The architect of the Msida Skate Park has rejected claims discrediting his work after Infrastructure Malta uprooted seven mature trees at the park and blamed its action on water seepage.

The agency claimed the landscaping pits had not been waterproofed or equipped with proper catchment when they were installed, with irrigation water now seeping into the tunnels beneath. This meant it had to redevelop the landscaping area and install proper waterproofing.

But the park’s architect, Ivan Coleiro, on Friday defended his design, saying an approved catchment system had been put in place in 2008 and all the agency needed to do was to maintain it.

He said a French drain had been installed, consisting of a perforated pipe surrounded by graded material, which worked perfectly.

“Discrediting a project that was well detailed is not right, especially when they are falsely stating there is no proper catchment system when there clearly is one. The real motives behind the works should be made clear,” Coleiro said.

He explained the system needed to be maintained occasionally to keep the pipes free from debris. But, from the records available to him, no maintenance was ever carried out.

“Ideally, this is performed annually and involves simply flushing down the pipes from the rodding station and collecting the debris from the end chamber,” he said.

He had monitored the catchment system for five years and the planters were never waterlogged in any of the heavy rainstorms lasting several days, which was solid confirmation that the system functioned, he pointed out.

He said waterproofing of the roof system was part of the original tunnel project, carried out before the skate park was built, which meant it was not necessary to waterproof the planters.

The report on the repairs was unprofessionally prepared, he added, as no one from the agency had bothered to contact him for details of the catchment system or the maintenance procedures before ripping it all up.

To add insult to injury, the planters were not designed to take heavy machinery, so the works on Tuesday most likely damaged the pipes, he said.

In response, Infrastructure Malta said it had not received any information that showed the French drains were not being well maintained. 

"Contrarily, initially investigations from the ongoing excavations indicate that the materials and construction methods used in this system were not in line with industry best practices, which continued to reduce its effectiveness."

It said that while a form of French drain system was embedded in the soil under the trees, "it was not functioning as it should have".

"Tests conducted before works commenced confirmed that the leaks in the tunnel practically stopped when the landscaping above was not being watered," it said. 

It said that there was also not a secondary containment measure, meaning any water that did not reach the French drains ended up in the tunnels' structure beneath.