To reach the horse trail where we walk several mornings each week, we hike a quarter mile or so through a swale. This is a shortcut that saves us a boring half-mile walk along a sidewalk.
Because we don't get much rain here in the desert, there are few very storm sewers installed to collect and channel the runoff whenever it rains. Instead, the rain drains through the streets and into swales, which then direct the water out into the desert, where it is absorbed by the ground. This usually happens within a few hours, but it sometimes takes as long as a few days, depending on the amount of rain.
This particular swale is approx.eight feet deep and has steeply sloped sides, as you can see. Being an old fogey in training, I have to be very careful when I climb down into the swale, lest I slip and fall. But Abby has four-paw drive, so has plenty of traction and scampers up and down the banks of the swale accordingly.