We are hoping to start a knock down-rebuild but have stalled at the design stage!!
We want to relocate the driveway to the opposite (lower) side of the lot, and design with garage under the house. There is Sydney Water main running parallel with street in the council verge. The problem is that effectively Sydney Water, (Waterboard) have laid the main almost at street level, then built a 600mm high mount over the top of it, rising level to my front boundary, but battering down sharply to the gutter edge (if you park you car parallel to my gutter, your open door will dig into the grass mound). To get levelish entry for driveway crossover we need to excavate into this mound. To determine the exact depth of the main, I have done Dial-before-you-dig, Sydney Water (4 calls), called Water Servicing Coordinators (WSC) and even met council driveway crossover inspector on site. Council guy suggested lodging DA for crossover with house plans, then once house finished my builder would do levels, etc. Obviously not ideal if we can't get a driveway in after we have built (or even after architect has designed house & lodged DA). On the advice of a WSC, we dug a hole to find the answer and the main is 600mm down, and 1m off the gutter. So if we excavate for a driveway in this location it will be less than 600mm from the water main - maybe 400mm - maybe less?? Where to next - encasing the main? Should I speak to a WSC, engineer, driveway contractor?
Has anyone had to encase a water main for a driveway? Any advice or ballpark costs on a 5m wide driveway? Is there a min. depth for Sydney Water main from natural ground level? Any advice greatly appreciated - I'd love to get past this hurdle & onto the next