Field drainage cost: why farm schemes are priced per hectare

Why there is no headline figure

• Drain spacing is designed, not standard: heavy land needs closer spacing than free-draining land, and spacing multiplies total pipe metres per hectare several times over.
• The outfall can dominate: a scheme that gravity-drains to a maintained ditch is one price; one needing a new main, a pumped outfall, or ditch work is another.
• Existing drains change the job: many fields have old clay tile or mole-drained systems; renewing, connecting to, or working around them all cost differently.
• Machinery and season: trenchers work fast in the right conditions; wet-season work costs more and damages the very structure you're paying to fix.

How a proper scheme gets priced

1. The contractor walks the land, looks at soil, existing drains and the outfall, often with old drainage maps where they exist.
2. A layout is designed: main drains, laterals, spacing, and any ditch or outfall work, and priced per scheme, commonly expressed per hectare for comparison.
3. The work is scheduled for ground conditions, not the calendar; a good contractor will refuse to trench land that's too wet, and that refusal is worth having.

The paperwork side

Field drainage frequently interacts with watercourses: outfalls discharge to ditches, and ditches connect to streams. If your land adjoins a watercourse you have riparian responsibilities for it (gov.uk, owning a watercourse), and works in an ordinary watercourse, culverting or obstructing it, need consent from the lead local flood authority or internal drainage board under the Land Drainage Act 1991. See the consent guide before any ditch is touched.

Grant funding for farm drainage and water management comes and goes with scheme rounds; check what is currently open before pricing a scheme, and tell the contractor if a grant deadline is driving the timetable. Get contractors quoting who actually walk the land first.