In compliance with Section 5937 of the Fish and Game Code, all permits for diversion of water from a stream by means of a dam which do not contain a more specific provision for the protection of fish shall require the permittee to allow sufficient water at all times to pass through a fishway, or in the absence of a fishway, allow sufficient water to pass over, around, or through the dam to keep in good condition any fish that may be planted or exist below the dam; provided that during a period of low flow in the stream, upon approval of the Department of Fish and Game, this requirement will be satisfied if sufficient water is passed through a culvert, waste gate, or over or around the dam to keep in good condition any fish that may be planted or exist below the dam if it is impracticable or detrimental to pass the water through a fishway. In the case of a reservoir, this provision shall not require the passage or release of water at a greater rate than the unimpaired natural inflow into the reservoir.