Posted By Ciaran McAleenan Ken I think if look under the definition for a structure you will find that constructing a lake will fit in there. Structure in CDM regulations has a very wide definition. Where it refers to lagoons and reservoirs I would presume that it would not be an unreasonable interpretation to include your ornamental lakes. Would the hazards and design issues not be similar? The nature and scope of the project might have to be scaled down accordingly. Best wishes Ciaran Extract from Statutory Instrument 1994 No. 3140 The Construction (Design and Management) Regulations 1994 ""structure" means— (a) any building, steel or reinforced concrete structure (not being a building), railway line or siding, tramway line, dock, harbour, inland navigation, tunnel, shaft, bridge, viaduct, waterworks, reservoir, pipe or pipe-line (whatever, in either case, it contains or is intended to contain), cable, aqueduct, sewer, sewage works, gasholder, road, airfield, sea defence works, river works, drainage works, earthworks, lagoon, dam, wall, caisson, mast, tower, pylon, underground tank, earth retaining structure, or structure designed to preserve or alter any natural feature, and any other structure similar to the foregoing, or (b) any formwork, falsework, scaffold or other structure designed or used to provide support or means of access during construction work, or (c) any fixed plant in respect of work which is installation, commissioning, de-commissioning or dismantling and where any such work involves a risk of a person falling more than 2 metres."

Posted By Gareth Bryan Whilst I agree with Dave, but let's look at it from a practical point of view: 1. Construction. How big, how deep over 2m?, how is it going to be lined (clay or membrane) both have manual handling implications, underground services?, how much water will it hold safely, and probably many more. 2. Design. Is it going to be wildlife and human friendly (no steep edges or sudden changes in level)can it easily be drained for maintenance / repair / cleaning. 3. Management. During construction, keeping kids out. When completed, keeping kids out. If not properly maintained and managed it will soon become a smelly eyesore. How about that lot then!