EPHRATA - The initial estimate of $61 million in repairs, other expenses and lost electrical generation has not changed in light of the list of repairs that will be needed at Wanapum Dam.

Grant County PUD officials announced Feb. 27 that engineers found a crack in one of the pillars supporting a spillway gate at the dam. Operators immediately lowered the water behind the dam, and the crack eventually closed.

The water remains low. Hydro Director Dawn Woodward said Tuesday the water probably would have to stay at current levels until at least October, and possibly later.

Chief Financial Officer Kevin Nordt said the estimate, announced April 22, was based on the possibility the pool behind Wanapum Dam won't be filled until the end of 2014. He estimated the impact to power sales would be about $8 million, and the PUD will spend about $15 million remodeling the fish ladders, providing security along the now-exposed shoreline and other services. The actual cost of repairs was estimated at a maximum of about $40 million, Nordt said.

Woodward reported on the investigation into the causes of the crack, and the repairs necessary, at the PUD commissioner meeting Tuesday. The cause was a math error during the design phase, which was repeated across the entire structure, Woodward said.

The miscalculation in the design led to some miscalculations in construction, Woodward said. There should've been more concrete or reinforced steel, or both, in the design, and there were places where the rebar design may have contributed to making the crack worse once it formed, she said.

To fix it, the PUD engineers proposed adding more steel reinforcement at the site of the crack, and possibly all the way through the bottom of the cracked pillar. All the pillars will be reinforced with additional steel, from the top of the dam to the bottom, and about 100 feet into the bedrock.

The cracked spillway will get additional steel and concrete reinforcement, both from the upstream and downstream sides, Woodward said. The crack and the concrete around it will be repaired, along with damage to pillars on either side of the cracked pillar, she said.

The Federal Energy Regulatory Commission has to approve the plan before the project can succeed, Woodward said. The official decision should come by the end of June, she said.