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    Advanced sewage treatment plant

    Storm Dammer ® stormwater attenuation and flood relief tanks

    Stormwater flow attenuation

    Available in capacities from 2800-110000 litres in multiple configurations with tank sizes ranging from Ø1.2m to Ø3m diameters, the Storm Dammer – stormwater attenuation tank – alleviates the risk of flooding and reduces pressure on drains/sewers by storing the excess flow of stormwater before controlled discharge downstream.

    Greater capacity, ease of inspection and maintenance makes Storm Dammer the industry choice for developers, municipal planners and civil engineers.

    Configuration and components are shown for illustration purposes only

    Underground stormwater attenuation tanks allow for high volume storage of runoff in a small footprint area.

    The tank is typically buried under a car park or other open land on the site. In the latter case this underground tank may be preferable to a surface detention pond if other uses are intended for the land (eg, a pedestrian area or park). In other situations a tank is used because installing a pond might pose other problems, such as attracting unwanted waterfowl or other animals. In some sites a tank may be installed in the basement of a building, such as a parking garage.

    The outlet is generally a restricted-flow drain from the retention tank, with a weir for containing detritus.

    Attenuation tanks delay water’s delivery downstream, and possibly creates a later water level peak post-rainfall. It is important to consider timing of water release and the types of reservoirs feeding a waterway.

    Operating principle


    1. Connecting pipework
    2. Internal vent pipes
    3. Flow control devices
    4. Outlet
    5. Access manways


    • Designed to meet latest UK and European standards
    • Multiple tank configurations and inlet orientations to suit storage and site layout requirements
    • Tank diameters range from Ø1.2 to Ø3m with length up to 20 metres
    • Heavy duty shells manufactured from virgin unfilled resin provides superior structural strength and durability. This also enables the tank to be significantly lighter for on-site handling/positioning and better suited to withstand greater hydrostatic pressures when in use
    • Tank design offers easy access for inspection, maintenance and cleaning when compared to inaccessible crate systems
    • Systems can be fitted with flow control devices and orifice plates to regulate storage and discharge
    • Easily accessible, low energy submersible pumps ensure minimal running, maintenance and servicing costs
    • Guaranteed for 25 years with a design life of 50 years

    Optional extras

    Orifice baffles

    Utilising Marsh Industries’ unique Gaia Storm Dammer program, in conjunction with the Micro Drainage Design program, the standard range of Storm Dammer tanks are designed using orifice baffles as the primary flow attenuation system.

    Precise calculations from the Gaia Storm Dammer program ensures that the correct type of orifice baffles are distributed throughout the system to deliver the optimum outflow required.

    Flood and storm control valves

    Storm Dammer systems can be designed to include Vortex Storm Control units which can reduce out-flow on varying scales.

    Pumps can also be fitted to upline chambers allowing stored water to be distributed to other chambers that may not be in the immediate area.


    Marsh Industries works in partnership with major UK pump manufacturers to develop attenuation tanks and pump chambers that are designed to distribute water to the mains drainage network or to other off-site storage tanks. Pumps can be supplied as single, twin or multi-line installations in both single and three phase.

    AUTOadapt™ sump pump

    Designed for a range of water and wastewater applications, the AUTOadapt pump removes the complexity of standard submersible pumps by combining all external sensors switches and cables from the pit within the pump itself. This simplifies installation and operation, vastly increasing reliability.


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