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Iowa's Lake Monitoring Program


Iowa’s lakes are an incredible and important water resource. They support excellent fisheries, provide a home to numerous plants and animals, create recreational opportunities for Iowans and tourists, and in some cases, supply Iowans with drinking water. State wide water quality monitoring is important so that we can better understand the health and status of our lakes.

Ambient Lake Monitoring Sampling Plan

In 2000, the Iowa Department of Natural Resources Water Quality Monitoring and Assessment Section began its ambient lake monitoring program. The Ambient Lake Monitoring program primarily focuses on monitoring Significant Publicly-owned Lakes or SPOL’s and other publicly owned lakes of interest for restoration. Currently the program samples over 140 lakes in Iowa each summer. Each lake is sampled three times throughout between May and September: once in early summer, once in mid-summer, and once in late summer/early fall. Lakes are sampled at the lakes point or historical deep point. Sampling target many parameters that are measured both in the field and laboratory. The parameter list is located below the map. Data from this project is used to assess the health of our lakes and target individual lakes for restoration and watershed improvement activities.

Links to Ambient Lake Monitoring Assessments, Data, Summaries, and Information


Lake Monitoring Parameters Collected

Field (Lake):

  • Temperature
  • pH
  • Dissolved Oxygen (mg/L and % saturation)
  • Specific Conductance
  • Total Dissolved Solids (Calculated)
  • Turbidity
  • Thermocline Depth
  • Lake Depth
  • Secchi Transparency
  • Photo of Secchi disc at 0.2 meters


  • Ammonia + Ammonium Nitrogen as N
  • Unionized Ammonia Nitrogen (Calculated)
  • Nitrate +  Nitrite Nitrogen as N
  • Total Kjeldahl Nitrogen as N
  • Soluble Reactive Phosphorus (Orthophosphate)
  • Total Phosphorus
  • Solids (total, inorganic, and volatile)
  • Alkalinity, Total as CaCO3
  • Chlorophyll A, free of pheophytin
  • Phycocyanin
  • Total Microcystin
  • Phytoplankton (identified, enumerated, and measured for weight)
  • Zooplankton (identified, enumerated, and measured for weight)

Contact Information

Daniel Kendall
P: 515-491-2226

Resources for additional lake information