In the previous newsletter, we gave information about the preliminary draft that is centred on the reconnection of the Po river corridor.
The barrier of the hydroelectric plant of Isola Serafini has interrupted until now the river continuity about 300 Km from the sea. Enel Green Power SpA, authority and operator of the Isola Serafini dam, is also the Life project co-financier and in particular, it helps the de-fragmentation work of the barrier. The first aim of the project is restoring the Po River continuity by re-opening this ecological corridor which will have positive effects for some migratory species endangered and protected by the EU such as sturgeon, eel, shad, mullet, who need to complete their life cycle passing from soft water to salted ones and vice versa.
Thanks to project official website the Preliminary draft was shared not only among the partner of the CON.FLU.PO project and their staff, but also among the stakeholders.
In drawing up the final draft, we have considered all the provisions, indications and suggestions received by the technical departments. However, the final design has maintained the general characteristics already defined in the preliminary one.
The fish pass to successive basins has a "Y" shape and allows the passage of the fish fauna in both directions. It also restores completely the Po river continuity. The common stretch upstream the Serafini dam presents a structure for monitoring and capture of fish in transit. This structure is highlighted in the yellow circle in the follow picture as well as his rendering.
Picture 1: placement for Fish Passage at Isola Serafini; in yellow monitoring and capture structures; in blue the water flow.
Through two large windows, you can observe, in presence of an optimum in water clarity, different fish species in transit. In order to have an idea about the functionality of the fish pass, specific cameras will save this transit automatically. In the same area will be built a structure for capture and selection, composed by four large cages organized in variable mesh-nets. They will allow not only the capture of the species in transit in the two different branches but also a specific selection. In fact, any invasive species, such as Wels Catfish will be taken, while others, e.g. specimens of sturgeon, will be marked and released immediately in order to collect important data on their movements.
In addition to the benefits listed above, we recall the support provided by these facilities to educational activities developed under the project, including a multimedia classroom.
From the common part of the fish pass upstream the dam, the two branches of the structure divide themselves and the left one (in picture 1) acts as a link with the natural branch of the river (Picture 2).
Picture 2: stretch that connects the upstream flow with natural branch of the PO River, downstream of Isola Serafini
The other branch, the right one (Picture1), acts as a link with the artificial branch (Figure 3).
Picture 3: stretch that connects the upstream flow with artificial branch of the PO River, downstream of Isola Serafini.
It is interesting to remember that every following basins of the fish pass, has a minimum length of 4.75 meters and a minimum width of 2.80 meters. These dimensions were chosen in order to allow the transit of sturgeon, which can reach to 1.5 / 2 meters in length and which was used as target species for this project.
Realized Conference Services for the fish pass
The fish pass of Isola Serafini is, without doubt, a work of extreme value and its realization does not end with just the design phase, but is bound by law to a series of technical and institutional steps.
In this complex process, the Conference of Services performs a key role. Infact, it is call, lawfully, not only in order to collect suggestions for improving the work but also in order to obtain the agreement by the Institutional Authority.
The AIPo (Interregional Agency for the Po River) is the managing authority of the entire procedure. It has, infact, the role of supervising the technical planning of the reconnection of the Po river corridor. AIPo called, on the 6th of March, at the Parma headquarters, 17 managing institution in order to express opinion about the final plan.
During the opening session, the designers have presented to the participants the final plan emphasizing its importance in the process of Po basin de-fragmentation, as well as explaining the technical aspects of the whole project realization.
After a deep analysis, the work realization has not only an ecological value but also different and relevant technical and legal interests involved; AIPo has incorporated the suggestions of the present Institutional bodies.
It was therefore expressed a favourable opinion about the acts concerning the procedure for approval of the project.
Designers will complete the executive draft on 30th April 2014.