The covered pool at Carlton School was damaged during the 7.8 earthquake that was felt in Whanganui last Monday.
Principal Gaye O'Connor said the damage could have an impact on the long-term future of the pool.
"Apart from water sloshing out of it completely, it sustained fine cracking on the bottom that added to previously repaired cracks, and it is now leaking continuously.
"We are one of the very few primary schools in Whanganui to still have a pool and the only school with an indoor pool, making it suitable for year-round use."
Ms O'Connor said that, by a stroke of good fortune, the pool was insured a few weeks ago.
"However, the excess that applies may mean that even if it is assessed for repair, the school may not be able to afford the excess amount."
The Ministry of Education does not pay for pool repairs, so the cost would have to come from the school's operational budget.
"We cannot afford to keep continually filling it and treating the water to make it swimmable, so it is out of action for the foreseeable future." She said the damage may lead to permanent closure of the pool.