Fuel Farm Bund Volume Calculator

Spill requirement regime

Choose a rule, or enter a custom requirement.

Custom required volume (m³)

Used only when regime is set to custom.

Safety factor on spill volume

Applied to spill requirement before adding rainfall.

Design rainfall depth (mm)

Set to 0 if rainfall is handled by drainage.

Rainfall area basis

Choose how to compute rainfall catchment area.

Custom rain area (m²)

Used only when rainfall area basis is custom.

Bund geometry

Internal length (m)

Internal width (m)

Wall height (m)

Freeboard (m)

Reserved height not counted toward containment volume.

Internal side slope (H:1V)

Slope reduces top area; uses frustum volume.

Obstruction area (m²)

Pumps, pipe racks, supports, and similar items.

Tanks inside bund

Add each tank type and quantity. For horizontal tanks, enter length. For vertical tanks, enter height.

Tank type

Diameter (m)

Height (m) (vertical)

Length (m) (horizontal)

Quantity

Tank type

Diameter (m)

Height (m) (vertical)

Length (m) (horizontal)

Quantity

Tank type

Diameter (m)

Height (m) (vertical)

Length (m) (horizontal)

Quantity

Example data table

This example illustrates typical values. Adjust to match your site and standards.

Item	Example input	Unit	Notes
Spill regime	Max of 110% largest or 25% total	—	Often used as a conservative check.
Bund internal size	28 × 18	m	Measured clear inside the bund wall.
Wall height / freeboard	1.20 / 0.20	m	Effective height becomes 1.00 m.
Rainfall depth	25	mm	Allowance added to the required volume.
Tank set	1× (6 m dia, 10 m high) + 1× (4 m dia, 8 m high)	—	Vertical tanks plus one small horizontal tank.
Obstruction area	3	m²	Pumps and pipe supports inside bund.

Formula used

Tank volume (cylinders):

V = π × (D/2)² × H (vertical) | V = π × (D/2)² × L (horizontal)

Required spill volume (typical rules):

Vspill = 1.10 × Vlargest or 0.25 × Vtotal or max(1.10×Vlargest, 0.25×Vtotal)

Rainfall allowance:

Vrain = Acatchment × (Rain_mm / 1000)

Effective bund height:

Heff = Hwall − Freeboard

Bund geometric volume:

If slope = 0: Vbund = Abase × Heff

If slope > 0: Vbund = Heff/3 × (Abase + Atop + √(Abase×Atop))

Displacement volume:

Vdisp = (Σ FootprintArea_tanks + Aobstructions) × Heff

Available containment:

Vavail = max(0, Vbund − Vdisp)

Final check (with safety factor SF):

Vrequired = (SF × Vspill) + Vrain and PASS if Vavail ≥ Vrequired

How to use this calculator

Choose a spill regime that matches your project requirement.
Enter bund internal length, width, wall height, and freeboard.
If the bund has internal slopes, enter the H:1V ratio.
Add all tanks located inside the bund and their quantities.
Enter obstruction area for pumps, pipe racks, and supports.
Set rainfall depth and area basis to include storm allowance.
Press calculate and review PASS/FAIL and the breakdown table.
Use the export buttons to save a CSV or PDF record.

Note: Standards vary by client, jurisdiction, and fuel type. Always verify assumptions (spill rule, rainfall depth, drainage, and freeboard) against your governing design criteria.

Bund geometry

Tanks inside bund

Example data table

Formula used

How to use this calculator

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