Products · water capture
Rainwater harvesting kits from totes with another life in them
A retired IBC tote is an inexpensive 275 gallons of water storage, and rain is free water. Put the two together with the right diverter and screen and a single downspout can irrigate a large garden.
Request a rainwater kit quote
Tell us your roof area, number of downspouts and whether the water touches edible crops. A partner supplier follows up.
Kit options and what they include
| Kit | Includes | Good for |
|---|---|---|
| Starter | Rain-grade 275 gal tote, leaf screen, 2 in → hose adapter, overflow elbow | One downspout, garden beds |
| Standard | Starter plus first-flush diverter, tap kit, steel stand | Gravity drip irrigation |
| Linked pair | Two totes, linking manifold, balanced overflow, screens and diverter | 550 gal buffer, greenhouse |
| Multi-tank bank | Four to six totes, manifold set, trunk line, float valve, pump-ready outlet | Market garden, non-potable livestock water |
| Blackout upgrade | Black bottle or insulated UV jacket per tote | Algae and freeze control |
| Winterising | Drain-down valve, jacket, heat-trace ready | Cold-climate sites |
Kit contents vary by partner supplier; pricing is by quote. Some states regulate rainwater collection volumes, so check current local rules before building a large bank.
Sizing a system without guessing
The arithmetic is simple and worth doing before you buy anything.
Catchment yield (gallons) = roof footprint in sq ft × rainfall in inches × 0.623 × 0.85 efficiency.
A 1,200 sq ft roof in an area with about 50 inches of rain a year theoretically yields around 31,700 gallons annually. You will not capture all of it: storage, not rainfall, is usually the limit. Two linked totes give you 550 gallons of buffer that refills many times over a season.
The three components people skip, and regret
- First-flush diverter. The first few gallons off a roof carry bird droppings, grit, pollen and shingle granules. A diverter dumps that and then fills the tote. Without one the bottle silts up and smells.
- Leaf screen at the inlet. Inexpensive, prevents the diverter from clogging, and keeps mosquitoes out. Fit a fine mesh under the 6 inch lid rather than relying on gutter guards alone.
- A real overflow. When the tote fills, water must leave in a controlled direction, away from the foundation. An overflow elbow and a short length of pipe prevents the one failure mode that actually damages buildings.
Installing a two-tote system
- 01
Build a level base
Water weighs about 8.34 lb per gallon: a full 275 gallon tote is roughly 2,300 lb of water plus the tote on a 48 × 40 in footprint. Use compacted gravel, solid blocks or a steel stand, never bare soil or hollow blocks on their side.
- 02
Cut the downspout and fit the diverter
Mount the first-flush chamber at a height you can service, with its drain aimed away from the building.
- 03
Screen the inlet
Fine mesh under the 6 inch lid, secured so it cannot sag into the water.
- 04
Link the totes
Bottom-to-bottom with a 2 inch manifold so both fill and draw evenly, and tie the overflows together so the second tote takes the surplus.
- 05
Fit the outlet
2 inch valve with a hose adapter, or a tap kit at a comfortable height. Add a short riser if you plan to run a drip line: drip emitters want a little head pressure.
- 06
Shade it and winterise it
A black bottle, jacket or simple plywood shroud stops algae. Before a hard freeze, drain down and open the valve.
Is rainwater in an IBC tote safe for vegetables?
Collected rainwater is widely used for soil irrigation. The variables are the roof material (avoid treated wood shakes and old asphalt with heavy granule loss) and the tote history.
Ask the supplier for a bottle with a documented benign prior content, and for edible-crop irrigation consider a food-history or rebottled unit. Never irrigate edible crops from a tote that held a pesticide, solvent or unknown chemical, no matter how many times it has been rinsed.
Questions people actually ask
How much water can I collect from one inch of rain?
About 0.53 gallons per square foot of roof at 85% efficiency. A 2,700 sq ft roof yields roughly 1,430 gallons per inch, a little over five totes.
Will the water go green?
Only if light reaches it. Use a black bottle, a UV jacket or a shroud, and keep the lid screened and closed. Clear bottles in full sun can bloom within weeks.
Can I raise rain totes to get pressure?
You can, on a properly engineered steel stand, but a full tote at height is a serious structural load. Many growers get better results from a small pump.
Do the totes freeze?
A full tote usually survives light frost; a hard freeze can split the bottle at the boss. Drain down, open the valve, and jacket the unit if it must stay outdoors.
What a roof can deliver, by annual rainfall
Theoretical annual capture at 85% collection efficiency, for four roof sizes. Look up your own area’s average annual rainfall and read across.
| Annual rain | 800 sq ft | 1,500 sq ft | 2,700 sq ft | 5,000 sq ft |
|---|---|---|---|---|
| 10 in | 4,240 | 7,940 | 14,300 | 26,480 |
| 20 in | 8,470 | 15,890 | 28,600 | 52,960 |
| 30 in | 12,710 | 23,830 | 42,890 | 79,430 |
| 40 in | 16,950 | 31,770 | 57,190 | 105,910 |
| 50 in | 21,180 | 39,720 | 71,490 | 132,390 |
These are theoretical yields, not capture. Storage is usually the limiting factor: with a few hundred gallons of tank you capture a fraction of the annual total but refill the bank many times across a season. Some states regulate rainwater collection, so check current local rules before building a large bank.
Building the base, which is the part that most often goes wrong
A full 275 gallon tote weighs well over a ton on a 48 × 40 in footprint.
- 01
Work out the real load
Gallons × 8.345 + tare. Two full linked totes are close to 5,000 lb; four are close to 10,000 lb.
- 02
Excavate and compact
Remove topsoil, lay compacted crushed stone or road base, and level it properly. Topsoil settles unevenly and a tilted tote stresses the pallet.
- 03
Or build a slab
For banks of three or more, a reinforced concrete slab is the durable answer.
- 04
Never use hollow blocks on their side
Concrete masonry units are strong in one direction only, and on their side under a full tote they can fail without warning.
- 05
Leave working room
Space around each tote for valve access, screening and the day you need to swap one out.
- 06
Plan the overflow path before you fill anything
Water will leave the tank at some point. Decide where it goes now, away from foundations and away from anything that will erode.
Water quality: what is in roof runoff, and what to do about it
Harvested rainwater is not distilled water. What it carries determines how you screen, divert and use it.
First flush
The first few gallons off a roof carry much of the accumulated particulate: grit, pollen, bird droppings, insect debris and, on asphalt shingles, granule loss. A first-flush diverter dumps that volume before the tank fills.
Organic load
Leaves and needles that get past a screen decompose in the tank, consume oxygen, and produce the smell people associate with rain barrels. Screening the inlet is easier than cleaning a tank.
Roof material effects
- Metal roofs: generally the cleanest runoff.
- Asphalt shingle: acceptable for irrigation; granule loss increases sediment.
- Treated timber shakes: avoid for edible-crop irrigation because of the preservatives.
- Copper or zinc flashing: can leach metals that are toxic to fish. Relevant for aquaponics.
- Moss-treated roofs: zinc-based moss treatments make runoff unsuitable for edible crops.
Biology
Warm water plus light plus nutrients equals algae. Block the light with a black bottle, jacket or shroud and the problem largely does not arise.
Not drinking water
None of this makes the water potable. Potable supply needs a never-filled bottle, a potable-rated gasket, a sealed system and appropriate treatment. Check current regulations.
Rainwater questions
How long does harvested rainwater keep?
In a dark, screened, sealed tank, a long time for irrigation purposes: light and organic load cause problems, not time. In a clear tank in the sun, expect algae.
Can I connect a rain tote to my house plumbing?
Not without backflow prevention and, in many jurisdictions, a permit. Talk to a licensed plumber and check local rules.
Do I need a pump?
For drip and flood irrigation, often not: gravity gives about 0.43 psi per foot of elevation. For sprinklers or long runs, usually yes.
What size first-flush diverter?
A common rule of thumb is about 0.5 gallons per 100 square feet of roof, so a 1,500 sq ft roof wants roughly 7–8 gallons of first-flush chamber.
Can I link totes of different sizes?
Yes, bottom-to-bottom, and they will equalise. Tie the overflows together and take your draw from the largest unit.
Irrigation demand: how much water your growing area needs
Sizing from the demand side rather than the supply side, which is the calculation most people skip.
| Growing area | Crop type | Weekly need | Totes to cover a 2-week dry spell |
|---|---|---|---|
| 200 sq ft raised beds | Vegetables | ~125 gal | 1 |
| 500 sq ft raised beds | Vegetables | ~310 gal | 2–3 |
| 1,000 sq ft intensive | Salad and greens | ~620 gal | 4–5 |
| 500 sq ft greenhouse | Tomatoes, peppers | ~450 gal | 3–4 |
| 100 sq ft container garden | Mixed | ~90 gal | 1 |
Actual demand varies with climate, soil and season. Beyond about ten totes the arithmetic starts favouring a larger tank or a pond: tote banks work well from one to roughly ten units and become awkward above that, with too many connections and too much to winterise.
A two-tote system, step by step
A common build, in the order the work actually happens.
- 01
Mark and prepare the base
Two totes side by side need a level pad of roughly 9 × 4 feet. Remove topsoil, lay compacted crushed stone, and check level in both directions with a long board.
- 02
Position the totes before plumbing anything
Valves facing the same way, working room at the outlet end, cages square to each other.
- 03
Link bottom-to-bottom
2 inch manifold between the two outlets with an isolation valve at each tote and a tee for the trunk line.
- 04
Cut the downspout and fit the diverter
At a height you can reach to service, with the first-flush drain aimed away from the building.
- 05
Run the inlet to both totes
A tee above the lids, with fine mesh screens under each lid. Do not seal the lids airtight: they need to breathe as the level changes.
- 06
Tie the overflows
From the first tote to the second, then one controlled discharge pipe leading well away from foundations.
- 07
Fit the draw-off
Tap or hose adapter on the trunk line, with a shut-off you can reach.
- 08
Shroud or jacket
Whatever blocks the light, such as plywood, jackets or shade cloth, keeps algae from starting.
More rainwater questions
Can I use well water in the same system?
Yes, with a float valve to top up from the well when rainfall is short. Keep an air gap between the well outlet and the tank water level: a submerged inlet is a cross-connection.
Do I need a permit?
Rules vary by state and locality. Check current local rules, especially if you are building a raised stand, connecting to a building’s plumbing, or storing large volumes.
How do I stop the totes moving when empty?
Empty totes are light enough to move in high wind. Strap them to a post or each other, or keep some water in them if freezing is not a risk.
Can I paint the totes?
The cage, yes; the bottle preferably not. Paint flakes, hides the level and makes the unit harder to resell. A jacket or shroud gives the same UV protection and comes off.
Reuse first, then recycle.