Scenario 1 - 你可能需要水公司来关/开curb valve. 还有,水管可能要比煤气管埋得深 (below frost line), 再有就是你需要 coordinate with 煤气公司和水公司closely for digging, installation, backfilling...
Scenario 2 - 建议改一下,问水公司可不可以 register 新水表. 如果可以,你就 install a new line after the existing main shut off valve. The new line should have another shut off valve, RPZ, and a new water meter for the commercial space. 希望现在的街管够大.