Sitka’s Blue Lake dam expansion project will cost about $3.6-million more than expected.
The total project — not including new backup diesel generators — was originally estimated to cost about $142-million. It is now up to about $145-million, Utility Director Chris Brewton told the Sitka assembly Tuesday night.
Brewton later told KCAW that this is the only major cost overrun the project has seen so far.
Most of the overrun will pay for construction of a temporary water filtration plant at Indian River. Sitka will rely on water from Indian River for about two to four months, starting in late August, when work on the dam will shut off access to Blue Lake, the city’s regular water source.
The city had originally budgeted $2-million for the temporary filtration system at Indian River — but, Brewton said, they always knew that number was a rough guess. As the project engineers completed the final design over the last several months, he said, it became clear that the final cost would be much higher. The city now estimates the total cost for the filtration system will be $4.7-million, or $2.7-million higher than expected.
The other unexpected cost is for debris removal. When the dam expansion is complete, Blue Lake will inundate over 360 acres of currently dry land, Brewton said, drowning trees, shrubs and undergrowth that will eventually die and bob up to the surface. That debris then has to be removed.
The city originally budgeted about $1.5-million dollars for the task, but both contractors who bid on the project estimated that it would take longer than the city thought. The total cost is now estimated to be $2.3-million, or about $800,000 more than originally expected.
The assembly approved a contract with Sitka-based ASRC McGraw Constructors LLC, to handle the debris removal.
The assembly voted to approve the increased project cost. Assembly member Mike Reif said he felt fortunate that the cost overrun was so small, given the overall size of the project.
Chris Brewton said he felt city staff were keeping a particularly close eye on expenses:
“We’ve got a big hairy guard dog on the project,” Brewton said.
The assembly authorized the administration to apply for a low-interest loan from the Alaska Department of Environmental Conservation to cover the additional expense.
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