As there are 13 sediment removal locations and 7 stock pile locations, I expect that work will be occurring at multiple sites concurrently in order to get the work completed within the required fisheries window.
I suggest not a same-same comparison to your context.
Its still ALOT of money. just for crude math sake, Each machine with operator charges out at about $250/hr. lets say 6 weeks x 5 days a week x 10 hour days x 20 machines x $250/hr = $1.5M
Sure there is some wood debris mixed in, but minimal processing (washing, screening) could make it quite valuable. Another $2M and it could all be hauled away to a fill site (dump). so we're at $3.5M. Maybe I underestimated the machine/manpower. so double it and we're at 3+2= $5M. A far cry from 13!