On site with Portadam13 December 2013
Portadam is a versatile temporary dam solution that can be used for many applications in a variety of aquatic environments.
Established in 1977 OnSite is a South Staffordshire Plc owned company that has grown through strategic acquisition and organic expansion to become one of the UK's leading wastewater management contractors. Recent developments have further broadened its range of applications and one such diversification was the 2007 acquisition of the Portadam temporary dam system.
The system benefits from a simple, two-component design, ie a steel supporting 'A' frame structure upon which a tailored vinyl liner membrane is suspended. The resultant hydrostatic seal provides a watertight barrier behind which essential maintenance or construction works can be safely carried out.
The Portadam's 'A' frame support structure has been specifically designed to transfer hydraulic loading to a near-vertical load. This creates a freestanding dam that requires no additional bracing or supports, and maximises the safe 'dry area' created for essential maintenance works, remedial or construction works.
The standard Portdam is available ex-stock and can dam water depths up to 2.5m. If water levels overtop the designed depth, water can simply spill over the upper edge of the membrane without affecting the Portadam's structural integrity.
OnSite deploy specially trained installation teams to rapidly erect the dam frame section by section before hanging the membrane. In deeper water, operators utilise floatation aids.
Key benefits of Portadam:
- Lightweight and portable.
- Fast deployment.
- Easy to transport.
- Easy access to remote sites.
- Quick and easy to install and remove.
- Adaptable to a broad range of environments.
- Can be erected in several common configurations.
- No damage to bed of watercourse or environmental damage.
- Minimal site footprint.
- Cost effective.
Portadam, because of its versatility can and has been used for many applications in a variety of aquatic environments including waterways, rivers, canals and locks, streams, channels, culverts, irrigation ditches, lakes, lochs, ponds, moats and harbours.
As well as providing dam solutions for civils works, remediation and bridge and bank inspection, Portadam offers an ideal solution for other water control requirements.
Temporary water tanks can be quickly constructed on any level piece of ground, tank size being limited only by the space available. To-date the largest Portadam tank erected had a capacity in excess of half a million litres.
Portadam is also ideal for construction of flumes. The use of twin dams combined with a pipe bonded directly into the membranes allows a watercourse to be fully dammed whilst maintaining a constant flow.
As major floods become a regular feature of British winters, Portadam is coming to the fore - diverting or holding back the floodwaters that threaten key infrastructure or historic buildings. Not only can Portadam be installed more quickly than sandbags, but the system can be installed in standing water - holding back floods that threaten to rise to more serious levels.
Case Study - OnSite's rapid response gets narrow boats moving again on the Shropshire Union Canal.
At 08:45 OnSite receives a call from British Waterways informing them of a breach in the Shropshire Union Canal in Grindley Brook, near Whitchurch, Shropshire, resulting in the complete dewatering of a canal pound.
An installation team is quickly deployed, loading a Portadam system into three vans.
Sole access to the site for men and equipment is through an ornamental rose arch within a private cottage garden.
The pressure to get the waterway back open increases with every passing hour as narrow boats begin stacking up on both sides of the breached area.
At 21:00 the dam installation is complete.
At 11.30 the canal is re-opened to traffic and the job of bringing the queuing narrow boats through the locks begins.
From breach to full operation took a little over 24hrs
Dr Steve Ovington is the Head of Business Development at OnSite. E-Mail: [email protected]