Sometimes the credit crisis seems like last year’s news. At least, you would think so if you looked at projected Wall Street bonuses and New York City and State public spending.

But a new Moody’s report shows how the crisis continues to impact infrastructure projects. It’s a reminder that municipalities can’t rely on fancy structured finance as a way to avoid making tough decisions on how to fund critical infrastructure with taxpayer money (optimally, by cutting spending elsewhere).

When states and cities borrow for infrastructure projects and back the debt with expected revenues from the infrastructure itself rather than with their own general credit, their lenders — banks and/or bondholders — often want them to set aside a “cash reserve” to pay a few months’ worth of debt costs in the case of a temporary cash shortfall in the project. The riskier the project, the bigger the required cash reserve.

But in recent years, states, municipalities, and other infrastructure-debt issuers often didn’t put their own cash aside in such a fund; instead, they could pay a company called a surety provider a fee to provide the cash on a standby basis in an emergency.

Trouble is, the surety providers were also, often, backing mortgage-related debt — and now their credit has suffered, meaning no investor wants them to back a fund to protect debt, current or future.

Now, Moody’s notes, public-sector issuers who relied on such funds as part of infrastructure-financing deals may have to pony up the money to replace the funds, representing another cash call on strapped municipalities.

The Los Angeles County Metropolitan Transit Authority, for example, has already replaced a surety fund. The Metropolitan Nashville Airport Authority has taken steps to do the same.

The disappearance of some surety providers will also affect future projects, since public-sector borrowers will have to find real cash for reserve funds rather than paying an outsider to provide standby cash in an emergency.

The change also further hurts states and cities’ ability to borrow through “public private partnerships” — that is, trying to transfer responsibility for something like a toll road from the government balance sheet to a private-sector partner. In Moody’s hierarchy of projects that require bigger cash reserves, toll roads run by private-sector partners rank higher on the risk scale than do public-sector toll roads.

The change could also affect issuers’ ability to raise debt for sports stadiums — possibly making things a bit tougher for the Atlantic Yards basketball project in Brooklyn, for which developer Bruce Ratner must raise financing by the end of the year.

Mass-transit agencies rank as pretty risky, too.