Sankt Annæ Plads - Saint Anne’s Square or Saint Anne’s Place - is almost back to normal after extensive excavations and engineering works to install storm drains. This has been necessary to cope with surface water when there are massive rain storms. With changes to the climate because of global warming sudden and devastating rain storms are becoming much more common and when the equivalent of a normal month of rain can fall in a few hours then the existing drains in the city cannot cope.
I actually experienced one of these storms just a few months after moving to Copenhagen. The first apartment I rented was on Bredgade and like many of the older buildings in the city we all had storage space in the basement for boxes and suitcases and spare furniture and so on. One morning I was looking out of the window amazed to see the amount of rain falling - quite literally torrents - when my phone rang and it was a neighbour suggesting I should go down and move as much as possible out of my store as rain was pouring in from the windows set low on the pavement side and was running down the external steps from the courtyard. The street was like a fast flowing stream as the drains just could not carry away that much water.
One of several ongoing schemes to resolve the problem has been to cut drains along the street, between the pavement and the road so, instead of a shallow gutter with grills at intervals, there is now a continuous grid and below it a wide concrete channel.
At Saint Anne’s Square the cobbles around the equestrian statue of Christian X have been reset to form a shallow and almost imperceptible basin so storm water in Bredgade will be encouraged to take a sharp turn into the square rather than running on down the street. There are the new surface drains on either side but also the area of grass that runs down the centre of the Plads has been lowered to absorb more water quickly.
the new storm drains about to be laid along the edge of the road last winter
If this all seems like a storm in a tea cup, as it were, the cost of storm damage and the disruption to businesses as they have to repair floors and replace plaster and electric wiring and so on is serious and the quantities of water are amazing. There is so much water running off the streets during these storms that sewers burst as water overflows from the street drains and the volume of water is almost impossible to imagine. Sankt Annæ Plads runs down from Bredgade, down from the statue to the harbour but potentially there is so much water coming off the streets in the district that it can cause problems if it is released straight into the harbour, particularly if it has been contaminated with sewage, so the most important part of the recent works was the construction of a massive holding tank that takes up to 9 million litres of water and from there it will be released as slowly as possible into the harbour. I think that tank is actually under new steps at the end of the basin by the Admiral Hotel and is part of the rebuilding of the pier to the north of the theatre that is now called Ofelia Plads. Walking past the works it was difficult to look behind the hoardings to see exactly which area was excavated and just how large and deep that tank is but for 9 million litres it must be big … not an amount I find easy to imagine or visualise.
the grass down the centre of Sankt Annæ Plads is back but at a lower level
the harbour end of Sankt Annæ Plads looking across the basin and the new steps ... somehow there is a holding tank for 9 million litres of rain water below this area
Around the city there are many more programmes of engineering work or solutions that use new surfacing materials or an imaginative redesign of park landscapes to deal with the problem of storm water ... see the post rains and drains ... and there was an exhibition last year at the Danish Architecture Centre about what is being done in the city to tackle this The Rains are Coming