Case study:Teglverksdammen
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Project overview
| Status | Complete |
|---|---|
| Project web site | |
| Themes | Economic aspects, Flood risk management, Habitat and biodiversity, Hydromorphology, Monitoring, Social benefits, Spatial planning, Water quality, Urban |
| Country | Norway |
| Main contact forename | Agency of Urban Environment (temporary) |
| Main contact surname | Oslo municipality (temporary) |
| Main contact user ID | |
| Contact organisation | Oslo municipality |
| Contact organisation web site | http://www.oslo.kommune.no |
| Partner organisations | |
| Parent multi-site project |
Case_study:Reopening and restoration of the stream Hovinbekken |
| This is a parent project encompassing the following projects |
No |
Project summary
The Teglverksdammen is a reach of the stream Hovinbekken which opened in 2015. The project was initiated to improve the water quality downstream, as the downstream area (Ensje) was to be transformed from an industrialized area to a new apartment center. The Tegiverksdammen consists of a stretch of riffles and pools, followed by the major pond (called Teglverksdammen), a short river stretch (to become a wetland) and a final pond for sedimentation. After the final pond (Grensedammen), the river flows into the Ensjø area. The water in this system originates from an 800 m culvert, and part of the flow is redirected to the original culvert, to prevent overflooding of the system. The water quality is typical of urban streams, i.e. high on nutrient and organic waste input.
Monitoring surveys and results
Lessons learnt
Based on studies of colonization of macroinvertebrates the first year after opening we found that colonization has drifted from species upstream of the culvert, and not (or perhaps to a very small extent) from the other Oslo streams. (Refer to David Arnott's master thesis here)
Benthic algae the first two years after opening the streams were a mixture of diatoms (most early spring and late fall), green algae and cyanobacteria. The main pond (Tegiverksdammen) had extensive growth of filamentous green algae (Spirogyra) during the warm summer months, which also flourished after mechanical removal in July. The shallow parts of the upper stream reach also had high production of benthic cyanobacteria, which broke off and flowed massively into the main pond as brown-black lumps on the surface. Whether these are temporary conditions due to the recent opening of the facility, or simply an effect of low water flow and depth remains to be seen. (Refer here to Karoline Dahl Myrstad's Master's thesis)
Due to maintenance needs the first summer after opening, the flow of water was shut down approximately one month. During this period, the pools and ponds had still-standing water, while the riffles dried out. The result of this was a massive increase in phytoplankton biomass in the main pond (Teglverksdammen). Other than that, biodiversity did not change significantly between the first two full years after the facility opened. (Refer here to Susanna Birgitta Diana Burgess's Master's thesis)
Monitoring of water chemistry at the inlet and outlet of the system the first two summer seasons after opening showed the potential of the facility for some purification of the water, but it was partly dependent on time of year, on the water actually flowing and on the nutrient concentration of the water entering the system.
Image gallery
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Catchment and subcatchment
Site
Project background
Cost for project phases
Reasons for river restoration
Measures
MonitoringHydromorphological quality elements
Biological quality elements
Physico-chemical quality elements
Any other monitoring, e.g. social, economic
Monitoring documents
Additional documents and videos
Additional links and references
Supplementary InformationEdit Supplementary Information
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