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Dutch experience integral to flood pump design

Edited by the Engineeringtalk editorial team Jan 11, 2001

Hidrostal's Dutch distributor Eekels developed the proven diesel driven Betsy self-priming pump package for flood conditions, in co-operation with the Dutch River Authority, Roer and Overmaas

Flooding has been front-page news for months, not the usual inundation of fields but the catastrophic submergence of towns and villages all over Britain.

For many communities this was to be their first exposure to flood waters since records began.

This salutary experience was accompanied by the experts' disclosure that similar events could happen again in the near future.

When coupled with the failure of installed pumps and scarce emergency equipment, this forecast gives cause for real concern.

This is a situation very familiar to leading pump supplier, Hidrostal, whose Dutch distributor Eekels developed the proven diesel driven Betsy self-priming pump package for such conditions, in co-operation with the Dutch River Authority, Roer and Overmaas.

Hidrostal's experience throughout Europe, particularly in the Low Countries, confirmed that both the failure of installed equipment and the lack of adequate reserves significantly increased the damage caused by flooding.

Permanent pumping station installations usually stop working when flood levels reach electrical equipment or when blockages can't be dealt with, due to pump wells becoming flooded.

The failure of power supplies was also a key factor.

Roer en Overmaas is responsible for a large part of the Maas catchment in the province of Limburg, Southern Holland.

In periods of high flows, the greater pressure on dykes causes increased leakage and possible subsequent flooding.

Eekels recently won a major contract for 45 skid-mounted 10" Betsy pumping systems.

The key difference between conventional, static mounted pumps used in flood water defences and those based around Betsy units is that Hidrostal pumps are transportable.

They are deployed to mounting platforms throughout the Roer en Overmaas catchment.

Each platform has permanently installed suction and delivery pipework to permit rapid installation.

The pattern of deployment can be altered to suit the location of heavy flows and the changing burden on flood defences.

Because Betsy pumps can be transferred from site to site as required, the system is more secure and reliable than a permanent installation, as they are only in situ when needed.

Routine maintenance can be carried out off-line, when the pumps are out of service and because they are only deployed when needed there is little risk of parts becoming damaged or broken in the field.

A critical factor affecting permanently installed pumps used for flood water defence is the level of confidence operators have that the pumps will actually work, when required in an emergency.

The Betsy units, that form part of the Roer en Overmaas project, are stored at a central depot when not in use and can all be operational within two hours.

The self -contained pump package, includes a quite running diesel engine drive with a large capacity fuel tank.

The pumps' screw centrifugal impeller, with vacuum priming equipment, has an automatic stop-start, electrical control gear, and storage facility for fuel and liquid leakage.

It's wide free passage offers the large solids handling capability, so essential in the emergency pumping of unscreened sewage and floodwaters.

Each Betsy unit is contained within an acoustic housing permitting the unrestricted deployment of the pump units in noise sensitive areas.

The Roer en Overmaas Authority adopted a standardised approach - all 45 units, each of which has an output of 500m3/hr, have the same specification.

It is a matter of record in the UK, that not every area at risk is flooded at the same time.

Scarce emergency pumps, such as those made available by fire brigades, are moved from one trouble spot to another with great efficiency, but there are simply not enough pumps available.

The Hidrostal self-contained pump package meets this need and is already a key asset in the infrastructure provision of many service providers in mainland Europe.

Across Europe operating organisations have been surprised by the lower whole life costs of Betsy options.

The exchange of operating units requires only minimum work on site.

The resulting reduction in costs, and increased operational reliability, which results from maintenance of plant in workshops, rather than in the field, could well benefit UK residents, should winter flooding be a problem in the future.