Parts of the Norfolk Broads could be lost to the sea
A conservation society is suggesting a fifth option to protect the Broads against encroachment by the North Sea.
The Broads Society, founded in 1956 to protect the inland waterways in Norfolk and Suffolk, wants the government to continue funding sea defences.
Natural England have set out four options in the light of climate change.
The most controversial plan allows sea defences to collapse near the River Thurne to create a large estuary which the Broads Society said is destructive.
Dr Martin George, a society committee member, said: "The area to be lost under three of the four proposals is an integral part of the Broads national park.
"The society considers it completely unacceptable to allow part of it to become an open estuary.
"If any of these three proposals were adopted, it would result in the loss of several hundred residential properties, destruction of Hickling Broad, Horsey Mere, Heigham Sound and Martham North and South Broads.
"Several thousand acres of farm land would disappear at a time of the growing world-wide food shortages.
"Valuable and fragile plant and animal life would disappear.
"This includes reed and saw-sedge fen, the habitat of the bittern, bearded tit, marsh harrier, swallowtail butterfly and nine rare or endangered species of moth."
The Broads Society's option would involve the creation of a new line of sea defences to the rear of the existing seawall and sand dunes.
They said that this would minimise the amount of land and property which would have to be surrendered to the sea, as well as safeguard Hickling Broad.
Dr George said: "We believe it could well prove less expensive to provide the sea wall with additional protection against the scouring effects of the sea than to construct a completely new line of defences to the rear.
"We believe that this issue needs to be subject to a full-scale investigation."