Environmental Risk Assessment of Morača Canyon and Skadar Lake
Total Page:16
File Type:pdf, Size:1020Kb
Proposed construction of dams on Morača river: environmental risk assessment of Morača canyon and Skadar lake Darko Saveljic (bird expert) Danilo Mrdak (fish expert) Mirko Kneževic (biotechnology expert) Jelena Marojevic (experts coordination) Francesca Antonelli (overall coordination) Short version of three reports commissioned by WWF MedPO and Green Home under the framework of Sharing Waters Project - Skadar Lake component. DRAFT Rome, June 2009 1 Table of contents 1. Introduction........................................................................................................................... 3 2. Executive summary............................................................................................................... 3 3. Hydrology of Skadar lake and Morača river and predicted impact of dams on Skadar water regime................................................................................................................................. 4 3.1. Hydrology....................................................................................................................... 4 3.2. Flooded areas of Skadar lake and correlation with Morača river.............................. 6 3.3. Simulated impact of dams on Skadar water regime .................................................. 7 4. Bird fauna of Morača river and Skadar lake ....................................................................... 9 4.1. Bird fauna of Morača canyon and Skadar lake......................................................... 10 4.2. Predicted consequences of dams on the bird fauna and flora................................ 11 5. Fish fauna of Morača river and Skadar lake ..................................................................... 12 5.1. Fish fauna of Skadar lake and Morača river ............................................................. 12 5.2. Commercial fish stock and its economy.................................................................... 14 5.3. Predicted consequences of dams on fish.................................................................. 14 6. Conclusions.......................................................................................................................... 16 7. Literature ............................................................................................................................. 17 List of figures Figure 1. Correlation between Skadar lake water level (hydrological station of Podgorica) and Morača flow (Kneževic, in prep) . ................................................................................ 5 Figure 2. Water inflow of Skadar lake (modified from Radulović 1997).................................. 6 Figure 3. Water outflow of Skadar lake (modified from Radulović 1997). .............................. 6 Figure 4. Wet surface categories of Skadar lake (Knežecic, in prep.). ................................... 7 Figure 5. Ornithological reserves on Skadar lake (G. Earth/ V. Bušković)........................... 11 Figure 6. Composition of Skadar lake fish fauna (Mrdack, in prep). ..................................... 13 Figure 7. List of most important endemic fish species of Skadar lake and IUCN conservation status. List of categories available at http://www.iucnredlist.org/info/categories_criteria1994 - categories...................................... 13 List of tables Table 1. List of fishery species of Skadar lake (Mrdak D. et al. 2003).................................. 14 List of annexes ANNEX 1. Ornythofauna of Morača canyon, their status according to international conventions and EU Bird Directive ANNEX 2. Variation of water level depending on realized or retained water quantity (Morača flow data used to derive the table provided by HMZ Podgorica) ANNEX 3. Variation of Skadar lake surface depending on water quantity that would be realized or retained in the accumulations (Moraca flow data used to derive the table provided by HMZ Podgorica) 2 1. Introduction Skadar lake and Morača river present both outstanding flora and fauna values at national and international level and the proposed construction of four dams on Morača has raised attention of the civil society as well as of the investors in terms of environmental and socio-economic impacts. In 2009 three studies were commissioned by WWF Mediterranean Programme and Green Home, respectively one on birds and one on fish of Morača river and Skadar lake, and one on the hydrology of Morača river and Skadar lake and the predicted flow/water regime changes in the river and lake due to the construction of four dams. The fauna study describes the current conservation status of species and habitats and the predicted impacts of Morača dams on that conservation status. The methodology of the studies is a mixture of desktop literature review and data analysis (fish and hydrological studies) and field data collection (birds study). Some important discoveries were made on the relation between Morača flow and Skadar lake as well as the importance of the biodiversity of Morača river. The three studies are finalized and the reports about to be made public. This document is a summary of the main findings of the three studies. They were conceived to raise the attention of decision makers and investors on the consequences of building dams on Morača and open a dialogue on this concern in the belief that the NGO sector can give an important contribution to sound decision making. The Strategic Environmental Assessment (SEA) of four dams to be constructed on Morača river in on going and these studies should be taken into serious considerations for the final results of the SEA. 2. Executive summary WWF and Green Home have commissioned three studies to simulate the impact on Morača river and Skadar lake of four dams to be built on Morača river. One study had the objective of clarifying the hydrological connections between Morača river and Skadar lake and simulate the impact of the construction of four dams on the water regime of Skadar lake. It was based on hydrological data collected in the past 40 years (1961-2001) by the responsible authorities which were used for mathematical simulations. The study had proved that the four dams on Morača will have an impact on the delicate water regime of Skadar lake and will change considerably the wetlands around the lake. A second study identified Morača river as a very important hotspots for birds and plants at a national and regional level and predicted that the impact of the four dams on these values will be very high wiping out key rare habitats which are home to a unique amount of plant species and birds. The third study assessed the fish fauna of the river and the lake and predicted an impact on rare endemic trout species in Morača river and on a very economically important species of Skadar lake, the carp. An economic loss of approximately 1.416.666 € per year is estimated. 3. Hydrology of Skadar lake and Morača river and predicted impact of dams on Skadar water regime The hydrological study had the objective of clarifying the hydrological connections between Morača river and Skadar lake and simulate the impact of the construction of four dams on the water regime of Skadar lake. It was based on hydrological data collected in the past (1961-2001) by the responsible authorities used for mathematical simulations. 3.1. Hydrology The Skadar lake basin belongs to the Adriatic watershed and its surface is 5,490 km2. It is rich in water sources of various quantities with the two biggest rivers, Morača and Zeta and their numerous tributaries, which directly supply the lake. Oscillation in the water level of Skadar lake depends indeed on the lake’s charging and discharging regime. Observing the water measurements during the period 1961-2001, the lowest water level was registered in September 1985 amounting to 4.76 m, while the average water level for the same period was 6.46 m a.s.l. The highest water level was registered in January 1963 amounting to 9.86 m a.s.l. The water level of Skadar lake determines its cumulative area, depth and water quantity. Excluding the existing wells in the lake the maximum water level is over 15m, while the minimum is around 10m. In this study the surface area of the lake and the water quantity were calculated on the basis of measured (from literature) water levels and topographic maps (Radulović 1997). The most important components affecting the water balance of Skadar lake are the rivers Morača and Zeta. The high oscillation of Skadar lake water level and the oscillation of water flow of Morača and Zeta rivers are determined by high precipitation in winter and a lack of precipitation in summer. The dependence of Skadar Lake water level on Morača river flow is confirmed by a regression analysis carried out by Kneževic (in prep.) for this study. 4 10 9 8 7 6 5 y = 0.0059x + 5.551 2 4 R = 0.6689 3 2 Skadar Lake water level (m a.s.l.) 1 0 0 100 200 300 400 500 600 Average annual flow (m3/s) Figure 1. Correlation between Skadar lake water level (hydrological station of Podgorica) and Morača flow (Kneževic, in prep) . The surrounding plains have a number of water sources (wells) known as “oka” which are found in Bjelopavlicka plain and in Zetska plain (also called “vrulje”). A great number of them are situated on the bottom of Skadar lake. Groundwater also springs in Skadar lake. The water quantity supplied into the lake by the vrulje is impossible to measure exactly and even a rough estimate is difficult. Radulović (1997) though has estimated the annual average