May 26, 2011

Invasion by sea

Here’s an unusual sight …

Tidally speaking.

Looking upstream at the Faka Union Canal, May 2011

What looks like a reflection pool is actually water – saltwater that is – rising up and going over the Faka Union weir in the wrong direction, as in “upstream.” More commonly we are used to seeing freshwater flowing downstream over the weir towards the coast.

In fact, that’s part of the problem too. Over the past decades the canal network that feeds the weir has robbed the adjacent wetlands of their waters, sending it too fast south, down the canal, and over the weir where it gets lost to tide.

High tide sends saltwater upstream (left) over the Faka Union Weir
Not to worry:

Efforts are underway (click here to find out more) to restore the freshwater wetlands upstream of the weir which, when complete, will pulse less freshwater to tide …

And hopefully help keep that saltwater back.


Janie said...

Once mankind starts "managing" water, it becomes a constant battle to keep the various forces in balance. We see the same thing here, with dams and canals interrupting the natural flow and overflow.

jabblog said...

That's extraordinary!