Something Not Quite Right

Is this failure of design or failure of implementation?

After the flooding from last winter, I have walked past this little detention pond a number of times. Each time I pause and wonder whether this was a design failure or an implementation failure.

They built a very nice rip-rap lined spillway along the left side of this image. However, when the pond filled and overflowed, the discharge passed along the left side of the sidewalk. Until recently, when it was repaired, there was a large rill that was scoured by the flow.

When I pass, I pause and shake my head a bit. I’m really glad this isn’t a large reservoir. That would be catastrophic.