Wiggle room in the general fund budgets for the Manteca Unified School District and the City of Manteca will shrink considerably over the next four fiscal years and beyond as two public sector mega-retirement plans impose larger contributions on cities, school districts, and counties as well as the State of California.The two funds — California Public Employees Retirement System and the California State Teachers Retirement System — are both significantly underfunded. Based on various projections by the fund managers as well as outside financial experts the will run out of money sometime between 2040 and 2046.And while pension funding shortfalls have been discussed since they started developing in earnest 15 years ago it wasn’t until both retirement funds last year took steps to work toward bridging part of their unfunded liabilities that cities and school districts have been forced to brace for what will be a series of four annual hits that for all practical purposes will increase their average share of retirement costs to roughly 20 cents on the dollar as opposed to today’s 13 cents on the dollar for overall employee pay.Given school districts spending almost 90 percent of all their general fund on benefits and salaries with cities not far behind at an excess of 80 percent, it puts pressure on other general fund expenditures and will likely slow down creating new positions or even force jobs to be shed to cover the growing pension fund costs.The State of California is in a similar position.Both CalPERS and STRS have been hit be the domino effect. STRS was 104 percent funded for its liabilities back in 1998.