Sika Greenstreak Waterstops have been keeping water in or out of structures for decades. Concrete structures are only as watertight as the waterstops that join them. Structures such as water treatment plants, reservoirs, locks, dams, and below grade facilities, most likely have a waterstop system in place. Several factors must be considered when selecting a waterstop. They include, but are not limited to, joint type and joint movement, hydrostatic pressure and chemical exposure. Greenstreak offers the industry's most comprehensive line of waterstops available today.