 Huge infrastructural works were done; the island called Grote Waard was enclosed with dikes all around and a dam was built at Spaarndam.New governmental bodies were created, the so-called "water boards", which were charged with the task of protecting the polders against ever-present threat of flooding.Count William granted city rights to Geertruidenberg in 1213, to Dordrecht in 1217, to Middelburg in 1220 and perhaps also to Leiden.