The Var has evolved over time due to urbanization and development reducing the Var bed. Over 100 years ago the Var flowed almost 1km wide. At the beginning of the 20th century construction of a dyke reduced the width of the Var. Further anthropogenic changes occurred, contamination of the water led to a reduction in surface area of deposition, thus increasing the carrying capacity. Canalisation in the 1960s reduced the area, increasing the volume of water being carried, increasing velocity.