For inland flood risk assessments where water courses may be influenced by tide, the CFB can provide the downstream tidal boundary. Levels included in tidal rivers, estuaries and harbours only take account of risk due to extreme coastal events. They don’t include risk due to extreme fluvial or combined fluival-coastal events, which requires additional modelling and analysis. Guidance may be sought from national coastal modelling teams on the appropriate use of levels in these areas. Additional information is also available on the methods and model information used to derive levels in estuaries from modelling teams.