directly from UPS website Valtellina, here's what to expect for 2011:
SVAS CHAPTER: WHAT DO WE EXPECT FOR 2011
Giorgio Lanzi
During the year 2011 is provided for the continued operation of flare of some hydro dams that will complete the operations started in previous years, included in the project Interreg - Ecoidro that will end this year. These operations will focus on the basin and the reservoirs of Cancano Valgrosina and Sernio.
Del. in the basin will continue the work of flare to open up and check the functionality of the discharge of depletion of the reservoir. The first phase of work was done last spring and with the operations planned for this year, if everything will spin smoothly, will close the chapter of the special measures had become necessary after decades of not maintaining this system. The start of activities is scheduled for February 15 and will continue until opening the bottom outlet of the dam and for the period concerning the implementation of the same efficiency. All activities will be monitored in the same way last year. Also this time the material will be floated specially conveyed in Val Pola, where they will be willing the work necessary to make the most of it decant within this basin. Therefore, if the weather conditions and weather will remain in the rule and the holding tank of Val Pola will continue its work, the conditions of most fishable Adda will remain as good as last year.
Valgrosina As for the potting of Valgrosina rafting operations will be conducted during the period between August and September. Even in this case will be performed in continuous monitoring of concentrations of suspended solids on fish fauna and the ecological and biological components of the underlying streams receptors.
Sernio Sernio The basin will be continued and completed in a few days in the period between June and July, in ideal hydrological conditions of the river Adda (soft), the operations of mechanical diggers and rafting in some slow residual of silt in the tank yet.
reaffirm that all operations related to maintenance of the basins are strictly subject to procedures and timelines established by special permission and published . Unfortunately the heavy weather of recent years, characterized by heavy snowfall and several violent storms, often produce small landslides in the side valleys that have an impact on the conditions of major rivers fishable.
Situation Mallero - Warnings For two years now, an important hydrological instability in Val Torreggio may involve, as a result of rain or storms, the turbidity of a sudden Mallero and then downstream of the river Adda di Sondrio. The occurrence of these phenomena, although brief, is in no way predictable. To the extent possible Ups inform the occurrence of the phenomenon through its portal.
DONE IT WITHOUT ANY flared BASIN MADESIMO
unfounded alarm during the flare: the color similar to oil streams and Liro Scalcoggia was due to a harmless pigmentation problems resulting from the decomposition of organic plant material on the bottom of the reservoir.
In October operations were completed rafting Basin Madesimo Edipower by the Company. For the basin of Madesimo, as was the case for other invasive, non-implementation of an effective monitoring and periodic action of sediment transport, coincided with the latent attitude of the authorities responsible for issuing permits and dealing seriously binding these situations led to the progressive and relentless silting of the reservoir. Data from the bathymetry, during the years 2002 and 2004, showed an annual intake of 2,600 cubic meters of sediment. Before the flare operation, there were a total of approximately 32,000 cubic meters. sedimented material which accounted for 25% of the total storage volume amounted to 126,000 cubic meters of the reservoir.
recover the capacity of the reservoir, and restore the patency of the organs and discharge branch had become an urgent need and no longer be put off by the operator.
During the discussion of the project work by Edipower was evaluating the option of making the mechanical excavation of the sediment. The solution was discarded because it would involve considerable problems of transit for heavy goods vehicles on roads in much of ice or snow, heavy traffic from local roads and tourism, and the difficulty of finding an area for storage material in the vicinity of the basin.
Verified Rafting as the operation more sustainable, the activity was preceded by the chemical and physical analysis on the material in the sediment basin for the definition of quality. The results of this analysis, compared with the references of the law, have shown the suitability of the sediment release through a operation rafting. All monitoring activities before, during and post flare was performed within the Interreg project called Ecoidro.
From a technical point of view and scientific operations flare conducted on the basin of the same were a major test for the attainment of new knowledge in the management and control of sediment and floated in the monitoring activities. The verification of the concentration of suspended solids, produced by this movement, was performed with a fixed probe at the bridge Starleggia and a mobile probe upstream of the basin of Prestone.
were also made through sampling Imhoff cones and a series of withdrawals made by the staff of Fisheries Supervisory Union. The value of the concentration limit imposed on the overall average was Edipower be less than 10 g / l. At the end of the operation have been analyzed data collected by the sensors continuously adjusted based on the results of the laboratory. The significant fact that emerged is that the value of the total average concentration of solids over the entire operation was of 2.4 g / l, 25% of the limit value . As for the fish samples taken after the first flare showed no significant changes in the same stream over the previous situation.
The color is similar to the oil-water streams in Scalcoggia and Liro three days of the flare (October 19-22-21) has alarmed the public and local media but was not sure a new "Case Mera". The cause was due to a problem of pigmentation resulting from the decomposition of organic plant material on the bottom of the reservoir, the observation was subsequently confirmed by laboratory tests on water samples from ARPA. We can say that 'Autumn operation conducted on the basin of Madesimo solved permanently is a serious situation, next to the collapse of the reservoir. now entering a new phase of the facility where ordinary Edipower, with a prudent management, will avoid future silting of the basin.
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