Water, water everywhere: sustainable redevelopment in Kolding, Denmark

From the Vault: I originally wrote the following story for Momentum Magazine in 2003 and had completely forgotten about it until speaking the other day with a co-worker interested in aquaponics.

That chat made me remember the first time I’d ever seen water, plants and urban fish in action together, in Kolding, Denmark.  While over a decade has passed since this story was written–and everyday in our communities there emerges even more examples of thoughtful development and design–I thought this piece deserved to see the light of day again.  Kolding’s pyramid still remains one of the most beautiful and most multi-purpose water facilities I’ve ever seen.

Even more so, I think this example still holds up well in terms of re-imagining neighbourhood space and the different possibilities that can be created within a community when we play with boundaries and share the land differently.  Enjoy!

Kolding, Denmark’s Bioworks facility.

My question wouldn’t have caused a single eye blink in Cairo, Egypt.  But announcing itself as it did in the grey fall environs of Kolding, Denmark, my request caused a trio of puzzled looks from the tourist information centre staff:  “Can you please tell me how to get to your pyramid?”

After more description and a call to the local planning department, my intrepid explorer friend and I were soon riding our travel weary bikes to one of the neatest sustainable developments I’ve ever visited.

I’d first read about this development in a planning book. 

A short paragraph had described a Danish neighbourhood that had been retrofit with energy efficient buildings and a pyramid-housed living machine to treat its wastewater.

How Kolding’s Bioworks pyramid nestles into the surrounding housing.

Coming from Victoria, where fresh water supply and wastewater management are a concern, this project had tickled my imagination.  It wasn’t the only example of a living machine that I’d read about, but it sure seemed like an especially beautiful one.  And now, wheeling my bike through a side entrance and into the block’s central courtyard, there it was in front of me.

The project bounded by the streets of Fredensgade and Holleandervej got its start in the early 1990’s.  Made up of a collection of three and four story buildings and a jumble of fenced backyards, the diamond shaped block was slated as next in line on the town’s urban renewal list.

Rather than just renewal, the Municipality of Kolding, the Danish National Building and Housing Agency, and area residents and consultants worked together to create a showcase for sustainable development technologies along with their improved housing.

The block’s multiple buildings—almost all built before 1950 and most built before 1920—became more energy efficient.  The project added building insulation and upgraded windows.  A number of the balconies were glassed in to create more livable space and take advantage of passive solar heating.  A formerly flat roof grew dwellings and a greenhouse-like common room under its new peak.  About 250 people now live on the rejuvenated block.

The transformation of the area’s grounds was even more significant. 

Through negotiation and hard work, a portion of each building’s private backyard was reclaimed to create a common shared space at the centre of the block.  Each building still retains its smaller private realm but gates and paths link it to the courtyard’s public space.

Shared space in the middle of the block reclaimed from a former jumble of private yards. In this picture alone includes fire pit, fruit trees/garden in background, bird nesting areas, brook and place to run around.

The new shared community amenities include recycling and composting facilities, fruit trees and garden plots, play areas and picnic areas, peaceful benches under shady trees and sunny grassy areas to kick a ball.

Site plan of the Kolding development. (Source: InsideFlows.org)

“Single use” is not the message here. Logs that serve as benches around a communal fire pit adjoin the playground and had kids clambering along them.  Sculpture-like structures incorporate bird nesting spaces.  The small automobile parking zone is roofed by solar panels and wisteria.

But even with all of this other nifty stuff, you can’t help but notice the water.

Some of the Kolding development’s more aquatic residents: fish in the ponds outside the Bioworks pyramid.

Rainwater from all of the buildings is collected in a central cistern and is then used to fill washing machines and flush toilets.  When not in use, this water gurgles in a cycle through an on-site brook and pond to stay fresh. Municipal water supplements the system in drier periods.

Building wastewater goes on an even more epic journey.  The dirty water flows into underground tanks where solids settle and bacteria start the decomposition process.  From here it is pumped through germ killing treatments of ultra-violet light and ozone and then into the great glass pyramid.

The bottom floor of the Bioworks pyramid is divided into a series of ponds.  As the water progresses along its journey, a hierarchy of living things feasts on its nutrients: first algae, followed by plankton, plants and then fish.

Inside Bioworks: base level plants and fish.

Standing inside the pyramid as the water bubbled around its aerators, I couldn’t smell a hint of the “waste” that had once been the start of this wastewater.  If anything, the air inside Bioworks smelled like what you might find inside a greenhouse, and for good reason.

Plants being raised by a commercial operator inside the Bioworks pyramind.

Its upper floors house tables and tables of bedding plants fed by water from the last pond downstairs.  This commercial greenhouse space is rented out and creates revenue for the community at the same time that it continues the water purification process.

Finally, the water flows into an exterior marsh area for a final cleaning and then seeps back into the groundwater.

The project isn’t perfect.  At its outset, it was planned that residents would be able to grow vegetables within Bioworks and that the cleaned water could be circulated back into toilets.  This has not happened due to health concerns.  Also not surprising is the fact that the cost to clean water in Bioworks is higher than what it would be in a larger city-sized facility.

But Kolding’s project does serve well for inspiration.  If a town of 61,000 people can create such a beautiful example of integrated water stewardship, maybe there’s hope that my own community of 300,000 (now 350,000!) might get it together enough to stop pumping sewage into the Strait of Juan de Fuca (now again the Salish Sea).  It’s this thought that I chewed on as we pedalled away from Kolding’s pyramid and onto the next leg of our journey.

2015 Update: Started in 1995, the Kolding project still appears to be going strong.  For more information, including a very detailed description of the development and Bioworks schematics see InsideFlows.org.