Guyana Browse regions with water & wastewater management location pages. Barima-Waini 1 cities Cuyuni-Mazaruni 1 cities Demerara-Mahaica 1 cities East Berbice-Corentyne 2 cities Essequibo Islands-West Demerara 1 cities Mahaica-Berbice 1 cities Pomeroon-Supenaam 1 cities Potaro-Siparuni 1 cities Upper Demerara-Berbice 2 cities Upper Takutu-Upper Essequibo 1 cities