]> 2026-04-06T04:55:23+00:00 Case study:TEST Deculverting the Texas Valley Stream 500 en Draft Deculverting County Governor of Oslo og Viken NIVA NINA Yes No Yes false No Opening the stream has had very good reviews from the local residents and on the ecological status for benthic algae and macroinvertebrates. The bank erosion measures seem to work well after installment, but were built in a period of heavy rain, causing surplus erosion that could have been avoided. If fish status is to be improved, then the downstream culvert also needs to reopen. The costs of these measures were similar to building a new culvert, but yearly maintenance costs have so far been lower, and the recreational benefits are positive. The local bicycle club also have some ownership of the area now, through their monitoring, which has resulted in their free involvement in keeping the area free of garbage. World Hertiage Site 59.979079672114,11.2416430463 Kari County Governor of Oslo og Viken Nordkvinne Deculverting,,Erosion protection,, construction of recreational facilities (trails and footbridges),,,Volunteer engagement,, Assessments of the ecological status based on nutrients, benthic algae, macroinvertebrates and fish were conducted twice, in 2017 and in 2020. The overall ecological status in 2017 and 2020 was bad due to lack of fish. This is due to a fish barrier (culvert) further down. However, macroinvertebrates increased from poor (2017) to good ecological status (2020), and benthic algae showed good status both years, thus these two organism groups had a good effect of the daylighting. Nutrients showed moderate status both years (Tot N and Tot P), which was the same as the upstream reference stretch. Embankments were set in place to reduce the risk of bank erosion after daylighting, as this could lead to negative impacts on local buildings and infrastructure. 2 years of continuous monitoring of particle runoff in the daylighted stretch was compared to similar measurements at the upstream open section, and there were no differences in particle runoff from the two stretches. To assess the recreational use of the area, the local bicycle club registered number of people using the new pathway and bench area every Saturday 10:00-14:00 from May-Oct 2017 and 2020. This showed an initial peak of users right after opening, then a slight decrease in 2017. However, the use was clearly higher in 2020, and the area was used by at least 9 people in the time registered every weekend in 2020. construction of recreational facilities (trails and footbridges) 26271 NIVA, NINA Yes No Yes Yes No change Improvement No Nutrient concentrations,No,Yes,No,Yes,Yes,No change Oxygen balance,Yes,Yes,No,Yes,Yes,Improvement Nutrient concentrations Oxygen balance Yes Complete Daylighting of a previously culverted stream in a suburban area. The culvert was old and under dimensioned, thus it had to be either exchanged with a larger culvert, or removed. Based on a cost-benefit analysis, the latter was chosen, and the land owner decided on three main goals for the daylighting: 1) improve the water quality to good ecological status, 2) reduce bank erosion after removing the culvert, 3) increase the natural recreational area within this suburban zone. The project was planned and prospected in 2015, the daylighting, flood protection and reconstruction of the riparian zone was conducted in 2016, and monitoring was conducted in 2017 and 2020. TEST Deculverting the Texas Valley Stream test deculverting the texas valley stream No Erosion protection Norway - Naturminne Texasbekken texasbekken Volunteer engagement Economic aspects Flood risk management Habitat and biodiversity Hydromorphology Monitoring Social benefits Spatial planning Water quality Urban REL2311 006-189-R Texasbekken oppstrøms Texasdalen 2021-02-02T20:23:26Z 2459248.3496065 2021-02-02T21:22:35Z 2459248.3906829 TEST Deculverting the Texas Valley Stream