Eight floating pontoons are being installed on the banks along Spalding’s River Welland to save baby otters from drowning.
The wildlife refuges are being sited along the sheet piled area of the river – which stretches 800 metres – because otters can’t stay in the water for long periods.
The Environment Agency stepped in with the £3,000 life-saving project after officials saw two baby otters desperately clinging to life by hanging on to a chain.
Environment Agency technical officer Nikki Loveday said: “It’s a sign of a healthy river to attract otters.
“The fact that otters have been seen is testament to our work cleaning the River Welland and it shows how good our river systems are.
“We first learnt otters were there when we saw two baby otters clinging on for dear life to a chain link attached to the sheet piled area.
“The otters were in the 800 metre sheet piled area, but they can’t stay in the water indefinitely and need a place to rest – just like any mammal.
“We wanted to make a safe habitat for them and these refuges float on the river to give them somewhere safely to go and rest.
The pontoons go up and down with the water level.
Five have already been put in place and three more are set to be installed.
• Otters suffered a serious decline in the late 1970s and were absent from most of England.
Their decline was linked to certain farm chemicals, which were later withdrawn.
In the early 1980s, when it looked like otters might be completely lost from England, conservationists began releasing captive bred otters into the wild.