Establishment of the Sediment Monitoring System for the Sava River Basin - page 02

Review of the Present Monitoring Networks, Standards, Techniques and Practices in SRB Countries

Slovenia. Hydrologic monitoring, including monitoring of sediment transport is performed by the Slovenian Environment Agency (ARSO). The results of the regular hydrologic monitoring are published in annual reports and the results of additional measurement, performed during flood events, are published in special reports. More details on monitoring can be found on http://www.arso.gov.si/.

Present number of monitoring sites for suspended load is far from being optimal. Suspended load monitoring was interrupted for some years, and will be re-established in the course of 2015 through the execution of the program BOBER (started in 2010) at 9 monitoring stations in the Republic of Slovenia - is presently done on only 3 rivers in the SRB: the Sava River (gauging station Hrastnik), the Sora River (g.s. Suha) and the Savinja River (g.s. Veliko Širje I). Suspended sediment is not monitored on any other 1st order tributaries of the Sava River (Ljubljanica, Krka, Sotla/Sutla and Kolpa/Kupa).

Measurements of suspended sediment are done continuously, using turbidity meters. The usual method for discharge measurements in gauging stations is nowadays the application of Acoustic Doppler Current Profilers (h-ADCPs). Knowing the profile of sediment concentration and discharge (measured at the same time) sediment transport rate (kg/s) through profile is calculated and finally summed up to an annual profile sediment load (kg/year). Sediment concentration is obtained through conventional filtration method. Suspended load data is gathered on daily, monthly and annual basis. Annual overview of daily suspended load concentrations (kg/m3) and daily transportation rates (kg/s) is freely available on the web in the ARSO hydrologic archive. Bedload measurements do not exist.

Water quality monitoring is also performed by ARSO at 6 water bodies/river reaches (2 reaches at the Sava Dolinka River, 2 sites at tributaries of the Lower Sava River (Krka, Sotla/Sutla Rivers), and 2 sites at the Lower Sava River (Vrhovo-Boštanj, border cross section at Jesenice na Dolenjskem). For sampling of river sediments standards SIST ISO 5667-12 & ISO 5667-15 are used. For the chemical analysis of sediments the wet sieved fraction < 63 μm is used. Primary substances in sediments are sampled 4 to 12 times a year.

Monitoring of reservoir sedimentation is an obligation of HPP owners (SEL - Savske elektrarne, Ljubljana and HESS – Hidroelektrarne na Spodnji Savi). Sedimentation is monitored in reservoirs of HPP Moste on the Sava Dolinka River, HPP Mavčiče and HPP Vrhovo on the Sava River.

For dredging of fluvial (river) sediments concessions for dredging are issued according to the Water Act as a stand-alone legislation act in alignment with the Water Management Plans. Data on dredging are collected on a few locations: Hrušica in the Sava Dolinka River upstream of the HPP Moste, cross section Hotič upstream of Litija on the Sava River, reservoir upstream of the weir for cooling water intake for the Nuclear Power Plant Krško on the Sava River.

Survey of cross sections on water gauging stations is performed by ARSO on a regular basis (on average four times a year), occasionally using ADCP on a boat (in existing HPP reservoirs).

Croatia. Sediment monitoring in Croatia is a task of the Hydrological and Meteorological Service, Hydrology Department (DHMZ). Suspended sediment is monitored on 10 gauging stations in SRB (4 stations on the Sava River and 6 stations on the tributaries). Grab samples (dipping a bucket/container in the river), point or depth integrating samplers are used, according to ISO 4365:2005 standards. ISO 4363:2002 standards are followed for profile mean suspended sediment concentration and mean particle size distribution measurements.

Point samples at all gauging stations are taken once a day. Profile measurements of sediment concentration and sediment load, at 3 stations on the Sava River, are done periodically. The usual methods for discharge measurements are Acoustic Doppler Current Profiler (ADCP) or hydrometric current meter. ADCP is also used in suspended sediment concentration measurement. Knowing the profile sediment concentration and discharge (measured at the same time) sediment transport (kg/s) through profile is calculated. Sediment concentration is obtained through standard vaporization and filtration methods. Bedload measurements do not exist.

 

Suspended load data is gathered on daily, monthly and annual basis and its correlation with water levels, discharges, and grain size distribution of the material is derived. All hydrological parameters, including sediment data, are being stored in hydrological database (Hydrological Information System 2000). Annual overview of daily suspended load concentration and transportation rates is published in the Hydrological yearbooks. Periodic profile measurements of concentrations and transportation rates and grain size distribution of material are published in annual reports and studies. More details on monitoring can be found on www.dhmz.htnet.hr.

Water quality monitoring is done by Croatian Waters on seven locations as part of the general plan for water quality monitoring (according to WFD requirements). As there are no standards for the assessment of the sediment quality, the content of substances are compared between different streams. Besides the regular monitoring, periodic chemical analyses are performed by different institutions on a project-to-project basis. DHMZ is responsible only for particle size distribution of suspended and bed load at some hydrological gauging stations.

Monitoring of reservoir sedimentation is obligation of HPP owners and Croatian Waters and is done by DHMZ. Presently done only in the reservoir upstream of the Novska lake in order to control intake of sediment load into the lake.

According to their responsibility, Croatian Waters collect data on dredging. Croatian Waters and Agency for inland waterways (Agencija za vodne putove) are responsible for surveys of the Sava riverbed, while DHMZ is monitoring morphological changes at the locations of hydrological gauging stations.

Bosnia and Herzegovina. The right bank of the Sava in Bosnia and Herzegovina belongs to Federation of Bosnia and Herzegovina, Republic Srpska, and Brcko District. Water monitoring is carried out by hydrometeorological services of 2 entities (FHMZFBIH and RHMZRS), but sediment transport is presently not done in this frame.

Water quality monitoring in Republic Srpska is performed by Javna ustanova Vode Srpske and Agencija za vodno podrucje rijeke Save in Federation BA. Sediment quality investigations were performed only through a few projects – NATO SfP DSS for river Bosnia and JICA Hot spots in BA, and "Sava River Basin project: Sustainable usage, management and protection of resources". Samples were collected four times (08/2005, 11/2005, 05/2006, 10/2006) after drought and rain periods.

Monitoring of reservoir sedimentation is obligation of reservoir owners, performed recently only by JP "Spreca", for reservoir "Modrac". Javna ustanova Vode Srpske in Republic Srpska and Agencija za vodno područje rijeke Save in Federation BA are responsible for dredging. Responsible institution for survey of river cross-sections is not defined.

Serbia. Sediment monitoring is still present in the Program of the Republic hydrometeorological service of Serbia (RHMZ), but presently not executed. In the past, RHMZ did regular suspended sediment monitoring on a number of gauging stations in SRB. Monitoring was done on the Sava River, at Sremska Mitrovica (1958-1980), Sabac (1958-2002), and Beograd (1958-1998), as well as on large tributaries: the Drina (Badovinci, 1990-2001) and the Kolubara River (Drazevac, 1958-2002). Instruments and methodology should be updated. Also, Institute Jaroslav Cerni conducted yearly programs of the Iron Gate 1 reservoir monitoring, between 1974 and 2014. These encompassed daily monitoring of suspended sediment transport at Beograd and Sremska Mitrovica on the Sava River.

Ministry of agriculture and environmental protection, Agency for Environmental Protection is responsible for sediment quality monitoring. River sediments are analysed at 4 locations on the Sava River (Jamena, Sremska Mitrovica, Šabac, Ostružnica) and many locations on the Drina, Lim, Kolubara and Topčiderka Rivers. Standard is set in by-law, but without sampling schedule.

Electric Power Industry of Serbia is responsible for monitoring of sedimentation of HPP reservoirs of on Drina River (HPP Bajina Basta and HPP Zvornik). Occasional monitoring include sampling of bed material and survey of the riverbed within reservoir space.

Ministry of agriculture and environmental protection, Republic directorate for water is responsible for dredging. Only data on water permissions for individual dredging fields are stored in a database. Actually dredged quantities are not available. Ministry of Construction, Transport and Infrastructure, Directorate for Inland Waterways is responsible for survey of the Sava riverbed. Sava riverbed was surveyed in 2004 and 2009.