May is a wonderful time to stroll or bike along Washington’s waterfronts and enjoy the riverscapes — shoreline parks replete with trees, shrubs and flowers, boats plying the Potomac, sunlight bouncing off the river’s shimmering surface.

At riverside cafes, you can pause, relax and enjoy a bit of food and drink while admiring scenic vistas. Oh, wait a minute! What cafes? Except for Washington Harbour in Georgetown, the capital has no riverside cafes to speak of.

How can a city as large as Washington have miles of shoreline and shoreline parks yet so few places, at or near the water’s edge, to sit and socialize while sipping a drink, snacking or dining?

The recently completed, handsomely landscaped Georgetown waterfront park, situated between the Potomac River’s edge and the Whitehurst Freeway, is more than a quarter of a mile long. Stretching westward from Washington Harbour and ending close to Key Bridge, it offers ample, well-deployed riverside promenades and pathways. But often there are no more than a few dozen people in the park. Why doesn’t the park include an eatery or two in attractively designed pavilions with commodious decks or terraces overlooking the river?

Such pavilions, appropriately sized, designed and located, also could be built along riverfronts in East and West Potomac Parks, and in parks along the Anacostia River. Pavilions not only could provide great views and assorted refreshments, but they also could offer additional amenities — most notably public restrooms — so lacking in Washington’s hundreds of acres of waterfront parkland.

A constellation of periodically spaced riverside destinations within parks makes more sense today than ever before. Great numbers of people who work or live in downtown D.C. would appreciate and regularly patronize waterfront eateries, as would tourists visiting D.C. in the spring, summer and fall.

Today thousands of Washingtonians and tourists willingly walk, bike or use transit, eliminating the need for on-site parking to serve eateries situated in waterfront parks. In fact, pavilions can be located within reasonable walking distance of nearby Metro stations, bus stops or vehicular drop-off points.

Using state-of-the-art architectural strategies and technologies, pavilions in parks can be designed to be exceptionally green and have a near-zero carbon footprint. Pavilions can lightly touch the land, minimally disturbing their sites. Sunlight can be readily harvested to produce electric energy and solar heating. Generously glazed exteriors enhance views while illuminating interior spaces using daylight rather than electric lighting, further conserving energy. Captured and retained rainwater, plus recycled wastewater, can satisfy most of a pavilion’s non-potable water needs.

Sustainability can be further enhanced by using recycled and renewable construction materials. And the construction process can be low-impact, creating limited parkland disturbance, through use of prefabricated, pre-assembled components transported to the site and quickly erected.

Even the challenge of servicing pavilions — deliveries and trash removal — can be met and managed unobtrusively. Small electric, off-road vehicles, parked at each pavilion, could periodically transport materials to and from pickup and delivery points in loading zones on nearby streets.

The lack of eateries or other services in the capital’s waterfront parks is in part attributable to National Park Service policies concerning urban parks, especially along the rivers. For many decades, the predominant NPS approach to managing shoreline real estate and federal parkland in Washington has been a combination of natural resource conservation and quasi-natural landscaping, along with keeping parkland operation and maintenance costs to a minimum.

Most NPS officials have long opposed the idea of allowing privately operated commercial structures to be built on federal parkland. Some of their reluctance stems from practical concerns: how to fairly select concessionaires; how to allocate operational and financial responsibilities; how to ensure that structures are well designed, built, operated and maintained; and where to put cars and service vehicles.

But reluctance also is attributable to a desire, wherever possible, to keep federally managed parks relatively pure and pristine. To some, pavilions serving food and drink within parks, even urban parks, seems blasphemous.

This NPS ethos makes sense for America’s extraordinary, ecologically fragile national parks, and for unique, topographically complex stream valley parks such as Rock Creek Park and Battery Kemble Park. It also makes sense for certain parts of the Potomac and Anacostia River shorelines. But it is not necessarily the right approach for most inner-city urban parks or squares, nor for many segments of Washington’s riverfronts.

The National Park Service should reconsider its riverfront park policies. Georgetown’s waterfront park and promenades are visually delightful. But it would be really nice to grab a bite from time to time at a place along the river other than Washington Harbour.

Roger K. Lewis is a practicing architect and a professor emeritus of architecture at the University of Maryland.