A paving system (10, 100, 200, 400) for paving comprising: • a top layer of a plurality of paving elements (12, 112, 212, 412); • an underlayment support layer (16, 116, 216, 316, 416) of polymeric material in the form of panels, in particular discrete panel sections (50, 150); and • an underlying ground in form of undisturbed, native soil, referred to as the substrate layer (20, 120, 220, 420), with the underlayment support layer resting on the underlying ground and the panels being suited to support the paving elements (12, 112, 212, 412), the panels being made of a core with a top side and a bottom side, wherein: the top side has a plurality of spaced apart, upwardly oriented projections that define top channels suitable for water flow along the top side of the core when the underlayment layer is positioned beneath the layer of paving elements (12, 112, 212, 412); and the bottom side includes a plurality of spaced apart, downwardly oriented projections that define bottom channels suitable for water flow when the underlayment layer is positioned beneath the layer of paving elements; wherein the underlayment support layer (16, 116, 216, 316, 416) is formed by placing expanded foam beads (30, 130) into a mold under pressure and subjected to a steam application sufficient to soften and melt together the beads (30, 130) at interfaces between the beads (30, 130) and the underlayment support layer (16, 116, 216, 316, 416) disperses concentrated loads that are applied from the paving elements (12, 112, 212, 412) onto a larger surface area of the substrate layer (20, 120, 220, 420), the top channels have drain holes spaced apart and extending through the thickness of the panels, the drain holes connecting the top channels for fluid communication with the bottom channels and for water flow downward through the paving system, and the panels are provided with a mechanism for interconnection in order to be configured for interconnection with each other such that the underlayment layer (16, 116, 216, 316, 416) may be formed into discrete panel sections (50, 150) that may be assembled to cover the entire substrate layer (20, 120, 220, 420). • a top layer of a plurality of paving elements (12, 112, 212, 412); • an underlayment support layer (16, 116, 216, 316, 416) of polymeric material in the form of panels, in particular discrete panel sections (50, 150); and • an underlying ground in form of undisturbed, native soil, referred to as the substrate layer (20, 120, 220, 420), with the top side has a plurality of spaced apart, upwardly oriented projections that define top channels suitable for water flow along the top side of the core when the underlayment layer is positioned beneath the layer of paving elements (12, 112, 212, 412); and the bottom side includes a plurality of spaced apart, downwardly oriented projections that define bottom channels suitable for water flow when the underlayment layer is positioned beneath the layer of paving elements; wherein the underlayment support layer (16, 116, 216, 316, 416) is formed by placing expanded foam beads (30, 130) into a mold under pressure and subjected to a steam application sufficient to soften and melt together the beads (30, 130) at interfaces between the beads (30, 130) and the underlayment support layer (16, 116, 216, 316, 416) disperses concentrated loads that are applied from the paving elements (12, 112, 212, 412) onto a larger surface area of the substrate layer (20, 120, 220, 420), the top channels have drain holes spaced apart and extending through the thickness of the panels, the drain holes connecting the top channels for fluid communication with the bottom channels and for water flow downward through the paving system, and the panels are provided with a mechanism for interconnection in order to be configured for interconnection with each other such that the underlayment layer (16, 116, 216, 316, 416) may be formed into discrete panel sections (50, 150) that may be assembled to cover the entire substrate layer (20, 120, 220, 420).