Powys County Council is working with partner agencies and local flood groups to prepare for Storm Ciarán.
The Met Office has issued yellow warnings for wind and rain across south, mid and north Wales on Wednesday and Thursday, beginning this evening from around 6pm.
The whole of Brecon and Radnorshire is included in the yellow warning for rain which runs from 6pm tonight (Wednesday) until the end of the day tomorrow (Thursday).
The warning indicates potential risks to life and property.
The council has said it is working together with groups to ensure communities are prepared for the expected heavy and persistent rain.
Preparations are being made to help keep people and property safe and teams are out checking flood defences are in good working order. Teams are also clearing gullies and ditches and operating temporary defences where needed to help reduce flood risk to communities.
Cllr Jackie Charlton, Cabinet Member for a Greener Powys said: “Together with our partners, our officers have been working hard to not only clear up from Storm Babet but also prepare for Storm Ciarán.
“Flood defences across the county are ready to be used and depots have supplies of sandbags ready to deploy, if needed. Flooding hotspots are being monitored and staff are engaging with local flood groups in to ensure that communities are as prepared as can be.
“We urge residents to stay safe and consider any steps they may need to take now to be prepared for the bad weather, to take extra care if you need to travel, and to always adhere to any warnings issued over the next few days.”