PittsburghTotes · RecyclingQuote
№ 015Article · Field Notes
9-minute read · weekend build

Building a 275-gallon rainwater harvester that works

Used totes make outstanding rain cisterns. Here's the build we recommend — parts, diameters, a first-flush diverter, mosquito screens, and the three lessons we've learned the hard way.

Form · Quick Quote

Skip the phone tag. Leave a note — we'll reply by email.

Response within 1 business day
Quick Quote
No phone needed
10 digits, North American format. Example: (412) 555-0173

Email reply only. No spam, no phone calls, ever.

What you can actually capture

A 1,200 sq-ft roof, in the Pittsburgh climate (38-inch average annual rainfall), will shed about 28,000 gallons of water per year. A single 275-gal tote is a buffer, not a reservoir — but the buffer is enough to smooth over the dry spells and water a large garden without touching municipal supply.

Good target: capture 4,000–8,000 gallons/year of that runoff into a single tote, with excess routed back to the storm drain or a rain garden.

Parts list

  • 1× used 275-gal IBC tote, Grade B or C (Grade C works fine here)
  • 1× 6″ screened intake insert (mosquito mesh, stainless preferred)
  • 1× first-flush diverter, 2″ diameter, with drip drain
  • 1× 3″ downspout-to-2″ adapter, gasketed
  • 1× 2″ overflow elbow with fitted cap
  • 1× brass or stainless spigot, ¾″ NPT
  • 2× cinder blocks (for a stand) — optional but helps pressure
  • UV-blocking tarp or opaque spray paint (we sell a moss-green variant)

The build

  1. Site it right. Place the tote on a level pad — two cinder blocks side-by-side work well — directly under the downspout you're tapping. Leave at least 18″ of clearance around it for maintenance access.
  2. Cut the downspout. About 30″ up from the tote top, cut the downspout and install the 3″-to-2″ adapter with the first-flush diverter directly in-line. The diverter's drain goes to a rain garden or your yard — not back to the tote.
  3. Screen the intake. Remove the 6″ blue cap on the tote and install the mosquito-mesh insert. Snap the cap back on — the mesh will self-clean most debris.
  4. Install the spigot. Drill out the 2″ ball valve or use the bulkhead fitting at the bottom. Install a ¾″ NPT brass spigot with plumber's tape.
  5. Route the overflow. Drill a 2″ overflow port about 6″ below the tote's top, on the side opposite your intake. This is where excess water exits in a heavy rain. Route it to a storm drain, rain garden, or swale.
  6. Block the UV. Either spray-paint the tote opaque or wrap it in a UV-blocking tarp. HDPE + sunlight + water = algae, and algae ruins your harvester in three months if you skip this.

Three lessons learned the hard way

  • First-flush matters. The first gallon or two off your roof carries most of the bird droppings, pollen, and roofing grit. A proper diverter keeps that out of your tote — skip it and your water will be gross.
  • Overflow is the single-point-of-failure. If the overflow plugs or freezes in winter, you'll have water backing up into your soffits. Size the overflow generously (2″ minimum) and keep it clear.
  • Don't drink it. This build is for garden and washdown use. For potable water you need a multi-stage filtration train we're not covering here.
← All articlesAsk us about your job →
Start a quote