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Water quality monitoring

Red Rock Lake_2014Oct14_Josh Filtering Water Sampling_reduced.jpgThe water quality monitoring program supports the District's 10-year Watershed Management Plan to remove waterbodies from the Impaired Waters list maintained by the Minnesota Pollution Control Agency (MPCA). Data collected during the field season (April to September) helps determine sources of water quality impairments and provides information needed to design and install improvement projects.

Water samples from lakes and creeks are collected manually and by automated sampling units. In-lake and in-stream sensors collect continuous data. In addition to regular monitoring sites, some locations are monitored on a rotational or as-needed basis due to project planning needs.

Water Quality Monitoring Stations

WQ monitoring eqiup_RML_fall 2023.jpgStaff at RPBCWD place water quality monitoring stations throughout the district. The monitoring equipment is housed inside heavy duty metal or plastic boxes and includes sensors that collect data on water flow, temperature, level, and other metrics. Some of these stations also automatically collect water samples after a rain event.

The data collected is combined with other information to assess the health of water resources including streams, lakes, and wetlands. Often, the monitoring stations are placed before and after a water quality improvement project installation to measure project effectiveness.

The photo shows a monitoring station installed in late 2022 in the park north of Rice Marsh Lake.  The station monitors a water quality improvement project finished that same year.

Stream Monitoring

The District monitors streams for six impairment categories defined by the MPCA. When a measured value does not meet the standard, the stream is designated as impaired for the category. Click the links below to learn more about monitoring results of each stream.


Creek Restoration Action Strategy

RPBCWD developed the Creek Restoration Action Stategy (CRAS) to prioritize stabilization or restoration projects for creek reaches or subreaches. Eight categories are used to prioritize projects:

  • Infrastructure risk
  • Erosion and channel stability
  • Public education
  • Ecological benefits
  • Water quality
  • Project cost
  • Partnerships
  • Watershed benefits

Scoring methods in these categories were based on a combination of published studies and reports, erosion inventories, field visits, and other existing scoring methodologies.  Individual sections (reaches and subreaches) of creeks are scored. Based upon their scores in the eight categories, creek sections are rated as low, moderate, high, or severe priority for restoration.

Lake Monitoring

Thirteen lakes are regularly monitored within the watershed district. Data collected is used to track water quality trends over time and to determine if a lake is meeting water quality standards set by the MPCA. Four lakes in RPBCWD (Ann, Lotus, Riley, and Round) are considered "Deep Lakes" and are compared to the deep lake water quality standards, which are stricter than the standards set for shallow lakes. See the table below for MPCA standards for phosphorus, chlorophyll-a, and water clarity.


Water Quality Parameter MPCA Standard for "Deep Lakes" MPCA Standard for "Shallow Lakes"
Total Phosphorus Less than 0.040 milligrams/liter Less than 0.060 milligrams/liter
Chlorophyll-a Less than 14 micrograms/liter Less than 20 micrograms/liter
Water Clarity Greater than 1.4 meters Greater than 1.0 meter


To see monitoring trends for each lake, visit the waterbodies page.

Wetland Monitoring

RPBCWD staff assess wetlands using the Minnesota Routine Assessment Method (MnRAM) as well as a modified version of the Rapid Floristic Quality Assessment (Rapid FQA). Information collected with these methods form the basis of wetland restoration prioritization in the District. The use of MnRAM also provides support for the RPBCWD regulatory program and implementation of the Minnesota Wetland Conservation Act (WCA), where the District is the local governement regulating body for Deephaven and Shorewood.

Wetlands are classified as low, medium, high, or exceptional value. These classifications are based on these functional categories:

  • Vegetation diversity/integrity
  • Habitat structure
  • Amphibian habitat
  • Fish habitat
  • Shoreline protection
  • Cultural/recreational/educational value
  • Stormwater/urban sensitivity
  • Wetland water quality
  • Characteristic hydrology
  • Flood/stormwater attenutation
  • Commercial use
  • Downstream water quality


Stream and lake monitoring:
 Josh Maxwell

 Zach Dickhausen

Related pages

Water quality info from others

Water Quality Parameters

Below are common parameters measured for water quality.

Abbreviation Parameter What it indicates
Chl-a Chlorophyll-a Level of algae growth
CL Chloride Level of salt pollution
DO Dissolved oxygen Oxygen level in water
TP Total phosphorus Level of all phosphorus
TDP Total dissolved phosphorus Level of all available phosphorus
OP Ortho phosphorus Level of biologically available phosphorus
TSS Total suspended solids Level of silt/sediment suspended in water