I am not sure that a pebble beach is the best idea for a wildlife pond, froglets and presumably other young amphibians stick, very quickly, to hot dry concrete, they then dehydrate and die, I would be concerned that they would sure the same fate when clmbering over hot dry pebbles. I turfed around my wildlife pond. Where I put my wildlife pond there is a slight slope and I had to raise 3 sides of the pond via a soil levee on those sides. The turf covered the levees and the levees prevent run off from any significant area of ground entering the pond. Along the 4th side of the pond there is no signifcant area of ground level with of above the pond so there is no run off into the pond.
My plant pond is also raised via levees and these too have been turfed over and the arrangement doent look odd to my eye. Its also a good way of using up the digging spoil