You're wrong. Unless you guessed $00.00. That's right, the Badger State's taxpayers don't pay any part of the pensions. The workers do, because their pensions come out of deferred compensation--that is, money that's owed to them as wages, but that they have elected (through their collective bargaining agreements) to defer and put into the pension system.
It is true that taxpayers would have to make up shortfalls if the projections of payouts fall short (i.e. retired workers live too long). But that is the product of short-sighted public officials who made overly-optimistic projections to make the deal seem sweeter to employees. (The plans are defined-benefit plans; if Gov. Walker really wants to save money down the road, he should negotiate with public workers so that new contracts, or perhaps newly-hired workers, go into less generous defined-contribution plans. But then again, saving money isn't what he's really about.)