Houses, roads, drains and other infrastructure.
Ecological engineering is a specialised field in environmental engineering. Ecology is about the interaction between organisms and their environment, called ecosystems. The engineering of ecosystems centres on their construction and maintenance. Engineers can either focus on natural ecosystem maintenance or the construction of artificial ecosystems. Fish living in a lake is an example of a natural ecosystem. An engineer will consider the health of the fish and the impact of factors such as water quality and bacteria levels.