(on certified questions from federal district court concerning issues associated with water from drainage project (installation of underground stormwater drainage associated with road project) that damaged hotel, state Supreme Court holds that under "all-risk Commercial Property Policy" of insurance, water discharged from pipe not properly characterized as surface water or flood water because such terms not defined in policy; such non-surface water cannot reacquire its classification as surface water upon exit from the stormwater collection system; under policy, "flood water" does not encompass water discharged from a stormwater collection system in concentrated form, pooled, and that thereafter enters a building).