River Kosi flows through Supaul. After the construction of Kosi Dam the flood situation has improved in Supaul.This year though (2008) the river Kosi changed its course and took the route it used to take 200 years ago. As a result major parts of Supaul districts were flooded. These were the worst floods since 1954.
Supaul is located at . It has an average elevation of 34 metres (111 feet).Rivers: Kosi
Supaul has a rich history. There is an ancient school called Williams High School which is 112 years old. There is a famous school called Jawahar Navodaya vidyalaya, which produce a scores of talented students with a high class achievement not nationally but internationally. There is a public club which is more than 100 yrs old. Supaul is well connected to capital of state and country with rail and roads. Politically Supaul stands ahead with comparison to other district and it is a lok sabha constituency which produced eminent leaders.