Sava River Basin Management Plan Background paper No.1 Surface water bodies in the Sava River Basin March 2013 This document has been produced with the financial assistance of the European Union. The contents of this document are the sole responsibility of the beneficiaries and can under no circumstances be regarded as reflecting the position of the European Union. Sava River Basin Management Plan Table of Contents 1. Introduction ......................................................................................................... 5 2. Description of the Sava River and its main tributaries ......................... 5 2.1 Sectioning of the River Sava.................................................................................................. 8 3 Delineation of surface water bodies ............................................................ 10 4 Surface water monitoring network in the Sava River Basin ............... 18 4.1 Introduction .................................................................................................................................... 18 4.2 Assessment of the existing national and Danube basin wide monitoring networks .................................................................................................................................... 19 4.3 Danube Transnational Monitoring Network ...................................................................... 21 4.4 Comparability of monitoring results ....................................................................... 23 4.5 Monitoring of hazardous substances in the Sava River during Joint Danube Surveys ....................................................................................................................................... 25 4.6 Description of the WFD compliant surface monitoring programmes in the Sava River Basin ..................................................................................................................... 26 4.6.1 Designing of surveillance monitoring ................................................................. 27 4.6.2 Designing of operational monitoring .................................................................. 28 4.6.3 Designing of investigative monitoring ................................................................ 29 4.6.4 Frequencies of the monitoring ............................................................................... 29 4.6.5 Methods for monitoring ........................................................................................... 30 4.6.6 Cost estimation of surveillance monitoring ...................................................... 30 5 Surface Water Status ...................................................................................... 36 5.1.1 Introduction .................................................................................................................. 36 5.1.2 Quality elements .......................................................................................................... 36 5.1.3 Reference conditions ................................................................................................. 38 5.1.4 Normative definitions ............................................................................................... 40 5.1.5 Setting Ecological Quality Rations - based class boundaries ..................... 41 5.1.6 Classification ................................................................................................................. 42 5.1.7 Confidence in the status assessment ................................................................... 44 5.1.8 Methods of assessment of ecological and chemical status. ...... ....................48 5.2 Ecological status/potential and chemical status assessment ...................................... 46 5.2.1 Gaps and uncertainties ............................................................................................. 50 6 References ......................................................................................................... 51 Background paper No.1: Surface Water Bodies in the Sava River Basin 2 Sava River Basin Management Plan List of Figures Figure 1: Sava River sub-basins (with catchment areas larger than 1,000 km2) Figure 2: Ecoregions within the Sava River Basin. Figure 3: Sectioning of the Sava River Figure 4: Number of all delineated surface water bodies in the Sava River Basin per country Figure 5: The length (in km) of the natural delineated WBs, HMWBs and candidates for HMWBs for the Sava River and its tributaries Figure 1: Surface water monitoring stations in the Danube River Basin District Figure 7: Stations for the different types of monitoring of surface water Figure 8: Distribution of Cadmium in the SPM along the Danube River during JDS2 Figure 9: Basic principles for classification of ecological status based on Ecological Quality Ratio (EQR). Figure 10: Basic scheme of ecological and chemical status assessment including quality elements. Figure 11: Indication of the relative roles of biological, hydromorphological and physico-chemical quality elements in ecological status classification according normative definitions. Figure 12: Confidence levels for ecological status assessment Figure 13: Confidence levels for chemical status assessment. Figure 14: Length (km) of the individual ecological status classes in the Sava River and its tributaries Figure 15: Assessment of the chemical status in the water bodies of Sava River and its tributaries (length of water bodies – km) List of Tables Table 1: List of the rivers in the Sava River Basin considered for the Sava RBMP Table 2: List of delineated surface water bodies Table 3: The share and area of the Sava River Basin per country; length and number of delineated WBs for Sava River Basin rivers with catchment areas >1000 km2 (including Sotla/Sutla, Lašva, Tinja) Table 1: a/b Water concentrations of organic substances determined in the Sava River during the JDS2 (in ng/L) Table 5: Frequencies of the monitoring Table 6: Cost estimation for the surveillance monitoring Table 7: Quality elements to be used for assessment of ecological status based on the list in Annex V, 1.1 of the WFD. Background paper No.1: Surface Water Bodies in the Sava River Basin 3 Sava River Basin Management Plan Table 8: The assessment of the ecological status for Sava River and its tributaries Table 9: The assessment of the chemical status for Sava River and its tributaries List of Annexes Annex 1: Details on surface water body delineation and status assessment in the Sava River Basin Annex 2: Surface water body status assessment in the Sava River Basin Background paper No.1: Surface Water Bodies in the Sava River Basin 4 Sava River Basin Management Plan 1. Introduction This background paper gives information on description of the rivers in the Sava River Basin, the process of surface water bodies (SWBs) delineation, assessment of surface water monitoring network including proposal for achievement of compliance with WFD and methodologies applied for surface water body status assessment. 2. Description of the Sava River and its main tributaries The Sava River rises from the Sava Dolinka and the Sava Bohinjka in Slovenia. With its numerous tributaries along 945 km waterway to the Danube, it represents one of the most significant basins in the region (basin area of 97,713.20 km2 – SRBA Report, 2009). Together with its longer headwater, the Sava Dolinka River, the length of the river is 990 km. Confluence of the Sava River into the Danube is in Belgrade (1,170 rkm of the Danube). Its average discharge at the confluence (Belgrade, Serbia) is about 1,700 m3/s which results in the long-term average unit-area-runoff for the complete catchment of about 18 l/s/km2. The most important tributaries are listed in Table 1. Based on the SRBA Report (2009), it was agreed that the rivers with drainage area above 1,000 km2 will be taken into account as well as reservoirs with a volume above 5 million m3. Next to the above mentioned rivers, three smaller rivers (Sotla/Sutla, Lašva, Tinja) of the basin-wide importance were included in the Sava RBMP. The detail hydrological features are described in SRBA Report (2009). In general, the upper part of the basin is characterized by torrential tributaries – Kkra, Kamniška Bistrica and Savinja (from the left side) and Sora, Ljubljanica and Krka (from the right). East of Ljubljana, the Sava flows through a 90 km long gorge and afterwards through the Karst Plain (Krško polje). In its middle and lower stretch, the Sava River flows through wide floodplain. Common feature of almost all right tributaries of the Sava River is their torrential character, particularly in their upper sections. River channels are often deeply cut into the hard rocks, with very violent flow through gorges. The Bosna, Una and Vrbas Rivers are, by the size of catchment area, as well as the length, among the most important tributaries. Background paper No.1: Surface Water Bodies in the Sava River Basin 5 Sava River Basin Management Plan Table 1: List of the rivers in the Sava River Basin considered for the Sava RBMP River name River River Sava RB Tributary Confluence to basin length countries order the size (km) sharing the Sava/tributary (km2) river basin L-left side R-right side Sava 97,713.2 944.7 SI, HR, BA, ME RS - - Ljubljanica 1,860.0 40.00 SI 1st R Savinja 1,849.0 93.60 SI 1st L Krka 2,247.0 94.70 SI 1st R Sotla/Sutla 584.3 89.70 SI, HR 1st L Krapina 1,237.0 66.87 HR 1st L Kupa/Kolpa 10,225.6 118.3