Records connected with the conservation of the Humber as a navigable estuary for shipping, and the employment of seamarks (i.e. beacons, buoys, lightships etc.) to mark navigable channels. It also includes material concerning the maintenance of the rivers Ouse and Trent.

The majority of the records within this subcollection were created by the Humber Conservancy Board during the course of undertaking its statutory duties and obligations: see

C DPD/1/3. However, it also incorporates material inherited by the Board at its formation in 1908 from Hull Trinity House [C DPD/1/1] and the Humber Conservancy Commissioners [C DPD/1/2] connected with the duties and responsibilities inherited from these bodies.

Only a tiny minority of records relating to the conservancy work undertaken by the British Transport Docks Board, following its absorption of the Humber Conservancy Board in 1968, are held at the History Centre: see C DPD/1/4.