Self-employed person in hydraulic engineering
For Leeghwater, the Beemster marked the start of a successful career as a hydraulic engineer and windmill builder. He was involved in all major land reclamation projects, from the Purmer (reclaimed in 1622) to the Starnmeer (reclaimed in 1643). However, he was never in charge and was never permanently employed. He also advised all kinds of polders on problems with water management and dikes. Leeghwater traveled as a freelancer, following the work. In 1629, for example, we find him at the besieged city of Den Bosch, where he helped drain the flooded area around the city. And in 1633, he worked in the peat bogs near Smilde. There he designed sluices in the Nijeveense Grift, a canal for peat ships.