Through working in partnership with the Scottish Government and Regulators we have been able to better target investment to deliver the best outcomes for customers and the environment. For example, science and evidence led decision making has underpinned our approach to improving Glasgow's wastewater systems, and also supported innovative approaches such as sustainable land management for drinking water.
We have created tools to enable carbon assessments within investment planning, to help drive thinking and to contribute to Scotland's goals. Development of our renewables portfolio, particularly from hydro generation is an example of where we are trying to utilise opportunities within our asset base to be more sustainable. Indeed it is encouraging that, despite continued drive for service and quality, in recent years we have been able to reduce our carbon emissions by around 15%.
There are many challenges in the coming years -- securing the gains made to date, addressing future environmental and quality issues, dealing with climate change, and ensuring we meet customer expectations on service and affordability. We will continue to work in partnership with our stakeholders to make the right choices and help us become more sustainable.