Oslo, the capital of Norway with a population of nearly 660,000, has won the European Green Capital Award for 2019 due to its commitment and actions to protect natural resources, reduce greenhouse gas emissions by 50% by 2020 (compared to 1990) and be carbon neutral by 2050.
Europe’s green (blue) capital decoupling water consumption from population growth
Oslo’s per capita water consumption has steadily declined over the past 20 years Click & Tweet! despite the city’s population increasing: over the past decade alone, Oslo’s population has increased by 110,000 while household water consumption has steadily declined from 200 liters/capita/day in 1990 to 160/liters/capita/day in 2015.
Cutting water consumption further
Oslo’s goal is to decrease daily water consumption per capita further to 130 liters by 2030 Click & Tweet! , however, this will be challenged by the city’s population projected to rise to 800,000 by 2030.
Oslo aims to achieve the 2030 target by reducing specific water consumption and therefore avoiding a considerable increase in total consumption, with a focus on reducing unaccounted for water (UFW), raising awareness and increasing water meter usage in private households.
Spotting the leaks
To reduce UFW – the current leakage rate is 31% due to frosts in winter reaching depths of 2 meters – Oslo is using smart technology such as acoustic- and correlating gprs-loggers. Furthermore, Oslo is using pipe scanners from the Norwegian oil sector to measure pipe wall thickness and detect corrosion from outside and inside the case iron water pipes. Over 2013-2015, the pipe scanner technology has been developed from scanning small pipes to scanning pipes up to 600 mm in diameter.
Restoring the pipe network
Over the past few years, Oslo has been focusing on maintaining and restoring the water pipe network, halving leakage compared to 1995 levels. Currently, the city has a minimum acceptable renewal rate of pipes set at 1% per annum, but this will be increased to 1.2% annually.
Water is valuable
To raise awareness on the need to protect the city’s precious resource, Oslo has developed the Water Is Valuable Internet-based initiative Click & Tweet! in which residents can identify their water usage. The site also offers information on how to reduce water consumption. In addition, Facebook and Twitter are used to actively inform people on how they can reduce water consumption.
Piloting household metering
Currently, all public institutions and commercial customers are required to have water meters installed, however, it is voluntary for residential customers. To reduce water consumption in private households, Oslo has allocated over EUR 200,000 towards a pre-pilot project where meters will be installed in a selected part of the city in 2016-2017.
Rather than spread its resources thinly, Oslo has taken a targeted approach to reducing water consumption in specific sectors that involves technological and social innovations.
*Robert C. Brears is the author of Urban Water Security (Wiley), and of the forthcoming titles Blue and Green Cities (Palgrave Macmillan) and The Green Economy and the Water-Energy-Food Nexus (Palgrave Macmillan). He is Founder of Mitidaption, which consults on climate change risks to business, governance and society.