By not dumping rubbish in it.
A river is cleaned up naturally by digestion.
river themes
They cleaned up and gave funding to support clearing up the flooding in the Arkansas River. This was how the river was cleaned up.
A river gets cleaned by the process similar to wwtp.In the middle coarse of the river it's speed is slow hence all the suspended impurities setttle at the bottom and the water that reaches the sea is clean.
the cleaned it in buckets by the river.
the Congo river
the longest river in the UK is the severn river.
ummm who knows go check it out ur self.....plus there isnt a river named themes....
they cleaned it because it was very dirty in the past.
The wonderful thing about a river is that is is always getting a fresh supply of clean water. The mess needs to be cleaned up by people, the source of the contamination needs to be stopped, and all will be well.
It is the River Thames for London, England
yes