# Highway 63 Gravel Pit 2.0 — preliminary pile volumes

October 1 DSM; calculation prepared October 7, 2026. User confirmed revised footprints for piles 1–6.

| Pile | Estimated volume (m³) | Footprint (m²) |
|---|---:|---:|
| 1 | 5,420 | 2,662 |
| 2 | 700 | 753 |
| 3 | 810 | 564 |
| 4 | 310 | 1,464 |
| 5 | 3,650 | 2,187 |
| 6 | 3,510 | 2,470 |

Combined estimate: approximately 14,400 m³.

## Method and limitations

Positive DSM height above robust least-squares sloping plane fitted to exterior ring 0.4–2.0 m from confirmed footprint. No surveyed pre-stockpile ground. DSM 20 cm, encoded centimetres. Base ±0.25 m is sensitivity only, not accuracy interval.

Footprints were drawn visually on the orthophoto, revised following the owner’s corrections, and confirmed by the owner. Each DSM cell centre inside each footprint was tested. Volume is the sum of positive height above the fitted base multiplied by cell area; cells below the plane contribute zero. All six footprints have 100% valid DSM coverage. This does not establish survey accuracy or correct hidden ground.

The base is an inferred sloping plane, not a measured pre-stockpile surface. Particularly for piles 5 and 6, adjacent ground does not fit a single plane well (retained fitting residual RMS approximately 2.01 m and 1.19 m). Results may include natural terrain and should be treated as screening estimates, not verified inventory or billing quantities. Source vertical datum and positional accuracy were not independently verified.

## Base sensitivity

Changing the exterior sampling band from 1 m to 5 m produced the following estimates; these are methodological comparisons, not confidence intervals:

| Pile | 1 m band (m³) | 2 m band, reported (m³) | 5 m band (m³) |
|---|---:|---:|---:|
| 1 | 5,371 | 5,423 | 5,506 |
| 2 | 601 | 701 | 986 |
| 3 | 778 | 805 | 858 |
| 4 | 348 | 307 | 312 |
| 5 | 3,492 | 3,649 | 4,287 |
| 6 | 3,127 | 3,511 | 4,413 |

For defensible inventory quantities, verify the toes and recover or measure an appropriate ground surface beneath each pile. The CSV includes a separate ±0.25 m base-shift sensitivity, which is not an accuracy bound.