This invention is a device for creating tidal action in a terminal lake. A first aspect involves staggering of input and output from the terminal lake, such that the level of the lake rises and falls on a daily basis to simulate tidal action. A second aspect involves the creation of a berm and islands, with a system of pumps and drains filling and emptying a series of holding ponds, creating an even greater “reach” of the tidal action. This tidal action allows for the growth of mangrove forests, which prevent land-based predators such as coyotes from accessing bird nests on the islands, as well as keeping the “playa” wet enough so that local wind does not pick up playa sediment and create toxic dust storms. The toxic upper 3″ of the “playa” is bulldozed to create the berm, islands, and access roads which bisect the newly-created intertidal zone.