Its “breezeway” design, with a gap between the top of the walls and roof, means water flies into the building when it rains.
The report by Civil Project Solutions also links the design to problems with vandalism and “excessive loitering” since the toilet block opened in September 2019.
Currie Construction was awarded the $598,000 contract to build the toilet block in August 2018, with the building meant to be completed by the end of November 2018 in time for the cruise ship season.
But issues with the site were discovered the very day that excavations began in September 2018, uncovering rail tracks, contaminated soil and fumes, the report shows.
What followed was a series of delays as the project team waited on soil test results and formulated a new plan for groundworks.
The final design included a liner to protect the toilets' foundations from oil seepage.
The project team were also forced back to the drawing board after heavy rain flooded the site while the concrete foundations were being poured in January 2019, and water settled between the liner and foundations.
Designs for the building's steelwork were the next source of delay, with several “additions and alterations” required.
Problems with installing the intricate roof structure and then a streaky, inconsistent paint job compounded the hold-ups that saw the planned three-month project turn into a year-long effort.
Meanwhile, the council's chief executive, Nedine Thatcher Swann, is reporting that councillors will be presented in August with initial designs and cost estimates for refurbishing Gisborne's earthquake-prone Peel Street public toilets.