Hydrowatt is our subsidiary dedicated to construction and operation.

Once the studies have been completed and the project has been authorised, the works are performed under UNITe’s supervision. UNITe draws on expertise from the regions in which it is established, by relying on partnerships with local companies. The works are performed with strict adherence to safety and taking into account any identified environmental issues. UNITe commissioned the plant in Meije in 2019. In 2020, work began on the Parpaillon facility.

Completing construction of a facility includes:

Project definition

  • Opportunity and feasibility studies (context analysis and legal, technical and administrative feasibility) 
  • The program (definition of requirements, estimation of investment and operating costs, optimisation of implementation methods)
  • Management of studies (coordination by experts)

Project management

  • Schedule of operations
  • Obtaining of administrative permits
  • Management of relationships with third parties
  • Operations management
  • Administrative and financial management

Operational studies

  • Establishment of the general and detailed schedule
  • Selection of companies (invitation to tender, bid analysis, contract drafting)
  • Monitoring and evaluation during the design phase

Project monitoring during the implementation phase

  • Operations monitoring (implementation studies monitoring, coordination of works phases, acceptance of works, monitoring of defects liability warranty)
  • Commissioning phase (commissioning, operator training, monitoring of performance obligations)

Our latest projects:

  • La Meije Power Plant, La Grave: Cost of the works €12,000, 6 lots, 15 companies, construction period 15 months.
  • Parpaillon Power Plant: Cost of the works €11,500, 6 lots: 10 companies, construction period 20 months.


A dedicated and structured team for the operation and maintenance of electricity production units. A local and skilled organisation, as close as possible to the facilities, with the site supervisor, assisted by a regional manager and strengthened by numerous administrative and technical resources at the headquarters in Lyon and at the factory in Saint Girons.

The operational duties and tasks crucial to the quality of the electricity production:

  • Operation of the facilities, supervision and monitoring, locally and remotely.
  • Definition of requirements for investment plans, continuous improvement for multi-domain optimisation (output, technical, safety, environment).
  • Organisation, management and monitoring of works and maintenance.
  • Administrative monitoring and exchanges with government departments (French Biodiversity Office (AFB), Regional
  • Infrastructure Department (DDT), regional committee, etc.) and the power grid operator (ENEDIS).
  • Management of the environmental and safety policy of the sites.
  • Organisation of any regulatory inspections performed by inspection bodies (fire extinguishers, fire, electricity, lifting, pressurised equipment, etc.) and any regulatory requirements based on the classification of the production sites.

Maintenance duties and tasks that are essential to the durability of the equipment, mainly carried out internally:

  • Preventive maintenance: a specific maintenance plan is drafted for each site. 
  • Corrective maintenance: on-site intervention, diagnostics and repair, responsiveness through proximity, efficiency through transferable skills.
  • Predictive and specific maintenance: vibration monitoring, thermography, oil and lubricant analyses, monitored data analyses, mechanical inspections, etc.
Unite e&m le g2


Each site is operated by a supervisor, assisted by a regional manager based on a regional breakdown covering the whole of France. The local teams are strengthened by numerous administrative and technical resources at the headquarters in Lyon where monitoring software retrieves information from all operated power plants.

Ecological Continuity

The environmental issues associated with the flow of fish and sediment in waterways are a major obstacle which must be comprehended as a whole.

Hydrowatt has a team specially dedicated to this mission which covers the following aspects:

  • regulatory and administrative: obtaining of new and renewed water rights permits, declaration of commencement of works application, management of grant applications, coordination of the various parties involved (research firms, works contractors, etc.).
  • technical: ensuring the compliance of any water intakes to make them fish-friendly, helping to supervise works, monitoring the compliance of any instream flows, completing hydraulic calculations and providing technical and regulatory support for operators and developers.

A wide variety of expertise is mobilised: between technical and hydraulic calculations, administrative relations and environmental compliance. 

Énergie hydraulique

Latest site studies:

  • Monitoring of implementation of fish-friendly water intake for the Urs power plant in Ariège.
  • Preparation of works on fish-friendly water intake for the Luzenac power plant in Ariège (works in 2021).
  • Dimensioning and consulting on ongoing construction for the Parpaillon power plant in the Parpaillon stream, estimate for reconstruction of the Villedubert power plant in Aude, installation of the Casamozza water intake in the Golo, Corsica.
  • Obtaining permits for and preparation of reconstruction of the Saint-Sauveur-de-Montagut power plant in the Eyrieux.
  • Preparation of water rights renewal application files for 3 power plants in Ariège and Palouma in the Bernede and Hounteyde streams.

Réalisation des travaux

Une fois les études achevées et le projet autorisé, les travaux sont réalisés sous la supervision d’UNITe par des entreprises locales avec qui nous cultivons une relation privilégiée, dans un strict respect des enjeux environnementaux identifiés. En 2019, UNITe a mise en service la centrale de la Meije [lien vers l’article]. En 2020, les travaux de l’aménagement du Parpaillon ont débuté  [lien vers l’article].