Bikers make their way along the Potomac River on the Rock Creek path near the Kennedy Center on Tuesday in Washington. (Katherine Frey/The Washington Post)

The District’s parks may be small, but they are plentiful, according to a new national survey, released Wednesday, that ranks the nation’s capital sixth among the 50 largest U.S. cities for park accessibility.

The Trust for Public Land ranks cities based on park access, park size and their investment in their park systems. The good news: According to the survey, 96 percent of District residents live within a 10-minute walk of a park. The bad: D.C. parks tend to be small — just 0.67 acres.

As neighborhoods redevelop across the District, demand for park space is growing, most notably in NoMa. The D.C. Council recently pledged $50 million to build a park in the increasingly pricey neighborhood north of Massachusetts Avenue.

Adrian Benepe, senior vice president and director of city park development for the trust, said that despite a tough economic climate, cities are investing in parks and playgrounds. Los Angeles, San Francisco, Milwaukee and Denver are among the communities that have passed bond measures or sales taxes to support parks.

In the District, Mayor Vincent C. Gray (D) has designated $35 million to renovate 32 playgrounds as part of his Play D.C. initiative. Gray’s predecessor, Adrian M. Fenty (D), also made parks, recreation centers and playgrounds a priority.

“Playground and play spaces are really critical,’’ said John Stokes, spokesman for the District’s Department of Parks and Recreation. “Anytime you have a recreation space, it becomes a community space. It’s a place to socialize and get that very important physical activity.”

More cities are embracing that notion, Benepe said: “I think we are in a golden age of park development. All across the country, cities are investing in parks in a way they haven’t since the 19th century.”

The trust’s survey ranked Minneapolis No. 1, followed by New York, Boston, Sacramento and San Francisco, all tied for third.

Nearly 20 percent of the District is parkland, a share that is boosted by the huge federal presence, according to the report. But some of the largest swaths of federal green space — most notably the Mall and Rock Creek Park — don’t provide the same level of amenities, such as playgrounds. Outside those federal parklands, the District has smaller parks and fewer playgrounds — 1.73 per 10,000 residents — than other cities in the survey. That’s part of the reason the District received only four of five park benches in the trust’s annual ranking.

The report said city officials should work to improve park and playground access for residents in Ward 1 in Northwest Washington and in Ward 5, which is mostly in Northeast. Stokes said D.C. officials are working on ways to add green space in those neighborhoods. This month, as the parks department begins its master plan process, the public will be invited to tell officials where they want more parks and playgrounds, he said.

“When we renovate, we want to make these spaces a family experience,” Stokes said. “While kids are enjoying the tots lots, we want the adults to be able to partake in physical activity. We’re adding community gardens so they’re not just playgrounds, they’re play spaces.”

Other ways in which the District could improve access for residents is by working to make more National Park Service land accessible to the public, said Peter Harnik, director of the Center for City Park Excellence, the trust’s research arm. For example, people may live close to the National Zoo or Rock Creek Park, but security fencing or walls might block their access.

Officials also should plan to include parkland as part of those plans before the land costs rise too high, Harnik said. That is the issue the city is facing in NoMa. “The area developed so rapidly and became so hot so fast, they didn’t get the parkland piece in before prices went up,” Harnik said.

Robin-Eve Jasper, president of the NoMa Business Improvement District, said residents have been holding events such as summer movie screenings and farmers’ markets in privately owned lots that have not been developed.