The Siret River Basin is characterized by an important use
of hydro potential, resulted in the number of reservoirs constructed and
operational. The cascade power stage of the reservoirs on Bistrita and
Siret rivers indicate the anthropic interventions with different purposes
(hydro energy, water supply, irrigation etc.) in the Siret River Basin. In
terms of the capacity in the Siret River Basin there is a dominance of the
small capacity reservoirs, which is given by the less than 20 mil m³
volumes. Only two lakes have capacities over 200 mil m³: Izvoru
Muntelui on Bistrita River and Siriu on Buzau River. Based on the
monitoring of the alluvial flow at the hydrometric stations, from the
Siret River Basin, there have been analysed the sediment yield
formation and the solid transit dimensions in order to obtain typical
values for the geographical areas of this territory. The silting of these
reservoirs was monitored by successive topobatimetric measurements
performed by the Bureau of Prognosis, Hydrology and Hydrogeology and
a compartment within Hidroelectrica S.A. Piatra Neamt Subsidiary. The
quantities of the deposited sediments are very impressive. The annual
rates range betwee3 000 – 2 000 000 t/year, depending on the size of
the hydrographical basin, the capacity of the reservoirs, the liquid flow
and many other factors which may influence the upstream transport of
sediments. These rates of sedimentation lead to a high degree of silting
in the reservoirs. Many of them are silted over 50% of the initial capacity
and the others even more. The effects of the silting have an important
impact when analysing the effective exploitation of the reservoirs.
Keywords:
Reservoir, silting, alluvial deposits, Siret River Basin