Mr Lucas explained that Ash and Ash Vale sit in the Blackwater Valley, a “flat-bottomed” valley at the bottom of three hillsides.
The area had severe flooding in 2013 and again last year, the latter leading to youngsters kayaking in the street, Mr Lucas said.
“If you get significant rain you get a surge in flow rate, so this project is about working out how best to build the ponds and slow that,” he said.
The project is also set to include dams made of natural materials which temporarily store water during heavy rain.
Work on the flood defences is set to begin next year.