Stairway to heaven

The ladder — which will replace an experimental, small-scale temporary fish passage system used since 2003 — will have 47 individual concrete step pools that will permit fish to gradually ascend about 75 feet to the top of, and over, the dam.

Now just because a ladder is built, it doesn’t mean the fish will use it.

Fish are extremely wary of changes in the water, and some actually may rise to the surface to check out if there’s a way to swim up the river rather than jump to the series of pools forming the ladder.

Some fish may jump from pool to pool within the ladder, which is what they’re supposed to do, while others may jump out of the fish ladder entirely.

If the river current is too fast at the exit, fish leaving the ladder may be swept back over the dam. “We have to take all that into consideration,” Jourdonnais said.