|
The quality of water can deteriorate
when it is stored in a reservoir.
River water contains dissolved oxygen.
Sufficient dissolved oxygen is needed to maintain aquatic
animal and plant life, and to prevent some types of chemical
reactions that form unwanted pollution in the water.
There are many factors that can reduce
oxygen levels in a reservoir, for example, organic
material in the water can use up oxygen as it decomposes (or
rots). The depth of the water, its temperature and its flow
can also affect the oxygen levels.
The type of land that is
inundated
by a reservoir may affect the water quality. Pesticides
from farmland and toxic materials from industrial land can
pollute the water. Also, the streams and rivers flowing into
the reservoir may be carrying pollutants.
The designers of a reservoir have to consider
whether any of these factors will have a significant effect
on the quality of the water and whether they have to include
special measures to offset any problems that could occur.
|
