Terrain Clone

I have been trying to clone my project for an system that I wanted to implement, but the problem is it turns out looking like this: Why is it ending up being this clunky?

Here is my code for the mesh generation:

             int ChunkWidth = 250;
             int ChunkCount = (int)Chunk.terrainData.size.x / ChunkWidth;
             //Chunk is my terrain instance.
             int hw = Chunk.terrainData.heightmapWidth;
             float[,] heightmap = Chunk.terrainData.GetHeights(0,0,aw,aw);
             Vector2 uvScale = new Vector2(1.0f / (hw- 1), 1.0f / (hw- 1));
 
             for (int cx = 0; cx < ChunkCount; cx++)
             {
                 for (int cy = 0; cy < ChunkCount; cy++)
                 {
                     GameObject water = new GameObject();
                     Vector3 p = new Vector3(cx * ChunkWidth, -1f, cy * ChunkWidth);
                     water.transform.position = p;
                     water.AddComponent<MeshRenderer>();
                     Mesh w = new Mesh();
                     MeshFilter mf = water.AddComponent<MeshFilter>();
 
                     Vector3[] vertices = new Vector3[ChunkWidth * ChunkWidth];
                     Vector2[] UV = new Vector2[ChunkWidth * ChunkWidth];
                     int[] triangles = new int[ChunkWidth * ChunkWidth * 6];
 
                     for (int y = (int)p.z; y < p.z + ChunkWidth; y++)
                     {
                         for (int x = (int)p.x; x < p.x + ChunkWidth; x++)
                         {
                             Vector2 curPos = new Vector2((x / Chunk.terrainData.size.x) * (hw-1), (y / Chunk.terrainData.size.z) * (hw- 1));
                             vertices[(y - Mathf.RoundToInt(p.z)) * ChunkWidth + (x - Mathf.RoundToInt(p.x))] = new Vector3((x - p.x), heightmap[Mathf.RoundToInt(curPos.y), Mathf.RoundToInt(curPos.x)] * Chunk.terrainData.size.y, (y - p.z));
                             UV[(y - (int)p.z) * ChunkWidth + (x - (int)p.x)] = Vector2.Scale(new Vector2(x, y), uvScale);
                         }
                     }
 
                     int index = 0;
 
                     for (int y = 0; y < ChunkWidth - 1; y++)
                     {
                         for (int x = 0; x < ChunkWidth - 1; x++)
                         {
                             triangles[index] = (y * ChunkWidth) + x;
                             triangles[index + 1] = ((y + 1) * ChunkWidth) + x;
                             triangles[index + 2] = ((y + 1) * ChunkWidth) + x + 1;
 
                             triangles[index + 3] = (y * ChunkWidth) + x;
                             triangles[index + 4] = ((y + 1) * ChunkWidth) + x + 1;
                             triangles[index + 5] = (y * ChunkWidth) + x + 1;
                             index += 6;
                         }
                     }
 
                     w.vertices = vertices;
                     w.uv = UV;
                     w.triangles = triangles;
                     w.RecalculateNormals();
                     w.Optimize();
                     mf.mesh = w;
 
                     yield return null;
                 }
             }

EDIT: Another screenshot with wireframe turned on, where you can clearly see that the problem is the difference between the heightmap width and the actual terrain size. How can I make some interpolation to fix this?