Can you give some more info on the size of this project? Hard to understand why a culvert on an unpaved (and presumably small water source) would cost much.
Almost any project on a highway costs a million dollars.
Take a peek down the rabbit hole. As a recent transplant, I, too, have a hard time understanding the cost(s). It is literally a creek, but it does get swollen when it rains. The other projects were on Holbert Cove Rd, in the same time frame.
Taking a look at that contract (I am not a professional), I note that the "culvert" is specified as a huge aluminum box culvert (19'5" span by 6'11" height) with concrete headwalls. It also includes the removal of an existing concrete structure with asbestos abatement. That plan also has a 36" diversion pipe 120 feet long.
I'd also add that any sort of stream crossing will have pretty stringent restrictions for working in the wet - you're limited to time of year, weather events, need to maintain safe overflow at all times, fish passage, etc - all of these add cost, and limit how many people will bid on the project (they need to dedicate schedule time to the work - can't push it off a month because of delays on another project, or it'll take them out of work period).
I couldn't tell if it also requires the maintenance of road traffic at all times - if it does, even maintaining one lane at a time (with automated signals) would easily add $100k to the price (culvert needs to be removed and installed in sections, then extra work to join them together, much smaller paving operations, etc etc)
It looks like the kind of project that might work better cost wise if you could lump say 10+ replacements together and have a 3-4 year long project.
Thanks for the insight, SECProto. IANAEngineer, either, but for the costs involved, I would imagine building a bridge would eliminate some degree of complexity(there are several spans on that same road, already). The road was closed for over a year, work stopped for some time due to the pandemic, too. I can only imagine what the cost over-runs added up to.
The other 2 projects on HC Rd were controlled with auto signals and occasional, brief closures. Unsure of time-frames, as they were already underway when I arrived.
it would be fun to personally work along with this project and understand the costs as they are happening. I feel like this would help me get a better feel.
I did wander down from time to time to monitor the progress. It was definitely a slow process where equipment and materials sat untouched for weeks at a time, outside of the pandemic shutdown. I presume they were awaiting inspections between phases.
> Port added the money, if approved, would go to install a 5 to 6-foot-wide pipe between Market Square and the Merrimack River.
It’s not 5-6 feet long, it’s 5-6 feet wide.
You need heavy machinery to move those culvert sections into place, heavy machinery to dig the trench, you can only get a couple 20’ sections of 5-6’ diameter concrete culvert on a semi so factor in lots of freight costs too. If you cross any roads or sidewalks, those need to be sawcut and removed, and then replaced afterwards. $655k sounds reasonable to me, if you include all the engineering/utility/heavy machinery/manpower/material costs.
Almost any project on a highway costs a million dollars.