Stronger muscles so that they can swim against the flow.
Suckers for anchorage
Water flowing out of the ground is a spring. An artesian well is one example of water under pressure flowing out of the ground.
Water
one of the ducks structural adaptations is its webbed feet to keep it a float in water. a behavioural adaptation is that they only feed in shallow water, by wading in the water.
fish live in flowing waters and water bugs do also, i am a scientist that studies lifeforms in water so i can give you a list if you need one
runoff
A better river would be a river with more water flowing and healthy wild life eg fish and birds
It's the Earth.
water, food
The balsam fir has at least one adaptation which is it's waxy resin like coating on the needles. They help to preserve water.
fresh flowing surface water is one of our most precious resources
One adaptation of the mute swan is that they have webbed feet to live near water.