Monitoring of the Iron Gate Hydropower and Navigation System on the Danube River - page 5

Fig. 10: Layout of drainage system in the Golubac municipality


Fig. 11: Number of piezometers in the riverine areas of the IG1 reservoir 



The Jaroslav Cerni Institute is authorized to recurrently review the monitoring data, to identify problems, and to indicate the need for any modification of drainage system operation plans or for the reconstruction of structures.

It may be concluded that adequately maintained drainage systems assure a good groundwater regime in most HPNS riverine areas. However, problems remain in some parts, and they will be solved after the completion of a designed protection system.

(III) Monitoring of sediment regime and deposition

Anticipating that impoundment would cause significant sedimentation, the initial investigations were carried out and IG1 reservoir siltation was predicted in the design phase (the Jaroslav Cerni Institute, 1962-1968). The forecast indicated considerable alteration of the sediment regime in the Danube and its tributaries, which would result in a relatively slow development of sediment deposits.

The sediment monitoring program within the IG1 reservoir was launched in 1974 (Sretenovic et al., 2004). The methodology for monitoring, measurements and analyses of the sediment transport parameters was developed in order to assess the annual balance of sediment within the reservoir. In view of the relatively low share of bed-load, the sediment balance estimates are based on suspended sediment records only. Following construction of the IG2 dam in 1985, the program was expanded to include the new reservoir.

Major attention was devoted to the selection and verification of a technology for water and suspended sediment measurements, and methods for laboratory processing. The methodology selected at that time is still in use today (Varga et al., 1989; Varga et al., 1996; Babic Mladenovic, 2006). This program continued from 1974 to 2012, but the scope of activities varied from year to year.

Four types of sediment monitoring activities were established, as presented in Table 1.


Table 1: Type and frequency of observations