"If you know those, you can go back and design turbines for safer fish passage," he said.

The dams have not produced power since that time, but continue to block upstream fish passage.

There are efforts currently underway to reestablish fish passage at the dam.

Dams need to be equipped with fish passages to connect fragmented habitats.

If designed properly, bridges and culverts can have little or no adverse effects on fish passage.

At least 6-inch depth of flow is required for adequate fish passage.

This made fish passage through the golf course on the West Fork nearly impossible.

Fish passes were built into these weirs to allow fish passage.

American eel are in serious decline, but increased fish passage will open the river for them.

And fish passages around the dams are to be provided.