A few homes and businesses in Riverside are being affected by a water main break that occurred yesterday. The Iowa Department of Natural Resources was notified Tuesday afternoon of the incident. According to state DNR Environmental Specialist Anne Lynam, a precautionary boil advisory is in place for a few homes and businesses, as well as the post office. She says they were told this was affecting an area north of Highway 22 to 3rd Street, in the 100 and 200 blocks of North Green Street. She adds instead of the DNR issuing a formal boil advisory, those impacted were contacted directly.