Due to the expected levels of rainfall today and over the weekend, Donegal County Council has put Prior Warnings in place at four Beaches for five days.
The Beaches are Lisfannon, Ladys Bay, Bundoran and Fintra.
Given the risk of heavy rain causing storm water to run off fields and houses into rivers which flow into bathing waters, the council says there is a risk of higher than normal E.coli levels in the water.
To reduce the risk of illness, the council says beach users should avoid swallowing or splashing water, aash their hands before handling food, avoid swimming with an open cut or wound, and avoid swimming if they are pregnant or have a weakened immune system.
The council is stressing hyigher levels of bacteria are usually short-lived and most bathers are unlikely to experience any illness.