The River Great Ouse in the heart of King's Lynn may have to be dredged for the first time in six years amid falling water levels and a drought.

The river is being regularly monitored by the Conservancy Board as it dropped to 1.4m during low tide this week – leaving ferry passengers having to use a temporary jetty to get to the boat.

There are now concerns about the impact the drought might have on the river and the town's harbour.

Gail Kingston, who runs the ferry service with husband Steve, said: 'We've been able to get across the low tides everyday because we have a low tide boat and have extended the jetty.

'However last year we only had three months with the jetty extended and this year we've been using the boards all the time depending on the weather and the tide.

'This is probably the worst year we have had for this as it is now a daily occurrence.'

She added: 'We don't think the river will dry completely. It also might be easier to cross in the summer as the beach dries out completely.

'At the moment the beach is still a bit wet and without the jetty, people's shoes will get muddy.'

On Thursday afternoon the River Great Ouse level dropped to 1.4m which is the lowest point of the typical river level range and the town's Conservancy Board is regularly monitoring the situation.

Harbourmaster Capt John Lorking said: 'Not having fresh water flows through the winter months has had an impact on the harbour.

'What concerns us now is what the impact will be through the summer with a lot of experts predicting a drought.

'We are hoping for a wet spring to ease our concerns but there is the possibility we may have to dredge here to remove material [and create more depth at high tide]. The last time we did that here was in 2006.'

It comes after a warning from experts this summer could be the worst for more than 35 years if the current period of low rainfall continues.

Soil moisture levels are at their lowest since the drought of 1976 and grassland habitats which need to be flooded have not had enough rainfall.

The Wildfowl and Wetland Trust at Welney says water levels on the washes have been maintained by tidal influence, but areas away from river channels are drying up, and demand for water from farmers could lead to wildlife suffering.

Rob Shore, head of wetland conservation, said: 'We're struggling to keep our wetlands wet in winter which is virtually unheard of.

'The knock-on effect will be on the birds breeding in spring, so it is easy to see how this can escalate.'

It also follows action being taken on an East Anglian flood relief channel to reduce the impact of the drought on fish and other wildlife.

The Environment Agency has decided to remove fish from the Maxey Cut, which is located between Peterborough and Market Deeping, before the ongoing drought causes water levels to drop further.

The fish will be removed and released into the River Welland.

Helen Vale, national drought co-ordinator at the Environment Agency, said many river flows in the region continue to drop 'rapidly'.

'This reflects the decrease in underground water that supports flows in many places,' she said.

'The news of hosepipe bans comes as a timely reminder that using water efficiently will help to ensure we all have enough water for our homes, to produce food and to protect the natural environment.'