Step 1: Understanding Soil Classification.
- SW (sand and gravel) has the highest hydraulic conductivity.
- SP (sand) is coarser than ML (silt) and has higher conductivity.
- ML (silt) has lower hydraulic conductivity than SP.
- CH (clay) has the lowest hydraulic conductivity due to its fine particles.
Step 2: Conclusion.
The correct order of hydraulic conductivity is: SW > SP > ML > CH.
Final Answer: \[ \boxed{\text{SW, SP, ML, CH}} \]

| Point | Staff Readings Back side | Staff Readings Fore side | Remarks |
|---|---|---|---|
| P | -2.050 | - | 200.000 |
| Q | 1.050 | 0.95 | Change Point |
| R | - | -1.655 | - |