The Clearlake City Council at its meeting on Thursday approved the purchase of four tax-defaulted properties by Lake County Special Districts. The purchase will allow the city to improve its sewer system. The vote on the purchase was unanimous. Two lots in the 14K block of Highlands Way and 2 in the 5800 block of Vallejo Avenue will allow the expansion of sewer system capacity for the Konocti Gardens Apartment complex and will allow additional flow from the other side of the highway.