ULL</code> if using <code>station_number</code> argument.</p></dd>


<dt>dates</dt>
<dd><p>Name of column in <code>data</code> that contains dates formatted YYYY-MM-DD. Only required if dates column name is not 
'Date' (default). Leave blank or set to <code>NULL</code> if using <code>station_number</code> argument.</p></dd>


<dt>values</dt>
<dd><p>Name of column in <code>data</code> that contains numeric flow values, in units of cubic metres per second.
Only required if values column name is not 'Value' (d