Best plants which use a lot of water

[crappy]

Hi folks,

I have a septic system which discharges to the bottom of my garden into a soak-away.
The ground is quite damp as a result. During the rainy times it pools too.

What can I plant there which uses a lot of water? It's a far and obscure part of the garden so not worried about appearance.

Does red robin hedging work well?

 

[Why Not Indeed]

Willow.
River birch. Looks great all year - bark is striking in winter.

 

[Stivino]

Reeds?

 

[Mottie]

Weeping willow.