The perfect tool to save time and preserve the environment
while keeping costs low!

Regular maintenance of waterways to limit the risk of flooding (log jams), emergency work following major weather events, hydro-morphological or hydro-ecological works, morphological crossing, landfill and restoration works: Water-Gate© flexible cofferdams are the perfect tool to help you save time and preserve the environment while keeping costs low.

The incredible efficiency of Water-Gate© flexible cofferdams

They count on us

Our services for river works


Feasibility analysis based on data: Profile | Flow.

watergate cofferdam feasibility study


Quickly recoup the purchase costs.
Rental possible for non-recurring flash floods.

river bins buy or rent


Video calls (WhatsApp, Skype, FaceTime) for remote advice during the initial installation.

Water-Gate remote assistance

River works: case studies

Repairing structures, maintaining waterways and canals.

Water-Gate© flexible cofferdams are acclaimed by contractors and site managers for their efficacy, simplicity and versatility.
Repairing structures, underpinning, reinforcing river supports, repointing, restoring ecological continuity, removing log jams, renovating banks, draining feeder canals, etc.

#1 | Installation ⊥ perpendicular

#2 | Dewatering between 2 cofferdams

#3 | Block a branch of river / intake canal

#4 | L-shaped cofferdam | Support on a bridge pile

#5 | Serial cofferdams between islets and the bank

#6 | U-shaped cofferdam | Rivers

#7 | U-shaped cofferdam | Moats – Water bodies

#8 | Installation on threshold – weir

#9 | Installation in a culvert

Usage conditions of the Water-Gate© flexible cofferdam

Works in water – rivers – canals – ponds. Flexible cofferdams can be used in the majority of situations.
Uneven ground increases friction and thus the stability of the dam. Care is required when using the dam on muddy ground. On a concrete surface, we recommend using the WL range of flexible cofferdams with ballast rather than the WA range of cofferdams. On a sandy surface, you must bury the leading edge to limit the effects of piping erosion.

* We recommend wearing a life jacket for any intervention in an aquatic environment

What are the limits for installing a flexible cofferdam in a river?

It depends on 2 factors: depth and speed of the current

The dangerousness of the flow depends on the Depth * Speed couple.
From 0.50 m / s, the speed of the current becomes dangerous for an adult, with a risk of being carried away by the stream or being injured by objects carried at high speed.

Do not intervene if D * V> 0.8

D = Depth in m | Depth in m
V = Velocity in m / s | Speed in m / s

Graphique indiquant la dangerosité d'une rivière en fonction de la profondeur et de la vitesse du courant
Mesure de la vitesse d'une rivière avec un courantomètre à hélice - MegaSecur Europe

WA: a comprehensive range of flexible cofferdams up to 2 m high

cofferdam works river schema of principle
Features :
*       Cofferdam designed without ballast: the flexible leading edge fits perfectly over uneven surfaces
**     Only for installation in standing water
***   Deep ground sheet that facilitates pedestrian passage and safe pumping for chutes
**** Limits the risk of erosion in the event of overflow, especially on sandy beds
explanation of the WA water gate range



No mobile flood protection system is totally watertight. We provide pumping solutions to collect water that has seeped through and discharge it beyond the dam: self-priming motor pumps or submersible pumps coupled with generators.

MegaSecur has developed a tailor-made spillway for lightweight discharge (DN 450). With no pump, it is environmentally friendly and features a flexible pipeline for downstream discharge. Several spillways can be positioned side-by-side if necessary.