Drainage advice for pen

[yarrowhouse]

In a heavy rain, our pen floods some. It slopes slightly towards one side, but we installed 2x8 all around the base of the pen for security. I attempted to provide drainage by digging 18 inches down under the 2x8 and filled with river rock... This worked for the first several months but has now completely clogged with clay/straw/presumably duck poop.

Looking for suggestions on improving the drainage, thank you!

Including a few pictures and duck tax as well!

 

[Jenbirdee]

Pretty ducks! I have similar problems in certain spots of the duck yard. The fun never ends. I end up poking holes through for water to escape. Adding more gravel helps sometimes. Good luck