The Upper Medway Internal Drainage Board’s drainage district covers the areas of East Peckham, Edenbridge, Forest Row, Frittenden, Groombridge, Headcorn, Lingfield, Maidstone, Marden, Paddock Wood, Penshurst, Staplehurst, Tonbridge and Yalding.
The Lower Medway Internal Drainage Board’s drainage district covers the areas of Cuxton, Faversham, Hoo, Isle of Grain, Isle of Sheppey, Lower Halstow, Minster, Seasalter, Sheerness, Sittingbourne and Snodland.