Shane Ruddy, a civil engineering student attending Worcester Polytechnic Institute in Worcester, Massachusetts, worked alongside Miljøpunkt Nørrebro to address the lack of green space and the flooding problem in Copenhagen. This page is a summary of the project.
Executive Summary: Daylighting Ladegårdsåen
Copenhagen faces many environmental problems; the most compelling are a lack of green space and recent extreme rainfall causing flooding. This project aimed to address these problems by (1) investigating the possibility of daylighting Ladegårdsåen, a piped canal that is located under the busiest road in Copenhagen, the Ågade-Åboulevard (AA), and (2) developing a feasible design concept that our sponsor, Miljøpunkt Nørrebro, and other stakeholders might pursue further.
Previous plans to daylight Ladegårdsåen failed due to a lack of funds and motor traffic considerations. Prior to our arrival in Copenhagen, a planned congestion ring was scrapped, meaning we could not rely on decreased traffic in our recommendations. The more recent need for flood alleviation was the remaining external change from previous attempts to daylight Ladegårdsåen.
Within this context, our objective became to design the daylighting and green space in a way that would alleviate flooding, while still meeting the demands of a major motor traffic corridor.
Our design solution, to both help with city-wide flooding and to make room for daylighting along the route, is a dual-purpose motorway tunnel design that can handle displaced traffic along the AA, while serving as an emergency reservoir system (inspired by SMART project in Kuala Lumpur). Reservoir capacity is preferable to direct outlets into the harbour because, (1) it is not realistic to divert huge amounts of water to the harbour directly, and (2) reservoir capacity is unaffected by extreme rains coinciding with high tides (while measures to bring water directly to the sea would be). Reservoir capacity would also not be affected by rising sea levels due to climate change.
Our designs and choice of route correlate with the City of Copenhagen’s policies to integrate blue (water) and green structures. Ladegårdsåen would be the missing thread to create a blue/green grid of connected green corridors and waterways, as well as strengthening Copenhagen’s claim to being bicycle capital of the world and a leading green city. Moving traffic underground would obviously remove noise and particle pollution, raising living quality in the area.
The supply of water from tributaries to the canal is low, so our stepped, double profile design allows for a narrow, but naturally appealing flow of water through its base channel; in times of heavy rain, the water can rise up and flood the canal’s ascending steps, increasing the capacity.
We propose the canal receive water from rooftops, the natural water catchment area, and foundation drains. During dry periods, some water would have to be recycled back into the canal. In times of rain, when the canal contains excess water, we propose that it be used as sekunda (semi-clean) water, for heating, industry, car washing, etc. Some of this water would be cleaned by rain gardens, using a natural filtration system, situated at various low areas along the canal. Collecting and using sekunda-water will decrease stress on sewers and drinking water supplies.