Of Scotland's 78,000 miles of rivers and 135 miles of canals, nearly half have been surveyed and classed as being in a good condition. However, this was not always the case and from the 1800s many of Scotland's rivers were badly polluted due to urbanization, with efforts to clean up them up not starting till the mid 1960s. The management of Scotland's waterways is now carried out by the Scottish Environment Protection Agency who monitor water quality and ensure regulations are complied with.