Sand-filling and land reclamation: what to agree before the dredger arrives

Hydraulic sand-filling raises land by pumping a mixture of sand and water from a source — a river, lagoon or borrow area — through pipelines onto the plot, where the sand settles and the water drains away. Most disputes on these jobs come from things that were never agreed in writing. These are the points to settle first.

How the volume will be measured

Agree whether payment is by volume placed on the plot, measured by a survey before and after filling, or by another method — and who carries out the surveys. A pre-fill topographic survey of the plot is the reference everything else is measured against.

The target level and the sand quality

• The final level to be achieved, tied to a fixed benchmark.
• The type of sand acceptable for what you plan to build on it.
• What happens to silt, clay or debris that comes up with the sand.

Containment and drainage

Bund walls hold the sand on the plot while water drains off. Agree who builds and maintains them, where the discharge water goes, and how neighbouring land and drains will be protected.

Access, distance and permits

• Distance from the sand source to the plot, and the pipeline route between them.
• Access for the dredger and support boats on the waterway.
• Which permits and approvals the project needs, and who obtains them.

Settlement before building

Newly placed fill needs time and, often, compaction before it can carry structures. Agree how long the plot will be left to settle and what testing will confirm it is ready, so construction is not scheduled too early.