City officials spent almost two hours poring over spending totals from the Duck River Dam project earlier this week, working to understand where every cent has gone and where a lot more dollars will be needed.
With the projected cost of the Duck River Dam still $40 million over the original $70 million budget, the utilities board approved two new studies at a cost of approximately $230,000 they hope will be able to bring expenses down a little further — though the total project is still expected to cost in excess of $100 million.
Potential savings of approximately $5 million from the studies approved this week were already calculated into the current $110 million total project cost estimate, though officials say they could create a savings of up to $10 million once complete and implemented into the final design.
Officials approved a $69,680 study from Applied Weather Associates, which will provide a site-specific rainfall study that officials hope will prove lower than the decades-old regional standards currently being used to measure the potential maximum rainfall. If officials are able to lower those totals — which are used to determine how large a flood the dam has to be designed to withstand — they believe it could save a few more million dollars. By lowering the rainfall standards, it would allow engineers to design a smaller and cheaper spillway.
The board also approved a $64,000 contract with Utah State to provide a design study for a fuse plug, which will be implemented into the design and serve as a “trap door” for any excess water in the event of a massive flood that could threaten the integrity of the dam.
The city also approved an additional $96,000 for project engineer of record CH2M Hill, which will cover coordination and facilitation costs for the studies.
At a meeting a few weeks ago, the utilities board hired national engineering firm URS to perform a third-party review of the design. URS also recommended the board move forward with these new studies.
Following a full-scale engineering study over the past several months, the utilities board received word last month that the total cost of the project is expected to jump from $70 million to approximately $110 million due to less-than-favorable geology and higher flood standards at the dam site in northeast Cullman County.
The cost increase is largely tied to an abundance of clay layers recently discovered at the construction site, which essentially made the original design untenable. Engineers say the latest redesign will work at the site, but at a considerable increase in cost.
To date, the city has spent a total of $30.9 million on the project — with more than $20 million of that total spent since land acquisition began in earnest in April 2011.
The board had entertained the idea of potentially reducing the capacity and output of the dam and lake to cut costs, though some new information from the U.S. Army Corps of Engineers makes that an unlikely route.
If the city reduced the scope of the project, then decided to come back in the future and increase it to the original level, it would require a new 404 permit — which can be a lengthy, expensive and arduous process. There is also no guarantee a new permit would be approved.
Stream mitigation costs would also have to be reassessed, which could cost between $8-10 million more at that point.
“The thing about a smaller dam or smaller reservoir is it’s something that could be done, but the issue is that whatever streams you might not have impacted, you’ll have to do mitigation,” Steve Newton, with CH2M Hill, said. “Also, most of your savings would come in the construction of the base, and you couldn’t reduce that if you wanted to expand later on.”
Project owner’s representative Bill St. John said he believes any move to reduce the scope would essentially be a “permanent” decision — due to the challenges of trying to get a new permit to expand in the future.
“Practically speaking, it sounds like that’s a permanent decision if you reduce size,” he said. “It is a decision that’s on the table, but I think it’s a permanent decision in that matter.”
* Trent Moore can be reached by e-mail at firstname.lastname@example.org, or by telephone at 734-2131, ext. 220.