With a huge swathe of land across north Powys on the market, BBC Wales' environment correspondent examines the prospects for the estate and its residents.
Some 23,000 acres of heath, forest and farmland is for sale around the Vyrnwy reservoir.
The asking price for four separate lots - which excludes the actual water in the lake - is about £11m.
But the complex selling-off of the estate will also include the Countryside Council for Wales (CCW).
The nature conservation advisor, usually for the Welsh Assembly Government, in this instance will advise the UK government's Environment Secretary Caroline Spelman, as Severn Trent Water is an English company.
The CCW's statutory role comes under the 1991 Water Industry Act, to advise on land sold off by water companies.
That consultation and advice process will start as soon as the water company issues its list of preferred bidders.
This will be done in private, but with only the two known parties interested in buying the 125-year lease on the largest slice of the estate - the farms and the heathland - it is not much of a secret.
We may get to hear of other bidders eventually, especially for the 5,000-acre forest.
So far only Bala-born businessman Rhys Jones and the Royal Society for the Protection of Birds (RSPB) have declared their intentions publicly to bid for the lease.
The CCW's role is interesting. As large swathes of the Vyrnwy Estate are a special area of conservation, and with several sites of special scientific interest, the preferred list of bidders known to Severn Trent's board of directors will need to be passed on for scrutiny.
The CCW's assessments of ability to care for these European and UK-designated conservation areas will be important.
Tim Jones, of CCW, said he did not want to discuss details of the conditions because they were part of the consultation.
"Also, we have to have regard for the commercial confidentiality of the whole thing but there would be conditions around the protection and nature conservation, the historic aspects of it and access to the countryside."
He added: "It's thousands of hectares but it's also got the highest, most important levels of nature conservation designation the European community and Britain can give.
"It's got a special area of conservation designation for its blanket bog and dry heath. It's got a special protection area of designation for the important populations of birds we get here."
According to the CCW's position statement on the Vyrnwy sale: "The uplands around the lake are not only important water catchments, but are also some of the jewels in the crown of the Welsh environment."
With that comes potentially a move to set certain conditions on the sale of the Vyrnwy estate because of the importance of the internationally-recognised habitats and wildlife.
Below the 130-year-old dam at Vyrnwy lies the village of Llanwddyn. Several villagers and tenant farmers have mentioned how little they understand the process of selling the estate.
Many have complained that the Severn Trent Water company has been "running the estate down" for a long time. Most locals would like to see new investments, and new jobs.
Ieuan Lewis, a farmer and bed and breakfast owner, said: "We're very concerned that we need work, more jobs, in the area.
"We've got the hotel which provides a lot of jobs but there's nothing else really - there's a little bit of agriculture.
"RSPB employs a few people but we want another enterprise in here."
Farmer Brian Ellis said: "We haven't heard anything off anybody about the sale at all.
"All we have are deadline dates and once the deadline date comes, it's been extended, it's been extended, it's been extended and we know no more now than what we did when we had the first meeting in the very beginning."
After a series of public meetings in Llanwddyn during the winter months, there seems to be a well-developed view amongst many villagers.
In the recent local monthly newsletter, there is a report of a petition organised to support businessman Rhys Jones's attempt to buy parts of the estate.
The petition was received by local Conservative councillor Simon Baynes, and the Montgomeryshire MP Glyn Davies, and handed over to Tim Wright of Severn Trent Water in Shrewsbury.
Mr Jones confirmed in a press release last September that he does not need to take on a debt to finance his bid, and says "… this is a long-term commitment that I would not take on lightly, but the language, the environment and Welsh rural life is important to me and my family and this will continue as we wish to hold the estate in the family".
He has also told a community meeting in Llanwddyn that he wished to invest "long term" and would work with local people, stakeholders, the community council and others.
He said he would set aside funding to bring the estate "up to a better standard".
Meanwhile, the RSPB has aspirations as well, and according to its head of public affairs, Delyth Willis, wants to "expand the conservation areas in the Berwyn Mountains, and to care for the special habitats in the area".
The society already runs an organic 6,000-acre farm in Vyrnwy, and if its bid on the lease is successful, is keen to retain control of it as well as other areas of the estate.
But while many of the 300 or so residents who live in and around Llanwddyn and the Vyrnwy reservoir are obviously concerned about the outcome of who will control the 125-year lease of the estate, they will have no say in any consultation.
The CCW will confer with the local authorities, Snowdonia National Park Authority, the Welsh heritage body Cadw and, most importantly of all, with the UK government department Defra - the Department for the Environment, Food and Rural affairs.