Miljøoppfølging E136 Tresfjordbrua. Sluttrapport

The Norwegian Public Roads Administration (Statens Vegvesen) has in 2015 compledet a new bridge over the fjord Tresfjord in Møre og Romsdal county. The bridge is approx. 1.2 km long with an 850 m long embankment from Vikebukt. Construction work started in 2012, and Norwegian Institute for Water Research (NIVA) has conducted several surveys of the fjord (2010 and 2011) as a basis to monitor the environment and with follow up surveys (2016 and 2017) after the bridge has been completed. This report presents the results from the after surveys and discuss these in relation to the before results. The discussion and conclusions are presented in a short section in the beginning of the present report, followed by comprehensive presentations of data from the different topics of the surveys. Overall assessment: Construction of a bridge with the embankment approx. 800 m from Vikebukt has led to a general increase in current speed as the same water masses driven by the tides shall now pass a narrower opening of the fjord. None of the results indicate however that the bridge will have major consequences on the physical, chemical or biological environment in Tresfjorden.