New questions were raised Thursday about whether the numbers add up in the plan to bring a new NBA/NHL arena to Seattle’s SoDo neighborhood.

The plan calls for the city to borrow as much as $120 million in bonds, but a new city analysis has concluded that revenues and rent payments from the proposed arena won’t be enough to meet the bond payments.

“Base rent, plus the anticipated taxes, will be below the debt service obligations,” council analyst Dan Elder said. “ArenaCo will owe additional rent each year.”

Developer Chris Hansen would be on the hook for that money, and he told the council he thinks their projections are too conservative.

“He believes that he will not have to pay additional rent,” councilmember Tim Burgess said.

Another blow came from the author of Initiative 91, which requires the city to make a profit on any money invested in private sports teams.

“What they did is take all the taxes that this private business would generate and use the taxes to pay the bonds – that’s not compliant with Initiative 91,” Chris Van Dyke said.

Hansen has the site in hand – it would be located just south of Safeco Field – but construction can’t start until the council approves the agreement.