The United Nations have defined sustainability in 1987 as,
“Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.”
An evaluation that refers to the principles of sustainable development needs to consider the social, environmental and economic impacts that each management strategy might have.
Social impacts refer to how a management method will affect people. It will look at how it impacts their houses and where they live, how it will affect their daily lives and their food and water supply.
Environmental impacts refer to how management methods will impact the natural environment. How will any development affect animals and plant life in the local area? How will it impact water quality and sewage?
Economic impacts refer to how the management methods used will affect how people work. How will this affect jobs and income? Will the measure make people richer or poorer – will it have a positive or negative impact on their livelihood?