The artificial breaching of existing seawalls - managed realignment - has been implemented to counteract habitat losses by re-creating saltmarsh on formerly reclaimed land. Changes in shoreline position and the re-establishment of tidal exchange are likely to have implications for salt marshes and mudflats in front of, and adjacent to, such newly created intertidal areas. However, the way in which such schemes should be designed for maximum benefit but minimal environmental impact on adjacent coastal ecosystems is still poorly known. Optical remote sensing, and particularly the recording of multi-spectral imagery from aircraft-mounted instruments flown over the coastal zone, offers a rapid, repeatable, non-intrusive and relatively large scale monitoring system for assessing these external impacts. The Wash Banks Flood Defence Scheme is being studied with ATM imagery collected once before breaching (pre-9/2002) and twice afterwards. It has identified the impact of inundation on formerly reclaimed land, the relative stability of the existing saltmarsh surface and the major changes to the depth and distribution of creeks. It is crucial that this data collection is continued to demonstrate the full impacts over a realistic time interval.