Now during dry summers the dam can nearly block the whole river.

The 17 dams in the Harz block a total of twelve rivers.

At present, two dams block fish from entering the river; there is some pressure for their removal.

Those dams have blocked salmon and steelhead runs in many parts of Idaho.

The dams block passage to and from the ocean leaving landlocked populations.

More controversy has risen about the American eel in that the dam blocks their passage as well.

The dam has also blocked the migration of salmon and other fish upstream to spawn.

Huge dams of clots block the way to the ruptures.

Over this stretch, four dams in Washington block the Snake.

The fish thrived there for centuries until dams blocked their path to and from the ocean.