Thank you for the supportive comments on Part One, please check out that post if you have just landed here.  In this one I will deal with making the pond(s).

After I'd mixed the gunge to base the buildings I made a much smoother version consisting of just acrylic paint, PVA and powder filler mixed to a consistency of thick, pourable yoghurt. I had designed the bases of the ponds (there were two within my map boundary) to have a slight dip and items to create a border.

Main pond just outside the North gate freshly filled with chocolate coloured "yoghurt mix"

A different view shows it had not settled to a level surface but reflects the light like mud - not yet what I wanted

While still wet I glued miniature "reeds" round the border and a couple within. these were made from a  combination of small pieces of rubber back doormat and some marsh pieces I made ages ago with sisal string.

This view shows the main pond and also another at the roadside nearest the camera. I treated them both the same way.

While that was drying, and it takes some time,  you can see below I was completing the "gunge" for surrounding grassy banks and the muddy road

When completely dry I used some of the "swirls' as inspiration for painting different effects of water in the muddy pond - being lighter near the edges and the reeds where it would be shallower. I'm now cutting a sheet of thin clear plastic to fit the shape, including a cut-out for the single reed clump, this is glued in place with clear-drying adhesive

Above and below: Applying Winsor and Newton acrylic Structure Gel with an old brush I filled up the edges and blended in the base of the free-standing reeds. Then I applied small dabs of the gel in rough lines as if a breeze was whipping up the water slightly. I think this is far more interesting than just the plain plastic card surface, or even gloss varnish.

A closer view reflecting the light to see the ripples better. There are other acrylic gels  and pastes besides this but I've not tried any of them yet.