The Sky Well
The master rainwater harvesting rig — the first and highest-priority water source for any Ark. Captures from every roof surface, diverts the dirty first-flush, stores in a network of tanks sized for the property's annual needs, and distributes with gravity priority so rain is used before any pumped or well water.
② The Manifest
The parts list. Cores are what you actually need; “if you prefer” opens cheaper, local, or heritage swaps — never budget fallbacks, just other good ways.
Every square foot counts. Metal sheds cleaner water faster.
if you prefer… (1)
Critical for quality. Must be sized correctly and emptied after each event.
if you prefer… (1)
Slope 1/4" per foot. Bury below frost line.
Link with overflow from highest to next. Dark or buried to control algae.
if you prefer… (1)
Prevents stirring settled sediment.
Route final overflow to landscape or Deep Reserve.
The philosophical core: rain first, always.
if you prefer… (1)
③ The Sequence
④ Reference Tables
Catchment Sizing Calculator
Annual capture estimate by roof area and rainfall
| Roof area (sq ft) | 10" rainfall/yr | 20" rainfall/yr | 30" rainfall/yr | 40" rainfall/yr | 60" rainfall/yr |
|---|---|---|---|---|---|
| 500 | ~2,600 gal | ~5,300 gal | ~7,900 gal | ~10,500 gal | ~15,800 gal |
| 1,000 | ~5,300 gal | ~10,500 gal | ~15,800 gal | ~21,100 gal | ~31,600 gal |
| 1,500 | ~7,900 gal | ~15,800 gal | ~23,700 gal | ~31,600 gal | ~47,400 gal |
| 2,000 | ~10,500 gal | ~21,100 gal | ~31,600 gal | ~42,200 gal | ~63,200 gal |
| 3,000 | ~15,800 gal | ~31,600 gal | ~47,400 gal | ~63,200 gal | ~94,800 gal |
| 5,000 | ~26,400 gal | ~52,700 gal | ~79,000 gal | ~105,400 gal | ~158,000 gal |
Tank Selection Comparison
Capacity, cost, and lifespan tradeoffs
| Type | Capacity range | Cost (per gallon) | Lifespan | Best for |
|---|---|---|---|---|
| 55-gal barrel (food-grade) | 55 gal each, networkable | $0.40–1.00/gal | 10–15 yrs | Entry / supplemental garden |
| IBC tote (used, food-grade) | 275 gal each | $0.30–0.70/gal | 10–20 yrs | Modular small-medium scale |
| Vertical poly tank | 500–10,000 gal | $0.25–0.40/gal | 20–30 yrs | Standard household systems |
| Slimline poly tank | 200–2,000 gal | $0.40–0.60/gal | 20–30 yrs | Tight footprints, against walls |
| Concrete cistern (poured) | 5,000–50,000+ gal | $0.50–1.50/gal installed | 50+ yrs | Long-term, large-scale, buried |
| Buried plastic cistern | 1,000–15,000 gal | $1.00–2.00/gal installed | 30–50 yrs | Freeze-zones, hidden install |
| Steel galvanized tank | 1,000–25,000 gal | $0.40–0.80/gal | 20–40 yrs | Agricultural / livestock scale |
First-Flush Diverter Sizing
How much to discard per event
| Roof catchment per downspout (sq ft) | First-flush volume (light rule) | First-flush volume (strict rule) |
|---|---|---|
| 100 sq ft | 4 gal (0.04 gal/sq ft) | 20 gal (0.2 gal/sq ft) |
| 250 sq ft | 10 gal | 50 gal |
| 500 sq ft | 20 gal | 100 gal |
| 1,000 sq ft | 40 gal | 200 gal |
| 1,500 sq ft | 60 gal | 300 gal |
| 2,000 sq ft | 80 gal | 400 gal |
Use-Case Treatment Matrix
Match treatment level to use
| Use | First-flush? | Sediment filter? | Carbon filter? | UV? |
|---|---|---|---|---|
| Drip irrigation (perennials) | YES | Optional | No | No |
| Drip irrigation (annuals/edibles) | YES | YES | No | No |
| Hose / overhead irrigation | YES | YES | No | No |
| Livestock drinking water | YES | YES | Optional | No |
| Washing harvested produce | YES | YES | YES | Recommended |
| Canning / preservation water | YES | YES | YES | YES |
| Household emergency potable | YES | YES | YES | YES + boil if doubt |
| Walipini / greenhouse interior beds | YES | Optional | No | No |
⑤ The Echo
Why rainwater is the sovereign baseline. Physics of collection, importance of first-flush, and why gravity systems are more resilient.
The core idea: rain water is used first, always. How the distribution logic makes this automatic or obvious.
Roof water after three dry weeks is not drinking water yet. Dust, bird droppings, and whatever the shingles shed ride the first rush off the eaves. The Sky Well's first-flush diverter is the honesty gate: that dirty slug gets shunted aside so the clean volume behind it can fill the tanks. Skip the diverter and you store the roof's worst day in your best barrel. Gravity does the ranking. Rain fills high tanks first; you draw from them before the pump ever spins for well water. That priority is not a software rule. It is pipe slope and valve placement. The Sequence spends time on gutters, leaf screens, and manifold layout because a clever pump cannot fix a dirty catchment. What changes in the household is how rain feels. A storm stops being "weather" and starts being inventory. You glance at tank levels the way other people glance at fuel gauges. The free water only stays free if the hardware enforces cleanliness and order when nobody is watching the sky.
⑥ Feeds
How this rig connects to the rest of the Ark.
- → material The Walipini Rainwater → irrigation
- → material The Guild Ring Rainwater → irrigation
- → material The Porch Garden Rainwater → irrigation
- ← information The Sentry Cistern water level monitoring
- → material The Window Farm Rainwater (or filtered water) from The Sky Well is the preferred jar fill source — naturally lower pH and chlorine-free compared to municipal tap water, reducing the need for pH Down at this scale
- → material The Rack Farm Water source for misting and bottom-watering — microgreens use very little water, just a few cups per tray per day; rainwater or filtered preferred
- → material The Shelf Stack Rainwater is the ideal source — naturally low pH (5.5–6.5 in clean rain), chlorine-free, and free; a 10-gal tote uses ~8 gal per cycle, so a Sky Well easily supports a 4-tote rig
- ← material The Walipini Rainwater collected off the angled glazing surface. A 12×20 ft Walipini with 30°+ glazing slope sheds ~150 sq ft of catchment. The Walipini is one of the two largest contributors to Sky Well capacity (along with house roof) — pipes directly to Sky Well rain barrels or cistern via the gutter / downspout system.
- → material Field Plot Stored rainwater for Field Plot establishment-year irrigation and drought-window supplemental watering. A mature Field Plot rarely needs irrigation past year 2; year-1 plots and drought-prone climates depend heavily on it. Drip lines from Sky Well manifold to the Three Sisters block and grain blocks.
- → material The Coop Clean rainwater for chicken drinkers. A 6-hen flock consumes ~1–2 gallons of drinking water per day — well within Sky Well capacity in any rainfall climate. Rainwater is preferred over chlorinated municipal water (chlorine disrupts gut microbiome) and over hard well water (mineral buildup in nipple drinkers).
- → material The Paddock Clean rainwater for goat / sheep drinkers and paddock troughs. Ruminants consume 2–5 gallons per animal per day; a 4-goat herd uses ~10–20 gal/day. Rainwater is the canonical choice — no chlorine, no excess minerals, no microplastics from municipal supply.
- → material The Smokehouse Clean rainwater (post-sediment + carbon filter) for corn nixtamalization, brine preparation, and produce washing. Avoids chlorine taint that municipal water leaves in masa and pickles. A 25 lb batch of nixtamalized corn uses ~5 gallons of cooking water — easily sourced from Sky Well storage.
- → material The Preserve Clean rainwater (post-sediment + carbon + UV filter for canning-safe water) for water-bath canning, pressure canning, brine preparation, and lacto-ferment starters. The Preserve uses 5–15 gallons per canning session; Sky Well supplies sustainably without depending on municipal supply.
⑧ Go Deeper
ManyArks endorses no single source — these are starting points that fit the Ark philosophy. In a Vault bundle, these external links require the clearnet.
Concept
What is this and why does it work?
Build
How do I build one?
Building a rainwater harvesting system DIY
First-flush diverter construction
Gutter installation and sizing for rainwater
Troubleshoot
Mine isn''t working
Adapt
How do I modify this for my situation?
well/sky-well
Offline? Same path on any Ark Mirror.