Standard & Poor’s on Tuesday affirmed Chicago’s BBB bond rating and negative outlook — even after Mayor Rahm Emanuel proposed a 30 percent utility tax to save the largest of Chicago’s four city employee pension funds.

“While we believe the city is moving in the right direction toward stabilizing its budget and its pension plans and that the announcement of the new tax is a positive development, in our view there is uncertainty around the new tax until fully approved,” the report states.

“The outlook could be changed to stable if the city’s new water/sewer tax revenue is approved by the City Council without any other obstacles.”

But, the report warned, “In addition to the pressure of funding pensions, there are other aspects of the structural imbalance that bear correcting such as the city’s approach to debt as a source of budgetary relief and the high fixed charges stemming from its high liabilities. We could lower the rating if the city’s budgetary performance worsens in such a way that we believe its budgetary flexibility and liquidity is compromised.”

Last week Emanuel put in place the final piece of the pension puzzle he was elected to solve, but in a regressive way that will impose another heavy burden on Chicago homeowners reeling from rising property taxes compounded by reassessment.

To generate the $239 million over five years needed to save the Municipal Employees Pension Fund, Emanuel wants to slap a tax on water and sewer bills that would grow to 30 percent over the next four years.

The average Chicago household that now pays $686.04 a year for water and sewer services will pay $53.16 more in 2017 and $225.96 more in the fourth year.

Emanuel has ruled out alternatives and blamed the Wall Street rating agencies. He says rating agencies are demanding a single, reliable source of revenue to put the Municipal Employees Pension fund on solid footing and it has to be a tax the City Council can enact on its own without having to rely on the Illinois General Assembly.

But that was not enough to raise Chicago’s BBB bond rating, nor was it enough to convince Standard & Poor’s to remove the “negative” outlook that could signal a further downgrade.

In the report issued Monday, S&P cited a host of other budgetary concerns:

• Chicago’s “very weak debt and contingent liability position” with debt service carrying charges at 11.9 percent of expenditures and net direct debt that is 159 percent of total governmental revenues.

• A large pension and other post-employment benefit obligation that’s “likely to continue rising” and the lack of a plan to sufficiently address the obligation.

• A “weak institutional framework” score and “budgetary performance” that could “deteriorate in the near-term.”

• Additional pressure on revenue to make up for “market returns that fall below performance expectations” and Chicago’s limited capacity to reduce expenditures in a city budget where 60 percent of all corporate funding goes to public safety.

“Chicago is gradually making progress in addressing its budgetary challenges. But some aspects remain significant. There are forecasted budget gaps to close and growing pension contributions to fund,” the report states.

“The city’s continued reliance until 2019 on scoop and toss, which delays debt payments and increases interest costs, adds to our view that the city’s budget remains unbalanced and structural deterioration is likely without continued deliberate and determined responses from the city.”

Standard & Poor’s noted that Emanuel has taken the “crucial steps” necessary to identify recurring revenue sources to support each of Chicago’s four city employee pension funds.

But the report states, “To meet its ongoing pension obligations, the city may be met with resistance to maintain or raise its levels of taxation beyond fiscal 2016.”

Molly Poppe, a spokeswoman for the city’s Office of Budget and Management, called the S&P report a positive sign.

“They note that the city is absolutely moving in the right direction and even predict an outlook change once the tax is codified,” Poppe said in an emailed statement.

“The city inherited these legacy liabilities, and we are following a deliberate reform and invest strategy to ensure the city remains on a path to long-term financial stability. We are not going to solve all these problems overnight, but we have made substantial progress and S&P highlights that.”

Civic Federation President Laurence Msall agreed that it’s “good news” that S&P is affirming Chicago’s existing bond rating and projecting an outlook upgrade to stable if the utility tax is approved by the City Council and the employee concessions and trade-offs are ratified by the General Assembly.

But, he said, “It also points to the heavy lifting the mayor and City Council need to do to not only implement the plan but begin to reduce the ongoing uncertainty surrounding how ongoing services will be funded and provided.”

Earlier Monday, Emanuel touted his ongoing efforts to right the financial ship and remove the “dark cloud” hanging over Chicago during an address to the Trustbelt Chicago 2016 conference.

“In the last five years, our structural deficit has been cut by . . . just shy of 80 percent. And we did it without relying on just random cuts or random tax increases. By balancing reform and revenue in a way that allows us to reduce the structural deficit . . . while continuing to grow the economy,” Emanuel said.

“We also have got three of our four pensions with a revenue stream on a 40-year arc resolved. And we will now embark on the final pension, the municipal fund, to have that fully paid for. So, all the pensions will have a revenue stream to keep our commitment to our employees, but do it in a way that does not tip the balance of the economy, but fixes once and for all . . . the biggest overhang over the economy and the uncertainty around the city, which happens to be the financial picture.”