The pond is centered at (8,-7) and its water disc is at z=0.25 with radius 7. The pond center surface projects to (0.67, 0.20) in-frame. But the sampled color there was dirt — meaning the water disc isn't visible. Possible causes: the water disc is below the ground (z=0.25 vs terrain -1.19 — no, water is ABOVE), or the water material is rendering transparent with the ground showing through (transmission weight 1 with no thickness → see-through), or the disc is being clipped.

The water at z=0.25 with the pond depression down to -1.19 means the water surface is 1.4 units ABOVE the pond bottom, but the GROUND at the pond edges (e.g., (8,-0.6) at 0.42) is ABOVE the water level 0.25. So the water disc only shows where the terrain is below 0.25 — but the disc itself is flat at 0.25 and radius 7. The pond rim (terrain at 0.3-0.4) is above water level, so water fills the depression up to 0.25. That should render fine — the water disc should be visible covering the depressed area.

Wait — the issue may be that the water disc is at z=0.25 but the terrain around it is higher, and the camera sees the water from above at an angle... Let me check if the water is actually being rendered. The sampled color 0.42,0.37,0.30 at pond center looks like the PathMat (dirt path) — the path boxes are at z = terrain+0.02. Maybe the path crosses the pond area. Let me check where the path is: path from door (-4,1.2) to shore — the path points go to x=4.2, y=-4.2 (end). That's not over the pond.

Let me look at what's actually at the pond center in the render. Let me render a region and inspect more carefully — or check the pond water in the viewport. First, check if the water disc has a material and is visible.

import bpy
pond = bpy.data.objects['PondWater']
print('materials:', [m.name if m else None for m in pond.data.materials])
print('visible', pond.visible_get())
print('hide_viewport', pond.hide_viewport, 'hide_render', pond.hide_render)
# check water material node tree
mat = bpy.data.materials.get('WaterMat')
print('water mat users', mat.users if mat else None)
if mat and mat.node_tree:
    for n in mat.node_tree.nodes:
        print(' node', n.name, n.type)
    for l in mat.node_tree.links:
        print(' link', l.from_node.name, '->', l.to_node.name)


materials: ['WaterMat']
visible True
hide_viewport False hide_render False
water mat users 1
 node Material Output OUTPUT_MATERIAL
 node Principled BSDF BSDF_PRINCIPLED
 node Noise Texture TEX_NOISE
 node Bump BUMP
 link Principled BSDF -> Material Output
 link Noise Texture -> Bump
 link Bump -> Principled BSDF