Lake Võrtsjärv
replaced by sandy mud and
sand in the direction of north;
the mud is lying on the marl.
The total thickness increases
southwards, up to 7.6 m.
Võrtsjärv has tens of inflows collecting their
water in three counties, on
a catchment area exceeding the lake surface
twelve times. Väike Emajõgi, Õhne, Tarvastu,
and Tänassilma rivers are the largest inflows.
Suur Emajõgi is the single outlet. Lake
Võrtsjarv is devoid of any outflow. As a result,
the high waterlevel usually lasts for several
months in spring, while even the rise in
autumn can be noteable. The mean annual
difference in the lake volume between the high
and low water level can be threefold.
A permanent current system in the lake is
lacking.
The lake is covered with ice on the average for
135 days a year, from the end of November till
the end of April. The average water temperature
rises up to 17-21°C in July. Võrtsjärv is a
strongly eutrophic lake
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