A team of water experts is helping safeguard three of Wales’s greatest gardens from flood damage.

Denbighshire-based Waterco are working with the National Trust on plans to protect the iconic properties at Bodnant Garden in the Conwy Valley, Dyffryn Gardens in the Vale of Glamorgan and Tredegar House, near Newport.

The three properties are among Trust’s biggest visitor attractions in Wales and attract over 400,000 visitors each year.

Waterco, whose headquarters are in Ruthin, have already prepared plans for Dyffryn Gardens and Tredegar House and work has started not only to make them as flood-proof as possible but also to manage their water supplies efficiently and environmentally sustainable.

Now they have also come up with a strategy for Bodnant Garden, which attracts over 230,000 visitors a year to view its spectacular laburnum arch, magnificent specimen trees, flower beds and the pools, weirs and waterfalls of the River Hiraethlyn and other man-made and natural water features.

But the Hiraethlyn can also cause damage too and in December 2015 a major flood swept away thousands of plants, smashed bridges and paths and deposited hundreds of tons of silt and gravel on flowerbeds and before that winter floods in 2012 had affected the newly renovated Far End of the Garden.

The 2015 storm cost the Trust £15,000, a significant amount of money and took two months’ work to put right ahead of last spring’s opening.

The Trust also have concerns over summer droughts which can pose problems for the magnificent 80-acre Victorian gardens but now Waterco, who also have bases in Chester and Manchester, are working closely with the National Trust to develop a plan to alleviate catastrophic flooding and drought.

The Waterco team is led by Associate Director Raffaela Whitehead and includes water management specialist Keith Stoops, principal civil engineer Mike Redding and hydraulic modeller Bethan Lloyd Jones.

Mike Redding said: “We are looking to future-proof the gardens as much as possible against damaging floods and also to look at their water use generally.

“At Bodnant they had a severe flood in December 2015 and although the fact that the river is in a narrow valley makes it impossible to prevent floods we can do a great deal to make the effects less damaging.

“We have advised on reinforcing bridges and pathways to make them more resilient and we can also work with other local landowners upstream to find ways to slow the flow of run-off water into the river at times of heavy rainfall.

“Just a simple thing like ploughing across the slope rather than down the slope can make a big difference and it causes less soil erosion and we can also look at tree-planting and creating run-off ponds.

Keith Stoops added that at Bodnant Garden and also at Dyffryn Gardens and Tredegar House they are also looking at the water supplies which have been of variable quality with old and leaking pipework.

Bodnant Head Gardener John Rippin recalled: “The heavy rainfall on Christmas Day and Boxing Day 2015 turned the river into a raging torrent and tore up a lot of planting and even small trees.

“It also dumped tons of rock, gravel and silt in flower beds and we had to get a digger in to clear it – it took six to eight weeks to restore everything.

“The weirs and dam walls were badly damaged and that’s why we’ve been asking for help so that they can be built to be more resilient in future.”

Dyffryn, Tredegar House and Bodnant are the first National Trust properties in the UK to have new water management plans.

Paul Southall, the Trust’s Environmental Advisor and Wales Projects Lead, based at Penrhyn Castle, Bangor, has overseen the works at the three properties and he said: “We are a complex organisation and what we want is the certainty that we have the best people possible working on our behalf.

“In Wales that works really well with Waterco, they understand us and our needs, and they’re providing us with a really good service and we have developed a very good relationship with them.

“The problems we have here are not unique and in Wales we have a really good mix of the kinds of properties we have across the UK, we’ve got castles on hills, the largest countryside portfolio in the whole of the Trust and 200 miles of coastline.

“So the chances are that if these programmes work in Wales then they’ll work elsewhere.”

Waterco, founded in 1990, are one of the UK’s leading Water, Flood Risk, Drainage and Geo-environmental consultancies offering a wide range of services including flood risk assessment, detailed drainage design, drainage strategies, SUDS design, river and coastal modelling and ground investigations.

From their offices in Ruthin, Chester, Manchester they work extensively with water utility companies across the UK and with local authorities like Denbighshire and Cheshire West and Chester Councils. In the private sector across the UK clients include developers and other consultants who value their specialist water sector knowledge.

Managing Director Peter Jones said: “With the entire business devoted to water, drainage and flood protection, we are committed to providing our clients with cost effective, practical solutions, compliant with legal and environmental requirements.”

For more on Waterco go to www.waterco.co.uk