The Tennessee Valley Authority had the difficult task of changing the landscape of the Tennessee Valley. In the 1930s, the farmlands had eroded, the soil was depleted, and the waterways were narrow, causing flooding. Through the decades, TVA has controlled these issues through soil erosion projects, reforestation, and by creating dams and reservoirs. Conflicts have flared at times between environmental groups, citizens, and TVA. In one instance, a species of fish classified as Endangered would possibly have been eradicated by the construction of the Tellico Reservoir.