World Rivers Day is a global celebration of the world's waterways held on the last Sunday of September, which this year will be the 27th.
The group writing project is to post about a river of your choice - and it can any bit of it from its source high in the mountains to the swollen estuary where it meets the sea.
It can be any river, from the little Piddle to the mighty Mississippi, the choice is yours. Just say why you've selected it, what it means to you, and why it should be celebrated.
And rumour has it that O'Docker has something already drafted to post for his all new blog - and the expectations are high about that!
I write a lot about the Thames so have already decided it;s not going to be my choice, so I'll mention a rather sad story about it now rather than next week.
A humpback whale was recently spotted in the Thames, but alas the excitement was short lived as sadly it died last weekend near the Dartford Bridge.
Maybe a reminder that we are messing up our planet big time and its time to take care of it a lot better.
More on the humpback whale story here.