A significant hazard in measuring streamflow is the inability to swim and to work free from equipment and clothing when footing is lost while wading or if a gaging structure fails. All hydrographers should be able to swim and should wear a lifejacket at all times. When wading measurements are being made, a tagline should be installed at the gaging section for the hydrographer to grab if he falls in the water.

Another hazard to the hydrographer may be caused by traffic on bridges where he often is required to work. Warning signs, traffic cones and safety vests are necessary to safely route traffic and protect field technicians. Requirements for traffic warning signs vary from state to state and local authorities should be consulted.

The hydrographer should carry a well-stocked first aid kit in his vehicle and should be familiar with the kit's contents and standard first aid practices. It is best to work in pairs when stream gaging with one person on the bank in the event of an accident.