Lake Moeris
During his long rule Amenemhat continued the work probably started by his father to link the Fayum Depression with the Nile. The area had been a mere swamp previously. A canal long and wide was dug, known as "Mer-Wer" (the Great Canal); it is now known as Bahr Yussef. The banks for the central deep side were at a slope of 1:10, to allow use of non-cohesive soil and rock fill. A dam called Ha-Uar ran east–west, and the canal was inclined towards the Fayum depression at the slope of 0.01 degrees. The resultant Lake Moeris could store 13 billion cubic meters of flood water each year. This immense work of civil engineering was eventually finished by his son Amenemhat IV and brought prosperity to Fayum. The area became a breadbasket for the country and continued to be used until 230 BC when the Lahun branch of the Nile silted up.