Floods?

Flood Location: Lanarkshire Scotland
My Location: South East England so can't be on site to view.

Even before this crap weather our friends rear garden and neighbouring properties have suffered from partial flooding since the college land behind their properties was sold and developed in to a mini housing estate. My theory is the 'run of' of surface water in the area immediately bordering the gardens has not been provided with adequate, if any, drainage so it will end up following its easiest route.
My suggestion was they should have installed a French drain connected to the site main drain point.
It seems both the contractor and council have now washed their hands of it after 2yrs doing nothing about it but talk, talk, and promise which the contractor broke.
Any suggestions may help if taken to court to force the contractor to resolve the flooding. It was suggested by a Land engineer they do away with their gardens, chip the area over and use planting tubs all at their own cost. Bet he'd complain if I flooded his garden and said that!.
Many thanks sorry its long.