1.1.1.WATER RESOURCES Depending on the physical and geographical conditions, a large part of the river discharge comes from either snow melt, groundwater or direct surface runoff. About 50-55 per cent of the waters of the Daugava, Venta, Lielupe and Musa rivers is melted snow, while for the Gauja and Amata rivers it is 35-40 per cent. About 10-20 per cent of the flow of some tributaries of the Lielupe (Memele and Svete) and the Aiviekste tributary of the Daugava is fed by groundwater, while for the Daugava and Gauja rivers it is 35-40 per cent. In the Kurzeme peninsula and in the middle uplands, direct surface runoff accounts for 40 per cent of the flow of the rivers, while in the Zemgales plain it represents 20-30 per cent. The country can be divided into eight river basins: -The Daugava basin. Its total area is 87,900km2, of which 28 per cent is located in Latvia. The Daugava River rises in the Russian Federation, flows through Belarus (where it is called the Western Dvina), enters Latvia in the southeast and flows northwest to the Gulf of Riga. Several tributaries enter the Daugava River inside Latvian territory, including four large ones: Ogre, Aiviekste, Dubna and Rezekne. -The Gauja basin. Its total area is 8,900km2, of which 88 per cent is situated in Latvia. The Gauja River rises in the Vidzeme upland and flows east, then turns northwest, becomes the border between Latvia and Estonia for a short distance, and then flows southwest to the Gulf of Riga. -The Salaca basin. It covers the north of the country, near the border with Estonia. Its total area is 3,600km2, of which 92 per cent is located in Latvia. The Salaca River rises in Lake Burtnieks in the north and flows west to the Gulf of Riga. -The Lielupe basin. Its total area is 17,600km2, of which 50 per cent is situated in Latvia. The Lielupe River rises in Lithuania, enters Latvia in the south and flows north to the Gulf of Riga through the most fertile regions of the country. It has many tributaries, the most important being the Memela, Jecava and Svete. -The Venta basin. Its total area is 11,800km2, of which 67 per cent is situated in Latvia. The Venta River rises in Lithuania, enters Latvia in the southwest and flows north through the Kurzeme lowland to the Baltic Sea. The Venta has many tributaries, but only one of them, the Abava River, exceeds 100km in length. -The coastal basins between Lithuania and the Venta. Their total area is 5,100km2. This area includes rivers such as the Barta, Durba, Riva and Uzava, which flow to the Baltic Sea. -The basins within the coastal lowland, on the opposite shores of the Gulf of Riga. Their combined area is 3,800km2. This area includes rivers such as the Irbe, Stonde, Roja, Svetupe and Vitupe. -The Velika basin. This basin consists of a number of smaller rivers flowing into the Velika in the Russian Federation. Its area within Latvia is 3,200km2. The total discharge of the Velika amounts to 4.2km3/year, of which 16 per cent is generated within Latvia. The total water resources are estimated at 16.54km3/year, incoming surface water resources at 18.709 km3/year. The internal renewable groundwater resources are estimated at 2.2km3/year. Part of the groundwater flows to the sea or is withdrawn by wells, and part is drained by the surface network. That part of the groundwater flow which does not contribute to the total IRWR (overlap) is estimated at 2km3/year. Groundwater use is estimated at about 800,000m3/day. In some regions, rapid depletion of the water table is observed. Quite a large quantity is used by cities. In the Jürmala area, close to the capital Riga, the groundwater is famed for its medicinal qualities

1.1.2.WATER USE In 1994, the total water withdrawal for agricultural, domestic and industrial purposes was estimated at 285.2 million m3, of which about 12.7 per cent for agriculture. Other water use, including water use for hydropower, was 149.1 million m3. In 1994, the total quantity of produced wastewater was 215.8 million m3, of which 119.4 million m3 were classed as clean without treatment, while 66.7 million m3 were treated to meet quality standards. The remaining 29.7 million m3 were not treated. The largest quantity of untreated wastewater flows into the Daugava and Lielupe river basins. In 1994, the total quantity of re-used treated wastewater amounted to 11.8 million m3.

1.2.WATER QUALITY, ECOSYSTEMS AND HUMAN HEALTH Latvia's environment has benefited from a shift to service industries after the country regained independence. The main environmental priorities are the improvement of drinking water quality and the sewage system; household, and hazardous waste management; and reduction of air pollution. In 2001, Latvia closed the EU accession negotiation chapter on the environment by committing to full enforcement of EU environmental directives by 2010. Eutrophication of water bodies and degradation of water ecosystems are priority environmental problems in Latvia, in relation to both inland and marine waters.

(Water Risk Filter)