If the mood of the 250 people who attended a ward five town hall meeting last week at McKinley High School is indicative, this city government has a serious credibility problem with some of its citizens who feel the city just isn't working.

"There is a bureaucracy in place," one leading ward Democrat remarked after the three-hour meeting, which at times had become a shouting match between city officials and frustrated city residents. "But a lot of things get lost in the channels."

Water meters run backward and the bills are all wrong. The grass in one city park gets so high that citizens turn to cutting it themselves, and the only thanks they get from the city's transportation director is the suggestion that perhaps citizens should be responsible for that anyhow.

"Since the district has taken it over, it's gone downhill," a woman complains about the park, once cared for by the federal governmen. "And I'm surprised that our ward representative hasn't done something about it."

That becomes another source of discontent - what to do to set things straight. The City Council doesn't cut enough red tape and Council members blame things on the mayor. The mayor says he doesn't have enough money and he blames Congress. The city has a delegate in Congress, but he can't vote.

All that makes it easier to read the frustration and bewilderment in the face of one young woman in the audience who throws back her head in disgust and asks a host of city officials on state, "Well, what did we elect you for then?"

There are no assurances that the political rhythms of the fifth ward - most of northeast Washington west of the Anacostia River - are the same drum beat to which the rest of the city is marching. But this ward is becoming increasingly important in city politics because it contains one of the larger numbers of registered voters. And it is here that one of the hottest issues to hit city hall in recent months - the furor over the city's water billing system - first developed momentum.

The water bill issue is a typical ward five concern, like many of the other worries that dominated the discussion at the meeting, part of a series of town hall gatherings held throughout the city by Del. Walter E. Fauntroy (D-D.C.)

There is minimal concern over whether Nick Antonelli bribed Joe Yeldell or if Marion Barry will be mayor next year instead of Sterling Tucker. What appears more important is that the coming of home rule has not improved city services in the ward or increased access to those in city hall who operate those services.

Understandably, much o f the criticism focuses on William R. Spaulding Council, the ward's representatives on the City Council, who, by the theory of home-rule government, is supposed to be the ward's pipeline to city government.

"As far as grass roots people are concerned and getting things done, his effectiveness is negotiable," one activist in the ward says. "People have seen that they can do as much themselves as Spaulding, which makes him just another John Q. Citizen."

Spaulding was the target of many of the harsh words at the meeting. He received a smattering of boo's when he was introduced and was fuzzy on the specific of some items under discussion.

But the real problem, he says, is that people, understandably at rope's end because of the water bills, just don't comprehend the system and its own limitations. "The executive has fouled up the thing and all we can do is make sure the constituents aren't penalized," Spauling explains. "This is all we can do. We can't go over there and correct the mess.

The meeting had all the indications of bearing bad news for Spaulding, who in 1974 won the Democratic primary in the overwhelmingly Democratic ward by a scant 54 votes - he lost before the recount was taken - and whose seat is up for grabs in 1978.

For the record, Spaulding is saying he is too busy dealing with 1977 to ponder whether he'll run again in 1978. And with things going the way they are with city government in general and ward five in particular, a few of his most outspoken and influential constituents are saying privately that he might be doing himself a big favor to keep on thinking like that.

The unofficial news for the past year has now become official - Marion Barry is a single man again. After 15 months of legal separation, the Council member and Mary Treadwell Barry have formally calted it quits as of Aug. 17, five years after the wedding. And he doesn'tplan to remarry soon, Barry says.

Conventional political wisdom has it that singles have a harder time getting elected, and, with Barry lustfully eyeing the mayor's seat in 1978, the divorce comes at a potentially vulnerable time.

But politics didn't lead him into marriage, Barry says, nor did it stand in the way when he wanted to get out. "I hope it would not have any (political) effect," he says of the divorce. "But if it has negative political overtones, I have to take the weight. The main thing is the two of us are happy."