Nerethia
Water intelligence for hotels in Greece

Two comparable hotels, on the same island, can differ threefold in the water they use.

One of them is paying for the difference every night of the season. Most of the time, nobody has measured which one it is.

0 L 234 L 675 L

Litres per guest per night, measured across three four- and five-star hotels in Rhodes. Same island, same category, same guests. The gap is pools, irrigation, laundry, hot water and leaks that nobody has metered.

Who it is forIndependent hotels and small groups, 50 to 250 rooms.
Where it mattersProperties with pools, irrigated gardens, laundry, restaurant or spa, in water-stressed destinations.
What it answersOf every upgrade you could fund, which one pays back first.
The gap

Greek hotels do the cheap, visible measures. Almost none of them measure.

Research by ITEP, the Institute of Tourism Research and Forecasts, shows how far hotels have gone with water. More than half ask guests to reuse towels and have fitted low-flow toilets. Only 12% use water meters or systematic leak detection, and far fewer reuse water at all.

A towel card does not find a leaking pool, or an irrigation schedule set for a wetter decade. You cannot cut what you do not measure, and you cannot rank an investment without knowing what each loss costs.

Adoption

Share of Greek hotels using each water measure. The visible measures are widespread. Measurement and reuse are not.

Source: ITEP, Institute of Tourism Research and Forecasts, Greece.

2to3×
Tourists can consume two to three times more water than residents. Source: OECD, 2025.
+192.4%
Growth in private and tourist swimming pools in Halkidiki between 2016 and 2024, from satellite analysis. Source: MDPI Sustainability, July 2026.
The audit

Fourteen days, twelve months of your data, one ranked list.

We build a full picture of where water goes on the property, price every loss in euros, and hand you a list of interventions ordered by payback period. No hardware, no disruption to operations.

What we do

Water Profitability Audit

Most hotels know what they spend on water. Very few know where it goes. In fourteen days we close that gap: twelve months of your own data, resolved into consumption by end use, each loss priced, and every available fix ranked by the speed at which it returns the money.

What we ask from you

  • Water and energy invoices for the last 12 months
  • Occupancy and number of rooms
  • Pool details: volume, filtration, backwashing routine
  • Garden and irrigated area
  • Laundry and restaurant operations
  • Water source: mains, borehole, tanker or desalination

What we calculate

  • Litres per guest per night
  • Cubic metres per room per year
  • Cubic metres per square metre of garden
  • Pool losses: evaporation and backwashing
  • Laundry consumption
  • Water cost per occupied room
  • Energy cost attached to hot water

What you receive

A consumption baseline you can defend, the cost of each loss in euros, and a ranked schedule of interventions with the capital required and the payback period against each one.

The purpose is a decision. When the next budget is allocated, it goes to the measure that returns fastest — not to the one proposed by the last supplier who called.

Pricing is set at first contact, once we know the size and configuration of the property.

Funding

Water investments in Greek hotels are eligible for substantial public co-financing.

An audit that ranks interventions by payback is also the document that supports an application. The instruments currently in force:

Law 4887/2022 70% Maximum aid intensity for investments in water infrastructure.
ESPA 2021–2027, Green Productive Investment for SMEs €30k–200k Eligible project budget per application.
Recovery and Resilience Facility, Greece 2.0 50% State financing available for green investments in hotels.
After the audit

Findings are worth nothing if nobody acts on them.

For properties that want to act, we prepare the action plan, coordinate implementation with technical suppliers, and set up continuous monitoring so the gains hold from one season to the next.

Water is where we start, because it is where the losses are least measured. The same method is built to extend to energy, waste and carbon.

MeasureEstablish a defensible baseline.
AnalyseLocate and price each loss.
PrioritiseRank fixes by payback.
ImplementCoordinate the suppliers.
MonitorVerify the savings appear.
ImproveReset the baseline, repeat.
About

Resource intelligence, not sustainability consulting.

Nerethia exists to answer one question for hotel owners and general managers: with a fixed budget and a long list of possible upgrades, which one pays back first.

Alexia Stan

Founder

Her work sits across governance, diplomacy and human rights law, with a long-standing focus on environmental protection. Based in Greece.

Environmental questions are rarely lost on the argument. They are lost in the gap between what a regulation requires, what a budget allows, and what anyone has actually measured. Closing that gap is unglamorous work, and it is where the outcome is decided.

A hotel that cuts its water use by a fifth has done more for a water-stressed island than most declarations of intent. It has also protected its own margin. Nerethia is built on the conviction that these two things are the same sentence, not competing ones — and that the case for acting is strongest when it is made in euros, on evidence the owner can verify.

Water is the entry point, because it is where the money leaks quietly and the measurement is thinnest. It is not the limit of the method.

How we work

We audit, we quantify, and we stay until the savings show up on the invoice.

We sell no meters, no sensors and no treatment systems, and we install nothing. That is deliberate: an analysis is only worth reading if it is independent of anyone's catalogue. Our recommendation is the one the numbers support, not the one we happen to stock.

When a fix is worth making, we specify it, brief the technical partners who install it, and verify afterwards that the saving is real. A finding nobody acts on is a cost, not a service.

Contact

Start with the audit.

Write with the name of the property, the number of rooms, and what is on site: pool, gardens, laundry, restaurant, spa. We reply with the data checklist and the scope.

alexia@nerethia.one
ResponseWithin two working days.
CoverageGreece, mainland and islands.
LanguagesEnglish and Romanian.