What are some examples of manmade water hazards?

Manmade water hazards are artificial structures or modifications created by humans that can pose risks or challenges in aquatic environments. Dams, for instance, create reservoirs and alter the flow of rivers, which can lead to danger for those engaging in water activities. Bridges can restrict water flow and create currents that may be hazardous, especially during flooding or storms. Roadways adjacent to water bodies can also increase risks of accidents or drowning, depending on the situations that arise in those environments.

The other options include natural features, such as lakes and rivers, wetlands, floodplains, ocean tides, and currents, which are not manmade and do not fit the definition of manmade water hazards. Hence, the correct choice reflects the human-created aspects that can generate risks around water.