West Sumba Regency (Indonesian: Kabupaten Sumba Barat) is a regency in East Nusa Tenggara province of Indonesia. Established in 1958,the regency has its seat (capital) in Waikabubak. Its population was 111,023 in the 2010 census.The region is rather dry. One of the main problems for people living in rural areas in the province is frequent shortages of water.