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There is a gutter that runs along the fron of the under deck roof and down spouts at each end. Just not visible in any of my pictures. And you don't have to have the black tarp but it allows you to essentially break up the concrete shim and carry it away without leaving any residual on the concrete pad underneath should one want to do away with the tub. At least in theory...Not that I have any interest in doing that but one never knows! Maybe if I sold the house and wanted to take the tub with me. Or the new buyers didn't want it but didn't want a funny little pad in the middle of the slab either.