Rogue River salmon and steelhead are again migrating over the Savage Rapids Dam fish ladder — but it will be the last time — as construction crews prepare for removal of the 88-year-old dam.

Rogue River salmon and steelhead are again migrating over the Savage Rapids Dam fish ladder — but it will be the last time — as construction crews prepare for removal of the 88-year-old dam.

Upstream passage for the Rogue's winter steelhead and spring chinook through the antiquated ladder was restored Tuesday for the first time in three weeks.

The ladder went dry as the reservoir behind the dam was lowered so construction crews could build a temporary dam to dry out Savage Rapids Dam's concrete on the north end so it can be cut and removed.

That temporary dam, called a coffer dam, was completed Monday and the Grants Pass Irrigation District slowly began filling the upstream impoundment to its normal level. That effort was completed Tuesday, GPID Manager Dan Shepard says.

During the past three weeks, Rogue flows were diverted through two radial gates at the dam's base, and water velocities were believed to be too high for migrating spring chinook to move through them.

But a small, yet steady, stream of spring chinook over Gold Ray Dam 19 miles farther upstream has convinced most onlookers that at least some fish made it through the radial gates.

As of April 23, 446 spring chinook have been counted passing Gold Ray Dam, according to the Oregon Department of Fish and Wildlife.

Longtime fishing guide Dan Stumpff says it's unclear whether the three-week operation interrupted the run, which is still in its early stages.

"I just don't think we have the numbers yet to tell," Stumpff says.

Stumpff says he will start fishing for spring chinook at Gold Ray Dam next week.

Shepard says plans are for construction crews to begin dismantling the dam early next month.

The dam will be replaced by an already completed electric pumping station ready to begin water-delivery for the Grants Pass Irrigation District when its irrigation season begins in mid-May.

The $39.3 million project is expected to be completed by December.

Reach reporter Mark Freeman at 776-4470, or e-mail mfreeman@mailtribune.com.