The steps to Petit Port Bay were shut in May after damage caused by heavy rainfall during storms.
An inspection by engineering consultants Frederick Sherrell Ltd will start on Monday and is due to end on 27 March.
The department said if no further work was needed the steps should be re-opened for the Easter holiday.
Four parking spaces will be suspended in the Petit Port car park for the duration of the works.
The bay was previously closed between 2001 and 2005, after a series of landslides made the area too dangerous to access.
It was only reopened after new concrete steps, handrails and fencing to contain rockfalls were installed.
Steps at a bay in Guernsey could be opened by Easter, according to the environment department.