HANNIBAL | Changes intended to protect electrical infrastructure during future floods on the Hannibal riverfront will add $34,382 to the total cost of the renovation project.
The change order, which is the project's third thus far, was approved by the Hannibal City Council during its Tuesday night meeting at city hall.
The latest change order raises the total cost of the project to $6,685,285. The original contract cost was $6,648,000.
The latest cost addition will be paid by the Hannibal Board of Public Works, which is paying the electrical costs for the riverfront project.
According to a memo by Director of Central Services Andy Dorian, this change order was requested to better protect electrical infrastructure that will be located east of the downtown flood levee.
Originally the two main electrical service panels were to be mounted at grade level on the riverfront, with the HBPW removing the panels in advance of floods. In late 2019 the HBPW decided it would prefer to see the panels elevated above flood level to eliminate the task of reconnecting all the wires after a flood. However, it was determined that a lift truck would be required to reach the elevated panels anytime maintenance to them was required.
Klingner & Associates, the project's engineer, proposed an option called a “dive bell.”
The dive bell features a tank that can be put over the panels ahead of flooding and then removed and stored off site after the flood threat has passed. As floodwaters rise above the bottom of the bell's tank, air is trapped inside the tank, preventing water from rising inside the tank which will keep the electrical panels dry.
Dorian added that all conduits in and out of the panels will be sealed, providing additional protection from flood water.
Last October the project's first change order resulted in a net savings to the city of $22,811, thanks to the fact a storm sewer did not have to be replaced.
In February change order No. 2 was approved by the council, which increased the cost of the project by $25,715. Of that amount, $22,318 resulted from the removal of additional old foundations that were discovered. Another $3,397 was due to the addition of chain hoops to each light bollard along the new riverfront sidewalk.
In other business:
• Permission was granted regarding the sale and consumption of alcohol on city-owned property, and for a street closure, during the Music Under the Stars program on Thursday nights, from June 4 through Aug. 27.
• A request for street closures was approved for Saturday, Sept. 12, during the Loafers Car Club's annual Reunion Cruise.
• A public hearing pertaining to the city's 2020-21 budget was scheduled for 6:45 p.m. Tuesday, June 16, in council chambers at Hannibal City Hall.
• Bid awards were approved for the purchase of street materials.
• The council approved the rejection of bids for the demolition of 214 S. Sixth St.