The 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.
Staff 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.
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.
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:
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.
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.
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:
Download the 2022 Water Resources Report.
Stream and lake monitoring:
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|