| Code | Observation Period of Scale Readings | Gap Period of Scale Readings | Flow Observation Period | Flow Gap Period |
| 58242000 | 1957 to 2016 | 1965 to 1967; 2007 | 1957 to 2016 | 1965 to 1978; 2002 to 2007 |
| 58250000 | 1930 to 2016 | 1949 to 1952; 1965 to 1967; 1969; 1980 to 1982; 1996 to 1998; 2008 to 2010 | 1930 to 2016 | 1949 to 1952; 1965 to 1967; 1969; 1980 to 1982; 1996 to 1998; 2008 to 2010 |
| 58300000 | 1932 to 2016 | 1937 to 1940; 1949 to 1952; 1965 to 1967; 1980 to 1988; 2008 to 2010 | 1941 to 2016 | 1949 to 1952; 1965 to 1967; 1979 to 1989; 2008 to 2010 |
| 58305001 | 1941 to 2014 | 1949 to 1952; 1965 to 1967; 1970; 1979 to 1988 | 1941 to 2014 | 1949 to 1952; 1965 to 1967; 1970; 1979 to 1988 |
| 58321000 | 1922 to 1995 | No gap | 1922 to 1994 | 1949 to 1952; 1965 to 1967; 1970 to 1975 |
| 58370000 | 1998 to 2012 | 2002 to 2004; 2011; 2012 | No data | No data |
| 58380001 | 1956 to 2014 | 1972; 2006; 2013 | 1973 to 2014 | 2006; 2013 |
| 58385000 | 1998 to 2012 | 2000; 2002 to 2011 | 1998 to 2012 | 2000; 2002 to 2011 |
| 58630002 | 1923 to 2014 | No gap | 1923 to 2014 | No gap |
| 58652000 | 1998 to 2012 | 2007 to 2012 | No data | No data |
| 58795000 | 1931 to 2014 | 1949 to 1952; 1965 to 1967 | 1931 to 2014 | 1949 to 1952; 1965 to 1967 |
| 58880001 | 1925 to 2014 | 1944 to 1970; 1972; 2008 | 1973 to 2014 | 2008 |
| 58974000 | 1923 to 2014 | 1949 to 1952; 1965 to 1967 | 1923 to 2014 | 1949 to 1952; 1965 to 1967 |
| 58242000 | 1957 to 2016 | 1965 to 1967; 2007 | 1957 to 2016 | 1965 to 1978; 2002 to 2007 |