On the quiet, tree-lined streets off Wisconsin Avenue in upper Northwest Washington, Sunday afternoon is a time when residents wash the car, run a few errands, walk in the park or just sit in the back yard, contemplating a glass of lemonade. The children of these relatively affluent neighborhoods tour the blocks and alleys on their bicycles, get in some batting or tennis practice at the nearest playground or wander over to the local pool.

But this peaceful and orderly routine is slowly giving way to the weekend and evening hustle and bustle generated by an increasing number of retail and entertainment outlets that have sprung up along the Wisconsin Avenue corridor. And of these, none so threatens the community, residents say, as the $40 million shopping/office/six-theater cinema complex under construction at 4000 Wisconsin Ave.

The five-story project, being developed jointly by the Donohoe Construction Co. and the Holladay Corp. on the former site of Johnson's Flower Center, is being called a downtown building in an uptown neighborhood -- in this case, the communities of Tenley Park, McLean Gardens, Cleveland Park and American University Park, among others.

"It's the biggest project between Georgetown and Friendship Heights, and it's going to have two to three times the density of the others," protested Barbara Burney, 41, whose home is on Upton Street NW, just across the street from the complex.

Burney and her Ward 3 neighbors, who have organized as the Tenley and Cleveland Park Emergency Committee, provide a laundry list of why the project shouldn't be built: It will increase traffic congestion and noise in the area, more so than when Johnson's operated at the site; an access road to the project will intrude on the northern tip of Glover-Archbold Park; the extra traffic will pose safety hazards for children, and there aren't enough parking spaces.

Residents, including many of the citizen groups that represent them, also accuse the developers of rushing to get the project under way before the community realized its size and impact.

And they are furious with Mayor Marion Barry, who is running for reelection, because he recently cleared the way for the issuance of two street permits for the development.

"The mayor couldn't run for dogcatcher right now in Ward 3," said Joel Odum, president of the Tenley and Cleveland Park Emergency Committee. "It's the No. 1 issue here."

Barry has said he sympathizes with the concerns of the Ward 3 communities and has invited several representatives to a June 5 meeting of a special task force studying development and redevelopment pressures along the Wisconsin Avenue corridor. As a further signal of his concern, he has named City Administrator Thomas Downs to head the panel and coordinate its meetings.

But the mayor has defended the project's legality.

"The law is very clear that whether I like it or whether they like it or not, the developers have a right to develop the site," Barry said.

Alvin McNeal, the city's chief of long-range planning, said the developers will need the additional road access -- the paving of Glover-Archbold Parkway and an extension of Upton Street -- to relieve the traffic congestion that is causing so much community concern.

"There's been fairly substantial, but allowable development in this area," said McNeal. "But the city did negotiate with the developers to get free and reduced rate parking in the complex to reduce the number of vehicles on residential streets."

Last week, an emotional, daylong Board of Zoning Adjustment hearing drew numerous Ward 3 residents, including Joan Mondale, wife of former vice president Walter Mondale, and the candidates for the Ward 3 seat on the City Council. Lawyers for the community groups and the project developers repeatedly clashed over whether the Advisory Neighborhood Commissions in the area had been given proper notice about the development.

"We never saw the plans," said Peggy Robin, chairwoman of ANC 3C, who testified. "We were always told they wouldn't be ready until the spring of 1986."

Whayne Quin, a lawyer for the developers, said affected ANCs routinely receive a list from the city of all building permit applications and that the Wisconsin Avenue complex was among those listed in last December's notices.

But Gloria Corn, a commissioner from ANC 3F and a candidate for the City Council from Ward 3, testified that community groups who received copies of the list of building permit applications mistakenly thought the permit had already been granted.

She reminded Quin of an earlier project in Ward 3 in which the community had been consulted, adding, "When you acted in good faith with us, we acted in good faith with you, and everybody was happy -- the community, the developer and the lawyers."

The zoning board said it will rule on whether to revoke the project's building permit at its July 2 meeting.