The newly-built Rossnowlagh campsite overlooks the beautiful and protected Donegal coastline. Part of the requirement to get planning permission for the site was that excess rainwater run-off from the hard-standing areas would be limited to the flow rate expected from a green field site.
Six Kingspan Water attenuation tanks including a flow control chamber have been installed to provide the required level of protection to safeguard the local environment.
The newly built Rossnowlagh campsite is situated on the beautiful Donegal coastline, close to the beach on a site that is protected by law.
The contractor working on the site got in touch with leading drainage and rainwater harvesting experts, Kingspan Environmental, to discuss the requirement for attenuation onsite to limit excess rainwater run-off from the hard-standing areas of the Park. In order to be granted planning permission, the owners of the site had to ensure that stormwater run-off did not exceed the flow rates that would normally be expected from a greenfield site – around five litres/second. Any more than this could cause erosion damage to the beautiful beach and coastline.
An external engineer had provided information to assess rainfalls in the area and the amount of run-off this could generate in order to assess the size and specification of the attenuation solution that would cope with the demands placed upon it.
Consideration had been given to installing either half shells or crates as two alternative attenuation technologies to deliver an adequate response; Kingspan was asked to assess the relative values of each.
National Sales Manager, David Best, was able to use his knowledge of the local area to advise against both options because of concerns over efficacy and the unsuitability of the substrate. Half shells depend on stone fillers for drainage, and the size of the stones has an integral part to play in determining the quality of drainage achieved. Meanwhile, crates would not be suited to an area surrounded by sand and would quickly silt up – the only method of de-silting them would then be to dig them up again.
Kingspan Water attenuation tanks, however, offer an alternative, with many benefits such as reduced health and safety risks from ease of installation through to full vessel access for routine service and cleaning negating the problem of silt and sand build up. The drainage system which has since been installed includes gullies to collect the stormwater run-off which then feed into a master Kingspan Water attenuation tank. The water is then stored and discharged at the correct specified rate to the water course by the flow-control tank – the latter has a high-spec flow control device designed to control the flow of the water run-off to five litres/second.
The tank was sized based on the retention volume and the capacity to store a 1-in-100-year storm event with the critical storm identified as 60-minute winter storm.
Brendan O’Hara, owner of O’Hara Developments Ltd, Ballyshannon, Co.Donegal comments: “As main contractor, we were looking for a solution that both worked and offered easy, quick installation. In this instance, the Kingspan attenuation tanks delivered on both counts. Not only are they designed to meet the challenging conditions on-site, we were also able to install the system simply and quickly without the need for additional subcontractors, which saved us time and money.”
David Best advises: “We offer range of attenuation tank systems suitable for the most demanding of site conditions or orientations: deep dig, shallow dig; small or large surface areas, standard shapes or odd shapes.
“We were delighted to be able to help manage the particular silt and sand build-up issues of this site with our easy access facility for easy cleaning and maintenance”