Independent presidential candidate John B. Anderson today proposed a new $8 billion federal aid program to help the nation's cities and towns fund mass transit projects, rebuild rutted roads and patch up rotting sewer systems.

"In many cities, the capital plant is near collapse," Anderson told the annual meeting of the U.S. Conference of Mayors here. "Federal money to rebuild streets and replace water mains may not seem as glamorous as money to build convention centers or shopping malls. Nevertheless, I believe that we must rebuild the foundations of our cities before we can worry about their superstructures."

Anderson said he would also seek ways to encourage private development of decent and affordable housing for low-income families as well as middle-class households. He said he would seek to change current federal policies to spur more development of rental housing and would favor special tax incentives in designated areas of cities to encourage commercial development.

Anderson reiterated proposals for paying youth at least 85 percent of the minimum wage in order to ease high unemployment among minority teenagers. He criticized Carter administration economic policies saying:

"Today, in an era of scarcity, we must make sure that we do not step backwards in our support for the poor, the unemployed and those without opportunity for economic advancement."

Anderson said he would raise the money for mass transit and what he called an "urban reinvestment trust fund" by diverting the $8 billion from the collection of excise taxes on alcohol and tobacco. The two programs would split the money, he said.

The proposal for new urban aid came in a speech in which Anderson laid out his program for the cities, sounding many of the themes being discussed in workshops and after-hours bull sessions.

"First, simply stated, you need more money," Anderson said, in an observation that is disco, jazz and symphony to the mayors' ears.

The independent candidate was critical of Congress and of President Carter for cutting social programs and said he favored more appropriations for cities hard hit by the recession, an extension of revenue sharing, community development programs and a revision of federal jobs programs to emphasize training for private employment.

Anderson also proposed that a "council of urban advisers" be created, similar to the existing Council of Environmental Quality, to advise the White House and federal housing officials on urban problems. He suggested that such an organization might undertake an overhaul of federal urban aid programs so that they might function more efficiently.

His appearance won him much admiration among the mayors, but no apparent converts.

"Mayors are very largely aligned to the two-party system," said Democratic Mayor Maier of Milwaukee. "I don't think very many of them are very impressed with [Anderson's] record. His record nowhere matches the span of what he was advising. But he speaks to the mood, and I must tell you I was surprised at that."

Atlanta Mayor Maynard Jackson, also a Democrat said of Anderson: "He's a nice guy and articulate, who did not impress tough, hard-nosed decisionmakers."

At a press conference after the speech, Anderson seemed to indicate that he had not expected to gain new supporters here.

"Mayors are in coventry, literally in conventry, if [they are] not identified with the re-election aspirations of Jimmy Carter," Anderson said.

"I believe it can be documented that politics have intervened into the administration of grants and programs. . . anyone who doesn't believe that believes the moon is made of green cheese, believes the economy has turned the corner."

Anderson also took a few swipes at GOP presidential candidate Ronald Reagan who said Sunday that more federal money may be needed to help ease unemployment, but mainly preached against the strings attached to federal dollars that mayors now receive.

"I want to caution you to beware of those who promise simply the elimination of strings," Anderson told the mayors. "For you may unwrap the strings and find the package is empty."