Phosphorus in Kent Park Lake

Phosphorus in sediments of Kent Park Lake, sedimentation ponds, and upland soils in Johnson County Kent Park, Iowa

Photo of Kent Park lake

Kent Park Lake, a popular recreation lake located in Johnson County east central Iowa near Iowa City and Cedar Rapids, IA. The 27 acre lake is used for fishing and swimming and is the centerpiece of the 1,000 plus acre county park, but is listed on the Iowa’s 303d list as impaired for chlorophyll, turbidity, and bacteria. Kent Park Lake was formed by damming a small intermittent tributary to Clear Creek in 1968. The Kent Park Lake watershed was formerly farmed and was mainly used for pasture because of the relatively steep slope. Much of the park area was reforested after acquisition by the Johnson County Conservation Board.

Water quality in Kent Park Lake, Johnson County, Iowa during the summer data from Iowa State University online. During the last decade, chlorophyll a concentrations increased significantly during the summer in Kent Park Lake. Phosphorus, commonly the limiting element in algal and aquatic plant production, also has been increasing during this period. Once in the lake, phosphorus is available for algal growth. Two other constituents associated with water clarity, total suspended solids and turbidity, also increased significantly from 2000—2013. Suspended sediment transported to the lake has been identified as the source of increased suspended solids and turbidity. Sediment has also been suspected of transporting phosphorus to the lake.