ESTONIA
ESTONIAN LAKES There are nearly 1,200 lakes in Estonia, 1000 of them are natural lakes and 200 are artifical lakes. Estonia has 2 big lakes: Peipsi-Pihkva (3555 km2 , average of depth 7,1m) and Võrtsjärv (270,7 km², average of depth 2,8m.). Estonia has only 46 lakes that are deeper than 15m, and as a matter of fact, they all are in South-Estonia. The majority of Estonian lakes are small and shallow. Half of them are smaller than 3 hectares. Estonian lakes are mixing water two times a year, in spring - usually in April-May and in October-November in the autumn, when the whole water column is at 4 ° C. In some lakes (eg Verevi) spring water does not mix, but only mixes in the autumn, but this is not the case every year. In summer, the temperature of the water layers can be quite different. Large and shallow lakes are open to the winds (eg Lake, Võrtsjärv Vagula, Ermistu) and the water temperature is relatively uniform. Small lakes have a layered surface and the bottom temperature difference is often 15-20 degrees. Particularly noticable, the temperature in dark-watered lakes where the surface temperature during the summer months is 20-25 º C, but at a depth of 3-4 meters can drop by 10 degrees per meter.
Lakes in Estonia