Swim beach monitoring

Swim beach closures
  • No closures at this time.
What is a natural swimming area?
A natural swimming area is defined in Regulation 5 CCR 1003-5 as a designated portion of a body of water that is devoted to swimming, bathing or wading. The area is typically separated from the surrounding area by rope or buoys to prevent other activities, such as boating, from occurring within the area. The user is charged a fee to use the area. An example of a natural swimming area is a designated swimming area in a state park where a park visitor pays a daily or yearly use fee. Areas that are free to use do not meet the definition of a natural swimming area.
Why might a swimming area close?
Natural swimming areas are required to report water quality data to us on a regular basis during the swimming season to ensure public health and safety. Water quality samples are analyzed for the fecal indicator organism E. coli​. If a laboratory analysis indicates an E. coli concentration above 235 organisms per 100 milliliters, the natural swimming area must be closed. Elevated concentrations may result from:
  • Runoff from urban, suburban or rural areas.
  • Malfunctioning septic systems.
  • Waste from swimmers, pets or wildlife.
  • Improperly disposed dirty diapers.
Guidance document
Fillable/electronic reporting forms