Despite hopes to the contrary, it is likely the river in Brigg will again go green this summer as temperatures increase.
With major developments taking place on the Ancholme riverside, anxiety is growing that a warm spell will lead to the growth of, what is now termed, blanket weed.
A pamphlet produced by the Environment Agency details the problems of managing the growth of the algae which cannot be controlled.
Causes are the growth of weed which takes place rapidly when water temperatures increase.
Slow moving, clean or shallow water contributes to increased growth because more light can penetrate the water.
Known problems are fish can suffer if there is too much weed as it removes dissolved oxygen at night.
Too much weed lowers water quality, disrupting anglers and boat users, while excessive weed can block water flows and increase flooding risks.
Benefits of aquatic weed include shelter for fish that helps them avoid predators and oxygenation of the water during the day through photosynthesis.
The Ancholme River Trust has worked with the Environment Agency and local councils to cut weeds between May and November, however, the algae cannot be controlled.
The Agency hopes that increasing local awareness of blanket green weed on the Ancholme will help river users and those who cycle and walk the banks in increasing numbers understand more of the problems.
The Environment Agency Service line is available to recreational users of the Ancholme on 03708 506506.
There is also an incident hotline on 0800 807060.