Technology has advanced enough recently enabling us to collectively map out all the exact locations of drainage grates in Tenerife. Considering the length of roads here, there aren’t actually that many.
This is an editable map so if you have found a drainage grate you believe to be a road hazard for cyclists, please update the place on the list. I highly encourage you to do so, because once we are armed with the exact location of ~20 or so known hazards, we can approach both the the Tenerife and Canary Islands cycling federations, local councils as well as the Tenerife Tourism department and see if we can get them to modify the design to be more cyclist friendly. The Tenerife deptarment of tourism once asked me something along the lines of “what could we be doing to improve cycling in Tenerife?”. I think eliminating these potential dangers is a simple and achieveable goal.