Project description
The project involves the construction of a pumping station in Val d'Ultimo, near Pracupola and Santa Valburga, with an estimated capacity of 400 MW.
This involves an underground connection between Lake Quaira (12.8 million m3) and the Zòccolo reservoir (33 million m3) located along the left side of the Pracupola valley. The diversion tunnel and the power station will be completely underground.
The water supply tunnel and the power station would also be built entirely underground.
Once construction is complete, only three access portals and a ventilation opening at the hydraulic castle would be visible:
- one portal near Lake Arzkarsee,
- one near the Zoggler reservoir,
- and one at the equipment chamber at the top of the penstock.
The national transmission grid operator, Terna, is currently working on a possible solution for connecting the plant to the grid.
In principle, a new underground route between the project area and Taio in Val di Non is being considered.
As soon as more concrete information is available, it will be shared with the für-ulten working group and made available to everyone.
STRENGTHS OF THE POSITION
- Use of existing basins and infrastructure: existing facilities will be used even more efficiently.
- Underground construction: only the three access points to the power station will be visible, while the entire power station will be built underground.
- Significant difference in altitude: the large difference in altitude of approximately 1,100 m will enable a high output of 400 megawatts to be achieved despite the relatively low flow rate.
ENVIRONMENTAL ASPECTS
- Landscape protection: with the exception of the three access portals and the ventilation window of the piezometric well, the new facilities will be completely invisible. The central body, located on the northern shore of the Zoccolo artificial lake, will be located inside the mountain at a depth of approximately 400 metres.
- The entire hydraulic system will be completely underground and the water intakes for the two reservoirs will be located below the water level. In addition, the power station will use existing reservoirs and facilities.
- Dust and noise. In order to protect nature, people and the environment, specific measures were planned during the design phase to prevent, reduce or, if necessary, compensate for any negative effects resulting from the construction site.
- Preservation of spring quality: initial investigations have shown that the springs are fed by surface layers and are therefore not affected by the underground tunnel route. Based on current knowledge, no negative impact on the springs is expected.
- At the request of the Citizens' Council, Alperia is conducting an in-depth investigation of the springs, together with external experts, based on continuous monitoring and geological surveys. The monitoring measures the flow rates, temperatures and conductivity of the springs, and the data is correlated with weather conditions. These analyses make it possible to determine whether a spring is fed by surface layers (interstitial water) or deep layers (fault water). Thanks to this information, geologists can assess whether the tunnel construction work could affect the springs.
- The Covolo lakes are located at an altitude of about 2,400 metres, behind Mount Gran Ladro. The lakes are about 515 metres from the planned tunnel and are located about 200 metres higher than the route. Their formation can be traced back to geological-tectonic processes linked to the birth of the Alps, in particular the formation of double ridges. The lakes are enclosed within virtually impermeable rock, with local permeability limited to fissures. Considering the topographical position and distance from the tunnel, together with the geological nature of the area, a direct negative impact of the construction work on the Covolo lakes can be ruled out.
Excavated material. Construction work will mainly take place underground. Three access points are planned: one at the top, near Lake Quaira, one at the bottom, near Lake Zòccolo, and one in the centre, near the equipment room. A ventilation window is also planned for the piezometric well.
Approximately 500,000 m³ of excavated material is expected to be produced.
According to initial assessments, this material is recyclable and can be reused both on the construction site itself and for other construction projects, such as the redevelopment of the banks of the Zoggler reservoir and the landscaping of the valley.
Rendering illustrating the design concept after completion:
