Surface water is water on the surface of the site and excavations.
Disposal of surface water is deemed to be included in NRM2 Section 5. However SMM7 had previously required disposal of surface water to be measured as an item and confusion can occur as to what constitute surface water and ground water
Best practice
Surface water is water on the surface of the site and excavations that arises solely from rainwater. Surface water escaping from other sources should be allowed for by inclusion of an appropriate risk allowance.
Duncan Cartlidge FRICS