Fresh water resources Moldova
Present situation in Moldova
In the Republic of Moldova surface waters are represented by basins of the Dniester and Pruth rivers which are transborder water sources, inland rivers and natural and manmade reservoirs. The biggest surface water source is the Dniester River having a total annual discharge of circa 10.7 km3. The second biggest river is Pruth, with an average annual discharge of circa 2.9 km3. All other inland rivers flowing on the territory of the country have an average annual discharge of circa 1.22 km3. The basin of the Dniester River with its tributaries occupies circa 67% of the country’s territory, and of the Pruth River circa 24% (8).
There are about 3,500 small and medium reservoirs and ponds with a total surface area of more than 300 km2 and total storage capacity of about 1.5 km3. There are two big reservoirs in Moldova: Costeşti-Stînca on the Prut River (the largest, 678 million m3), jointly operated by Romania and the Republic of Moldova, and Dubăsari (235 million m3) on Dniester River. Reservoirs in the northern and central part of the country play the role of seasonal
regulation of water, while in the south they mainly serve for inter-annual distribution due to the region’s greater water deficiency (10).
The waters of the Dniester and Pruth rivers are considered to be relatively clean to moderately polluted. The waters of small rivers are medium to highly polluted (8,10). Circa 44% of the population does not have access to safe drinking water sources. At present all towns and municipalities and over 65% of rural settlements have centralized drinking water supply systems. Only 50% of this type of systems is in satisfactory technical condition. The rest needs capital repairs or rather reconstruction (8).
Of the sub-surface water reserves only 50% comply with water quality requirements. So, for irrigation purposes the waters of transborder rivers can be used, in the first place. The waters of the inland rivers and lakes can be used for irrigation only after improving the quality of the water to exclude salinization and alkalinization of soils. Wide use of water resources for irrigation purposes is limited due to a high weariness degree of the irrigation systems and their scarcity (8).
The main ground water reserves are located in deep confined aquifers. There are approximately 7,000 boreholes for ground water withdrawal; their total debit (annual groundwater resources) accounts for approximately 1.3 km3, including 0.7 km3 of drinking water. The natural recharge capacity of the confined aquifers is limited, and there is a risk of overexploitation (10).
Sub-surface waters are the main source of potable water supply in the Republic of Moldova, for 100% of the rural population and 30% of the urban population, or 65% of the total population of the country. The remaining 35% of the population use surface waters as a source of potable water, including 32% from the Dniester River, 2.8% from the Pruth River and 0.2% from other surface waters (8).
Water quality in wells in the unconfined aquifers does not comply with the national standard for drinking water. Investigations indicate a strong correlation between groundwater quality in unconfined aquifers and land use.
Continuous degradation of drinking water quality is attributed to increased livestock growing in households. There are signs that the human factor plays an increasingly significant role in polluting water in confined aquifers as well, through infiltration of polluted water and through abandoned boreholes. Man-made pollution results in an increasing number of polluted water withdrawal sources that threaten centralised water supply systems in several towns (10).
Available water resources
Taking into consideration different sources of water and various usage restrictions (agreements on
transboundary rivers, ecological water resources, etc.), the total economically available water resources in Moldova amount to 5.6 km3, including 4.3 km3 surface water and 1.3 km3 ground water (10).
As a result of the deteriorating economy, just 16% of available water resources are withdrawn at present: 18% of surface waters and 10% of the groundwater reserves are used. However, economic decline has had a different impact on unconfined aquifers. Due to the uncontrolled use of water from wells and short boreholes for crop watering in households and small farms, the water table depth in these aquifers has increased drastically, leading to depletion of the aquifer, in many regions of the country (10).
Currently, about 65 to 70% of total water is used in industrial heating and cooling and hydro-energy production, 15 to 20% for drinking and domestic purposes and 5 to 8% for irrigation (10).
Available surface water resources may diminish by 16 to 20% already in the 2020s. Thus, according to the water-
intensive target of national economic development, secure supply for all water users will be threatened by climate-related change in water resources already in the 2020s, when the intensity of surface water use will be close to 100%. However, taking into consideration ground water supply as well, the point when water scarcity will
become a brake to development will set in after 2030. However, if the business-as-usual scenario of water use is followed, depletion of water resources will not occur at least until the end of the century (10).
The southern region is among the most exposed to water shortages; medium and long distance water transfer systems are almost non-existent in the south. Moreover, local surface water resources in the south (and, less frequently, in the central part of the country) are exposed already today to depletion in drought years (like in 2007, when several reservoirs on the Işnovăţ River dried up) (10).
The expected impact of diminishing water resources likely to occur in the near future will depend on human and economic activity within the affected regions (11):
- In traditionally water deficient zones climate change will put pressure on current economic activity, but water scarcity will not be a new phenomenon for the area and its inhabitants;
- Areas with vulnerable, mainly rural, populations, especially the southern Transnistria region, already experience water shortages as well as decreasing water table depth in unconfined aquifers due to overexploitation;
- Central Moldova is exposed to the complex impact of likely diminishing water resources on both rural and urban populations.
Europe: five lake categories
There are almost one and a half million lakes in Europe, if small water bodies with an area down to 0.001 km2 are included. The total area of lakes is over 200,000 km2; in addition the manmade reservoirs cover almost 100,000 km2. The response of European lakes to climate change can be discussed by dividing the lakes into five categories (9):
Deep, temperate lakes
Typical representatives of this class are e.g. Lakes Maggiore, Ohrid, Geneva and Constance with mean depths of 177, 164, 153 and 90 meters, respectively. Due to the great depth and relatively mild winters, there is usually no ice cover. The future climate change in Europe may suppress the turnover in deep lakes. This implies the enhancement of anoxic bottom conditions and an increased risk of eutrophication. The oxygen conditions can also be anticipated to deteriorate due to increased bacterial activity in deep waters and surficial bottom sediment.
Shallow, temperate lakes
Balaton (600 km2, 3 m) in Hungary and Müritz (114 km2, 8 m) in Germany belong to this class. Increasing water temperatures may result in intensified primary production and bacterial composition. The probability of harmful extreme events, e.g. mass production of blue-green algae, will increase. The impacts may extend to fish life; changes in species composition and reduced fish catches will be anticipated. The use of the expression 'thermal pollution' is well justified for these lakes.
Ladoga (17 670 km2, 51 m), Onega (9670 km2, 30 m) and Vänern (5670 km2, 27 m) are the largest in this class, being also the three largest lakes in Europe. This group includes about 120 lakes with an area exceeding 100 km2. Most lakes of the boreal zone mix from top to bottom during two mixing periods each year. Shortening of the ice cover period will be the most obvious consequence of climate change in these lakes. This could improve the oxygen conditions in winter and spring.
These are mainly small water bodies in northern Scandinavian mountains and in the tundra region. Arctic lakes are generally considered to be particularly sensitive to environmental changes. Melting permafrost may seriously threaten the ecosystems of arctic lakes. In some cases the whole lake may disappear as a consequence of ground thaw and enhanced evaporation.
To this class belong all high altitude lakes in central Europe and also those located in southern Scandinavia. Even if mountain lakes were connected by channels, physical and ecological constraints limit species migration between them. In a warming climate, there is no escape route; the only possibility for survival is adaptation.
South-eastern Europe: four types of lakes
In order to discuss the effect of climate change to lakes in south-eastern Europe, the region is divided into three climatic sub regions. The main characteristic in this subdivision is the mean temperature in January, because the severity of winter has an essential influence to the lakes. The sub regions and the anticipated influences of climate change, around the year 2050, are as follows (9):
The Mediterranean sub region
In today's climate the mean temperature varies in January between +10 and -2°C, in July it is generally 20 - 25°C. This sub region covers the narrow coastal area on the Adriatic Sea, most of the Greek territory and the lowlands on the southwest side of the Black Sea.
Only the smallest lakes have short ice cover season every winter in today's climate, in the future climate ice will be almost non-existent. Summertime water temperatures will get very high, leading to algal and water quality problems. Water balance will be negatively affected by climate change; evaporation will increase and inflows tend to decrease. The use of lakes as water sources, e.g. for rising needs of irrigation, will be limited.
In today's climate, the runoff in the Adriatic part of this sub region is generally over 1000 mm, while it ranges between 30 and 200 mm in the vicinity of the Black Sea. The difference of lake precipitation and lake evaporation is 200 - 600 mm in the former area, whereas it is between -200 and -400 mm in the latter. In the climate of 2050, shallow lakes in the latter area will become intermittent and reservoirs will have considerably high water losses.
Mean temperature in January is between -5 and -2°C, in July around 20°C. This sub region covers large parts of Hungary, eastern Croatia, central parts of Serbia, southern and eastern Romania, and Moldova. As to the runoff, this is the driest area in south-eastern Europe; in Hungary and on the Black Sea coast annual runoff is locally less than 20 mm. The difference of lake precipitation and lake evaporation is between 0 and -300 mm.
In today's climate most lakes in this sub region mix from top to bottom during two mixing periods each year and have an ice cover for 1-3 months. They may still freeze in 2050, but the possibility of ice-free winters will increase. Adverse water balance changes may affect many lakes; intermittency and increased salinity can be anticipated.
South-eastern Europe is topographically one of the most diverse regions in the world. In addition to two main mountain ranges, Carpathians and Dinaric Alps, there are numerous other ridges and plateaus. At highest elevations, mean temperature in January can be as low as -10°C and extremes below -30°C have been recorded. In July typical mean temperatures are between 10 and 20°C. Precipitation is generally abundant but very variable even at small scale.
Most lakes are located in river valleys, but smaller ones occur also at high plateaus and depressions. Ice cover season may be as long as 5-6 months, snow on lakes further reduces the penetration of radiation into the water mass. Some of the highest lakes mix once a year but mixing twice a yearis much more common.
Climate change may not cause very harmful changes in water balance of these lakes. Increased erosion by intense precipitation may lead to sedimentation and degradation of water quality. At lower elevations, the occurrence of ice cover may become uncertain. For water supply, the mountain lakes and river basins will probably be very important in south-eastern Europe in the future, because run-off may considerably decrease at lower altitudes.
Underground (karstic) lakes
This is a special type of lakes. Due to the karstic geology, there are underground lakes in the Balkan region. They are not immune to the impacts of climate change; in fact their water balance and ecology may be sensitive to changes of the quantity and quality of inflowing waters.
Present situation in Europe
In the EU as a whole, energy production accounts for 44% of total water abstraction, primarily serving as cooling water. 24% of abstracted water is used in agriculture, 21% for public water supply and 11% for industrial purposes (3).
These EU-wide figures for sectoral water use mask strong regional differences, however. In southern Europe, for example, agriculture accounts for more than half of total national abstraction, rising to more than 80 % in some regions, while in western Europe more than half of water abstracted goes to energy production as cooling water. In northern EU Member States, agriculture's contribution to total water use varies from almost zero in a few countries, to over 30% in others (7). Almost 100% of cooling water used in energy production is restored to a water body. In contrast, the consumption of water through crop growth and evaporation typically means that only about 30% of water abstracted for agriculture is returned (3).
Currently, just two countries, Germany and France, account for more than 40% of European water abstraction by manufacturing industry (3).
In general, water is relatively abundant with a total freshwater resource across Europe of around 2270 km3/year. Moreover, only 13% of this resource is abstracted, suggesting that there is sufficient water available to meet demand. In many locations, however, overexploitation by a range of economic sectors poses a threat to Europe's water resources and demand often exceeds availability. As a consequence, problems of water scarcity are widely reported, with reduced river flows, lowered lake and groundwater levels and the drying up of wetlands becoming increasingly commonplace. This general reduction of the water resource also has a detrimental impact upon aquatic habitats and freshwater ecosystems. Furthermore, saline intrusion of over-pumped coastal aquifers is occurring increasingly throughout Europe, diminishing their quality and preventing subsequent use of the groundwater (3).
Virtually all abstraction for energy production and more than 75% of that abstracted for industry and agriculture comes from surface sources. For agriculture, however, groundwater's role as a source is probably underestimated due to illegal abstraction from wells. Groundwater is the predominant source (about 55%) for public water supply due to its generally higher quality than surface water. In addition, in some locations it provides a more reliable supply than surface water in the summer months (3).
Fresh water reservoirs
Currently about 7000 large dams are to be found across Europe, with a total capacity representing about 20% of the total freshwater resource (3). The number of large reservoirs is highest in Spain (ca 1200), Turkey (ca 610), Norway (ca 360) Italy (ca 570), France (ca 550), the United Kingdom (ca 500) and Sweden (ca 190). Europe's reservoirs have a total capacity of about 1400 km3or 20% of the overall available freshwater resource (6).
Three countries with relatively limited water resources, Romania, Spain and Turkey, are able to store more than 40% of their renewable resource. Another five countries, Bulgaria, Cyprus, Czech Republic, Sweden and Ukraine, have smaller but significant storage capacities (20–40%). The number and volume of reservoirs across Europe grew rapidly over the twentieth century. This rate has slowed considerably in recent years, primarily because most of the suitable river sites for damming have been used but also due to growing concerns over the environmental impacts of reservoirs (3).
Projected future situation in Europe
Appliance ownership data is not currently readily available for the new Member States but it is believed that rates are currently relatively low and likely to rise in the future. Higher income can also result in increased use and possession of luxury household water appliances such as power showers, jacuzzis and swimming pools. Changes in lifestyle, such as longer and more frequent baths and showers, more frequent use of washing machines and the desire for a green lawn during summer, can have a marked effect on household water use. The growth in supply within southern Europe has been driven, in part, by increasing demand from tourism. In Turkey, abstraction for public water supply has increased rapidly since the early 1990s, reflecting population growth and a rise in tourism (3).
Water stress over central and southern Europe is projected to increase. In the EU, the percentage of land area under high water stress is likely to increase from 19% today to 35% by the 2070s, by when the number of additional people affected is expected to be between 16 and 44 million. Furthermore, in southern Europe and some parts of central and eastern Europe, summer water flows may be reduced by up to 80% (4).
Runoff is estimated to increase north of 47°N by approximately 5-15% by the 2020s and 9-22% by the 2070s. North of 60°N, these ranges would be considerably higher, particularly in Finland and northern Russia (1). Average annual runoff in Europe varies widely, from less than 25 mm in southeast Spain to more than 3000 mm on the west coast of Norway. Climate change is thus going to make the distribution of water resources in Europe much more uneven than it is today. And even today's distribution is highly uneven, particularly considering the distribution of population density. Almost 20% of water resources are north of 60°N, while only 2% of people live there (2).
Not only will climate change affect the spatial distribution of water resources, but also their distribution in time. In northern Europe, the flows in winter (December to February) will increase two- to three-fold, while in spring they will attenuate considerably, in summer increase slightly and in autumn almost double by the period 2071-2100 (2).
Supply-side solutions are based on high-cost infrastructural projects like dam building, the construction of dykes and stream channelization. In the case of the Republic of Moldova, none of these on their own are an optimal solution. Older dams and dykes can actually increase the risk of extreme fl ooding rather than serve to control or prevent fl ooding. Stream channelization will reduce the infi ltration of surface water into confi ned aquifers, thereby reducing ground water storage. Thus, solutions that combine supply-side and demand-side approaches should be considered (10).
Infrastructural solutions should be combined with such systemic adaptation measures as a change in land use in the fl oodplains that would allow natural ecosystems to return to these territories through the rehabilitation of naturally fl ooded areas. This approach will not just increase soil moisture and the recharging of local ground waters, but will contribute to an extension of natural ecosystems, enriching ecosystem services and conserving
The degree of success of any adaptation measure in Moldava will depend on demandside solutions.
A number of measures exist that may potentially reduce the use of publicly supplied water. These can be broadly grouped into the categories of water saving devices; greywater re-use; rainwater harvesting and the efficient use of water in gardens and parks; leakage reduction; behavioural change through raising awareness; water pricing; and metering. Since treating, pumping and heating water consumes significant amounts of energy, using less publicly supplied water also reduces energy consumption (3).
In Denmark and Estonia, for example, a steady rise in the price of water since the early 1990s has resulted in a significant decline in household water use. Metering leads to reduced water use; in England and Wales, for example, people living in metered properties use, on average, 13% less water than those in unmetered homes (5).
Managed aquifer recharge
Comprehensive management approaches to water resources that integrate ground water and surface water may greatly reduce human vulnerability to climate extremes and change, and promote global water and food security. Conjunctive uses of ground water and surface water that use surface water for irrigation and water supply during wet periods, and ground water during drought (12), are likely to prove essential. Managed aquifer recharge wherein excess surface water, desalinated water and treated waste water are stored in depleted aquifers could also supplement groundwater storage for use during droughts (13,14). Indeed, the use of aquifers as natural storage reservoirs avoids many of the problems of evaporative losses and ecosystem impacts associated with large, constructed surface-water reservoirs.
For policy the following high priority recommendations have been summarized (10):
- Attention in national and regional economic planning should be paid by the Government to the vulnerability of the economy and local communities to water supply;
- The state agency Apele Moldovei in water use planning should take into account the diminishing of available water resources due to expected climate change;
- Apele Moldovei should create scenarios for water use under severe drought and water shortage conditions, and it should prioritise water use (focusing on drinking water and irrigation) under these conditions;
- The national government, in cooperation with Apele Moldovei, should consider establishing strategic water reserves. In this respect a regulation on efficient water use could be devised, incorporating new sustainable methods, like the rain water and snow collection for irrigation purposes;
- The Ministries of Industry and of Agriculture and the Food Industry, in cooperation with the Apele Moldovei, should make efforts to adjust existing water supply systems to the current needs of national economy in order to diminish losses of water in transportation networks and irrigation facilities;
- Apele Moldovei should be responsible for assessing the balance between preserving capacity and potential losses when considering adaptation measures such as building new dams etc.
- Climate change should be considered among the factors that influence water availability and quality in Moldova, and, therefore, specific adaptation measures should be applied to control and improve it;
- There is a need to increase the self-regulatory function of water bodies in both water quality and quantity. This can be achieved by diminishing the human impact on existing water bodies;
- Adaptation approaches should be carefully differentiated by type, region and by social groups; no single solution fits everywhere; adaptation measures and priorities should be publicly debated;
- Special attention should be paid to reassessing national traditions that affect water use and the search for new approaches to the consolidation of a water saving culture and ethic;
- Design and prepare permanent emergency plans for extreme weather events and water scarcity with traditional approaches (humanitarian aid) and design and prepare complementary emergency plans supporting demand for education and health in order to ensure the continuity of capacity development in the young population;
- Public awareness and information campaigns, including training sessions for authorities, the general public and the private sector regarding water and sewage solutions should be performed on a continuous basis. Local authorities should cooperate closely with the community and monitor the implementation of these solutions;
- Strengthen governance in order to avoid governance problems with future lower availability of water.
The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Moldova.
- Alcamo et al. (2007)
- Eisenreich (2005)
- EEA (2009)
- EEA, JRC and WHO (2008)
- Environment Agency (2008a), in: EEA (2009)
- EEA (2007), in: EEA (2009)
- IEEP (2000), in: EEA (2009)
- Ministry of Environment and Natural Resources (2009)
- Kuusisto (2004)
- UNDP (2009)
- Sîrodoev and Knight (2007), in: UNDP (2009)
- Faunt (2009), in: Taylor et al. (2012)
- Scanlon et al. (2012), in: Taylor et al. (2012)
- Sukhija (2008), in: Taylor et al. (2012)