ersey Water has sold its head office to make way for part of the island's new hospital.
The site on Westmount Road has been occupied by the company for more than 30 years.
Jersey Water will vacate the premises in 2022, but the large service reservoirs are not part of the sale.
Jersey's new hospital is set to cost nearly £805m, if approved in the autumn, with part of it expected to be built on the Westmount Road site.
Following sale to the government, Jersey Water's corporate staff will move to offices in New Street, St Helier.
The company has also submitted plans to develop two of its sites at Millbrook and Grands Vaux, which will include a new operational hub.
The proposed facilities at Millbrook will, if approved, see the restoration of the listed buildings at the site.
Plans also show proposals for the creation of a public footpath through land at Grands Vaux, north of the reservoir.
Helier Smith, chief executive of Jersey Water, said: "We have been working with the Our Hospital Project team for several months and we are pleased to have reached an agreement and completed the sale of our property to facilitate the new hospital.
"We look forward to once again having a town presence as we move into our new offices from early 2022."
Subject to planning approval, the Millbrook development will start in 2022.
Construction of the footpath at Grands Vaux is dependent on completion of the Millbrook development and is expected to start by 2024.
The new hospital is expected to be built at the existing hospital site at Overdale, with other parts of the island also being used.