My two little Welsh Harlequins started yesterday, very exciting! It must be the change in weather that's kick-started the egg production.
As for the pond question... I sympathise, as we only have a small yard for our girls too.
We started with little trays when they were ducklings, then moved up to an inflatable paddling pool - but that was very difficult to empty. We now have a tin bath (bought for about £25) which they love - it has plenty of depth for them to splash in, and they just about fit in it side-by-side. It has a nice big rock inside and another outside, which they manage to use as steps very well.
We tried sand in the bottom, or gravel, but nothing seems to make a difference. It can be crystal clear one minute, but as soon as they get in the girls muddy it up again. We empty it, rinse it, and refill at least every week. They have a bowl of fresh water every day for their heads.
We also put some of that pipe-insulating foam around the edge to protect their feet. I've got a photo to explain what I mean, here's the link:
Hope this helps!