River Watch issued an ice movement and flood advisory on Wednesday afternoon, saying people in all regions should be prepared.
Although there is no precipitation in the immediate forecast, parts of the province received moderate rainfall over the past couple of days, coupled with above zero temperatures.
As a result, water levels have started to rise and ice movement has begun in some waterways, the organization said in a statement.
Temperatures are expected to remain conducive to melting the snow pack and the deterioration of ice covers in all regions.
"This could lead to additional break-up, movement of ice covers and could cause jams as well as associated flooding," it said.
Rivers outside the St. John River system could be affected as well.
Ice jams formed in January could hold back water as river levels rise, leading to localized flooding.
Those ice jams are located at:
- Nashwaak River at MacLaggan Bridge, Tay Bridge, Durham Bridge and Marysville Bridge.
- Kennebecasis River at Hillsdale and Norton.
- Southwest Miramichi River: below the Doaktown Bridge and at Norrad's Bridge in the rural community of Upper Miramichi.
- Hammond River between Smithtown and Upham.
People living or working along streams, tributaries and rivers are urged to be on the alert for ice movement and the possibility of ice-jam formation resulting in rapid water-level increases.
They should also take precautions to safeguard their homes and possessions, such as moving personal property near watercourses to higher ground and moving valuables out of their basements, River Watch said.