21. Responsibility for watercourses other than the main rivers resides with Internal Drainage Boards ( IDBs ). 22. These four internal drainage boards reduce the flood risk to the surrounding properties, land and environment. 23. A public enquiry resulted in the exclusion of the reserve from the Internal Drainage Board scheme. 24. ADA has assisted internal drainage boards by developing a national flood risk management assets database system. 25. A review of internal drainage boards ( IDBs ) was announced in June 2005 by Defra. 26. St . Catherine's is also the former home of the Upper Witham Internal Drainage Board offices. 27. Dyke and Dyke Fen fall within the drainage area of the Black Sluice Internal Drainage Board. 28. The fundamental role of an internal drainage board is to manage the water level within its district. 29. Consequently, all external drainage boards were within a river board area, and they became internal drainage boards. 30. The whole civil parish falls within the drainage area of the Welland and Deepings Internal Drainage Board.
