Ah, yeah, that’ll involve draining the tank completely, probably cleaning the inside, and then also welding it in place - municipal water tanks need to be able to keep their repairs intact when the water is out of them, so just slapping it on without permanently attaching it is just asking for problems the next time there’s a drought, or high water demand in the area.
Definitely going to be expensive and time consuming, but at least the internal patch method doesn’t need to be re-painted.
