New reservoir planned for Rotherham's Boston Castle grounds
Plans for a new reservoir near an eighteenth-century castle in Rotherham have shocked residents.
Yorkshire Water wants to create the new reservoir in Boston Park to replace two older ones in the grounds.
Friends of Boston Castle and Parklands said they were "gobsmacked" and concerned by the loss of green space.
Yorkshire Water said it would give £80,000 to improve the park plus 2.6 acres (10,500sqm) of old reservoir space nearby.
Boston Castle was built by Thomas, 3rd Earl of Effingham in 1775 and sits within 23 acres overlooking Rotherham and Sheffield.
A new reservoir is "urgently needed" to serve 20,000 Rotherham homes and a hospital as the old ones are at the end of their useful life, Yorkshire Water said.
Polly Hamilton of Rotherham Borough Council said Yorkshire Water had been "very generous" in offering to fund repairs and improvements.
She said: "There's some really good news here in that there's a gain in the amount of land available.
"Subject to planning approval we can get on with making these improvements as soon as possible."
The Friends group said they felt "miffed" and "dumbfounded" and would have liked to have been told in advance of the plans.
Ms Hamilton said they could be "excited" about "much-needed improvements" to the park and that they would be consulted over details.
Friends group chair Andrew Emery said £80,000 "would go a long way" to fund improvements including a cafe, children's playground and refurbishment of the Dell area.
The council is being asked to transfer about two acres (8,880sqm) of land to Yorkshire Water who would then need planning permission before they could build the reservoir.
In return, Yorkshire Water said it would release 2.6 acres (10,500sqm) of land back to the council although the local authority admitted it would be "less useful as recreational green space" because it is further from the castle and car park.
The council's cabinet is being advised to approve the plans when its meets on 12 December.