Between 1998 and 2003, about 99% of the Sistan wetlands were dry, another result of continued drought and lack of water management. The wetlands, an important habitat for breeding and migrant waterfowl including the dalmatian pelican and the marbled teal, have provided water for agricultural irrigation for at least 5,000 years. They are fed by the Helmand and Farah rivers, which ran at 98% below average in drought years between 2001 and 2003. As in other areas of the country, the loss of natural vegetation resulted in soil erosion; here, sandstorms submerged as many as 100 villages by 2003.