A 2-1/2 foot miscalculation proved an expensive mistake in St. Charles Parish, Louisiana, where a faulty elevation survey put an additional $100,000 on the construction of a new middle school.
A survey conducted in 2002 recorded the lowest elevation of the site to be 4 1/2 feet above sea level,. But the school district recently discovered the true elevation is 6 inches lower. Because the site is in the flood-prone lowlands, the board decided to add an additional 2 1/2 feet onto the site’s foundation to ensure flooding won’t occur.
TCC Construction of Thibodaux, La., the lead contractor on the project, decided to use a combination of concrete, sand and dirt to solve the elevation problem. In areas of the site where the building’s foundation had already been poured, workers poured a double layer of concrete with Styrofoam in between and used steel bars in the top layer to reinforce the foundation and prevent cracking. On other areas of the site where the foundation had not yet been poured, the ground level was raised with sand or dirt.
Surveyor Michael Bernard has acknowledged his error in the original elevation of the site, but is still unsure how the miscalculation was made. Because the $11 million construction of the school is the most expensive project in the district’s history, school officials hope to reclaim the added construction costs from Bernard or his insurance company.