"The 1959 Nile water share agreement signed between Egypt and Sudan which gave the lion share to Egypt (78% to Egypt and 22% to Sudan on the net annual flow after deducting 10 billion cubic meters for evaporation loss) was signed with the Egypt friendly Sudan President Gen. Ibrahim Abboud. Considering, the flow measuring point is deep in Egypt at the Aswan High Dam and the annual hypothetical evaporation loss of 10 billion cubic meters, the share for Sudan is substantially lower than 22%. However, If the water share allocation was done considering “population size and arable land area” as factors, Sudan’s share should have been not less than 40%."
https://sudantribune.com/article66779/