Hrvatska Elektroprivreda

MULTIPURPOSE PROJECTS

NOVO VIRJE HYDROELECTRIC POWER PLANT

ENVIRONMENTAL IMPACT STUDY SUMMARY

Multipurpose Projects

Novo Virje Hydroelectric Power Plant

Environmental Impact Study Summary

Client:

Hrvatska Elktroprivreda

(Croatian Power Board)

Contractor:

Elektroprojekt Consulting Engineers

Prepared by:

Zdenko Mahmutović, B.Sc.

Vladimír Žarković, M.Sc.

Dr Stjepan Mišetić

Vladimír Sečen, B.Sc.

Design Volume:

Y2-E54.00.38.-H01.0

Zagreb, November 2000

TABLE OF CONTENTS

1. INTRODUCTION

1.1 General 1.2 Project Development Objectives 1.2.1 Power Generation 1.2.2 Flood Control and Watercourse Training 1.2.3 Agriculture 1.2.4 Roads 1.2.5 Water Supply 1.2.6 Growth in Reservoir Fish Mass 1.2.7 New Jobs 1.2.8 Other Purposes 1.2.8.1 Fish Farming 1.2.8.2 Recreation and Tourism 1.2.8.3 Processing Industry Development 1.2.8.4 Environmental Quality Assurance and Control 1.2.8.5 Cultural and Historical Heritage 1.2.8.6 Demographic Revival 1.2.8.7 Increased Job Opportunities 1.3 Major Project Structures 1.3.1 General 1.3.2 Resenroir 1.3.3 Concrete and Backfill Dam 1.3.4 Powerhouse 1.3.5 Outlet Canal 1.3.6 Other Structures 1.3.7 Power Plant Operating Mode

2. SITE AND LOCATION DESCRIPTION

2.1 General 2.2 Climate 2.3 Hydrology

2.4 Hydrogeology 2.5 Agricultural Land Characteristics 2.6 WaterQuality 2.7 Habitats, Flora (plants) and Fauna (animals) 2.7.1 Water and Wetland Habitats 2.7.2 Land Habitats 2.7.3 Rare, Endangered and Protected Plants in the Study Area 2.7.4 Rare, Endangered and Protected Plants in the Occupation Area 2.7.5 Animals 2.7.6 Rare and Endangered Animals 2.7.7 Protected Animals 2.8 Forests 2.9 Valuable Nature 2.10 Structures and Infrastructure 2.11 Hunting 2.12 Fishery 2.13 Population 2.14 Economy 2.15 Natural and Cultural Capital 2.16 Landscape Characteristics

3. BASIC INVESTMENT DATA

3.1 Reservoir 3.2 Lateral Canal 3.3 Dam 3.4 Powerhouse 3.5 Outlet Canal 3.6 Infrastructure 3.7 Agricultural Land Drainage 3.8 Power Generation Data 3.9 Permanent Occupation Area 3.10 Construction Costs 3.11 Construction Duration 3.12 Novo Virje HPP Annual Operation Description 3.13 Economic Indicators

4. OVERVIEW OF POSSIBLE ENVIRONMENTAL IMPACTS

4.1 General 4.2 Physical Impact on Surface Waters 4.3 Impact on Climate 4.4 Impact on Hydrological Characteristics 4.5 Impact on Earthquakes 4.6 Impact on Water Quality 4.7 Impact on Agricultural Land 4.8 Impact on Plants, Animals and Characteristic Habitats 4.9 Impacts on forests 4.10 Impact on Valuable Nature 4.11 Impact on Structures and Infrastructure 4.12 Impact on Hunting 4.13 Impact on Fishery 4.14 Sociological and Demographic Impacts

4.15 Impact on Business Sector 4.16 Impact on Cultural Heritage 4.17 Impact on Landscape

5. PROTECTIVE AND MITIGATION MEASURES

5.1 General 5.2 Agricultural Land Protection 5.3 Water Quality Protection 5.4 Protection of Living World and Characteristic Habitats 5.5 Protection of forests 5.6 Protection of Structures and Infrastructure 5.7 Protection of Hunting 5.8 Protection of Fishery 5.9 Sociology 5.10 Economy 5.11 Protection of Cultural Heritage 5.12 Protection of Landscape

6. DRAFT ENVIRONMENTAL MONITORING PROGRAM

7. REFERENCES

1. INTRODUCTION

1.1 General

The Environmental Impact Study (EIS) Summary is an abbreviated presentation of the Novo Virje HPP Final Environmental Impact Study. The Summary will be used to inform the wider community about the existing natural and developed status of the narrower and greater surroundings in which the planned hydroelectric power plant will be integrated, and about possible environmental impacts of the planned hydroelectric power plant, the measures to be undertaken for alleviation of such environmental impact and the environmental monitoring program to be enforce before during and after the project implementation.

The Study development has been undertaken to assess the project environmental impact. The assessment is aimed at environmental protection. The basic environmental protection objectives aimed at ensuring the conditions for sustainable development include:

● permanent preservation of genuine biodiversity of natural communities and ecological stability,● preservation of animate and inanimate nature and conservation of nature and its capital,● preservation and revitalization of cultural and aesthetic values of landscape,● environmental improvement and ensuring better living conditions.

The environmental impact assessment must be based on awareness of all solution which are often beyond the scope of a particular environmental impact study. Such comprehensive solution sets include all the considered concepts for a project (alternatives) and possible replacement concepts (options). A set of alternative concepts for the Novo Virje HPP includes all the options considered for the Ðurðevac Hydropower System and the Novo Virje HPP, while the options include either construction of a coal-, oil- or gas-fired thermal power plant on some other location or setting up of a biosphere reservation.

For the purpose of comparison with optional power generation concepts, it should be highlighted that the Novo Virje HPP has numerous purposes in addition to its primary role, and they are all contributing to the overall development of the region and the country as a whole. The Novo Virje HPP does not cause air, soil or water pollution and has no public health impacts. Further on, it uses a renewable energy source - water- rather than fuel the global reserves of which will be probably depleted during the power plant lifetime.

The Novo Virje HPP Conceptual Design has been developed pursuant to the decision of the Government of the Republic of Croatia of July 7, 1992 to substitute the Ðurðevac HPP envisaged by the Master Plan of the Republic of Croatia (Official Gazette 12/1989).

The Novo Virje HPP is a multipurpose hydraulic engineering structure adjacent to the dam, located in the Koprivnièko-Kri§evaèka County. It is located some 120 km north of Zagreb, and occupies the Drava River section between Botovo and Kingovo.

The power plant location is part of the Pannonian valley where enormous arable land areas alternate with comparatively large forest, meadow and grove areas. The landscape is particularly attractive for mild meandering of the Drava River and its tributaries, numerous backwaters, ponds and dead waters (Fig. 1.1).

The Novo Virje HPP Final Environmental Impact Study has been prepared on the basis of conclusions of the second session of the Expert Commission of the Republic of Croatia set up to evaluate the Novo Virje HPP environmental impact, and derived from the documents and discussions contributed by the Commission members during the two sessions. The first session was hold on March 5 and 6, 1996 and the second on March 27, 1996. This Summary has been prepared for public presentation and hearings pursuant to the Commission's request, after Commission had accepted the Final Study on its third session of October and 2, 1997.

The principal system purposes and values include:

● power generation by harnessing a renewable resource (water) without environmental pollution and ad e impact on public health,

● protection of population and property against detrimental impact of water, financed through a grant from the state budget,

● increase in agricultural and animal husbandry production● infrastructural improvements (construction of a water supply network, roads, bridges).

Although the Drava is a border river, according to the Preliminary Study within which 110 alternatives have been analyzed, the entire project would be built on the Croatian territory (Fig. 1.1).

The occupation area and the hydroelectric power plant valley have no specially protected natural capital stipulated by the Nature Conservation Act of Republic of Croatia.

It is important that construction of the project will not lead to extinction of any Croatian or European plant or animal specie and, will exercise maximum protection of the natural capital in the river valley. However, the project will bear direct impact on about 22 km of undeveloped but trained river course of the Drava with marvellous landscape typical for high biodiversity, ecological variability and beauty.

The environmental protection was paid particular attention in the design development.

The environmental protection in the area by and along the Novo Virje HPP, namely alleviation of possible adverse impact of the project on the Podravlje (the Drava Basin) region landscape includes:

● Preservation and protection of aquatic habitats● Preservation and protection of wetland habitats● Preservation and protection of terrestrial habitats● Maintenance of eroded banks● Maintenance of steep banks● Regeneration of natural habitats in part of designed landscape● Making habitats for imperilled animal species● Integration of the project structures into the morphological and vegetation characteristics of the landscape

To clarify:

● The study area is an area considered and researched for the Environmental Impact Study. The area encompasses the left and right Drava River valley, from Legrad to Ferdinandovac, with total surface area of approximately 40,600ha, wherefrom about 9,650ha in the Prekodravlje region; the study area is much wider than the influence area (Fig. 1.1).

● The occupation area is the site to be occupied by the Novo Virje HPP of approximately 2,685ha.● The system area is the site planned for construction of all the structures within the multipurpose Novo Virje HPP

system. It encompasses the occupation area (2,685ha), and the arable land drainage area (12,085ha), 3,330 ha in the Prekodravlje region, 8,755 ha in the Pridravlje region, that is total of 14,770ha.

Figure1.1 Figure1.2

1.2 Project Development Objectives

The Novo Virje HPP construction objective is multipurpose development, protection and utilization of the Drava River water and adjoining catchment on an approximately 30 km long stretch.

The system falls within the framework of the strategic development of both the region and the state and should be evaluated correspondingly, considering all involved interests in comprehensive and integral manner.

The primary purposes of the system include:

● power generation● reliable flood control● tributaries and torrent control● improvement in farming and animal husbandry production● roads construction● new jobs

● reservoir fish mass growth

Other purposes include:

● fish farming● recreation and tourism● processing industry● environmental quality assurance and control● conservation and revitalization of cultural and historical heritage● demographic revival● increased job opportunities

1.2.1 Power Generation

Regarding its capacity and output, the Novo Virje HPP is the largest undeveloped hydropower system in the Republic of Croatia (Fig. 1.3).

The installed discharge is 960 m3/s, total mean head 16.4 m, average capacity 138 MW and average power output 640 GWh/an.

The average Novo Virje HPP output makes:

● 14% of average annual generation of 21 hydroelectric power plants in Croatia for the period 1990-1994,● over 22% of average generation of the thermal power plants in Croatia for the period 1990-1994,● over 7% of total average power generation in Croatia for the period 1990-1994,● 6% of average direct consumption (industry, transport, general consumption) for the period 1990-1994 (Figs. 1.4

and 1.5)

The Drava River regime is suitable for water harnessing for power generation since its largest discharges are in spring and late summer when the discharges of other water streams are minimum.

Figure 1.3-1.4 Figure 1.5

1.2.2 Flood Control and Watercourse Training

Construction of the Novo Virje HPP system will bring about a comprehensive and more safe control of the Drava River floods. The existing system of dikes has never been finished and it therefore does not protect all potentially endangered areas within the river valley.

Construction of the Novo Virje HPP and control of the Drava River flow will abolish the need for construction of new and maintenance of old protection structures.

1.2.3 Agriculture

Construction of the Novo Virje HPP system, which includes drainage of arable land on surface area of about 12,085 ha eliminates adverse effects of the power plant construction and removes limitations to agricultural production caused by high groundwater tables in the river valley. Further, construction of the drainage system protects the arable land from the water in the river valley.

1.2.4 Roads

Construction of the Novo Virje HPP will include construction of road on the, left and right sides of the reservoir and lateral canal. An access road will be built, running from the settlement of Novo Virje to the intake structure, where a bridge across the Drava will be built as an additional public traffic crossing of the Drava River.

1.2.5 Water Supply

The settlements located in the Novo Virje HPP valley are supplied with water from the local driven or dug wells, and the water is generally not of drinking quality. Therefore, the water supply network construction is planned for these settlements. The Novo Virje HPP construction is an impetus for faster development of these significant utilities which had

to be built sooner rather than later.

1.2.6 Growth in Reservoir Fish Mass

Construction of the Novo Virje HPP will result in changes regarding composition and quantity of fish in the Drava water stream, and in increase of water surface. Productivity of fish in this section of the Drava River prior to construction has been estimated to approximately 40 kg/ha. However, the reservoir fish productivity has been estimated between 50 and 60 kg/ha, and productivity of fish in the Drava between the dam and the outlet canal mouth is between 35 and 40 kg/ha.

The fish stock may be managed by classical methods, through the fishing sport organized by the sport fishing societies. However, possible annual fish catch of 100 ton can hardly be achieved by such classical methods, so the reservoir could also be used for business purposes pursuant to the legislation on fresh-water fishery

1.2.7 New Jobs

Construction of the Novo Virje HPP will enable new employment. The vacancies are expected to be open in the power plant and the appurtenant structures, and in the river valley protection structures, primarily for canal network maintenance.

1.2.8 Other Purposes

Other purposes have not been separately evaluated, but their benefits are estimated to approximately 10% of the primary purposes. Such secondary activities include: fish farming, processing business development, environmental quality assurance and control, protection and reconstruction of cultural and historical heritage, demographic revival, and increased job opportunities.

1.2.8. Fish Farming

The hydropower structures in Croatia have been used for fishery-related purposes mainly through the fishing sport organized within the sport fishing associations. However, investment of capital, know-how and work in the Novo Virje HPP project will result in considerable increase in the water utilization efficiency. The proposals are interesting regarding new job opportunities, environmental development, and increase in quality of life of the local population.

Possible options for fishing and fish-farming use of the Novo Virje HPP include:

● Recreation and game fishing (angling)● Professional fishing business● Cage breeding● Hot water fish breeding in compartments (fenced lagoons)● Trout breeding in water stream along the lateral canals● Hot water fish breeding in ponds

Some of the above options could be cross-linked. Further, the fish breeding could be connected with duck breeding, agricultural irrigation and truck farming fertilization.

1.2.8.2 Recreation and Tourism

The natural capital within the planned hydroelectric power plant valley and the reservoir itself are attractive areas for recreation, leisure, tourism and fishing activities.

Construction of the Novo Virje HPP system will enable development of sports and recreation centers which would attract additional visitors to the site. The amenities for walking, bird watching, fisherman pathways, swimming, rowing, excursions and camping will be built, along with the grounds for sports activities and various accompanying, facilities. Such development will contribute to the tourist offer of this part of the Podravina Region.

1.2.8.3 Processing Industry Development

Generation of electric power, development of agriculture, fish farming, recreation and tourism establish favorable conditions for increase in income in the processing industry within the greater area of the Novo Virje HPP. The arable land reclamation results in increased agricultural production and growing of valuable cultures, and that will affirmatively reflect on the local food industry.

Impoundment of the reservoir, construction of roads and sharing of space by larger number of visitors creates the option for development of recreation and tourism. Consequently, this regions will in some periods be occupied by larger number of people and that should result in increased sales of different products and services.

1.2.8.4 Environmental Quality Assurance and Control

The Novo Virje HPP project construction and later operation will not cause pollution of water, soil and air, and will not be a source of noise emissions. However, the construction of the system will encourage resolving of the problems in the region and set up the environmental monitoring system used prior to the project onset, during construction and after the commissioning.

The Novo Virje HPP multipurpose system design elaborates the environmental improvement and development concepts for the project river valley.

1.2.8.5 Cultural and Historical Heritage

Although the studied region accommodates no archeological sites (such as the remains of cultural monuments) entered into the Register of Cultural Monuments, construction of the Novo Virje HPP initiates protection and further research into the possible archeological sites.

Most settlements in the region have long history, but the poor level of research has caused that only Gola settlement has been protected as the cultural monument.

The indirect benefit of the improvements and development in the region will be public awareness of need for permanent protection and revitalization of cultural and historical values, namely protection of the traditional architecture from further degradation.

1.2.8.6 Demographic Revival

Long-term decrease in population and decline in age-structure are the Basic characteristics of the region. According to the analyzed 1981 Census data, share of older population is on increase while the share of the young, particularly in rural communities of the Prekodravlje Region, is on decrease.

One of the long-term benefits of the planned project would be improvement in the living conditions and thus lower migration of the young and mature population and resettlement of new inhabitants.

1.2.8.7 Increased Job Opportunities

Realization of chances opened by construction of the Novo Virje HPP would result in a corresponding number of new jobs in agriculture, fish farming, processing and tourist industry. The new jobs will primarily depend on the size and rate of investment into the subject activities.

1.3 Major Project Structures

1.3.1 General

All parts of the power plant, i.e. reservoir, embankments, lateral canals around the reservoir and the river closure section (dam, powerhouse) are planned for construction in the riverbed and flood plane within the existing water management dikes, while about 60% of the lateral canal is located in the existing flood plane area. Consequently, the demand for agricultural land occupation is very low, the forests and settlements are not affected but for five households and 13 summer cottages downstream the Repaç bridge (Fig. 1.1).

1.3.2 Reservoir

The embankments are original sand-gravel material, with asphalt concrete lining on the reservoir side, with the exception of the most upstream reservoir section which is not permanently impounded.

The lateral canals are built in immediate vicinity of the reservoir embankment. They are planned as recipients for the seepage from the reservoir and the runoff from the river valley. Their capacity is such that they will ensure favorable groundwater levels in the river valley. They are fitted with weirs and bridges. The weirs are built to maintain the flow and natural condition of the backwaters, ponds and still waters in the planned power plant valley. The right-hand lateral canal will receive water from the Gliboki stream and Bistra canal (Fig. 1.6).

1.3.3 Concrete and Backfill Dam

The backfill dam is located between the left reservoir embankment and the concrete dam. Total dam length in its axis is 377 m. The dam crest elevation is 126.000 m a.s.l.. Maximum dam height is 20.5 m.

The dam impermeability is achieved with asphalt-concrete lining and by its connecting with the vertical clayconcrete curtain. The dam air face slope protection is grassed top soil. The dam crest is accessible from an access ramp. The access ramp, the dam crest, and the left platform are asphalt coated. Along the dam crest, construction of a wave wall is planned (Fig. 1.7).

The concrete dam is a reinforced-concrete structure with low spillway sill, four spillway bays with span distance of 4x18 m, separated with columns, fitted with radial gates and flaps (total height 15.80 m). The dam crest is on el. 126.00 m a.s.l., the dam sill is on el. 106.70 m a.s.l., and the spillway crest is on el. 108.50 m a.s.l. (Fig. 1.8).

1.3.4 Powerhouse

The powerhouse is located in immediate vicinity of the concrete dam in the southern part of the intake structure. The powerhouse is a massive mostly underground structure. The powerhouse is to be furnished with three generating units with vertical-shaft turbines and Kaplan turbines. The power plant capacity at installed discharge of 960 m3/s will be somewhere between 123.2 MW and 139.2 MW, depending on the extent of the riverbed dredging downstream the outlet canal mouth (Fig. 1.9).

A fishway is planned for both the dam and the powerhouse.

1.3.5 Outlet Canal

The outlet canal starts in the point where the powerhouse reinforced-concrete stilling basin ends. Its total length is 3.5 km, and maximum depth is 14 m. Minimum discharge at the canal mouth into the Drava River is 237m3/s, which establishes an international category IV waterway downstream. The right lateral canal is running in parallel with the outlet canal, and thus reduces the groundwater level in the neighborhood of the outlet canal (Fig. 1.10).

1.3.6 Other Structures

A public local road, 770 m long, is planned for passage across the dam and powerhouse structures on their downstream side.

The Drava riverbed between the outlet canal mouth and the dam, on a 5 km long stretch, is permanently impounded. To ensure necessary flow, it will be continually fed with minimum 40 m3/s of water as a biological minimum.

The roads are planned along the reservoir left- and right-hand lateral canal, along the outlet canal left and right bank, and the Crnec-intake structure road.

Figure 1.6 Figure 1.7 Figure 1.8

Figure 1.9 Figure 1.10

1.3.7 Power Plant Operating Mode

The Novo Virje HPP can operate as a run-off-the-river plant, and in variable or in combined mode (combination of run-off-the-river and variable). The run-off-the-river operation mode is the one when the power plant discharges the incoming water without its storing in the reservoir. When the inflows are below the installed discharge, the operating power plant discharge equals the inflow. When the inflow exceeds the installed discharge, the difference is released through the spillway or the flap on the concrete dam. The variable operation is the one when the hydroelectric power plant retains the water inflow in the reservoir and uses it according to the requirements and turbines operation possibilities. This is called flow regulation. The flow regulation can generally be daily, monthly, annual or multi-annual. Considering the reservoir capacity and the water regime characteristics, the Novo Virje HPP could most of the time operate as a variable plant with daily regulation, with the exception of high water periods when it has to operate as a run-off-the-river plant (about 24 days a year). The Novo Virje HPP operation could also depend on operation of upstream hydroelectric power plants on the Drava River, which mostly run variably.

Considering the above, the installed discharge of 960 m3/s has been selected and the operating mode analyzed and evaluated on the basis of the run-off-the-river operating mode to the 12-hour variable mode (daily), with defined minimum discharge. The power generation and power generation effects have been - calculated by using of standard hydrology methods, i.e. mean annual discharges.

The Novo Virje HPP is planned to run in a combined mode. The minimum mean daily discharge at the outlet canal mouth will be 237 m3/s, which corresponds with 95% discharge duration at the Botovo water gauging section. Necessary quantity of water is ensured by the discharges through the right- and left-hand lateral canals, additional discharge over the concrete dam (biological minimum) and the discharge through the powerhouse; this quantity needs to be maintained for 95% of discharge duration which is natural duration time. The planned minimum mean discharge is much higher from the minimum discharge of 117 m3/s recorded in this section of the Drava River. This will ensure not only the present navigability of the Drava River but also its turning into the category IV international waterway.

Figure 1.11

2. SITE AND LOCATION DESCRIPTION

2.1 General

Characteristics of both natural and developed areas in the Novo Virje HPP valley have been evaluated on the basis of 318 different data sources.

The Drava River has undergone significant changes throughout its history. Generally, its course has been considerably shortened, which could be attributed to the riverbed deepening. The result of this process is drop in the groundwater table in the valley (Fig. 2.1).

In his book “To My Homeland”, Ivan Veèenaj-Tišlarov says:

“However, the Drava has never been timid and humble. Through three or four centuries, the river has reached the today’s Drnje, Petranec, Sigec, Hlebina and Molve and thus formed what is called Prekodravlje Region on this territory.

The history of continuous changes in the Drava River course are both interesting and tragic. It has most affected inhabitants of Legrad. In 1912, Jenö Haller, the local teacher, published a history of Legrad. He writes wrote that, until 1710, Legrad was on the left Drava bank, thus in Meðimurje Region. So it is not strange that initially Legrad was territorially part of the Prelog County until the period between the two wars.

However, during a disastrous flood of the Drava River the torrents bypassed Legrad on its north.

Thus, the settlement was simply moved to the southern bank of the Drava River, into the Podravina Region, its present location. In early Middle Ages, the Prekodravlje Region was actually in the Podravina Region, and presently it is located to the south of the Drava course. The old Drava riverbed is presently occupied by the Ždala Brook, therefore the disputes about the state border “

The Drava River stretch upstream the Mura River mouth has been completely harnessed for power generation. Twelve hydroelectric power plants had been built in Austria, eight in Slovenia and three in Croatia (Fig. 2.2.).

The analyzed Novo Virje HPP valley is located between 110 and 125 m a.s.l. The land is predominantly agricultural (26,861 ha) and forest (10,086 ha). The area accommodates 28 smaller and medium settlements, some valuable natural sites such as the Stružice backwater, Ješkovo and Èambina ponds, Virka backwater, Osredak dead water, Èingi Lingi gravel borrow area and Karaš backwater that will be conserved and fully protected (Figs. 1.1 and 2.3).

However, the Novo Virje HPP site occupies a comparatively narrow area by the Drava River that is, being inside the dikes occasionally flooded. In addition to the major river course, the site encompasses backwaters, dead water, pastures, meadows, natural forest, bush and plough land, total of about 2,685 ha. Further, the mouths of the right-hand and left-hand tributaries Gliboki and Bistra and Izidorius and Domba, respectively, are located in the ares.

Local earthquakes are mostly originating from the Bilogora earthquake zone. The powerhouse and intake structure are located in 6EMCS seismicity zone.

2.2 Climate

The site is an area of moderately fresh and humid continental climate.

Mean annual air temperature 10° CMean annual Drava water temperature 10° C

Mean long-term precipitations 800 mm

Relative air humidity 80%

Max. mean with force 3 to 4 Baufort

Average long-term fog durationKoprivnica 70 days/yrÐurdevac 53 days/yr

Average long-term water surface evaporationKoprivnica 668 mm/yrÐurdevac 509 mm/yrEvapotranspiration, Ðurdevac 550 mm/yr

2.3 Hydrology

Total Drava catchment area 41,238 km2

The Drava catchment area in Croatia 7,440 km2

The Drava catchment area to Novo Virje HPP 31,038 km2

The Drava catchment area in Croatia at theNovo Virje HPP site 850 km2

Lowlands 500 km2

Hills 350 km2

Total Drava length 695 kmThe Drava length in Croatia 314 kmThe Drava length on the Novo Virje HPP section 34 km

Drava at BotovoMean annual discharge Qmean 526 m3/s1000-year flood 4,057 m3/s100-year flood 3,079 m3/s

Maximum recorded discharge 2,652 m3/sMinimum recorded discharge 83 m3/s

Annual drop in minimum water level 2.56 cmAnnual drop in mean water level 1.70 cm

Maximum suspended load transportation 1,700,000 ton/yrMinimum suspended load transportation 170,000 ton/yrSuspended load grain median, Dso 0.10 mmBed/total load transportation 90%

Mean Drava speed for Qmean 1.4 m/sMean Drava depth in the main riverbed for Qmean 2.2mMean Drava width for Qmean 270 m

Average long-term water temperature increase after 1980 1.2°CNumber of years with ice occurrences after 1946 21

Mean long-term discharges for tributaries:Gliboki 0.81 m3/sBistra 0.62 m3/sIzidorius 0.016 m3/sDombo 0.119 m3/s

2.4 Hydrogeology

Composition of soil underlying the surface layer gravel and sand

Aquifer thicknessKoprivnica 80 mFerdinandovac 140 m

Horizontal filtration coefficient

Surface layer 10-4to 10-8 m/sec

Aquifer 10-3 to 5 x 10-3 m/sec

Groundwater table drop between 1967 and 1990

Left valleyMinim u m level about 30 cmMaxim um level to 90 cm

Right valleyMinimum level about 25 cmMaximum level to 100 cm

Water level drop at Botovo water gauging sectionbetween 1926 and 1995 about 130 cm

The Drava water level effect on groundwater tableLeft valleySettlement Repaš 1.8 kmSettlement Otoècka 3.2 km

Right valleySettlement Gabajeva Greda 6.0 kmSettlement Novo Virje 1.5 km

Changes noticed in the groundwater regime within the studied Novo Virje HPP area are evolving faster than adjustment of the ecosystem to the new situation, and that causes changes in composition of plant and animal communities. So, it would not be correct to engage alt efforts to maintain the present status despite the observed trends of groundwater table drop, since such engagement could have adverse impact on the ecosystem and give the effects opposite to the expected.

2.5 Agricultural Land Characteristics

Total arable land in the system area 12,085 ha

The most frequent arable land types in the system area:

■ Semi-gley alluvial shallow and medium shallow gley-shallow, medium shallow and deep soils, 1,500 ha (17%).

■ Gley/hypogley-mineral-medium deep and deep marshy soils, 1,500 ha (17%).

■ Gley/hypogley-mineral and humus- medium deep and deep marshy soils, 1,100 ha (13%).

Land area per farmer 1.32 ha

Agricultural production is dominated by:Cereals 54%Fodder 9%Vegetables 4 %

2.6 Water Quality

The Drava at BotovoPursuant to the Streams Categorization Ordnance (Official Gazette 1511981) falls into category II

Determined statusGeneral physical/chemical parameters category II to IIIHeavy metal group indicators category III to IVpH value category IDissolved oxygen category lBOD5 (five-day biological oxygen demand) category II to IIICOD (chemical oxygen demand) category IIAmmonium category III to IVNitrate category I to IINitrite category III to IVPhosphate category I to IICopper category III to IVLead category III to IVManganese category III to IVNickel category III to IVCadmium category III to IVChromium category I to IIZinc category I to II

Bacteriological evaluation class II

Saprobiologic evaluationto 1985 class II to IIIsince 1985 class II

The Drava tributariesPursuant to the Streams Categorization Ordnance (Official Gazette 15/1981) fall into category II

Determined statusGliboki - Sigetec category III to IVBistra - Molve category IVKomarnica - Molve category III to IVDombo - after confluence with Ždalica category II to III

GroundwaterPursuant to the Streams Categorization Ordnance (Official Gazette 15/1981) falls into category I

Determined statusGroundwater in 46 stations (Fig. 2.4) in the planned hydroelectric

power plant valley is not clean in 98% cases and falls into category II to III

Figure 2.4

2.7 Habitats, Flora (plants) and Fauna (animals)

2.7.1 Water and Wetland Habitats (Fig. 2.3) Occupation area Surfaces with running water (the Drava and backwaters)

Surfaces with stagnant water (dead water, pond, gravel borrow areas) Surfaces with high groundwater table, i.e. those flooded in some periods of the year (forest communities black poplar and silky willow).

Off the occupation area Surfaces with running water (the Drava tributaries and backwaters) Surfaces with stagnant water (dead water, pond, gravel borrow areas) Surfaces with high groundwater table and flooded areas (communities common oak with great broom, black alder with bird eye, common oak i English elm, common ash and blackberry, bullpates grass meadows, and crested dog's tail and bromegrass

2.7.2 Land Habitats

Occupation area Habitat of tall oat grass meadows, plough land, orchards and bush

Off the occupation area Habitat of mixed common oak and hornbeam forest, tall oat grass meadows, and plough land

2.7.3 Rare, Endangered and Protected Plants in the Study Area

Rare plants White alder - Alnus incana (Gabajeva Greda, Sekuline) Field eryngo - (Eryngium campestre) (Sekuline, Pijesci) Fringed buck bean - Nymphoides pellata (Ješkovo, Èambina) Ordinary bladderwort - Utricularia vulgaris (Èambina) Odder's tongue - Ophioglossum vulgatum (Peteranec)

Endangered plants Marsh gentian - Gentiana pneumonathe (Berek, Siget) Green-winged orchid - Orchid morio Orchid - Orchid simia

Protected plants Guinea flower - Fritillaria meleagris (Èambina) Butcher's broom - Rucus hypoglossum

2.7.4 Rare, Endangered and Protected Plants in the Occupation Area

Presence: Not present

2.7.5 Animals

Invertebrata Numerous, particularly snails and clams, and insects (Libellula 46 species and.830 species of forest butterflies)

Vertebrata

Fish 50 speciesAmphibians 15 speciesReptiles 10 speciesBirds 95 speciesMammals 48 species

2.7.6 Rare and Endangered Animals

Insects Nine Libellula species Among butterflies: Zerynthia polyxena Synanthedon mumi (Ðelekovac, Repaš) Maculinea teleius (Peteranec)

Amphibians Salamander - Salamandra salamandra Frog - Rana Ridibunda Fire-bellied toad - Bombina bombina Marsh frog - Rana arvalis

Birds (European level) Night crow - Nycticorax nycticorax Purple crane - Ardea purpurea Eagle - Haliaeetus albicilla Tern - Sterna albifrons Kingfisher - Alcedo atthis Bank martin - Riparia riparia Turtledove - Streptopelia furtur Red-backed shrike - Lanius collurio

Birds (Croatian level) Crane - Egretta garzetta Crane - Egretta alba Plover - Charadrius dubius Sandpiper - Actitis hypoleucos Sheartail - Sterna hirunda

Mammals Otter - Lutra lutra Squirrel - Sciurus vulgaris

2.7.7 Protected Animals

Invertebrata Four day butterflies: Apatura iris A. ilia Iphiclides podalirius Papilio machaon Red ant - Formica rufa (Repaš, Gabajeva Greda, Jasenovaèki Berek)

VertebrataAmphibians Salamander - Salamandra salamandra

Amnions - Triturus dobrogicus, Triturus alpestirs Yellow-Bellied toad - Bambina variegeta Fire-Bellied toad - Bombina bombina Toads - Bufo bufo, Bufo viridis Tree toad - Hyla arborea Spade foot - Pelobates fuscus Wood frog - Rana dalmatina Marsh frog - Rana arvalis Meadow frog - Rana temporaria

Reptiles Turtle - Emys orbicularis Anguid - Anguis fragilis Meadow lizard - Lacerfa agilis European green lizard - Lacerta viridis Grass snake - Natrix natrix Natrix tessellata Elaphe longissima Coronella austriaca

Birds All but: jackdaws magpies jays hooded crow night crow which are protected under the Game Act, same as other feathered game.

Mammals Shrews - Sorex araneus, Sorex minutus, Crocidura leucodon, Neomis fodiens, Neomis anomalus House shrew - Crocidura suaveolens Squirrel - Sciurus vulgaris Hamster - Cricetus cricetus All bats Otter - Lutra lutra

2.8 Forests

The forests potentially influenced by the Novo Virje HPP belong to lowland and swampy deciduous forest types, typical for the large river valleys in moderate zone of northern hemisphere. Spatial vegetation variability is mostly determined by micro-relief, which indirectly proves that primary ecological factors are related to the groundwater regime. The forest of the pedunculate oak (Quercus robur L.) and common hornbeam (Carpinus betulus L.) resides on the highest positions (most distant from the groundwater table). Pedunculate oak and narrow-leaved ash (Fraxinus angustifolia Vahl.) forest grows on the lower positions. Monodominant forest of narrow-leaved ash or forest of narrow-leaved ash and sticky alder (Alnus glutinosa (L.) Gaertn.) resides in the micro-depressions with temporary stagnating surface water. In the area close to the current Drava riverbed, as well as on the lowest parts of the local relief with frequent flooding and/or stagnation of the surface water, willow (Salix sp.) and poplar (Populus sp.) forest types reside.

The largest and the most valuable forest potentially influenced b the Novo Virje HPP which is located near the future reservoir of HPP, is Repaš forest. This forest, as well as other forests in the area, is managed by the uniform shelterwood method, producing high, mixed, even-aged stands of excellent timber quality. The forest is today mostly close to harvestable age, which also increases its environmental value. The whole of Repaš forest area is in the vegetation succession towards the less hygrophilous vegetation types, which results in spreading of common hornbeam, the species intolerant to high groundwater levels. Moreover, the forest management authority registered the increased dieback of the pedunculate oak during the last decade. These facts correspond to the lowering of the groundwater table within the area, correlated with a decreasing trend of water levels of the Drava river observed from mid last century, probably as a consequence of the combination of natural (riverbed erosion) and artificial (hydro-technical measures) processes.

Figure 2.5

Figure 2.5 Spatial distribution of groundwater depth in the Repaš forest for April, 1900, 1930, 1960 and 1990, derived from mathematical model in a function of water levels of the Drava river and from digital terrain model based on

topographic map (scale of 1:2000,

equidistance of 10 cm). Depths are stretched in the brown scale from 0 m and less (surface water) - dark brown to 3 m and more (out of the rooting zone) - light brown.

Area under forests within the study area:state owned 8,695 haprivately owned 1,391 hatotal 10,086 ha

Area under forests under direct occupation:state owned 25 haprivately owned 260 hatotal 285 ha

Most important forest communities: Forest of pedunculate oak and common hornbeam (Carpino betuli - Quercetum roboris) Forest of pedunculate oak and common hornbeam with slender false-brome (Carpino betuli - Quercetum roboris brachypodietosum sylvaticae) Forest of black poplar and white willow (Salici - Populetum) Forest of narrow-leaved ash (Leucoio-Fraxinetum angustifoliae) Forest of sticky alder and narrow-leaved ash (Pruno-Fraxinetum)

Total standing volume of public forests within the study area 2.1 mil. m3

The most important tree species on the basis of standing volume (%) and mean annual increment (%):

Pedunculate oak (Quercus robur L.): 62%, 55% Sticky alder (Alnus glutinosa (L.) Gaertn.): 14%, 14% Common hornbeam (Carpinus betulus L.): 9%, 10% Narrow-leaved ash (Fraxinus angustifolia Vahl.): 9%, 11% Other: common maple (Acer campestre L.), poplars, conifers - 6%, 10%

Degree of forest damage:up to 10% 42% of forestsbetween 11 and 25% 23% of forestsbetween 26 and 60% 29% of forestsbetween 61 and 99% 4% of forests100% 2% of forests

2.9 Valuable Nature

Protected natural capital Ðurðevaèki Pijesci geographical and botanical

reservation, 20 ha, protected since 1963, off the system location.

Other valuable nature in the planned hydroelectric power valley (Figs. 2.6 and 2.7).

Right valley (Fig. 2.6) Virke backwater (2.8 km) Area between Virke backwater und lateral canal (120 ha) Osredak dead water (2.5 km) Area between Osredak dead water und lateral canal (230 ha) Common juniper near Gabajeva Greda (2 ha) Èingi Lingi gravel borrow area (40 ha) Karaš backwater (3.5 km) Area between Karaš backwater and outlet canal, i.e. the old Drava riverbed (85 ha) Sekuline area (550 ha).

Left valley (Fig. 2.6) Struzice backwater (8.5 km) Area between Stru~ice backwater and lateral canal (175 ha) Jeskovo pond (40 ha) Cambina pond (45 ha):

Figure 2.6

Typical habitats in the right valley to be preserved and protected

Figure 2.7 Typical habitats in the left valley to be preserved

and protected

1. Running water - Diversity of water (free water, vegetation, steep and low-lying banks) and terrestrial (meadows, forests) habitats at the confluence of the Gliboki Brook and the Virka backwater (photo: dr. R. Kranjcev)

1. Running water - Diversity of habitats (free water, vegetation, eroded banks) along Struzica backwater (October 1995)

2. Fresh stagnant waters - Genuine natural habitats (reed, cane, willows, water) Osredak dead water (November 1995)

2. Fresh stagnant water - Genuine natural habitats (free water surface, above and underwater plants) Ješkovo pond (October 1995)

3. Rare habitats - Community of common juniper near Osredak dead water before the fire (Photo: dr. R.Kranjcev)

3. Terrestrial habitats - Typical terrestrial habitats (meadows and forests) along Struzice backwater (October 1995)

2.10 Structures and Infrastructure

Dikes Water management dikes for flood control and stabilization of the Drava “changing” course

Drainage of the catchment lowlands section Open canals without pumping stations

Mountain torrents regulation Low level

Railroad MG-105

Arterials and regional roads Group I M3 and M1.2 Group II M3.2 regional roads 2220, 2224 and 2225

Oil and gas facilities Six gas fields with 88 boreholes, one oil field CPS I to III Gas mains and the Adriatic Oil Line run through the area

Power transmission facilities 110 kV, 35 kVi 10 kV transmission (overhead) lines and substations

Telephone transmission facilities Network of intercity lines and cables; underground and overhead cable routes

Water supply Individual dug Wells; exception Ðurðevac which has a water supply system

Water consumption for the major industrial polluters 5 mil. m3/yr

Sewage 280,000 m3/yr Koprivnica, 310,000 m3/yr Ðurðevac

Waste water treatment Initial stages

Navigability The Drava not navigable in the Novo Virje HPP area

2.11 Hunting

Hunting grounds in occupation area Own hunting grounds: Repaš (about 550 ha) and Pesci (about 300 ha) and jointly owned hunting grounds Koprivnica (about 1380 ha) and Ðurðevac (about 450 ha)

Big game Deer, doe, boar, rabbit

Feather game Pheasant i partridge

Game not protected by closed season Fox, weasel, skunk, stone marten, pine marten, wild cat and muskrat

2.12 Fishery

The Drava fish productivity 30 kg/haThe most frequent fish Carp, pike, pike-perch and catfishManagement Angling

2.13 Population

Population of settlements situated up to 4 km from the Drava (1991 Census)Pridravlje region pop. 12,855Prekodravlje region pop. 3,741

Population of former municipalitiesKoprivnica pop. 61,052Ðurðevac pop. 40,901

Share of farmersFormer Ðurðevac municipality 52%Zdala 68%Repaš 93%

2.14 Economy

AgricultureMajor cultures corn (60% plough land)

wheat (17% plough land)

Average corn yieldprivate sector 3.7 t/hacompanies 8.0 t/ha

Livestock breeding (1991)Cattle 31,000 headsPigs 47,000 headsPoultry 183,000 heads

Major animal products milk, eggs, meat

ForestryForest management Hrvatske šume (Croatian Forests)

Public Company

IndustryIndustry in the region (study area), Food and pharmaceutical, 7000employees (1992) Building industry, 7000

Transportation of goods and passengers, 1700 Trade, catering and tourism, 1600 Natural gas exploitation, 600 Wood industry, 600

Tourist industry Initial stages

2.15 Natural and Cultural Capital

Biodiversity Mixed numerous natural and man-made habitats of the Drava and its valley and diverse flora and fauna enable settlement and survival of numerous invertebrata and vertebrata

Cultural capital (Fig. 2.8) No archeological sites entered into the Cultural Monuments Register. A number of facilities entered into the Register of Archeological Finds and Museums

Protected cultural monuments Gola settlement

Registered church buildingsChurches in: Peteranec

Hlebine Moive

Figure 2.8 Charactersitic historical architecture of Pridravlje

region which is being graduelly abandoned1. Maintained houses in settlement of Virje (October 1997)2. Derelict house in settlement of Virje (October 1997) 3. Wicker-work cribs in settlement of Novo Virje (October 1997)

2.16 Landscape Characteristics (Fig. 2.9)

Physical and geographic characteristics Plane, mild changes in relief, varying image, state border belt, multifaceted small settlements, visible benchmarks in space (church towers)

Vegetation characteristics Forest massive, groves, individual trees, meadows and pastures

Habitats The Drava (bare and overgrown sandbanks, islets and backwaters, steep and eroded banks). Valley (ponds, dead waters, gravel borrow area, channels, forests, bushes, reeds, individual tree, plough land, meadows, pastures and the like).

Built features Settlements, roads, transmission lines, railroads, and canals.

Changes in space Minor because of traditional agriculture, industrial development level, depopulation of frequent historical changes

Space evaluation subjective Calm, attractive, indifferent, repulsive

objective Particular uniformity, calm, one of rare landscapes so close to the nature in the Central European region

Similar spaces in Croatia

Europe

sections of the Drava, Mura and Sava rivers

Elba

The planned project occupies about 2685 ha, wherefrom:

%

the main Drava course 575 ha 21.4bare and overgrown sandbanks and islets 210 ha 7.8backwaters 125 ha 4.7dead waters 155 ha 5.8degraded forests 285 ha 10.6degraded forests 285 ha 10.6bare ground and underbrush 435 ha 16.2meadows 465 ha 17.3pastures 95 ha 3.6arable land 305 ha 11.3gravel borrow area 10 ha 0.4roads and farm buildings 25 ha 0.9

Total: 2685 ha 100.0

3. BASIC INVESTMENT DATA

3.1 Reservoir

Dam pool level 124 m a.s.l.Length * 25 km Medium width 630 m Surface area at normal pool 16 mil. m2

Total capacity for mean discharge(526 m3/s) 127 mil. m3

(Upper meter capacity 16 mil. m3)

* about 3 km downstream the Botovo bridges the reservoir will have natural conditions

3.2 Lateral Canal

Length Right 25,738 km

Left 25,281 km

Discharge at mouth Qmean = 47.2m3 Qmean = 44.7 m3/s

Inflow from tributaries

Bistra Qmean = 0.62m3/s Q 25 year = 190 m3/s

Izidorius Qmean = 0.016 m3/s Q25 year = 3.5 m3/s

Gliboki Qmean = 0.81 m3/s Q 25 god = 102 m3/s

Discharge into the Drava Through outlet canal EP 125

Through Domba mouth EP 129/3

3.3 Dam

Type backfill/concrete gated backfill/concrete gatedConcrete dam height 27.5 m Concrete dam length 96.0 mSpillway bay width 18.0 m Spillway bays number 4 Backfill dam height 20.5 m Backfill dan length 377.0 m

3.4 Powerhouse

Installed discharge 960 m3/sType adjacent to dam, outlet canalHeight 53.6 m

Lowest foundation elevation 79.5 m a.s.l.Max. foundation depth 32.5 m

3.5 Outlet Canal

Type canal in trench, unlinedLength 3.5 kmBottom width 62 mLowest bottom elevation 97.5 m a.s.l.Slide slope 1H:2.5V

3.6 Infrastructure

Roads Paved roads length 30.1 kmUnpaved roads length 29.8 km

Bridges (number and total span)On road by reservoir 2 bridges, 80 and 120 mAcross lateral canals 9 bridges, span 8.5-84.7 mAt intake structure 6 bridges, span 6.0-105.5 mTotal new bridges 17 bridges, total span 796 m

Molve-Repaš bridge reconstructionExisting part 372 mNew part 346 mTotal 718 m

Gas and oil linesLine revamping length 1,006 m

Water supplySystem. length 60 km (dia. 160-355 mm)Water supply rate 671/sPopulation. 16,600

3.7 Agricultural Land Drainage

Drainage area (gross/net) Pridravlje 8,755/8,193 haPrekodravlje 3,330/3,177 haTotal. 12,085111,370 ha

Canal length Prekodravlje Pridravlje Total1st category 40.6 km 54.8 km 95.4 km2nd category 6.7 km 31.2 km 37.9 km3rd category 40.7 km 80.0 km 120.7 km4th category 132.9 km 333.3 km 466.2 kmTotal 220.9 km 499.3 kmTotal canals length 720.2 km

Surface with pipe drainagePridravlje (drains spacing 10-80 m) 8,193 haPrekodravlje (drains spacing 20-80 m) 2,851 haValley, total. 11,044 ha

3.8 Power Generation Data

The Drava harnessing section 34 kmHarnessing section of the Drava length in Croatia 11%

The Drava head at harnessing section 17.3 mAverage Bross head for Qi 16.4 mAverage net head for Qi 16.2 m

Average installed power plant capacity 138 MW

Average outputRun of the river mode 640 GWh/yr

Variable operation to 12 hours/dayBasic output 408 GWh/yrVariable output 204 GWh/yr

Average operating time 4,655 hours/yr 53%

Installed: medium discharge 1.8

3.9 Permanent Occupation Area (Fig. 4.5) 2,685 ha

Private 45.9%Companies, state-owned 54.1%

3.10 Construction Costs (Fig. 3.1)

January 1, 19951evel

USD:HRK = 1:5.63 USD 493.5 mil

3.11 Construction Duration

Preparatory Works about …………………..4 years

Construction about …………………..4 years

3.12 Novo Virje HPP Annual Operation Description

Operation Duration days/yr

Run-off the-river HPP operation, 24 hours at 960 m3/s, dam spillway in operation 20

HPP runs 12 hours a day at 960 m3/s without spillway, another 12 hours with discharge between 237 and 960 m3/s 71

HPP operates at 960 m3/s from 1-12 hours a day, on average 5.7 hours a day, remaining time with the discharge that in sum with the later canals discharge gives 237 m3/s, on average 18.3 hours a day.na dan. 244

Run-off-the-river operation during the day, maximum to 260 m3/s 30

Total 365

3.13 Economic Indicators

Assuming min max

Annual discount rate % 6.0 6.0Basic power price, UsGkWh 6.0 9.0Annual price increase, % 0.0 1.0

Total benefit, present value mil. USD 729.0 (100%) 1307.0 (100%)

Energy 578.0 (79%) 1021.0 (78%)

Other main benefits (Section 1.2) 85.0 (12%) 167.0 (13%)Other benefits (Section 1.2) 66.0 (9%) 119.0 (9%)

Cost-benefit ratio, B/C 1.57 2.21Net benefit, B - C, mil. USD 26.9 57.3Internal rate of return 9.4 11.3

Generation costs, UsGkWh 3.4 to 4.4

4. OVERVIEW OF POSSIBLE ENVIRONMENTAL IMPACTS

4.1 General

Possible environmental impacts are those that should be expected unless the technical and other protection measures have been undertaken.

The Environmental Impact Study evaluation is intended to determine whether alt possible major impacts have been accounted for so that the land-use conditions could be properly set up.

However, evaluation of technical design concepts or other environmental protection measures encompasses the effects after the project construction and not the possible impacts.

The proposed environmental protection measures from the study are becoming final only after the site permit has been granted; the site permit determines the requirements to be met by tailoring of technical solutions and adequate documentation.

The influence area is an area suffering changes of the current situation in the environment. The influence area size depends on technical solutions that are expected to bring about a desired or allowable impact level. The impact criteria and standards are determined by authorized institutions and state authorities on the basis of the design engineer and planner proposals, while respecting the requirements of both the user of land occupied by the project and the user of land affected by the project.

The study area is an analyzed and investigated area, and in this case it is larger than the influence area.

The direct, influence area is an area occupied by the project. This is a site on which the civil works will be carried out, which shall occupy and change habitats of plants and animals. The direct influence area of the Novo Virje HPP is an area mostly within the occupation area boundaries.

The indirect influence area is an area on which the project is not physically situated, but which suffers the impact of construction of the project structures. The indirect influence area size depends on the criteria and standards for the environmental impact assessment. Therefore, the indirect influence area changes with changes in the criteria and standards.

Whether an impact is considered as beneficial or adverse depends on the environmental impact assessment approach. As pointed above, the users of opposing interests in the same area or in the same natural resource very often take the opposing views in evaluating the same impact. As an example, in the impact area under forest and arable land, a change in the groundwater table is considered as favorable and unfavorable, respectively. Also, the positive targets of land reclamation (drainage, irrigation) are not favorable from the environmental protection view since soil dessication causes reduction in diversity of habitats, flora and fauna.

The major impact in case of an accident could theoretically be caused by flooding of part of the valley or high discharges in the Drava riverbed downstream from the dam caused by demolition of the embankments or the dam.

The consequences of demolition of the embankments and the dam for the Novo Virje HPP have not been investigated. However, based on the investigations conducted for the Ðurðevac Hydropower System, demolition of embankments would cause a 2 m high flood wave within the area up to 2 km from the Drava, within 1 to 3 hours, and would withdraw within several hours. Demolition of the dam would cause increase of the river water level in the riverbed by approximately 2 m above the main riverbed banks, so mainly the inundations will be flooded.

It is important to underscore that these events are probable in case of an instantaneous demolition of the a embankment or dam; however, such accidents usually evolve gradually which considerably reduces the said effects.

During the project construction, the fauna in the area will become significantly poorer. Once the situation settles and the project construction is finished, and after the aquatic and terrestrial vegetation has developed, the game will gradually recolonize the newly formed areas.

The Novo Virje HPP does not pollute water, air or soil, and emits no noise.

Although the most favorable concept is selected, it is not possible to completely avoid individual direct or indirect, environmental impacts of the Novo Virje HPP. The area along the Drava River occupied by the parts of the multipurpose

scheme will be under direct influence. The indirect influence in the valley are the consequence of a changed regime of the surface water, primarily the Drava, and the groundwater in immediate vicinity of the project.

4.2Physical Impact on Surface Waters

The major changes in water regime of the Drava River are expected along the reservoir, between the dam and the outlet canal mouth, and immediately downstream the outlet canal mouth. The confluence points of the right tributaries Gliboki stream and Bistra canal are relocated into the right lateral canal.

Depth of water in the main Drava riverbed will raise 3.6 times and the water velocity will decrease 3.6 times. In the section of the Drava River between the dam and outlet canal mouth, the flow (biological minimum of 40 m3/sec) will be sufficient to satisfy needs of all users of water in the influence area along the river, as well as for survival of plant and animal species living in this river stretch.

The regime of the sedimentation transport changes in the first few years of the power plant operation. This results in the upstream aggradation and downstream scour of the riverbed, which caused lowering of mainly low Drava River levels. The design water level lowering is by 2 m during a 10 year period. These effects stagnate with time and their downstream effect diminishes with the distance until disappearing completely.

Variable daily operation regime of the Novo Virje HPP may bring about oscillations of the water level downstream of the power plant. The largest oscillations are immediately below the powerhouse and at the outlet canal mouth where they, once to two times a day, amount to about 1.8 m in the most unfavorable case. Downstream from the powerhouse the oscillations are gradually diminishing until disappearing completely. The power plant operation mode will not affect the existing navigation regime.

4.3 Impact on Climate

The project construction will not affect precipitations, wind and sunshine exposure duration. Within a comparatively narrow area, the air and soil temperatures might drop, while fog, air humidity and evaporation might increase.

4.4 Impact on Hydrological Characteristics

Construction of the Novo Virje HPP will result in reduction of groundwater table fluctuations related within the natural water level ranges, and decrease of distance between the ground and the groundwater (Fig. 4.1).

Figure 4.1

The expected changes are particularly interesting since the groundwater changes which might affect the environment have already been happening within the study area. Generally, this is the matter of the groundwater table lowering which might adversely affect the forests, and positively affect living conditions and groundwater quality.

Should the groundwater tables be higher or lower than they are currently, it depends on the requirements of all the users in the area.

The ecosystem and particularly forests, are not tailored to the existing groundwater regime. We are intentionally referring to the existing rather than to the natural groundwater regime, since the groundwater regime analyses for the period for which the data are available (1966-1990) indicate the existing groundwater table lowering trend. This lowering is within the river water level lowering limits (Section 2.4).

4.5 Impact on Earthquakes

Construction of the Novo Virje HPP will not cause or occurrence or affect intensity of earthquakes in the Drava River valley.

4.6 Impact on Water Quality

Construction of the Novo Virje HPP will have no adverse impact on the surface water quality in the reservoir, outlet canal and the old Drava riverbed, although these habitats will see cement, of certain communities (plankton) or their members (phytoplankton, zooplankton) not encountered in the original river course (the Drava before construction).

4.7 Impact on Agricultural Land

Direct influence of the proposed project includes direct occupation of 871 ha of arable land. However, the project enables agricultural production on new 523 ha of land located within the existing dikes, i.e. 423 ha in the left and 100 ha in the right river valley.

The indirect influence area encompasses 12,085 ha of arable land (8,755 ha in Pridravlje, and 3,330 ha in Prekodravlje). These surfaces can be protected with the open canal drainage network and pipe drainage network, depending on the impact level and soil water holding characteristics. The said protection system ensures high-input production on arable land without reduction in agricultural land area.

The exception from the above are small and some medium local depressions for which the new conditions ensure normal drainage for meadow and pasture cultures, while the Drava backwaters, dead waters and saturated depressions will in the future be replenished with fresh surface water and/or groundwater.

4.8 Impact on Plants, Animals and Characteristic Habitats

Construction of this project will not cause extinction of any plant or animal species in Croatia and Europe.

There are no endangered or protected plant species in the occupation area, while rare, endangered and protected animals do not live exclusively in the project occupation and influence areas.

However, disappearance of some habitats (Section 4.17) in the direct influence area will reduce the spatial

distribution for the species living there.

The dominant habitat in the Drava valley which is permanently flooded includes the areas covered in black poplar and silky willow, tall oat grass meadows, reed beds, plough land, orchards, pastures, tree lines and the like, with total surface area of about 1,775 ha.

The Drava River habitats that will be permanently impounded include: the Drava River main course, gravel riverbed with islets and sandbanks, the Drava riverbed with sand drifts with bare and overgrown banks, muddy banks, scoured banks, backwaters, ponds and dead waters, total surface area amounting to 910 ha (Figs. 4.2 and 4.3).

Figure 4.2 Repas bridge to be reconstructed and habitats to be

flooded

Figure 4.3 Intake structure site and habitats to be flooded

1. Aerial photograph of bridge (October 1995)

1. Aerial photograph of intake structure (October 1995)

2. Sandbank, islet, vegetation downstream from the Repaš bridge (October 1997)

2. Bare islet and eroded banks upstream the intake structure (October 1997)

3. Steep banks, river course and the islet overgrown with vegetation downstream from the Repaš bridge (October 1997)

3. Vegetation at the begining of the Karas backwater (October 1997)

4. Characteristic terrestrial vegetation between tha Drava and the right reservoir embankment (October 1997)5. Dead water with habitats along the right reservoir embankment (October 1997)

Among the animal species, the changes will happen in the fish structure. The fish quantity will increase for bream, pike-pearch, catfish and carp, while nose carp, trout, huchen, barbel will decrease in quantity or become extinct.

Among the amphibians, the influence area will loose fire-bellied toads, marsh frog, toads, tree toads, forest frog and salamander.

The planned project will adversely affect the turtle and grass snake.

Out of 13 endangered bird types, the survival possibilities for 11 types (but for turtledove and red-backed shrike) will decrease both in Croatia and even in Europe.

The direct influence area will loose the habitats of some types of bats and shrew.

4.9 Impacts on forests

The Novo Virje HPP will have direct and indirect impact on forests and forest land. Direct impact comprises land use changes by direct occupation and by building of structures. Structures of planned Novo Virje HPP do not occupy single established forest or it’s part. However, 285 ha of private forest land and 25 ha of state forestland will be occupied, all of that in the nearest neighborhood of river banks where willow, poplar, alder and other soft broadleaved species dominate. Direct impact on forests and forest land is unfavorable, from the land use view.

Regarding the indirect impact, it has to be emphasized that lowland hardwood forests in the flood-plains of large rivers are under the major influence of flood and groundwater as additional sources of accessible water. The changes in the groundwater regime, either natural (i.e. as a result of changes in riverbed morphology), or artiflcial (as a result of hydro-technical measures), could unfavourably influence these forests. Forest decline could be equally caused by lowering of groundwater table (disturbance of plant water balance due to reduction in water availability) or raising of groundwater table (due to reduction in oxygen levels in soil pores required for root breathing). The first leads to the vegetation succession toward the vegetation types intolerant to the additional moistening from groundwater (vegetation basically influenced by macroclimate) and the second leads to the vegetation succession toward the swampy vegetation types.

Consequently, the major indirect impact of Novo Virje HPP on forests and forest land is related to additional water supply by leakage from the reservoir to groundwater aquifer, which results in the increase of groundwater table.

Having in mind the registered 100 -year trend of groundwater table lowering (probably caused by hydrotechnical measures in the past), decrease in forest soil moisture, nonappearance of floods in forests, wilting and damage of pedunculate oak (Quercus robur L.) during droughty years and existing forest succession, namely increasing portion of mesophytes (i.e. common hornbeam (Carpinus betulus L.)), it is thought that favorable changes of groundwater regime could provide positive effects for survival and development of forest communities. Control of groundwater level and regime can be achieved in several ways. Oscillations of groundwater levels can be achieved by seasonal distribution of precipitation in river valley and the whole of catchment and by structures for regulation of water levels in the lateral canals (weirs), by release of flood waters from reservoir according to desired rate, and through release wells.

After the building of embankments for the Novo Virje HPP, the level of flood control will be increased in the whole of surrounding area, including forests. However, imponded reservoir s a possible of water for occasional controled flooding of forest areas (so called "ecological floods"). Release of water from reservoir could reestablish the forest watercourses, which are today mostly dry due to the increased soil water holding capacity, induced by lowering of groundwater table. Currently, precipitation quickly fills soil water retention capacities above the first watertight layer and in most cases can not induce surface flow. Due to this fact, former watercourse network in forests is mainly dry or poor in water. Occasional stagnant originating from precipitation, retained in depressions on watertight layers of hydromorphic soils are dried by evaporation.

Potential non-favorable drainage activity of the outlet canal, as indirect impact of HPP, which results in decrease of groundwater table in forests, is avoided in the right bank by parallel flow of Karaš backwater which receives it's waters, and in the left bank by continuous impoundment in the former Drava riverbed caused by short outlet canal and minimal mean daily discharge of 237m3/s during 347 days a year.

Briefly, taking in consideration the influence area, impacts on groundwater, data about wilting and damage of pedunculate oak, experience from upstream hydroelectric power plants, and possibilities of predicted and available measures, it is possible to avoid alt unfavorable impacts on forests. In fact, building of Novo Virje HPP with alt protection measures will have favorable impact on survival and development of forest communities due to:

● stopping of unfavorable 100 year trend of lowering of groundwater table,● enabling of "ecological flooding" of forest areas and renewal of forest watercourses,● enabling of establishment of desired regime of groundwater in forest area.

4.10 Impact on Valuable Nature

The occupation area and the project valley have no particularly protected valuable nature as defined under the Nature Conservation Act. However, the planned power plant valley accommodates some beautiful examples of natural capital.

The left valley encompasses Stružice backwater and islet, and Ješkovo i Èambina ponds, and the right valley Virke backwater and islet, Osredak dead water and area, Èingi Lingi gravel borrow area, Sekuline area, and Karaš backwater and islet.

The surface irrigation system, conceived for agricultural land protection, is not planned to discharge into any of the above natural areas. Certain increase in the water level in Osredak dead water, Èingi Lingi gravel borrow area, and Sekuline area will not have adverse impact on natural processes - development of plant and animal communities. Increased water level in the Ješkovo pond will be regulated by construction of a connecting canal between the pond and the left lateral canal, while the lateral backwaters of the Virka backwater will be supplied with water from the right lateral canal. Deceleration of Èambina pond dessication which is already underway will be addressed by discharging of water from the left lateral canal (Figs. 2.5, 2.6 and 4.4).

Figure 4.4 Part of valuable nature to be conserved and protected

1. Running water - Virke backwater. Located in the right reservoir valley (October 1995)2. Fresh stagnant water - Jeskovo pond. A genuine natural Podravina habitat with typical hygrophytic plants at the shoreline. Located in the left reservoir valley. (October 1995)3. Terrestrial biotope - along the Struzice backwater. The most impressive in the landscape are the forests of silky willow and black poplar and meadow community of oat-grass. Located in the left reservoir valley. (October 1995)

4.11 Impact on Structures and Infrastructure

Direct impact of the planned project affects 13 holiday cottages and includes relocation of five households downstream the Repaš bridge.

Out of the existing water management system for the valley flood control and protection against the Drava water, a part of the right dike downstream the Bistra mouth to the outlet canal mouth will remain in operation.

In the future project, the regulation structures built in the Drava riverbed will also loose their function. Only the water

management structures built in the planned hydroetectric power plant valley will remain operational.

The indirect influence of the planned hydroelectric power plant includes 1,047 ha of agricultural land that needs a canal network while further 323 ha need a pipe drainage in addition to the canal network.

In addition to the existing Drava river crossings, construction of the project will offer another public crossing in the dam area.

To facilitate access to the hydroelectric power plant from the main roads, another 30.1 km of asphalt roads and - 29.8 km of roads with gravel surfacing will be built. Smaller parts at the Gola and Molve gas fields boundaries fall into the reservoir occupied area. The Ferdinandovac gas field and two oil boreholes are located at the outlet canal route. The gas mains running to Gola and the Adriatic Gas Line cross the Drava under the Repaš bridge.

The planned project will have direct impact on the power grid and its facilities. The study area across the Drava River accommodates 10 kV grid and telephone lines.

The Novo Virje HPP concept does not envisage lowering of the groundwater table which could adversely affect water supply of the local population.

The planned project has no influence on the polluters and the waste water treatment methods. However, its construction stimulates resolving of the environmental issues.

The Novo Virje HPP will not adversely affect the present navigability of the Drava. On the contrary, minimum mean daily discharge at the outlet canal mouth (237 m3/sec) will enable establishing of a category IV international waterway.

4.12 Impact on Hunting

Disappearance of parts of genuine habitat and noise that will be generated during the project construction will certainly affect the game. However, once the situation calms down after the construction has been finished, the game will recolonize these areas following development of aquatic and onshore vegetation. Further, flood control system will protect the game. After it has been constructed, the project will cut and interrupt paths of some game, primarily of the deer and boar.

4.13 Impact on Fishery

The reservoir will be rich in fish. The less economically worth and more adjustable fish types will predominate. Possible productivity of fish has been estimated between 50 and 60 kg/ha, and of the ichthyomass from 150 to 250 kg/ha. The estimated fish productivity in the outlet canal is 20 to 25 kg/ha, and the total mass is between 60 and 250 kg/ha. The biological minimum area will be permanently inhabited by diverse fish species. The fish weight gain is estimated to 35 to 45 kg/ha and mass to 50 to 130 kg/ha. The lateral canals will be poorly populated with fish because of low oxygen concentrations and low water temperatures.

Possible annual fish catch of 100 ton can hardly be achieved by such classical methods, so the reservoir could also be used for fishing industry. In addition to the classical exploitation, the other hatchery methods may be applied in the reservoir such as cage breeding, low-input fish breeding, duck breeding, and the like. There are a number of favorable sites for construction of hatcheries off the Novo Virje HPP site.

4.14 Sociological and Demographic Impacts

Construction of the Novo Virje HPP will cause changes in the landscape; and in life and business activities of the local population

The local population survey has shown that the project is considered to be useful for the Republic of Croatia, but it should in no way be harmful for the local population.

The Prekodravlje population is particularly sensitive to the issue of commuting workers and students.

However, the positive effects of the Novo Virje HPP project, such as increase in quality of the living milieu, as a result of more secure and increased yield of agricultural products, higher water supply quality and road network, development of tourist industry and new employment might retain the young and mature population and stimulate settlement of new population in the study area. This would result in changed age structure, improve natural population migrations and could have long-fetched positive effect on increase in population in the area. Number of new jobs will primarily depend on the size and rate of investment into the mentioned activities.

4.15 Impact on Business Sector

Impact on agriculture as an economic sector ensues from the Novo Virje HPP impact on the agricultural land. Direct impact includes loss of agricultural production on about 871 ha of surface area, while enabling high-input agriculture on 523 ha of currently flooded land. Further, the project opens a possibility of development based on land reclamation, including drainage, irrigation, farm consolidation, setting up of cost-effective road network and the like.

New agricultural land of higher quality opens the new market possibilities for different producers, from the seed producers to machinery manufacturers.

Possibilities for fish and duck breeding could additionally improve the present and lead to the new food production.

To maintain the production, numerous products may be placed in the market, from the fish breeding cages to the fish food.

Impoundment of the reservoir, construction of road and use of space by a larger number of visitors will create a space suitable for recreation and tourism. This means higher customer density in some periods which opens a chance for sale of different goods and services.

The Novo Virje HPP effect on forestry will ensue from the project impact on the forests and forest land. Construction of the project will terminate management of about 285 ha of occupied forest land predominated by underwood and bush of soft broad-leaved vegetation, while the established woodland in the river valley is not expected to suffer any change in management.

Industrial centers and some companies are located outside the occupation area, so the construction of the project has neither indirect nor direct impact on these facilities.

Construction of the Novo Virje HPP has basically positive effect on development of tourism since it stimulates resolving of the present environmental problems of the area.

4.16 Impact on Cultural Heritage

The studied region accommodates no archeological sites (such as the remains of cultural monuments) entered into the Register of Cultural Monuments.

Among the identified local sites, only a smaller part of the Novaèka site located in the reservoir impoundment area is entered into the Register of Cultural Monuments.

Potentially, the occupation area might accommodate part of an antic road route, on a stretch Gabajeva Greda - Novaèka, and a part of an archeological site downstream the Repaš bridge.

4.17 Impact on Landscape

The scale of the project impact on the landscape and visual image of this part of Podravina that has an immense cultural, historical and environmental value will depend on proper incorporation of the planned project into the landscape and the design engineer skills to fulfill such tasks.

However, about 575 ha of the main Drava course, 210 ha of bare and overgrown sandbanks and islets, 125 ha of backwaters, 155 ha of dead waters in the process of overgrowing, 285 ha of degraded sort broad-leaved forest, 435 ha of bare underbush and groves, 465 ha of meadows and meadows with individual trees, 95 ha of pastures, 305 ha of arable land, 10 ha of gravel borrow area, and about 25 ha of roads and farm buildings, i.e. altogether about 2,685 ha will come under direct impact (Figs. 2.3 and 4.5).

Indirect impact on agricultural land results from decrease or increase in the groundwater table. The initial idea to drain part of these areas has been abandoned, and they will be left to natural development of plant and animal communities, free of human interference, such as the islets Stružice, Virke, Karaš and Osredak and Sekuline areas (Fig. 2.3).

The reservoir construction will certainly bring about building of human settlements in the area. This is a good trend, particularly because the ongoing devastation of the historical architecture will be stopped.

5. PROTECTIVE AND MITIGATION MEASURES

5.1 General

Numerous technical and other solutions will be applied to mitigate the Novo Virje multipurpose scheme environmental impact to minimum, and conserve the unique habitats in order to preserve diversity of plant and animal species. The major problem to be resolved is the Novo Virje HPP impact on the groundwater flow regime in the valley. However, the basic condition is acknowledgement of requirements of all the area users (agriculture, forestry, settlements) regarding possible time-and space-related groundwater table fluctuations, and compilation of such requirements into integral future groundwater regime conditions.

The Novo Virje HPP Conceptual Design and the Novo Virje HPP valley drainage Preliminary Study conceive that the following will be undertaken for the valley protection against indirect reservoir impacts on the valley groundwater replenishing and increase in groundwater table:

● lateral canals, on both sides, along the whole reservoir length● horizontal sealing, along the embankment toe in the reservoir● poorly permeable vertical curtain, on both sides, on the downstream third of the reservoir● agricultural land drainage system, open canal network and pipe drainage system

Mitigation of possible adverse effects of the planned project on the landscape includes:

Conservation and protection of aquatic and marsh habitats

● backwaters● ponds● dead waters● channels● silky willow and black poplar forest● crested dog's tail and bromegrass meadows● bullpates meadows

Conservation and protection of terrestrial habitats

● common oak and hornbeam forests● tall oat grass meadow

Maintaining of eroded and steep banks

● in the abandoned Drava riverbed, from the intake structure to the outlet canal mouth● in the shallower part of the reservoir● in the part of the reservoir where the current flow regime will be maintained for the medium and higher

discharges (downstream the Botovo bridges)

Rehabilitation of natural habitats in the designed landscape

● area to the north of the Stružice backwater● Sekuline area

Revitalization of naturally damaged habitats

● Ješkovo pond● Èambina pond

Development of specific areas for setting of recreation amenities naturally designed space

● Kancel area downstream the Botovo bridges● area by the Virke backwater● area around the Repaš bridge (Èingi Lingi, Repaš viflage)● Sekuline area

● area by the Karaš backwater● connecting the recreation sites planned as walks, bird-watching spots, fisherman paths, picnic sites, and the like

Building of habitats for some endangered animal species

● islets in the shallower part of the reservoir● floating platforms in reservoir● eroded banks in reservoir

Mitigation of visual changes in space

● reservoir embankment route design '● gradually steeped lateral canal embankments● overgrowing of the left banks of the left and right lateral canals with higher terrestrial vegetation● natural development of cenoses between the lateral canals and reservoir embankment.

5.2 Agricultural Land Protection

The agricultural land protection is a permanent task undertaken by all direct and indirect land users. Thus, construction of the hydroelectric power plant is only a cause to impose respecting of the legislation on agricultural land and obligations of design engineers to maximally protect the existing agricultural land fund.

The agricultural land protection encompasses 3,330 ha in Prekodravlje and 8,755 ha in Pridravlje, which is total arable land surface area planned for drainage (12,085 ha).

Both drainage systems discharge by free fall into the left or right lateral canal or into the Drava downstream from the power plant intake structure. The agricultural land protection engineering concept has not intended to retain the current extent of drainage, namely the soil water-air regime (which is unsatisfactory in some points); the designed system ensures drainage rates as required by the farming cultures and, to a certain degree, by meadows in the total protected area.

The valley drainage systems include open canal networks, pipe drainage systems that depend on the reservoir impact and soil type, road network and appurtenant structures and facilities.

5.3 Water Quality Protection

To maintain the Drava River water quality within the category II, as stipulated by the Water Streams Categorization Ordnance, particular protection measures need to be undertaken upstream the dam (municipal and industrial waste water treatment plant) and in the catchment stretch that falls within the study area (elimination of eutrophication causes and consequences).

Most of the measures have been stipulated by the municipal water contamination control plans and the Multipurpose River Basin Development Study for the Drava and Danube in the Republic of Croatia, but they are unrelated to the construction of the project. Some of these measures are binding on the future project user.

5.4 Protection of Living World and Characteristic Habitats

It has been proposed to select aquatic and terrestrial biotopes on

the stretch between the Botovo bridges and the outlet canal mouth at the 192nd kilometer of the Drava course for monitoring of the groundwater and surface water regime and changes on plants, and to evaluate quantity and diversity of individual animal communities, particularly fish, birds, mammals and typical invertebrata.

This is a necessary step in order to promptly detect any adverse impacts and find the necessary measures for their mitigation.

To ensure conditions for nesting of bank swallow and kingfisher, and some other less endangered bird species, vertical

eroded banks have to be built in several locations along the reservoir embankment.

The shallower part of the reservoir will accommodate a number of ring-shaped islets, which is a measure for protection of wading birds and particularly of endangered species of heron.

To protect small and common tern, a number of anchored floating platforms will be built in the reservoir.

An additional important protective measures include maintaining of gravel banks, sandbanks and islets, steep eroded banks on the stretch between the intake structure and the outlet canal mouth at the 192nd km of the Drava.

The protective measures for conservation of the flora (plants) and fauna (animals) diversity include protection and further development of the natural habitats off the project occupation area, such as:

● backwaters● dead waters● ponds● wetland● groves● underbush● flood forests

Protection of these habitats is given in more detail in item 5.12 Landscape Protection.

An important measure for mitigation of adverse impacts is protection of as natural groundwater regime as possible in the project valley since that is the only way for conservation of the living world characteristic for this part of the Podravina region.

Because of the succession of cenoses in the newly established biotopes they should be, as good secondary habitats, left to the maximum possible extent to the natural succession.

For conservation of biological and ecological characteristics of the area, namely diversity of habitats and enormous diversity of biota in the Drava River stretch between the intake structure and the outlet canal mouth, a minimum water quality has been defined that must be discharged into this part of the water stream. This biological minimum is 40 m3/sec when the water inflow is below the installed discharge, and it will be supplied from the left lateral canal and reservoir.

5.5 Protection of forests

A human need for river regulations in the area of lowland hardwood forests was and still is substantial (e.g. flood control, hydro-melioration of arable land, energy production, etc.). That is along with urbanization process and

changes in land use the primary reason for disappearance or significant reduction of lowland forests in Europe and in other parts of the world. The remaining areas under those ecosystems should be protected primarily as natural heritage, as areas of environmental importance (melioration and multiple forest use), and finally as renewable natural resource for biomass production. Resulting from this, any hydro-technical measure in the future should follow principls of environmentally sustainable development, which would be, in this case, a survival and a conservation of lowland forest ecosystems.

Reservoir of the future Novo Virje HPP, could permanently raise and significantly reduce fluctuation of the groundwater levels during the year. This could have negative effect on valuable lowland forest ecosystems in the neighborhood, especially Repaš forest. To prevent it, a number of hydro-technical measures is being planned. To make designing process of such system of hydro-technical measures possible, it was necessary to determine which groundwater regime is acceptable from the forest survival view. This was done through the dendroecological research, which was undertaken aiming at modelling of such regime.

In an effort to find the solution, the basic idea of this research was:

1. to build the model which describes relevant response of forest condition (growth of endagered species, especially Quercus robur) as a function of environmental indicators (including the groundwater level regime),

2. to simulate this response by the model under different groundwater level regimes,3. to compare simulation results with critical response value and

4. to design the envelopes of the acceptable regimes (simulated response is larger than critical).

Modelled marginal monthly mean absolute groundwater levels were used as the basis for design of protection measures (e.g. surface drainage).

The problem of the influence of groundwater quality on forest ecosystems (especially quantity of the dissolved oxygen in the groundwater) was also examined in this research. It was concluded that the groundwater quality after the construction of the HPP should not be worse than the current groundwater quality.

With appropriate design of protective measures these conditions will be ensured, the most important of them

being a groundwater regime with no negative impact on forest communities in the neighborhood. The use of passive and active systems of protection can regulate groundwater regime in a way to increase the stability of forests. By eliminating recognized trend of groundwater table lowering and its global raising, will return to a certain degree, lost moisture into ecological profile of forest soils. The danger of generation of swampy areas in topographically lower areas will be avoided by spatially limited technical measures. Protection of quality of surface water and groundwater as an important element of forest protection will be encouraged after the HPP construction.

Applied general protective measures of the neighborhood area, comprised of lateral canals to reservoir, 10 m deep vertical poorly permeable curtain to be built on one of third downstream section of water accumulation and of drainage systems on agricultural land. The main purpose of those applied measures is to retain levels of groundwater in future state of development on elevated points in relation to existing average levels. Raising and regime of groundwater levels could be induced by structures for water regulation in lateral canals, by release of flooding waters from the reservoir towards targeted area or by release wells.

Built reservoir is a potential source of water for occasional controlled flooding of forest areas. By building of structures for release of water into existing (mainly dry) channel network during the Drava River flooding, it is possible to realize so called "ecological floods" within the surrounding lowland forests.

5.6 Protection of Structures and Infrastructure

All the existing roads across the Drava River must remain in function. To enable access to the area between the outlet canal and the Drava River, construction is recommended of a bridge across the outlet canal and the right lateral canal. To make the reservoir more accessible to the people, construction is planned of two bridges on the road along the reservoir, nine bridges across the lateral canals and six bridges in the intake structure, i.e. total of 17 bridge.

The next stage of the design documentation development should resolve crossing of the oil line, gas line, power and telecommunication transmission installations across the lateral canals and the reservoir.

The measures to be undertaken for improvement of the water supply are not initiated by construction of the Novo Virje HPP, but rather caused by increased groundwater contamination. Construction of 60 km of the water supply line is planned. The earlier used method of waste water discharge from the households will be integrated with the general measures for protection of the valley against the groundwater level increase. The concept of runoff drainage prior to its release into the recipient should envisage adequate separators.

5.7 Protection of Hunting

Construction of islets or systems within the reservoir and conservation of maximum number of biotopes in the planned hydroelectric power plant valley, are envisaged as one of the protection measures for flora and fauna and some parts of valuable nature in this part of Podravina since it protects numerous game.

To prevent drowning of game, a fence is planned to be mounted in the part of the embankment upstream the dam. The hunting management documentation should include elaboration and implementation of protective measures pursuant to applicable regulation (Official Gazette 1011994).

5.8 Protection of Fishery

Because of the lower water levels, warmer waters, coastal macrophilic vegetation and character of habitats, the biological minimum discharge must be treated as a natural spawning area. Particular care should be taken that the discharge during the spring/summer season does not fall below the specified value.

Another measure for establishment of fish species important for fishery industry is stocking of the newly created system with fish.

Considering biological and environmental standing, the open water fishery protective measures include construction of the fishway. However, its construction cannot make up for or endanger in any way intensive fish stocking. The protective measures in fishery include transportation of the migrating fish over the dam.

5.9 Sociology

Affirmative attitude of the local population towards the Novo Virje HPP project depends on a properly determined compensation for the property in the project occupation area, ensuring of unobstructed flow of people and goods from the area across the Drava river into the right valley, and resolving of potable water supply issue.

5.10 Economy

Protection of agriculture and forestry as economic sectors are explained under sections 5.2 and 5.5, above. This is in compliance with the provisions of the agricultural land and forest management legislation and the forestry code of practice.

Construction of the planned project will have no adverse impact on the industry.

The planned project will positively influence development of processing industry, while development of tourism is cross-linked with implementation of all protective and other measures in the study area.

5.11 Protection of Cultural Heritage

To avoid stoppage of works at the Novo Virje HPP site, the archeological survey will be conducted prior to commencement of the project activities in possible archeological sites within the direct influence area. Further, during the construction of the entire route, and particularly in position of potential archeological sites, supervision will be ensured of the archeological experts during the earthworks so that no objects of historical value are damaged.

5.12 Protection of Landscape

Landscape protection, and mitigation of the project incorporation into the landscape of the Podravlje region, are based on protection of maximum number of natural habitats located immediately by and along the structures, and the natural habitats in the part of the designed landscape. This will, to a certain extent, make up for the occupied natural capital, ensure accessibility of the reservoir and development of certain areas for new recreational amenities, while taking care of access roads and diversity of use.

The design of landscape and some structures should primarily be tailored to the requirements and needs of the users, and of the subject space. It is of particular importance that the use of the space and the structures meets requirements of all generations of people.

Possible concept for maintaining of natural conditions in particular locations has been defined on the basis of the analyses of groundwater table levels, lateral canals impoundment and the valley drainage concept.

The basic technical concepts include intake and outlet structures in adequate sections of the lateral canals, construction of connection canals for water supply and connecting canals for drainage.

Among the valuable nature features in the left valley, particular care will be taken of the Stružice backwater and islet, Ješkovo and Èambina ponds, and in the right valley of the Virke backwater and islets, Osredak dead water and area, Èingi Lingi gravel borrow area and Karaš backwater and islet. (Fig. 2.3).

The measures that could make up for the lost ambient characteristics in the area and mitigate the visual effect of the Novo Virje HPP technical structures location in the landscape, and thus make the whole project more acceptable to the neighboring population include:

● Construction of a number of ring-shaped islets, steep eroded banks along the reservoir embankment and placing of anchored floating platforms.

● Conservation of valuable nature in the shallower part of the reservoir (Fig. 5.1).

Figure 5.1 Habitats downstream the Botovo bridges to be conserved

and protected1. Bridge aerial photo (November 1995)2. Bare and overgrown islets downstream the bridge, where natural conditions will prevail (Photo: dr. R. Kranjcev)3. Islet overgrown with initial vegetation downstream the bridge, where natural conditions will prevail (September 1997)4. Typical vegetation along the bank downstream the bridge, which will be preserved (Septemper 1997)5. Terrestrial habitat in the reservoir tail, which will be preserved (Septemper 1997)

67 kép Spring colors on the Drava drifts and meadows in Podravina (Photo Dr. R. Kranj~ev)

The Drava riverbed from the dam to the outlet canal mouth should be left to the natural course of development. For cleaning of bare surfaces and the eroded banks, the discharge in this section of the Drava needs to be increased several times during the fall and winter.

Further, construction of sports and recreation amenities and landscape design is proposed for the area where the changes are visible, primarily the free space between the lateral canals and the dike and between the dike and the outlet canal, and in the area downstream the Botovo bridges.

The measures that could mitigate visual impact of the project on the landscape include design of the embankment route and changes in embankment slope to the extent that will ensure public acceptance of the project is construction of the sports and recreation facilities. Design of the embankment route should harmonize the new project structures with the landscape.

The mitigation extent will depend on allowed natural development of the plant communities on the right bank of the lateral canals. The left bank must be free from higher vegetation because of monitoring of the reservoir embankment seepage (Fig. 5.2).

6. DRAFT ENVIRONMENTAL MONITORING PROGRAM

The Novo Virje HPP environmental impact cannot be determined unless the relevant environmental data are available for the project occupation area and its valley. The environmental monitoring is a comprehensive task, which should ensure a database (zero status) prior to commencement of the construction works.

The priority parameters include:

● Rainfall, surface water and groundwater quality and regime● Biological and ecological characteristics of aquatic (backwaters, dead waters, wetland, ponds, gravel borrow

areas) and terrestrial (meadows, pastures, forests) ecosystems● The Repaš forest boundary conditions● The valley groundwater regime● The downstream Drava regime dependent on the Novo Virje HPP● Morphological changes in the Drava under present and future conditions within the Novo Virje HPP reservoir site

and on the downstream section

Monitoring of forest ecosystems has to be established before the HPP construction. This monitoring has to ensure permanent control of habitat conditions and ecosystem health and vitality during the building and exploitation of HPP. Relevant variables are: actual soil moisture, soil redox potential, actual transpiration of trees, concentrations of pollutants in the groundwater, soil and air, health condition of tree crowns, population density of mycorrhizal fungi (indicators of forest ecosystem stability) and population density of parasitic fungi and xylophagous insects (indicators of forest decline).

The monitoring should be continued throughout the construction, after putting of the power plant into operation, within the regular structures monitoring in order to control the environmental impact of the power plant and undertake necessary protective measures. The monitoring results would be a good background for discussion with the Hungarian party on the power plant environmental impact.

Further; to determine the microclimate conditions in the immediate project valley, setting up of the weather station is planned in the right and left valley, in Molve settlement and Repaš forest, respectively.

The measurements will be conducted in old and new stations, prior to, during and after construction of the planned power plant.

Since the water gauging section at Novo Virje will be impounded, the new section will be set up downstream the Novo Virje HPP. The new sections will be set up in the Gliboki, Bistra, Hotovo and Rog Strug courses, Stružice backwater, Èingi Lingi gravel borrow area and Ješkovo and Èambina ponds.

The proposed hydrology investigations encompass aquifer filtration characteristics and groundwater time- and space-related condition.

To obtain comprehensive information on the local seismicity, it is proposed that the temporary seismic station at Javorovac remains in operation.

The surface water monitoring that has been underway in this part of the Drava basin should be extended to the stagnant waters (Èingi Lingi, Ješkovo and Èambina).

In some areas under forests and meadows in the power plant valley, a number of locations should be set up for monitoring of the surface water and groundwater regime along with monitoring of changes in the plant and animal world.

Protection of water against contamination is a legal obligation unrelated to the project construction.

The hunting societies managing hunting grounds in the area should tailor their management methods to the applicable provisions of the new hunting act (Official Gazette 10/1994, Official Gazette 22/1994, Official Gazette 5/1995 and Official Gazette 25/1996).

The biologic and ecological research of valuable nature should include piscicultural research in the Ješkovo and Èambina ponds, Èingi Lingi gravel borrow area and Stružice, Vírke and Karaš backwaters.

Before the works on the project start, sounding of possible archeological sites should be conducted within the direct influence area such as the Roman road that was once running in the south-north direction, between Molve and Novaèka,

and the Hambari and Kingovo sites downstream the Repaš bridges.

The environmental status is planned to be presented in GIS technology. The GIS program for the Novo Virje HPP construction has been developed.

71. kép

THE NOVO VIRJE ENVIRONMENTAL IMPACT STUDY SUMMARY WAS PREPARED BY:

Elektroprojekt Consulting Engineers:

Zdenko Mahmutoviæ, B.Sc., Project Manager

Vladimír Žarkoviæ, M.Sc., Project Manager

Dr Stjepan Mišetiæ, Design Engineer

Vladimír Seèen, B.Sc., Design Engineer

Šime Kezele, M.Sc., Design Engineer

Zlatko Bašiæ, B.Sc.

Marija Berakoviæ, B.Sc.

Todor Bjedov, B.Sc.

Damir Boroviæ, B.Sc.

Zdravko Drmiæ, B.Sc.

Ivan Glunèiæ, M.Sc.

Grgur Hubeny, B.Sc.

Janko Jurkoviæ, B:Sc.

Alan Kerekoviæ, B.Sc.

Zlatko Pletikapiæ, B.Sc.

Željko Žgalin, B.Sc.

Mario Sudžuka, A.A.S.

Mladen Batiæ, Technician

Bozidar Pavišiæ, Technician

Dijana Miroslav, Technician

Vlatkica Èaržavec, Draftsman

Antun Krušlin, Draftsman

Katarina Radoèaj, Draftsman

Nada Soldo, Draftsman

Alemka Miholiæ, Draftsman

Sabina Ekinoviæ, B.A.

Roberta Delivuk

Biserka Halambek

Patricija Krsnik

Ljiljana Šimec

Extemal Collaborators:

Professor Dr Željko Vidaèek Agricultural College, University of Zagreb

Professor Dr Zoltan Racz Agricultural College, University of Zagreb

Professor Dr Matko Bogunoviæ Agricultural College, University of Zagreb

Dr Dobrila Habekoviæ Agricultural College, University of Zagreb

Dr Sulejman Èamdžiæ Agricultural College, University of Zagreb

Branko Rezo, M.Sc. Agricultural College, University of Zagreb

Stevo Husnjak, B.Sc. Agricultural College, University of Zagreb

Dr Sonja Jurkoviæ Architectural College, University of Zagreb

Željko Štahan, B.Sc. State Directorate for Cultural and Natural Heritage Protection

Professor Dr Ivan Šugar. Pharmaceutical College, University of Zagreb

Dr Milorad Mrakovèiæ College of Natural Sciences and Mathematics, University of Zagreb

Professor Dr Mladen Kerovec, B.Sc. College of Natural Sciences and Mathematics, University of Zagreb

Bozena Tušar, M.Sc. Civil Engineering College, University of Zagreb

Davorka Tušar Civil Engineering College, University of Zagreb

Vladimír Lay, M.Sc. Social Research Institute, Zagreb

Dr Radovan Kranjèev Koprivnica High School

Dr Oleg Antoniæ Oikon, Zagreb

Daibor Hatiæ, B.Sc. Oikon, Zagreb

Dragan Radoviæ, B.Sc. Orinthology Department ofthe Croatian Academy of Science and

Arts, Zagreb

Gordana Goldstein, B.A. Cultural Monuments Protection Institute, Zagreb

Katica Mutak; B.A. Cultural Monuments Protection Institute, Zagreb

Zofia Mavar, B.Sc. Cultural Monuments Protection Institute, Zagreb

Dražen Živiæ, B.Sc. Zagreb

The Republic of Croatia Commission for Novo Virje HPP Environmental Impact Assessment:

Franka Odac, M.Sc., State Directorate for Environmental Protection

Professor Dr Stjepan Maðar Agricultural College, University of Osijek

Ana Mrak-Taritaš, B.Sc. Ministry of Physical Planning, Building and Housing

Vera Cvek, B.Sc. Ministry of Agriculture and Forestry, Forestry and Hunting

Directorate

Dubravko Mojaš, B.Sc. Ministry of Agriculture and Forestry, Agricultural Land

Managment Directorate

Krešimir Cerovac, M.Sc. Ministry of Economy

Jasminka Radoviæ, B.Sc. Ministry of Culture, Cultural and Natural Heritage Protection

Directorate

Zorislav Baliæ, B.Sc. State Water Directorate

Željko Trstenjak, B.Sc. Varazdin Cultural and Natural Heritage Protection Directorate

Dr Melita Mihaljeviæ Teaching College, Environmental Department, Osijek

Dr Branka Anièiæ Agricultural College, Landscaping Department, University of

Zagreb

Professor Dr Boris Berakoviæ Civil Engineering College, University of Zagreb

Mijo Koprièanec, B.Sc. Varaždin

Željico Cvrtila, B.Sc.