Key data
| Regulation | Resolution of October 20, 2026, from the Under-Secretary, publishing the Agreement between the Ebro River Basin Authority, O.A., and the State Agency Spanish National Research Council, M.P., for the application of the Geoterz geothermal model |
|---|---|
| BOE Publication | October 27, 2026 |
| Entry into force | October 27, 2026 |
| Signatory bodies | Ebro River Basin Authority (CHE) and CSIC-IGME |
| Technical model | Geoterz — hydraulic and thermal simulation of Zaragoza's urban aquifer |
| Affected parties | Companies and developers with geothermal installations or exploitation applications in Zaragoza |
| Category | Energy |
| Year | 2026 |
Companies and developers operating or planning to install geothermal climate control systems in Zaragoza face a new regulatory scenario. The city's urban aquifer presents poor status due to contamination and bears growing pressure from geothermal installations for building climate control. From now on, the CHE will not resolve concessions or thermal discharge authorizations without the backing of the Geoterz model, published through the Resolution of October 20, 2026 (BOE-A-2026-22505).
This represents a qualitative change in the authorization process: decisions cease to be based exclusively on administrative criteria and become backed by numerical simulations of the aquifer's hydraulic and thermal behavior. For applicants, it means that cases will be more technically demanding and that model results can determine the viability or denial of a project.
What does this regulation establish?
The agreement formalizes collaboration between the Ebro River Basin Authority (CHE) and CSIC-IGME to update and apply the Geoterz numerical model. This model simulates the hydraulic and thermal behavior of Zaragoza's urban aquifer and has two main functions:
- Support for administrative decisions: provides the CHE with a scientific basis for resolving groundwater exploitation concessions and thermal discharge authorizations.
- Climate change analysis: incorporates the study of climate change impact in the short and medium term, given the foreseeable increase in climate control demand in the city.
Zaragoza's urban aquifer is in poor status due to contamination, which justifies the need for more rigorous management based on scientific evidence. The Geoterz model allows evaluation of different management alternatives for geothermal exploitations with groundwater, assessing their cumulative impact on the aquifer.
| Element | Detail |
|---|---|
| Applied model | Geoterz — hydraulic and thermal numerical simulation |
| Territorial scope | Zaragoza's urban aquifer |
| Aquifer status | Poor due to contamination |
| Bodies involved | CHE (Ebro River Basin Authority) and CSIC-IGME |
| Decisions it conditions | Groundwater exploitation concessions and thermal discharge authorizations |
| Additional variable incorporated | Impact of climate change in the short-medium term on aquifer management |
Economic and operational impact
The direct impact of this agreement is not a fee or fine: it is a technical constraint that can block or delay investment projects in geothermal climate control in Zaragoza. The operational implications are clear:
- Greater technical demands in cases: concession or authorization applications must be consistent with Geoterz model results. Projects that previously could be processed with standard documentation may now require additional hydrogeological studies.
- Risk of scientifically grounded denial: if the Geoterz model detects that a new installation worsens the aquifer's status, the CHE will have scientific arguments to deny authorization.
- Uncertainty in processing timelines: the integration of the model into administrative processes may extend resolution times while the procedure is consolidated.
- Impact on building projects with geothermal climate control: real estate developers and managers of large buildings planning geothermal systems in Zaragoza must incorporate this factor into their feasibility analyses.
In the medium term, the climate change analysis incorporated into the model anticipates increased demand for climate control in the city, which could result in additional restrictions as pressure on the aquifer grows.
Who does it affect?
- Developer companies with building projects that include geothermal climate control systems in Zaragoza.
- Owners and managers of buildings with geothermal installations already in operation that need to renew or expand their concession.
- Engineering and consulting companies that process groundwater exploitation cases before the CHE.
- Investors in real estate assets in Zaragoza that consider geothermal systems as a climate control solution.
- Local administrations and managers of public infrastructure with geothermal systems in the city.
Practical example
A real estate developer plans to build an office building in Zaragoza and has designed the climate control system based on geothermal energy with groundwater capture from the urban aquifer. Before this agreement, the concession application to the CHE was processed with the standard technical documentation required by water regulations.
From October 27, 2026, the CHE will evaluate that application against the results of the Geoterz model. If the simulation indicates that the new capture, added to existing ones, worsens the aquifer's poor status or generates thermal interference with other installations, the CHE will have scientific basis to condition, limit, or deny authorization. The developer must therefore anticipate this analysis in the project design phase and possibly commission a specific hydrogeological study that is consistent with the Geoterz model framework.
What should companies do now?
- Review the status of your active cases before the CHE: if you have concession or thermal discharge authorization applications in process in Zaragoza, contact the CHE to find out if they will be evaluated with the Geoterz model and at what stage.
- Incorporate regulatory risk into feasibility analyses: any new geothermal project in Zaragoza must consider the possibility of technical constraints derived from the aquifer's status and model results.
- Commission prior hydrogeological studies: before submitting an application, it is advisable to have a technical analysis that anticipates the installation's impact on the urban aquifer, aligned with the Geoterz model methodology.
- Consult with the CHE on the updated procedure: given that the agreement has just entered into force, it is advisable to request direct information on how the model will be integrated into case resolution processes.
- Monitor regulatory developments: the climate change analysis incorporated into the model may result in additional restrictions in the medium term. Maintain active monitoring of CHE resolutions on geothermal exploitations in Zaragoza.
Frequently asked questions
What is the Geoterz model and why does it condition my authorizations?
Geoterz is a numerical simulation model that reproduces the hydraulic and thermal behavior of Zaragoza's urban aquifer. It has been developed by CSIC-IGME and the CHE will use it as a scientific basis for resolving groundwater exploitation concessions and thermal discharge authorizations. If the model results indicate that a new installation worsens the aquifer's status — which is already in poor condition due to contamination — the CHE can condition or deny authorization.
Since when does the Geoterz model apply to geothermal applications in Zaragoza?
The agreement between the CHE and CSIC-IGME was published in the BOE on October 27, 2026 and entered into force that same day. From that date, the CHE has the tool to back its administrative decisions on geothermal exploitations in Zaragoza's urban aquifer.
Does this agreement affect only new applications or also existing installations?
The agreement has direct implications for companies and developers requesting geothermal exploitations in Zaragoza, according to the regulation text. Existing installations that need to renew, expand, or modify their concession will also be subject to evaluation through the Geoterz model when processing any new case before the CHE.
Why is Zaragoza's urban aquifer in poor status?
Zaragoza's urban aquifer is in poor status due to contamination, as stated in the agreement. Added to this is the growing pressure from geothermal installations for building climate control. The Geoterz model is activated precisely to manage this situation and prevent further deterioration of the groundwater resource.
What role does climate change play in managing Zaragoza's aquifer?
The agreement expressly incorporates analysis of climate change impact in the short and medium term on aquifer management. The reason is the foreseeable increase in climate control demand in the city, which will increase pressure on the resource. This analysis may result in additional restrictions to geothermal concessions in the future.
Official source
Consult complete regulation at official source
Notice: This article is for informational purposes only and does not constitute legal advice. For specific decisions, consult a qualified professional. Source: https://www.boe.es/diario_boe/txt.php?id=BOE-A-2026-22505
