrainment
  • checking of efficient effluent dilution following release from an outfall
  • checking of the hydraulic stability of intake and outfall protection structures.