The advert is for two to three days a week and offers the successful candidate £60,000 a year.
According to the job specification posted by Defra, the Environment Agency operates “at the place where environmental change has its greatest impact on people’s lives. It works to reduce the risks to people and properties from flooding; makes sure there is enough water for people and wildlife; protects and improves air, land and water quality and applies the environmental standards within which industry can operate.
“As its chairman, you must have a strong commitment to the environment.”
The closing date for applications is January 30 2014.
Defra said the role would require “an exceptional leader with strategic vision who can steer the organisation through this challenging period”.
“Alongside excellent ambassadorial skills you’ll also be a team player able to build effective collaborative partnerships that deliver shared goals,” it added.
Lord Smith has held the role of chairman since 2008.