Plans have been revealed to attract more visitors to one of the most picturesque parts of Wales while trying to protect its natural beauty.
The dam creating the lake was closed in the 1880s
New offices, visitor and tourist information centres, and parking at Lake Vyrnwy in mid Wales would cost about £2m.
It is hoped to increase the number of tourists from the present 200,000.
Water company Severn Trent aims to start work this autumn if it gets planning permission.
The area attracts visitors from a wide area, as it is relatively close to the English border.
As well as the lake, the attractions include a nature reserve and an organic farm.
Severn Trent has submitted its plans to Powys Council. Among the ideas is a scheme to turn the existing tourist information centre into a museum on the history of the area.
Severn Trent said the revamp was to attract more people to "such a beautiful area", but also to benefit the many thousands who already visit.
It described existing facilities for visitors as "limited".
The seclusion and beauty of the lake are among its attractions
The company said it had been consulting residents and businesses on the plans since last November, and some of their ideas had been incorporated in the designs.
The lake is man-made, and the dam that created it was closed nearly 120 years ago. The village of Llanwddyn was drowned by the lake, but its remains can reappear in dry summers if the water level drops far enough.
A wide variety of birds live and breed in and around the lake, such as goosanders, common sandpipers and great crested grebes. Others, including teals and tufted ducks, make their homes there in winter.
The reserve is run by a partnership which comprises the water company, the county council, the Royal Society for the Protection of Birds and Forest Enterprise.
The RSPB's Mike Walker, the reserve's senior site manager, said: "We've been in consultation with them (Severn Trent) from the very start.
"We are very conscious that any development has got to be done sensitively. We don't want to detract from what people are coming here to see in the first place."
Visits are also encouraged to the site's 4,700-hectare organic farm, which has sheep and cattle.