In a Slog post yesterday, I chronicled a spat between mayoral challenger Mike McGinn and incumbent Greg Nickels over which would be less expensive: a deep bore tunnel under downtown, which Nickels prefers, or McGinn's preference for a surface transit option. But in the end, it seemed like Nickels had the upper hand—breaking down numbers that indicated McGinn's project would cost the city more ($936 million compared to $930 million). It seems like an inconsequential difference, but it's relevant to the race if McGinn's plan doesn't actually save the city dough. After all, his campaign is largely based on the argument that a tunnel would cost too much. I wrote, "Voters want to know: Will the surface plan that McGinn wants actually cost us less?"

Today, McGinn writes back:

You asked a fair question: "How much will my viaduct replacement plan cost?" First, let's look at the current state/federal funding situation.

State voters have now approved two tax increases to take care of the Alaskan Way Viaduct. In 2003, we added a nickel per gallon gas tax and set aside $251 million for the viaduct. In 2005, we agreed to a further 9.5 cent gas tax increase, allocating another $2 billion for viaduct replacement. On top of that, the federal government has provided $300 million.

Total: $2.551 billion (not including toll revenue or contributions from the Port of Seattle)

That is the budget we have to work with and I think we can replace the viaduct and deal with mitigation issues within that budget.

More from McGinn after the jump.

Here's how:

I-5 Widening
$553 million

Utility Relocation
$250 million

Seawall Replacement
$255 million

Viaduct Removal, Street Grid, and Alaskan Way
$825 million

$500 million

Total: $2.4 billion

But, of course, building a deep bore tunnel would cost more. A lot more. And that's where Seattle taxpayers would have to get involved, because a tunnel exceeds the state budget. Involved to the tune of a nearly billion dollar subsidy and the liability for all cost overruns.

Politicians need to learn to live within their means. We have a lot of very pressing needs in Seattle and taxpayers don't have bottomless pockets. We have to prioritize and become more efficient. The effort to replacing the viaduct would be a good place to start.

Zooming out of the financing details, there's a larger question at play here. Why is Mayor Nickels trying to put Seattle on the hook for $930 million viaduct replacement costs that even WSDOT and Judy Clibborn are saying Seattle is not necessarily responsible for? (see

At best, Nickels puts Seattle in a horrible negotiating position and at worst, he's committing Seattle taxpayer money in an attempt to score political points.

With this type of representation, it's no wonder that there is a State Law that holds Seattle taxpayers liable for all cost overruns of a State Highway.

Michael McGinn