Many Janesville residents are likely in for a nasty surprise when they get their property tax bills this month.

A big clue came at Monday’s city council meeting, where Finance Director Max Gagin broke down this year’s tax bill by government body: the city, Rock County, Blackhawk Technical College and the Janesville School District. Gagin projected this year’s tax bill to increase by 11.1% for the average homeowner living in the Janesville School District. (For those living in the Milton School District, it’s a 16.6% increase.)

By “average,” the city means a homeowner whose property assessment increased by the average amount of 31% during the recent citywide revaluation. While the city’s tax rate is expected to drop by 18.6% (normally great news), the revaluation will cancel out the decrease and then push taxes 11.1% higher for the average homeowner.

On Monday, the city council passed the 2020 budget, which Councilor Doug Marklein described as “fair,” and he’s right in that the tax levy increased by only 1.3%, from $38.8 million to $39.3 million. But the revaluation distorted the budget’s effect, shifting the city’s tax burden from commercial to residential properties. While residential property values increased by an average 31%, commercial values increased by only 12% on average. Homeowners are picking up the difference, which hardly seems “fair.”

Meanwhile, Janesville homeowners are facing a 53% increase in their water bills, which probably also doesn’t feel “fair.”

To be clear, the city isn’t the only source of homeowner’s pain this year, or even the worst offender. In fact, the city’s portion of the bill increased by only 7%, according to Gagin’s figures. That compares to a projected 16% rise for the Janesville School District, 10.6% for Rock County and 11.4% for Blackhawk Technical College.

We blame the school district tax hike, in part, on the district’s last-minute maneuvering to include in its 2020 budget an additional $4.4 million in debt service payments. While the move will save about $500,000 in interest payments, it was bad timing.

December could be brutal, and we’re not talking about the weather. Those 11.1% hikes could make for disgruntled taxpayers, which could make for disgruntled voters. Many people who save money automatically each month through their mortgage escrow accounts will likely need to write additional checks, possibly for hundreds of dollars.

Against this backdrop, the Janesville School District recently kicked off discussions about holding a referendum for maintenance to school district buildings. Its wish list isn’t controversial, containing what most taxpayers would consider “needs,” such as asbestos abatement and security upgrades. These types of projects need to get done...eventually. But taxpayers experiencing sticker shock might be tempted to conclude the district’s maintenance “needs” can wait a few or several more years.

School district officials would be wise to give taxpayers time to recover before entertaining serious discussions about a referendum. Voters might be in no mood to sign up for higher taxes come 2020.

A previous version of this editorial included incorrect information about the city of Janesville levy amounts.