hello

[Craig58]

Depends on what type pond you have. Is this a liner pond? Concrete? Are the pipe holes earthen? PVC? Metal?

If they are pipes, end caps can be glues or threaded on. If just a hole in the wall, they can be filled with concrete. What little will be exposed to the pond will be insignificant.

Depending on the size of the pond it might be hard to have natural pond without some filtration or air bubbling system unless you have a constant way of replacing some water on daily basis.

You still haven't given us a good description of the pond.

Size?
Gallons?
Construction type?
Depth?
Watefall systems?

It could be as easy as sealing the pipe holes, adding sometype of bubbler or small fountain to keep the water moving and adding the right combination of plants.

On the other hand.. it could get really complicated!!

Craig

 

[Big Lou]

What I was going to advice has already been very well written by Craig.

 

[capewind]

Welcome!

In addition to the above that has already been asked, pictures are helpful, as well as understanding your goals. A water feature can be as simple or difficult as you want. You can do an amazing amount of things with a 5 gallon bucket of water, and if you have more room than that... well... LOTS of options!