Simplify the following text for a Grade 6 native English-speaking person.
Original: In dry years , the Lachlan can have periods of zero flow of over a year ( for example from April 1944 to April 1945 ) , which is a complete contrast to the Murray and Murrumbidgee which have not been known to cease to flow since European settlement .
Simplified: In dry years , for example April 1944 to April 1945 , the Lachlan may have no water flowing in it at all .