Delft in 1712 - Kruikius (detail)

Nicolaas Kruikius

The polders around Delft in Leeuwenhoek's time, now housing the bulk of Delft's almost hundred thousand citizens.

On the map, the straight black lines are raised dikes between the drained fields. The land in South Holland had been managed for centuries, since 1289, by the Hoogheemraadschap van Delfland. This water control board managed the water barriers (dikes), the waterways (canals), the water levels, and the water quality. It did not manage the water supply for human use. Along with the other ancient water boards, the oldest forms of local government in the Netherlands, the Hoogheemraadschap set the stage for the decentralized Dutch Republic's astounding success in its Golden Age.
Comparing these old maps to what you see today on Google Earth reveals almost exactly the same pattern. In other words, other than pavement poured on the tops of many dikes for auto and bike traffic, the South Holland countryside hasn't changed much in the last 400 years. It was crowded and the land was all accounted for then; it's the same now.