Climate park in Vejle to keep basements and roads dry

Vejle Municipality, the local water utility company and a local housing association have joined forces in a climate change adaptation project to prepare some of the eastern district of Vejle for more extreme rainfall in the future. The climate project consists of five sub-projects to ensure rainwater is effectively channelled into Vejle Fjord rather than into basements and onto roads. The new area will also offer a recreational space for play, ball games and outdoor relaxation. The first sub-project is the Climate Park: a green 750-square-metre wedge with an open, several-hundred-meter-long water channel. The Climate Park sub-project is part of a larger climate project in the eastern district of Vejle, the aim of which is to channel rainwater runoff along a 3.5-kilometre-long conduit from the higher-lying northern part of the district downhill into the fjord. The entire water passage can cope with as much water as will fall during an 80-year to 100-year rainfall event, projected to the year 2100.

• Fittingly inaugurated during heavy rain

  The new water channel in the eastern district of Vejle proved its worth from day one: on the day of its inauguration in June 2020, the sky opened and sent cascades of rain pouring down on the new climate change adaptation project. 

   

  The Climate Park in Vejle was inaugurated in June 2020 and is one of several climate change adaptation projects that Vejle Municipality and Vejle Spildvand, the local water utility company, are carrying out jointly.

  
  The Climate Park is one of five sub-projects, the purpose of which is to direct rainwater runoff from the northern part of the eastern district of Vejle into the fjord to keep it from flooding basements, green areas and roads.

  
  Several sports fields comprise another of the sub-projects. The fields lie just uphill from the Climate Park on the water's passage to the fjord. The sports fields will serve as a reservoir in the event of cloudbursts.

  
  The climate change adaptation project was approved by the Water Division of the Danish Competition and Consumer Authority in 2016 and is being financed 75% over wastewater bills.

• Too much flooding a nuisance to residents

  A certain area of the eastern district of Vejle has seen much flooding. The ØsterBo housing association has experienced repeated flooding of basements and outdoor areas. Train services in the area have been affected due to flooding of tracks. 

   

  The entire city of Vejle is prone to flooding during heavy rainfall. This is because the city lies "at the bottom of a funnel" with relatively steep-sloping land all around.

  
  The municipality and the local water utility company have therefore initiated a number of climate change adaptation projects to protect the city.

  
  The eastern district of Vejle, close to the fjord, frequently experiences problems with flooding when the northernmost parts of the district send large volumes of stormwater gushing down towards the lower-lying parts.

  
  Furthermore, the municipality, a local school and the ØsterBO housing association wanted to improve the recreational opportunities in the area.

   

  Photos: Vejle Kommune

• Meandering watercourse and small lakes

  The Climate Park contains a water channel with around 750 metres of open waterway, here and there interrupted by small lakes. A pumping station helps the water travel the last leg of its journey into Vejle Fjord. 

   

  The total project takes up 182 hectares and will keep the water away from the buildings of the ØsterBO housing association and from railway tracks and critical infrastructure. The project will achieve this by cutting off and retaining stormwater runoff in the higher-lying areas of Vejle's eastern district.

  
  The water that runs down into the district and onward into Vejle Fjord will be guided through a 3.5-kilometre-long continuous waterway consisting of closed pipes, basins and open water conduits.

  
  The Climate Park is the first completed part of the total project. The park contains an around 750-metre-long, open water channel. The channel consists of a narrow concrete conduit that expands into small lakes along the way.

  
  When the channel fills to the brim, the excess water spills over into a wider green area. In this way the water is guided away from housing blocks and out into the Climate Park, where there is plenty of space for it.At the end of the water channel is a pumping station, which pumps the water from the low-lying area into Vejle Fjord.

  The remainder of the large project area lies uphill from the water channel. This area contains retention basins and a large new pipe that leads water directly into Vejle Fjord.

  
  In an area uphill from the water channel, a sports field has been converted to retention basins and an activity park. The landscape has been altered, so that the sports field now consists of three independent basins able to retain a total of 5,300 cubic metres of water.

  
  Uphill from the sports fields is yet another basin that the local water utility company is already using to store rainwater. This basin, called Rom's Hollow, can hold around 2,500 cubic metres of water. The outlet from the basin will be changed so that more water can be led onwards to the sports field.

  
  Even further uphill, in a forested area of the water system, is a natural ravine called Abeburet, the monkey house. Abeburet will be expanded to a capacity enabling it to retain 19,400 cubic metres of water. That's 12,000 cubic meters more than today.
  Closed pipes will be established as well as an entirely new drainpipe to the fjord to direct some of the rainwater around the area and directly into the fjord.

  
  The total project has an expected average lifetime of 63 years and can cope with as much water as will fall during an 80-year to 100-year rainfall event, projected to the year 2100.

• From flat, damp grass field to hilly park landscape with watercourses

  The challenge posed by large amounts of rainwater has been addressed and turned into a benefit for the public. The eastern district of Vejle now has a new, undulating landscape with watercourses, small lakes and new recreational opportunities. 

   

  Vejle Municipality wants to turn the challenge posed by large amounts of rainwater into something that benefits the public.

  
  From the beginning, it was important for the municipality and the ØsterBO housing association to create new recreational opportunities and at the same time address the problem with managing the large volumes of rainwater.

  
  The Climate Park was therefore established as a new recreational area. A flat grassy area, often too soggy to use, has now been transformed into an undulating park landscape with watercourses and small lakes.

  
  The park has paths, and picnic tables and benches will soon be installed. In the adjacent, renovated sports field, children and adults can now enjoy themselves with many types of activities, sports, games and play, except after a cloudburst event.

• The local water utility company is paying 75% of the project

  The total project cost will come to almost DKK 47 million. That is DKK 15.6 million more than originally expected. However, the cost is still considerably lower than a traditional solution with underground pipes. 

   

  The first part of the total project is clearly the most expensive. The sports fields, the Climate Park and the pumping station were budgeted at a cost of DKK 25 million.

  
  The final cost turned out to be DKK 9 million more than that. This overrun was due to challenging hydraulic conditions that did not reveal themselves during the preliminary investigations.

  
  These challenges meant that a different solution than that budgeted for had to be chosen between the housing blocks and the Climate Park.

  
  Operation of the technical installations at the sports field, the Climate Park and the pumping station are estimated to cost DKK 170,000 annually. The local water utility company is financing the operation of these installations.

• The entire process will take seven years

  The project started in 2014 with a pilot project with extensive involvement of residents, schools and other local stakeholders. The Water Division endorsed the project in 2016. If everything goes according to plan, the entire project will have been completed before the end of 2021. 

   

  The first vision plan for the area that is today the Climate Park of the eastern district of Vejle was prepared by the municipality, the water utility company and the housing association back in 2014.

  
  The ØsterBO housing association was willing to cooperate with the municipality and made an area available for water management.

  
  In 2016, the three parties applied to the Water Division for approval of the current project instead of a traditional solution, with underground pipes.

  
  The Water Division said yes, and in the summer of 2019, work was commenced. The Climate Park was inaugurated in the summer of 2020. It is expected the total project will be completed in 2021.

• The project turned out to be more expensive than estimated and has confirmed that patience and goodwill are virtues in project cooperation.

  Several virtues are needed, in fact: Patience, trust, goodwill, openness and compromise. The good rapport between the project partners survived the extensive budget overrun. 

   

  It was a real setback that the pilot project did not reveal the hydraulic conditions that were later uncovered in the detailed planning phase. It meant that the project became much more expensive than first estimated.

  
  Project developer Ulla Pia Geertsen from Vejle Municipality is certain that patience and mutual trust are absolutely crucial in projects. This is especially true when the budget changes and new solutions have to be found.

  
  Furthermore, projects on private and municipal land are particularly challenging because there are so many different interests at play, according to Ulla Pia Geertsen.

   

  It takes more time, and it requires that everyone understands and recognises their project partners' unique and often very different situation.