This created a shallow, wide river which flowed slowly south through the everglades to the mangrove estuaries of the Gulf of Mexico. The summer rains would then give way to a six month dry season. During the past 100 years this river has been altered by people. There now exists an elaborate system of dikes, canals, levees, floodgates, and pumps which moves the water to agricultural lands, urban areas, and, finally, to Everglades National Park. Quality Water runoff from farms brings excess nitrates and phosphates into the park.
Excess nutrients reduce beneficial algae and promote unnatural growth of marsh vegetation.
Quantity and Timing Many animals are specifically adapted to the alternating wet and dry seasons. When human manipulations of the water supply are ill-timed with natural patterns, disasters can result. Alligators build their nests at the high-water level. If more water is released into the park, their nests are flooded and eggs destroyed. Wading birds cannot find concentrated food sources for feeding young.