Some embodiments of the present disclosure include a water purification system for producing purified water from a body of water. The water purification system may include a floating platform having a ramp extending from an edge thereof at a downward angle into the body of water, a primary impoundment area extending from a top portion of the ramp onto the floating platform, a pair of sub-impoundment areas attached to an end of the primary impoundment area distal from the ramp, at least one hydraulic cylinder and at least one accumulator attached to the sub-impoundment areas, and a nanofiltration system operatively attached to the at least one hydraulic accumulator. Water may be configured to flow from the body of water onto the ramp and through the system, exiting the nanofiltration system as purified water.