To improve a draining performance by forming a compression strain on the surface layer of a glass coil spring by a heat treatment or the like to increase strength and coating it with a cover made of a glass fiber.

A coil spring 1 made of a glass wires is treated with heat or chemically treated to form a compression strain layer at the surface layer in order to secure a strength durable against impact in construction works. Subsequently, a plastic solution or a plastic solution mixed with a short glass fiber material is applied thereon to increase still more the strength. Then, a cylindrical cover 2 that the glass fiber or its twisted yarn is woved is set on the spring 1 to increase the shape-retaining property and constitute a penetration water drainage member. When using the member, it is embedded in a drainable pavement to drain penetrated rainwater cut off by a waterproof layer through the penetration water drainage member. In this way, cost can be reduced, and extension/contraction or meandering at the laying time can be prevented, and fine granules of the pavement are prevented from penetrating into the inside not to deteriorate the drainage function. Further, obstruction against grinding is eliminated when the pavement is recycled.