A doer-upper?

I have spent the afternoon doing up my 'nursery' pond. When we moved here 3 years ago I just dug a hole and lined it with some left over liner just to keep a few plants alive until I built the proper one. About a year ago it developed a slow leak and today I decided it was time to see what could be done with it. I had some more left over liner from the big pond so I took the old one out, made it a little larger (don't tell MrRR) , found some old carpet and the laid the new liner.. I was going to start filling it but as it is due to rain tonight (when isn't it?) I will leave  it to Mother Nature.