The deep-bore tunnel isn’t evil, it won’t destroy the environment, the city will keep ticking whether we build it or not.

The only problem with the tunnel is the cash. It will cost $4.2 billion for the current Alaskan Way Viaduct Replacement Project that includes the tunnel. The interest on bonds will reportedly cost another $1.9 billion, bringing the total to $6.1 billion. But most drivers won’t pay a $5 one-way toll. They won’t take a freeway with has no exits. The traffic diversion caused by the high tolls, as I write in a long article this week, will require more expensive mitigation for all the Highway 99 traffic that won’t use it. As per on the state's Final Environmental Impact Statement, this will require redesigning lanes on downtown arterials, optimizing capacity on certain streets, modifying intersections, adding vanpools, beefing up transit, and boosting bus service into and through downtown. The state can’t explain how much this essential mitigation will cost, but everything the state is going to have to do to build the tunnel is, in a nutshell, the same shit the state would have to do if it went with the surface/transit option (which was chosen, then rejected at the behest of well-heeled groups in favor of a tunnel). Previous estimates say surface/transit would cost about $3 billion. So the “tunnel” option, already a megaproject in itself, is really only one half of the mega-megaproject we’re signing up for when we pick the tunnel. Because we're going to have to build surface/transit, too.

That actual cost of all of this—the tunnel and the surface work combined—could total $7.2 billion (plus billions more in interest). Love or hate the tunnel, let’s be square here: We don’t have that money. Here's what we do have:

The state has committed $2.4 billion, from gas tax bonds. That's essentially in the bank.

The Port of Seattle has pledged $300 million, but we don’t have it yet.

The city has pledged $930 million, but we don’t have that yet, either.

The state says it will come up with $400 million from tolling bonds, but the legislature has yet to authorize them.

The tunnel is actually a $4.2 billion project, $1.9 billion in financing for the interest, and up to $3 billion for mitigation project on surface streets and transit. Who will pay that bill? Pardon me if this sounds strident, but it’s important here…

WE’RE GOING TO NEED BILLIONS OF DOLLARS MORE.

The pro-tunnel argument is this: It’s just money. Someone, somewhere will find that money. Let’s Move Forward, the pro-tunnel campaign, is proving that it’s good at finding money from their friends. Downtown business, labor, and nearly everyone in the local political establishment is throwing money at the pro-tunnel campaign. They’re out-fundraising the anti-tunnel groups in run-up to the August referendum vote. The Mariners gave $5,000, the Westin Hotel gave $5,000, the Greater Seattle Chamber of Commerce gave over $20,050, the Downtown Seattle Association gave $20,550, and property owners downtown have contributed thousands more. They’ve raised about $130,000 and are reporting about $15,000 more every week (while the anti-tunnel campaign is expecting to run to the ballot with less than a quarter of that money).

The pro-tunnel folk are essentially promising that the money will be there when we need it.

Okay, fair question then, where will the extra billions—to cover the city’s part of the tunnel, the money from the Port, the unknown amount required for mitigation (a.k.a. the surface transit option)—come from?

Just to cover the city’s baseline obligation to the tunnel—$930 million—we could be paying a Chex party mix of property tax levies, utility taxes, tolls on other roads. The Port’s baseline $300 million, mostly funded from property taxes on King County residents, will be coming out of our annual property tax bill. We'll be paying those bills for years.

And what about the rest—the billions for transit and mitigation?

More gas taxes? More car tab fees? Even more utility rate hikes? Added sales taxes for buses? Higher parking rates for street improvements? Additional property taxes? And we haven't even touched cost overruns typical for a project like this.

It’s going to cost a lot—billion of dollars, largely from Seattle residents—and it’s going to come out of our pockets years after this summer’s decision on the tunnel. It’s just money, sure. But it’s our money. Enough money to build Portland's light-rail network twice. And to be clear: It's not the money of big business and the political constellation (the ones paying the campaign and making the promise) that will pay for the final tab for the tunnel. The tunnel will mostly be paid for by drivers, homeowners, renters, utility rate payers, sales-tax payers, bus riders...

The final bill for the tunnel—the tunnel plus the surface/transit option and all the financing—will be borne mostly by Seattle's middle class and lower-income residents, not by the wealthy and connected people who backed, promoted, and underwrote the campaign for the tunnel.

But it's just money. Mostly yours.