In Lime Kiln car park at 11am on Friday 16th February, a plaque will be unveiled to mark the official declaration ceremony.
The now completed site of the Lower Otter Restoration Project is to be announced as a National Nature Reserve.
Covering a span of almost 90 hectares (more than 222 acres) in the bottom of the Otter Valley in Budleigh Salterton it includes the iconic Otter Head at the mouth of the River Otter.
As an extension of the Pebblebed Heaths Nature Reserve it will receive the highest level of conservation possible under UK legislation.
For the recognition of the area as a nature reserve, during the rest of the day there will be an event for the local community to celebrate.
Managed by the Pebblebed Heaths Conservation Trust, the owner is Clint Devon Estates.
Completed last year, the Otter Restoration project was carried out by the Environment Agency in partnership with Clinton Devon Estates.
55 hectares (nearly 136 acres) of carbon capturing wetland are the result of the River Otter reconnecting with its historical floodplains. It attracts a variety of Wading birds, making it internationally important.