Washington Mayor David Rhoads says a recent fish kill in Baumert Lake in East Side Park was caused by the lake turning over.
Turnover is the mixing of levels of pond water caused by the changing temperatures of the surface water.
This occurs as summer heat yields to crisp fall weather.
While turnover happens in natural ponds as well as those constructed in backyards, the process can result in the death of fish and algae.
Many fish were lost in Baumert Lake.
However, many more were saved by moving them to the upper lake.
Rhoads says the DNR will restock both lakes in October.
He says many hours have been spent cleaning up the dead fish with help from volunteers.
Rhoads says there is nothing the city can do about the smell.
He says it will eventually go away.