67.0°

Sound off on the important issues at

Coeur wants permission to construct a diversion ditch at the lake in preparation for spring runoff. The ditch would serve as backup to a temporary coffer dam constructed during the summer of 2006. Overflow water would be diverted into Slate Creek.

The U.S. Army Corps of Engineers has approved the ditch. In a request to the court, it estimated that it would take about 48 days to finish the ditch in favorable conditions.

It also said that runoff flow could begin as early as April.

SEACC worries that there's not enough time to dig the ditch properly and that it could cause water quality problems. It claims the mining company failed to plan adequately, saying that it has known since August to prepare for spring snowmelt.

"The time frame just doesn't add up if Coeur is really concerned about water quality," said Rob Cadmus, SEACC'S mining and water quality organizer.

"Even if the court authorizes construction of the ditch, Coeur couldn't complete construction before the spring runoff starts," he said.

"Was Coeur gambling that it wouldn't snow in Berners Bay this winter?"

"We have been working with relevant agencies to make sure that they knew what we were doing, and we certainly took our time to do it right," said Scott Lamb, a spokesman for the Idaho-based mining corporation.

"I think you can assume that we wouldn't be proceeding at this point unless we thought it would be done in time to prepare for runoff," he said.

SEACC also said, however, that two federal agencies - the Environmental Protection Agency and National Marine Fisheries Service - have suggested viable alternatives to the diversion ditch that would have less of an impact on waterways.

These included building a spillway on the coffer dam, improving erosion control measures, or adding more water pumps, SEACC said.

The conservation groups says the ditch proposal is part of Coeur's plan to develop the lake by reducing costs associated with treatment of polluted water.

Lamb said that the diversion ditch is designed only to handle runoff during this period of inactive construction.

He said experts at Coeur and the U.S. Corps of Engineers were confident that this plan was the best way to prepare for the spring melt.

Coeur had requested the court to remove the injunction restricting construction activity at the lake on Nov. 7, 2006. That request was denied in December.

• Brittany Retherford can be reached at brittany.retherford@juneauempire.com.