The Rain Garden That Wouldn't Grow

Recently, my wife and I were out on a date and taking a stroll through Harlem before dinner when we stumbled on a dog relief area at the corner of Manhattan Avenue and East 122nd Street. I was excited and my wife was, well, glad to see me enjoying myself.

A few years ago while musing about planning for pets, I came across the French canisites. Now I had stumbled on one in my own town, and I hadn't even heard about it!

It is a wonderful little example of the transformation of a residual space. Initially it was a hatched area in the roadway where northbound traffic is diverted as Manhattan Avenue becomes a southbound one-way street. It was just the sort of dead space that was long common on our paved streets. In 2012, it was converted into a rain garden to improve storm water management and probably contribute a few count toward the Million Trees program, but the plants just wouldn't grow on the street side of the triangle. After a few years of the vegetation struggling and consistently dying off, it appears somebody had the genius to stop fighting the inevitable and repurpose the space to address the dog poop problem that is chronic on sidewalks throughout New York City.

Filling the Void, Maintaining Sight Lines

When cars park too close to the corner, drivers and pedestrians often cannot see each other well enough to make safe decisions. To correct the problem, parking is frequently prohibited near intersections to improve sight lines, a practice sometimes referred to as "daylighting." Nevertheless, regulations cannot actually prevent the hazardous conditions from continuing. The public and even some enforcement agencies seem to have a low level of awareness or appreciation for the need to keep these locations clear, and the residual nature of these spaces continues to be problematic.


In an effort to improve the situation, enhanced markings are often used to reinforce the regulatory signage. Even with this effort to emphasize the regulations and create some illusion of occupancy, the space continues to feel unused. In an active urban environment, a space marked off for the sole purpose of a sight line really is, in practice, underutilized. The demand to make more intense use of it is probably inevitable.

The solution to these residual spaces is to provide them with uses that do not compromise the sight lines. To be effective and persuasive enough to continue installing them elsewhere, treatments must embrace uses that are appealing to the community.

The classic response is to install a curb extension, sometimes called a "neckdown." These rely on the curb as a physical barrier that effectively discourages parking. They also provide benefits for traffic calming and shortening crossing distances for pedestrians. A curb extension is an expansion of the sidewalk, creating more usable space for pedestrians, although they may recognize relatively little value in the extra panels of concrete. This solution is often complicated, though, by mundane engineering details like drainage or even traffic signal location. Capital costs can discourage or delay construction.