A proposal to drain the lake to solve the problems of malaria and depth changes was rejected.

By autumn, the tunnels to restore the flow of the river and drain the lake were operational.

In the 15th century inhabitants attempted to drain the lake to prevent annoying plagues of mosquitos.

As a result, attempts were made as early as 1859/60 to drain the lake for agricultural land.

These are usually partially or completely plugged with sediments, but collapse when groundwater levels drop, allowing lake water to funnel into the aquifer, which can virtually completely drain the lake.