Division 40 · outside
Rainwater tank: effective life and depreciation rate
A plastic tank is plant over 15 years; its pump has a row of its own in the Commissioner's table, water pumps for rainwater tanks, at 5 years. The price on this page is for a tank with its pump, and so are the five years worked from it, at the tank's life: no price we hold gives the pump's share, which a schedule can deduct over the pump's shorter life. A concrete tank set into the ground is capital works.
- Effective life
- 15 yrs
- DV · PC rate
- 13.33% · 6.67%
- Installed new, 2026
- $3,169
The slab under the tank, the gutters and downpipes that fill it and the plumbing from it into the house are part of the building, not of the tank. Water from it is often filtered: a water filter is a separate asset with a 15-year life, about $167 installed new.
Five years of a rainwater tank bought new
A rainwater tank costing $3,169, held for each full year, under each method. These figures take the price of a tank with its pump as one asset at the tank's 15-year life, so they include the pump, which has a row of its own in the Commissioner's table, water pumps for rainwater tanks, at 5 years: over these five years they deduct less on its share than its own life would. No price we hold gives its share, so this page cannot work it apart. At $3,169 it is above the $1,000 low-cost threshold as one asset, so it is deducted at its own rate. Under diminishing value its written-down value is $874 after nine full years, under $1,000, so from year 10 it can go into the low-value pool.
| Year | Diminishing value 13.33% | Prime cost 6.67% |
|---|---|---|
| 1 | $423 | $211 |
| 2 | $366 | $211 |
| 3 | $317 | $211 |
| 4 | $275 | $211 |
| 5 | $238 | $211 |
| Five years | $1,619 | $1,055 |
Full years of 365 days. Diminishing value and prime cost are worked by days held ÷ 365 (sections 40-72 and 40-75), so a year that includes 29 February, held throughout, claims 366/365 of what a 365-day year would on the same value. The first year is pro-rated by the days the item is held for earning rent, except in the pool, whose rates are not by the day.
What a rainwater tank cost installed, by year
- 2000$1,950
- 2010$2,348
- 2020$2,650
- 2026$3,169
The effective life of a rainwater tank fitted new in a property built in 2011 ends in 2026, while the building's own capital works deduction runs to the 2050–51 income year: see depreciation on a property built in 2011.
Price is for a tank with its pump.
Common questions
What is the effective life of a rainwater tank?
15 years, as the Commissioner of Taxation determines it for "Polyethylene" under "Rainwater tanks" in the residential property operators' table of the Income Tax Assessment (Effective Life of Depreciating Assets) Determination 2025, which most schedules use (an owner may estimate its own instead, section 40-105). Seven of the other 36 items here share it, among them a solar hot water system and a gas space heater.
What is the depreciation rate for a rainwater tank?
13.33% a year under diminishing value (200% ÷ 15), taken from what is left of the value: $423 of the $3,169 it costs installed new in the first full year, $238 in the fifth. Or 6.67% a year under prime cost (100% ÷ 15), taken from the cost: $211 in each of the first five. Both take the price of a tank with its pump at the tank's life, so they include the pump. An item first held before 10 May 2006 takes 150% ÷ 15 under diminishing value.
Can I claim a rainwater tank that came with the property?
Generally not, for an individual, a self-managed super fund or most trusts and partnerships that bought an established property at or after 7.30 pm on 9 May 2017 (section 40-27; the 2017 rules set out who it reaches and the exceptions). Such plant is still valued, at what it costs new in the year the property is bought less its age and condition: for a rainwater tank 8 years old in good condition, about $1,479 of the $3,169 new in 2026, a value whose decline can make a capital gain or loss when it is sold or scrapped. That value is worked on the price of a tank with its pump at the tank's life, and so includes the pump. For a rainwater tank bought new for the property while it is let, and never used while it was the owner's home, deductions start on the day of installation.
What does it cost to install a rainwater tank?
About $3,169 installed new in 2026, from our cost database (a tank with its pump), and about $2,348 in 2010. The other items here nearest it in price are a split-system air conditioner (about $2,751, with a 10-year life) and curtains (about $2,571, with a 6-year life).
Other items
General information only, not advice about your circumstances. Speak to a registered tax agent before relying on it.