trees will remove the impurities in the water.
The trees stop the soil from falling/dropping into the water in the reservoir. Hence, it prevents soil erosion.
because tree will be able to get plentiful of water from the reservoir.
There many more than three reservoirs in England.
Neal Lake and Negley Pond are two of the many Pennsylvania reservoirs.
there are 17 reservoirs
As of the 2nd of April 2010, there are 15 reservoirs that are in nature, 8 are service reservoirs and 2 more are still in planning, namely Punggol and Serangoon.
yamuna and there are many more
roots of trees can prevent soil erosion (which may potentially pollute the river) trees can get water from reservoir trees prevent erosion of outer bank of reservior due to river meandering
There are 108 dams or reservoirs in Cyprus. Although during the current drought, most are close to empty.
swithland cropston thornton
Because of the dustbowls
They would help to keep the air surrounding full of water vapour so the reservoir would not dry up easily.