In total, 61 fish that had been waiting in the pool below the dam passed safely through the modified ladder on the first day Tuesday.
The Yakima Herald-Republic reported Thursday that a few migrating fish are also being trucked around the dam and released upriver to reach spawning grounds.
"We're being cautious because it's a bell we can't un-ring," said Jim Brown of the state Department of Fish and Wildlife. "The entire spring chinook run is listed under the Endangered Species Act at this point in the river and we can't just be risking large numbers of fish when we don't need to."
After a 65-foot-long fracture was discovered in one of the dam's concrete spillways in late February, the water level was drawn down by 26 feet to reduce pressure on the crack. The dam stabilized, but it left the fish ladders high and dry
Modifications were designed to pump water into the ladder and install a slide from the outlet so fish can reach the lowered reservoir safely, according to the Grant County Public Utility District, which owns the dam.
"We turned on the pumps at 7 a.m. and removed the screens and just over two hours later, the first chinook jumped onto the ramp," said Russell Langshaw, a fish biologist for the PUD.
The fish ladders at the Rock Island Dam, upstream from Wanapum, also had to be extended 30 feet because of the lowered river level.
So far, the PUD has spent $1.5 million on modifying the ladders and setting up the collection and hauling, according to spokesman Chuck Allen.
The fish are being collected 18 miles downstream at the Priest Rapids Dam, where a collection facility was modified to divert the fish into tanker trucks.
A team of biologists and state hatchery staff started the hauling operation Tuesday. On the first run, they drove one fish 26 miles north to the release point in Vantage. Wednesday, a truck was loaded with just three steelhead.
"Each fish is very valuable," said Janet Eckenberg, a technician for Fish and Wildlife. She added that while it might seem silly to do all this work for a few fish, it helps test the system before more fish arrive.
About 15,000 spring chinook are expected to hit Priest Rapids Dam between now and mid-June. The hauling system can move 1,500 fish per day, Langshaw said. The rest must go up the fish ladders.