Poor water quality in rivers around a Powys lake is being tackled by a £1.2m fund.
Water firm Hafren Dyfrdwy is funding it after classing the status of the rivers Cownwy and Marchnant as poor.
The rivers flow south of lake, near Llanwddyn, and into the River Vyrnwy.
However, there are concerns from people in the area about flooding as a result of the works. The water company is holding an information event on Monday at Llanwddyn Community Centre.
Hafren Dyfrdwy, which supplies 100,000 customers, has vowed to follow its legal obligation and improve each of the rivers from poor to good.
Catherine Webb, community communications officer for Hafren Dyfrdwy, said: "We're committed to making sure we not only provide our customers with a fantastic water supply and service, but also that we take care of the environments that we work in."
But Llanwddyn councillor Phil Graham, said: "There is concern amongst residents that the works may cause some flooding to their properties and surrounding roads and are questioning who will pay for any repairs arising from this."
The information event will be held from 13:00 - 15:00 GMT where members of the public will be able to learn more about the project, which is expected to last five months.