This evaporation system capitalizes on a double-layered material that floats and uses freely available solar energy to treat produced water. The wavelength-selective, insulating-thermally, salt-repelling, porous (WISP) material features a spectrally-selective solar absorber layer that harvests sunlight and a bottom foam insulator layer that localizes heat to promote high evaporation rates. The top absorber layer, comprised of a carbon material (e.g. carbon black) and possibly a polymer mix, also has a layer of anti-scaling lubricant that prevents salt deposition and performance degradation over time. This floating absorber-insulator structure serves to heat the surface of an evaporation pond and enhance evaporation. A transparent cover sits above the pond to condense and collect the vaporized water for reuse.