Potable and process water reservoir covers are provided that exhibit an advantageous balance of rainwater drainage and light transmittance properties. The reservoir covers generally include one or more floatation panels formed from bonded foam particles that are adhered to a fabric layer. The present invention provides a reliable, cost-effective means by which to decrease the algae growth generally associated with water reservoirs. The present invention further decreases reservoir contamination issues associated with dust, sand, debris and waterfowl.