Summary
- Sien Real plans four data centre buildings on a 45,305 sq m site between Piaseczno and Józefosław.
- Project water demand has been compared with a residential development of up to 3,000 people, intensifying concern where local supply problems already occur.
- Cooling, water, emergency generation, and network capacity are becoming part of the same planning test as Warsaw’s data centre market expands.
A four-building data centre development on the southern edge of Warsaw is facing growing local opposition over water demand, with residents questioning whether an already pressured supply network can support another large industrial user.
Sien Real, a joint venture involving Polish contractor Budimex and Spanish infrastructure group Ferrovial, plans the facility on a 45,305 sq m site between Piaseczno and Józefosław. Construction is expected to begin in 2027.
No compute capacity has been disclosed for the campus. Budimex has said projected water consumption would be comparable with a residential estate of up to 3,000 people, while residents have linked the proposal to existing periods of low water pressure in Józefosław.
Cooling sits behind the water figure
A daily water estimate gives only part of the operating picture because data centre consumption depends heavily on the thermal system selected for the site. Facilities using predominantly dry cooling can consume relatively little water for heat rejection, while evaporative systems exchange higher water use for lower cooling electricity demand in suitable conditions.
Hybrid designs can move between those operating modes as weather changes, making peak summer demand different from an annual average. That difference becomes particularly important where a local water network already struggles during periods of high residential consumption.
Budimex has said the development will incorporate measures intended to reduce water consumption, noise, and dust, while its cooling and emergency power installations will meet modern data centre standards. Detailed cooling architecture and operating water metrics have not been disclosed.
The planning material provides more visibility on backup power. The project is expected to contain 49 generators rated at up to 2,420kW each, giving an aggregate maximum generator rating of roughly 118MW. Generator capacity is not a direct measure of IT load because standby systems also support cooling, electrical losses, and other facility services, but the figure indicates a sizeable electrical installation.
Four large diesel storage tanks are also included in the environmental documentation. Those assets bring air quality, noise, fuel handling, testing schedules, and physical safety into the local infrastructure discussion alongside water.
Warsaw growth is moving closer to residential areas
Warsaw has become Poland’s largest data centre market, supported by domestic digital demand, cloud investment, fibre connectivity, and the country’s role as the main Central and Eastern European economy. As available sites are developed, larger facilities are reaching suburban locations where industrial infrastructure sits closer to homes.
That proximity changes the planning process. A campus that might sit comfortably within a major industrial estate can face much closer examination of cooling equipment, generator testing, traffic, lighting, noise, and utility consumption when neighbouring communities depend on the same local networks.
Water supply is particularly difficult to separate from climate and compute density. AI deployments can produce much more heat per rack than conventional enterprise computing, increasing the amount of thermal energy a facility must remove. Liquid cooling can collect that heat efficiently at the server, but the facility still needs equipment capable of rejecting it to the outside environment.
Operators can reduce direct water consumption by favouring dry heat rejection, although doing so may increase electrical cooling demand during hotter periods. Evaporative cooling can lower electricity use but creates a greater dependency on water. The optimum design therefore depends on grid conditions, climate, water stress, operating temperatures, resilience targets, and capital cost.
Warsaw’s continental climate exposes facilities to both cold winters and warm summers, requiring plant capable of operating efficiently across a wide range of external temperatures. Without published details for Sien Real’s design, residents and planners have little basis for judging how its cooling strategy will behave during periods when the local water network is under the most pressure.
Planning consent does not settle infrastructure capacity
The development originally received planning permission in 2024, but consent for buildings does not guarantee that every utility can accommodate the operating load without reinforcement. Water, electricity, roads, drainage, and telecommunications each follow their own capacity and connection processes.
The project includes a retention reservoir intended to manage rainwater and meltwater, although that system serves a different purpose from supplying the cooling demand that has prompted local concern.
Further disclosure on annual consumption, maximum daily water use, cooling mode, electrical capacity, backup power testing, and noise limits would allow the development to be assessed against measurable operating conditions rather than building area alone.
Large European data centre projects are increasingly being judged on that basis. Securing land and planning remains essential, but water and electricity networks can still limit a scheme after its buildings have been approved.
Piaseczno now provides a clear example of the pressure moving beyond the site boundary. The campus may be technically deliverable, but its cooling and utility strategy will have to coexist with a community that is already questioning whether the local infrastructure has enough spare capacity.
