Cutting peat is never sustainable in the sense of being replaced, so a limit means a fixed budget set before the first block is cut. A hectare of bog 2 m deep holds roughly 2,860-4,290 tonnes of fuel at 30% moisture, enough for one household for centuries but only about 6.7-10.7 years for a village of 100 households, so cut from the edges, leave the centre and plan the switch to coppice.
Part of Peat Harvesting
Setting a total peat budget from bog volume and household use, and the rules that keep the cutting within it.
The Parent’s Rules
The parent article gives these limits: never drain a bog entirely; harvest only from the edges, leaving the centre intact; replace turf caps after cutting; rotate cutting areas with 20-30 year rest cycles; and it states that a 1 ha bog with 2 m of peat holds roughly 3,000-5,000 t of fuel, enough for one household for decades if managed carefully.
Worked Example: A Bog’s Budget
Inputs: 1 ha = 10,000 m²; depth 2 m; dry matter 100-150 kg/m³ (an assumption, recalled for undisturbed bog peat; measure your own); target moisture 30% wet basis; household use 15-24 m³ cut a year (5,000-8,000 blocks of 3 L); working fraction 80% (leaving 10-20 cm of turf at the top and 10-20 cm at the base, so about 1.6 m of the 2 m is usable).
- Volume in the ground = 10,000 × 2 = 20,000 m³.
- Dry matter = 20,000 × 100 = 2,000 t to 20,000 × 150 = 3,000 t.
- At 30% moisture: 2,000 ÷ 0.7 = 2,860 t to 3,000 ÷ 0.7 = 4,290 t. The parent’s 3,000-5,000 t is of this order, a little high at its upper end.
- Usable volume = 20,000 × 0.8 = 16,000 m³.
- One household: 16,000 ÷ 24 = 670 years to 16,000 ÷ 15 = 1,070 years.
- A village of 100 households: 1,500-2,400 m³ a year, so 16,000 ÷ 2,400 = 6.7 years to 16,000 ÷ 1,500 = 10.7 years.
On these inputs the parent’s “decades” for one household understates the single-household figure by roughly an order of magnitude, and it says nothing about a settlement. The limit is how many people are cutting, not how much peat there is.
Setting A Budget
Step 1: Map the bog and its depth (Depth Assessment).
Step 2: Decide the total you will cut, in cubic metres, and the years it must last. Divide by years to get the annual cut.
Step 3: Limit the cutters. Assign cutting rights or plots by household so that use does not grow unnoticed.
Step 4: Cut edges first, in the order of the plan (Bank Management), and keep drains short.
Step 5: Start coppice now. Peat is a transitional fuel (parent); a coppice woodland takes years to reach its first cut.
Step 6: Record each season (Record Keeping).
What The Rest Cycle Does
A 20-30 year rest (parent) lets vegetation recover. At 0.5-1 mm a year it restores only about 10-30 mm of peat (Regrowth Rate), so it does not renew the fuel. Treat a rested face as recovering habitat, not as replenished supply.
Common Mistakes
- Reading a total as a yearly allowance. The volume is a one-off store.
- Letting the number of cutters grow. A village uses it up in years.
- Cutting the centre. The edges hold back the water.
Safety
Hard-used bogs are fire and drowning traps
Dry cut faces and dumped ash burn underground; cut-over ground hides deep water. Keep a clear path network and stay off smoking ground (Environmental Considerations).
What’s Next
- Learn next: Coppicing & Fuel Management — the renewable fuel to move to
- Combine with: Carbon Implications — the climate cost of the budget