Nguyen household, Alice Springs: specialist findings
Release B for the Alice Springs home: what a twelve-month measurement year found, the specialists' implications, and the data as CSV. Synthetic case data, handed over in week 7.
Synthetic case data. This is a generated measurement year, produced by the course's model to be consistent with the Alice Springs home. It is not a measurement and no instrument recorded it. It stands in for the year the story says passed between week 7 and Assignment 2, and it is identical for every student who took this home, whatever their Assignment 1said.
Memo
- Dr Mara Quinlan — water systems and hydraulics
- Tomasz Ferreira — soils and horticulture
- Aisha Rahman — monitoring, data quality and records
The specialists report conditions and what follows from them. They do not choose the system. That is your recommendation to make inAssignment 2.
What the year found
| Rain at the site | 297 mm | long-term mean 284 mm |
|---|---|---|
| Roof inflow to storage | 21.3 kL | 98 m² connected at a runoff coefficient of 0.8 |
| Overflow | 0 kL | 12 months with storage empty at month end |
| Indoor use | 218.9 kL | 150 L per person per day |
| Water imported | 140.2 kL | plus 99.6 kL drawn from the bore |
| Garden water applied | 42.6 kL | estimated unmet demand 99.6 kL |
| Pump energy | 228 kWh | electricity at $0.33 per kWh |
| Harvest weighed | 44 kg | food waste 7.2 kg/week, 373 kg/year, 61 % plant-based |
| Peak simultaneous flow | 21.5 L/min | 70th percentile event 18 L/min; static lift 2.1 m |
| Frost nights | 13 | air temperature below 0 °C |
The measured year, month by month
An extract. The full table, with every fixture group, the bore, overflow and the quality flags, is in SYNTHETIC-monthly.csv below.
| Month | Rain (mm) | ETo (mm) | Roof in (kL) | Tank end (kL) | Indoor use (kL) | Imported (kL) | Garden applied (kL) |
|---|---|---|---|---|---|---|---|
| Apr 2027 | 32.2 | 128 | 2.4 | 0 | 17.8 | 10.1 | 3 |
| May 2027 | 31.5 | 90 | 2.3 | 0 | 17.7 | 9.1 | 2 |
| Jun 2027 | 16.6 | 71 | 1.1 | 0 | 16.7 | 9.1 | 1.8 |
| Jul 2027 | 10.8 | 72 | 0.7 | 0 | 17.3 | 10.1 | 1.8 |
| Aug 2027 | 14.5 | 101 | 1 | 0 | 17.7 | 10.9 | 2.6 |
| Sep 2027 | 8 | 138 | 0.5 | 0 | 17.8 | 12.5 | 3.5 |
| Oct 2027 | 21.2 | 185 | 1.5 | 0 | 19 | 13.8 | 4.6 |
| Nov 2027 | 23.6 | 198 | 1.7 | 0 | 18.9 | 13.8 | 4.9 |
| Dec 2027 | 28.9 | 206 | 2.1 | 0 | 18.6 | 13.2 | 5 |
| Jan 2028 | 35.3 | 220 | 2.6 | 0 | 20.1 | 14.4 | 5.3 |
| Feb 2028 | 56.2 | 178 | 4.2 | 0 | 18 | 9.2 | 3.8 |
| Mar 2028 | 17.8 | 168 | 1.2 | 0 | 19.3 | 14 | 4.3 |
Growing zones
| Zone | Area (m²) | Texture | pH | Organic C (%) | Rooting (cm) | Sun, summer / winter (h) | Class | Note |
|---|---|---|---|---|---|---|---|---|
| G1 Shade-house garden | 54 | sandy loam | 7.9 | 0.9 | 60 | 12 / 8.5 | A | shadecloth transmits about 45 per cent of light after ten years |
| G2 Main garden | 168 | loamy sand | 8.2 | 0.6 | 80 | 13 / 9 | B | calcium carbonate at depth; emitters scaled |
| G3 Windbreak strip | 90 | loamy sand | 8.3 | 0.7 | 80 | 10 / 6.5 | D | tree roots; wind-exposed edge |
| G4 Trial plot | 96 | sand | 8.4 | 0.3 | 90 | 13.5 / 9.5 | C | bare; surface temperature above 60 degC in January |
Water quality
| Month | Source | Turbidity (NTU) | E. coli (MPN/100 mL) | Hardness (mg/L CaCO₃) | pH | Note |
|---|---|---|---|---|---|---|
| 2027-04 | tank T1 | 1.8 | 3 | 210 | 7.8 | tank holds mixed rain and bore water |
| 2027-10 | bore | 0.4 | 0 | 385 | 7.6 | hardness and iron explain the emitter scale |
| 2028-01 | tank T1 | 4.9 | 18 | 150 | 7.6 | after the January storm |
| 2028-02 | bore | 0.5 | 0 | 392 | 7.6 | |
| 2028-02 | drip emitter deposit | white scale, effervesces in acid: calcium carbonate |
Hydraulics
Tank outlet at RL 100.25 m; highest fixture is the ensuite shower rose at RL 102.35 m, giving a static lift of 2.1 m. Currently served: whole house and drip, through the existing pressure pump.
Existing pump cuts in at 20 m and out at 34 m of head; the drip zones run off the same pump.
| Fixture | Flow (L/min) |
|---|---|
| shower | 9.1 |
| ensuite shower | 8.4 |
| basin | 5.2 |
| kitchen tap | 7.4 |
| toilet cistern refill | 7 |
| washing machine fill | 11.5 |
| drip zone (shade house) | 6.2 |
| drip zone (fruit block) | 7.8 |
What it costs the household now
- Electricity at $0.33 per kWh.
- No reticulated supply and no water bill; all water is carted, drawn from the bore or caught on site.
- Carted water at $28 per kL delivered.
- Drip emitters cleared four times, 2 hours each; two lines replaced.
- Cartridge filter changed every eight weeks, $12 per cartridge.
- Bore pump serviced once, $180.
What the specialists conclude
- Emitter blockage is calcium carbonate scale from hard bore water, not biofilm; the fix is filtration and flushing, not new lines.
- Carted water arrived in 12 loads of 12 kL, mostly between October and March. The bore allocation was fully used, evenly across months, because the bore pump tops up the tank whenever there is room.
- Only one of the five guttered roof zones is connected; the other four together are about twice its area.
- The tap timer gave the shade-house vegetables and fruit block about 30 per cent of the irrigation they needed; from December to February the tank was usually empty by mid-morning.
What they could not settle
- Whether the bore allocation could be renewed on the same terms; the licence is reviewed in 2031.
- How the family would run a composting toilet during summer heat, which the specialists did not observe.
Gaps in the record
- 2028-02, rain_mm: Rain gauge funnel blocked by a grasshopper swarm; February total taken from the Alice Springs Airport station
A gap is marked as a gap. Interpolated values are flagged in thequality_flag column of the monthly CSV, and anything you conclude from those months should carry the same flag.
Download the findings
Every file's first line says what it is. The data dictionary gives each column its unit, meaning and kind — synthetic measured year, derived,calendar or sourced. Keep those apart in your own workbook.
| File | What is in it | Size | Basis |
|---|---|---|---|
| SYNTHETIC-monthly.csv | The measured year, month by month: rain, temperature, roof inflow, tank level, indoor use by fixture group, imports, garden application, pump energy, frost | 12 rows | synthetic case data |
| SYNTHETIC-zones.csv | Soil and shade by growing zone: texture, pH, EC, organic carbon, nutrients, rooting depth, summer and winter sun, relative productivity | 4 rows | synthetic case data |
| SYNTHETIC-water-quality.csv | Water-quality samples: turbidity, E. coli, hardness, TDS, pH, iron, with the sampling note | 5 rows | synthetic case data |
| SYNTHETIC-flow-events.csv | The ten largest simultaneous-draw events: fixtures involved, peak flow and duration | 10 rows | synthetic case data |
| SYNTHETIC-food-waste-audit.csv | Four one-week kitchen and garden waste audits, split into plant, meat and dairy, and garden | 4 rows | synthetic case data |
| BOM-long-term-015590.csv | Long-term climate statistics for Bureau of Meteorology station 015590, all years of record | 12 rows | sourced |