Puddles in High Holborn 

• YOUR correspondent chartered engineer Dugald Gonsal’s diagnosis of the drainage problems at the recent Camden Council highway schemes is not correct, (How those puddles came about… April 9).

The problems are due to the road levels not being set out correctly for the new surfacing and gulleys installed too high.

The correct procedure to ensure that there is no ponding at new schemes, is to determine the height of the gulleys so that there is sufficient fall of the road surface to drain rainwater. So the new road surface at the kerb face is not level but is a series of very wide inverted V shapes.

However this clearly not the case at High Holborn, and in fact I pointed out the ponding problems to Camden in March 2019 immediately after the new kerb line had been installed and it was perfectly clear that the repositioned gulley was too high.

I would mention that there are worse cases than this in Camden and round off by saying that I am also a chartered engineer.

RICHARD WALKER
Red Lion Street, WC1