Reparation - nuisance - flooding - construction of culvert on land of upper and lower heritors to alter flow of water in stream - flooding on land of lower heritor at time of heavy rainfall - whether nuisance of upper heritor. Reparation - negligence - duty-of-care - construction works on behalf of landowner causing loss to adjoining proprietor - works negligently designed by independent agents of landowner - reasonably forseeable that works attended with risk - whether duty of care owed by landowner to adjoining proprietor in respect of agents` negligence. River, loch and sea - river - alteration in flow of water in stream - opus manufactum - construction of culvert on land of upper and lower heritors - flooding of land of lower heritor at time of heavy rainfall - whether absolute liability of upper heritor for prtective measures by lower heritor. Constract - construction - contract negotiated between parties - warranty conceived in favour of one party - warranty making provision di