The lake covers about 25% of the entire surface area of the reserve. Its waters are considered eutrophic, meaning that they are highly productive due to the decomposition of the plant species present and those brought in from neighbouring agricultural areas; all this, together with the high temperatures reached in summer, creates the conditions for the reduction of the concentration of oxygen dissolved in the water. Some of the plants in the lake grow up from the bottom while others are floating species.

Particularly attractive in spring are the white water lily, the yellow fringed heart and bladderwort. The resident bivalves and gastropods are joined by populations of ducks with a limited number of individuals, like mallards and garganeys, which feed in water with a maximum depth of 50 cm, dipping their heads only. In winter the range of avian species expands, and the number of individuals swells, ranging from around 1500 to 3000 per season. Most common are teals, gadwalls, shovelers and wigeons, but with patience you can also see the endangered ferruginous duck, with just 25 to 50 pairs nesting in Italy. This species visits the waters of the lake regularly during the winter, nesting there from time to time in spring.