DAYS of heavy rain and the installation of a complex watering system should have left Piccadilly Gardens' newly-laid lawn in central Manchester looking lush and verdant.

But the scorched grass has been caused by a hidden heatwave - generated by an electricity substation below ground. Earlier this year, workmen drilled a 200ft borehole to a natural water source in an effort to help the gardens maintain a green sheen throughout summer.

The water is used to irrigate the gardens and supply the 180-jet fountain.

The system was switched on last month, after new turf was laid and the gardens were landscaped to encourage people to walk on paved areas rather than the grass.

But after only a few weekends, it is already showing signs of wear.

City centre councillor Marc Ramsbottom said: "It's pretty appalling. Thousands of pounds have been spent on the new turf and patches are already going brown.

"They knew there was an electricity substation under the gardens and should have anticipated the problem."

A council spokesman said contractors were working to rectify the problem.

"The irrigation system came into operation last month," he said.

"Given its pioneering and complex nature, we anticipated some minor modifications might be required in the early days.

"Once these are completed, we are confident the issue will be resolved."