High-level workshop “Action across sectors and borders for sustainable future of the River Basin” Organized by UNECE with support from the Italian Ministry of Environment, Land and Sea

Addressing the pressures on water quality: sedimentation Dr Marina Babić Mladenović, Executive director, Jaroslav Černi Water Institute Scoping study on erosion and sedimentation in the Drina River Basin

• Intends to provide a consistent picture about the occurrence of sedimentation and erosion in the basin and related existing problems, using data available in the three basin-sharing countries (Montenegro, and ). • Study is based on a combination geological/earth scientific and engineering expertise with water management and hydraulic infrastructure expertise + knowledge of the regional and the SRB level institutional and policy framework • The study datasets and geographical information system (GIS) shapefiles are developed and will be shared with the authorities and institutions concerned by erosion and sedimentation in the riparian countries. Activities

Preparation of the Study included the following steps:

▪ Collection of data from national authorities;

▪ Situation analysis;

▪ Identification of sources of sediment in the Drina River basin;

▪ Identification of areas with a deficit/surplus of sediment in the Drina River Basin;

▪ Analysis of the anthropogenic impact on erosion/deposition

▪ Identification of possible measures

▪ Proposal of priority measures. Basic characteristics of DRB

Slope gradient Land cover Runoff Hydrographic network Collection and review of data and documentation JCWI prepared a questionnaire which was delivered to competent authorities in Serbia, Bosnia and Herzegovina (Federation of Bosnia and Herzegovina and ) and Montenegro Results: Montenegro: Only data from Water Management Master Plan from 1997 are available. Data and shapefiles are used for this Study, with permission of Water administration. The erosion map was prepared according to the method of “Erosion Potential”, in which erosion was classified into 5 qualitative-quantitative categories, corresponding to the average value of the erosion coefficient - Z. Bosnia and Herzegovina, Federation of Bosnia and Herzegovina: Competent authorities form FB&H didn’t respond to questionnaire; therefore, data are not available for this Study. Bosnia and Herzegovina, Republic of Srpska: Erosion data were obtained from PE “Water of Srpska” in pdf format, without accompanying text. The erosion map for this DRB part was prepared according to the modified method of Gavrilovic, which contains 5 erosion categories divided into subcategories. The .pdf file was digitalised to obtain shape files for GIS map of the entire DRB basin. Serbia: only data from Water Management Master Plan from 2001 are available. Data and shapefiles are used for this Study, with permission of Ministry of agriculture, forestry and water management, Directorate for Water. An erosion map was prepared according to the method of “Erosion Potential”, in which erosion was classified into 5 qualitative-quantitative categories, corresponding to the average value of the erosion coefficient - Z. DRB erosion map

DRB Category of erosion Country Area I - II – III - IV – V – (%) Excessive Heavy Moderate Slight Very slight Serbia 30.44 1.54% 8.85% 23.51% 59.10% 7% Montenegro 32.57 0.30% 4.63% 20.93% 59.41% 14.74% Rep. of Srpska 31.90 1.08% 0.04% 2.83% 19.02% 77.03% Feder. B&H 4.38 0.43% 1.09% 46.64% 44.07% 7.78% DRB 0.93% 4.27% 15.95% 44.98% 33.87% Areas prone to erosion

The erosion areas = areas of the most intensive erosion processes (I, II, III) = Steep terrains with erodible geological substrate, or the areas adversely affected by excessive logging, fires etc.

Erosion areas are widespread in all major sub-basins of the Drina River (, Rogacica, Lim, Piva, Tara, Sutjeska, Drinjaca, Janja).

Total I+II: 5% or 1045 km2

Total I+II+III: 33,6 % or 6710 km2

Measures need to be applied! Sedimentation in reservoirs

• Surveys are sporadic • Reservoir volumes reduced 3-50% • Difficult to compare with erosion rates Sedimentation on river mouths

• Surveys are not available • Problems are evident Lower Drina – combined erosion/sedimentation problem

Development of the Lower Drina riverbed is very irregular and dynamic. The main river bed is relatively shallow and winding, and has relatively small capacity. New branches and cut-offs are developed during high water, with frequent erosion of river banks which leads to the degradation of agricultural land, and also endangers nearby houses and communications Proposal of key measures in DRB

Develop and update erosion maps to guide actions

➢ Prepare new erosion maps and define areas prone to erosion every 10 years, using the common methodology in all DRB countries

➢ Integrate erosion measures into spatial plans and forestry and agricultural master plans

➢ Integrate erosion and sedimentation map into the GIS Apply and monitor appropriate erosion control measures

➢ Apply measures to reduce erosion and torrent impact

➢ Prepare and maintain cadastre of erosion areas and structures built for anti-erosion and torrent control purpose

➢ Regularly assess the conditions of the existing structures and maintain them properly

➢ Apply biological and biotechnical measures to reduce soil erosion, providing beneficial results in synergy with torrential flood control and sustainable forestry Proposal of key measures in DRB

Raise awareness, promote and exchange good practice

➢ Raise awareness of sectoral actors and the population on the consequences of inadequate land use practice and appropriate recommended anti-erosion measures

➢ Exchange experience about good practices among DRB countries

Establish sediment monitoring system in DRB

➢ Set a network of suspended and bed load monitoring stations

➢ In cooperation with HPP operators regularly survey the existing reservoirs and analyse the sedimentation process development

➢ Investigate sediment quality, especially of sediments retained in reservoirs

➢ Regularly survey cross sections along the Drina River and the main tributaries. Estimate of anti-erosion and torrent control works and measures for in DRB Unite Unit of Type of work Quantity price Total (Eur) measure (Eur) Afforestation ha 12,000 1,500 18,000,000

Biological works Forest reclamation ha 3,000 1,000 3,000,000 Pastures and meadows planting ha 12,500 480 6,000,000 Masonry, wickerwork, trenches and Biotechnical works m 50,000 150 7,500,000 terraces Regulation of torrents (different Technical works m³ 170,000 350 59,500,000 structures) Preparation of cadasters km² 20,000 100 2,000,000 Other Maintenance km² 20,000 1,000 20,000,000 TOTAL 116,000,000

RS 35,5 Mio €; BH RS 45,1 Mio €; MNE 31,3 Mio €; F BH 3,9 Mio € Any questions?