A drainage board could be forced to increase rates to find what officials say is the “astronomical” cost to install an eel passage channel.
The Downham Group of Drainage Boards has been told that it must add a £650,000 bypass channel at its Polver Pumping Station at Watlington under European law.
The annual income for the East of Ouse, Polver and Nar Internal Drainage Board, which is part of the Downham Group, is £400,000.
General manager Gerald Allison is expecting the bill to rise even further as he has five other pumping stations which are also said to need work to help the eels.
The Environment Agency (EA) is working on measures to increase the eel population and has identified more than 700 abstraction sites, including pumping stations, nationally as high priority.
The board, which is funded by a special levy on councils, farmers and residents, is waiting to find out if the bypass will be funded by the EA.
Mr Allison said: “It is not the fact about putting something in to help the eels, it is the astronomical cost.
“The East of Ouse drainage board’s income is £400,000 a year and we have to find £650,000 to install a bypass channel.
“If we have to pay for it, it could mean an increase on the rate for cash strapped councils or farmers.
“We as a drainage board are not against putting something in to allow the free passage of eels but there must be something at a cheaper price.”
The bypass at the pumping station, which dates back to the 1960s, would have to be installed by December 2020.
Other pumping stations identified by the EA are: Puny at West Winch, Southery, Hockwold, Catsholme near Methwold Hive, and Wretton Fen.
The EA has not yet informed Mr Allison what works are required at these sites.
The Downham group receives a total annual income of £1.5 million which is used to maintain pumping stations and its drainage network, which covers 60,000 acres.
Mr Allison said: “In the middle of January, I get an electricity bill of £5,000 per pumping station.
“We have to protect people, property and agricultural land and we do what we can for the wildlife.”
A spokesman for the EA said: “In the last 30 years the European eel population has dramatically declined, putting it on the endangered species list.
“The Environment Agency has been working on a number of measures to increase the prospects for eel and boost their numbers, such as removing barriers and installing eel passes which have made more than 5,000km of river easier to access.
“As part of this work, we have identified sites where high priority action is needed to ensure the safe passage of eels and we are working with these companies to help them make these improvements.”
Since 2009, new developments have been required by law to include fish friendly designs.