Worked example

An illustrative seasonal resort.

A 72-key independent resort on the north-east coast of Corfu. Open late April to late October, mains supply topped up by tanker in August, central chilled-water cooling, on-site laundry, one main pool and around 2,400 m² of planted grounds.

It is deliberately typical of the properties Aquiterum is built for: complex enough to have several reusable streams, small enough that nobody on site is a water engineer. This property is fictional and the figures below are generated by the same engine that runs your own snapshot.

Water Snapshot

Cape Almyra Resort (illustrative)

72 keys · Island aquifers are small and recharge slowly; peak tourist demand coincides with the driest months and tanker or desalinated supply is common.

Evidence confidence

76/100

Good enough to brief a specialist

Total water in

21,500 m³

21,500–21,500 m³ per year

Measured

Per occupied room

2,018 L

Normalised to the HWMI unit

Measured

Potentially recoverable

6,110 m³

About 28% of total demand

Modelled

Taken from the consumption figure you supplied.

Your water loop

21,500 m³ per year

Where it goes

Guest rooms9,729 m³
Landscape irrigation4,522 m³
Pools1,119 m³
Laundry1,807 m³
Kitchens and F&B1,112 m³
Spa and wellness1,081 m³
Losses and back-of-house2,131 m³

What could come back

Greywater→ Toilet flushing2,480–9,410 m³/yr
Pool backwash→ External washdown264–1,000 m³/yr
Laundry rinse→ Laundry pre-wash253–961 m³/yr

Opportunities, ranked for this property

Ranked on recoverable yield, how well the stream matches demand you actually have, retrofit feasibility, and the quality of the evidence behind each figure. Categories only - Aquiterum never names a product or vendor.

Priority 1

Greywater recycling

Modelled

Lightly-soiled water from showers, baths and washbasins, treated and reused for non-potable duties.

Potentially recoverable

2,480–9,410

m³ per year

Share of total demand

23%

if fully used

Effort

Very high complexity

Large capital

Where it could go on this property

Toilet flushing · Biological treatment + disinfection
Landscape irrigation · Biological treatment + disinfection
Laundry pre-wash · Advanced treatment

Health-critical. Requires treatment to a defined quality class, continuous monitoring, marked separate pipework, backflow prevention and — in the EU — a documented risk-management plan. Never proceed without a qualified engineer and the local regulator.

Why it ranks here

Could displace roughly 23% of total property demand. Best-matched use on this site is toilet flushing. Retrofit complexity is the main obstacle in an existing building.

Why it gets overlooked

It is by far the largest recoverable stream in a hotel, but in an existing building the drainage is already combined with WC waste — separating it is the real project.

Timing

Available whenever the property is occupied; closely tracks occupancy.

Score components

Recoverable yield40 / 40
Match to on-site demand22.5 / 25
Retrofit feasibility4 / 20
Evidence quality9 / 15

Sources behind these coefficients

Priority 2

Pool filter backwash recovery

Modelled

Water discharged when pool sand filters are backwashed, plus pool drain-down at season change.

Potentially recoverable

264–1,000

m³ per year

Share of total demand

if fully used

Effort

Low complexity

Small capital

Where it could go on this property

External washdown · Filtration
Landscape irrigation · filtration-disinfection
Pool top-up · Advanced treatment

Carries chlorine or bromine residual, high solids and sometimes cyanuric acid or salt. Dechlorination and salinity checks are essential before any irrigation use — salt-chlorinated pools are frequently unsuitable.

Priority 3

Laundry final-rinse recovery

Modelled

Final-rinse water from an on-site laundry, captured and reused as wash water for the next cycle.

Potentially recoverable

253–961

m³ per year

Share of total demand

if fully used

Effort

Moderate complexity

Medium capital

Where it could go on this property

Laundry pre-wash · Filtration
External washdown · Filtration

Surfactant and temperature carry-over affect wash quality and machine warranty. Confirm the approach with the machine manufacturer and the chemical supplier before committing.

Priority 4

Rainwater harvesting

Modelled

Rainfall collected from roofs, terraces and hard standing, stored, and used for non-potable duties.

Potentially recoverable

51–194

m³ per year

Share of total demand

if fully used

Effort

Moderate complexity

Medium capital

Where it could go on this property

Landscape irrigation · Filtration
External washdown · No treatment
Toilet flushing · filtration-disinfection

First-flush diversion and covered storage are required. Roof materials, bird fouling and stored-water stagnation all affect quality; local rules on rainwater use vary widely.

Priority 5

Air-conditioning condensate

Modelled

Water condensed out of humid air by cooling coils in fan-coil units, air handling units and split systems, then usually discharged to drain.

Potentially recoverable

12–46

m³ per year

Share of total demand

if fully used

Effort

Moderate complexity

Small capital

Where it could go on this property

Landscape irrigation · Filtration
External washdown · Filtration
Toilet flushing · filtration-disinfection

Condensate is low in dissolved solids but can pick up metals, biofilm and Legionella risk from drain pans and pipework. It is not potable and must not be cross-connected with the potable network.

The balance behind these numbers

Guest roomsMeasured4,378–18,680 m³
Showers, basins and WCs. Usually the largest single block and the source of greywater.
Landscape irrigationMeasured2,782–6,261 m³
Modelled from irrigated area and regional demand. The easiest place to absorb recovered water.
PoolsMeasured267–3,255 m³
Evaporation plus filter backwash across the operating season.
LaundryMeasured556–4,818 m³
On-site laundry only. Off-site linen leaves the HWMI boundary.
Kitchens and F&BMeasured306–3,321 m³
Spa and wellnessMeasured347–2,594 m³
Losses and back-of-houseModelled518–7,007 m³
Leakage, cleaning and unmetered back-of-house use. A large figure here is itself a finding.

What to measure next

These are ordered by how much each one would tighten the numbers above. This list is the point of the snapshot: it is what turns guesswork into a brief.

1
Whether shower and basin drainage is separable from WC wasteOne walk-around
Greywater is almost always the largest stream and almost always the hardest project. Existing riser layout decides the cost, not the volume.
2
Where the AC condensate drains actually runOne walk-around
Condensate volume matters far less than whether the drains can be brought to one or two collection points. This decides whether the project is small or unviable.
3
A sub-meter on the irrigation supplyNeeds a meter
Irrigation is the usual home for recovered water. Metering it turns the biggest modelled number in this snapshot into a measured one.
4
The pool backwash schedule and filter typeYou already have this
Backwash volume varies fivefold between sand and regenerative media, and salt chlorination can rule out irrigation reuse entirely.
5
Laundry throughput in kg per week and machine ageYou already have this
Litres per kilogram varies more than twofold between an old washer-extractor and a modern tunnel washer.

This is a pre-feasibility snapshot, not an engineering study.

Every opportunity above must be verified by a qualified water engineer before any implementation work begins. Aquiterum does not certify safety, potability, permitting or regulatory compliance, and does not sell or recommend equipment.

Engine engine-1.0.0 · Knowledge base kb-2026.08.1 · Computed 03/08/2026

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