Down the drain

Sustainable drainage as offered by the Tarmac product mentioned in your feature 'Running Dry' is nothing new. Coventry University and others have hosted seminars on the subject over many years and there are several products similar to Tarmac’s available.

One problem with them, however, is the additional maintenance cost over fast run-off drainage — in effect, all the drains are filter drains and thus require regular unclogging.

As maintenance generally falls to local authorities after the developers have gone, this implies some form of recompense over the years.

J Gray

Warwicks