MPCA Waterfront Bulletin

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Waterfront Bulletin
January/February 2020

Extremely wet 2019 dampened, but didn't drown MPCA bio, water quality monitoring efforts

The monitoring season in 2019 was a very wet one in many parts of Minnesota and this did have an impact on the agency's ability to carry out monitoring activities in certain areas at certain times; however, much important work was accomplished. Biological and water quality monitoring efforts are important for many reasons. Collecting and analyzing monitoring data is one way we can track progress in achieving water quality improvements that result from projects implemented by various organizations working together, including watershed districts, the MPCA, SWCDs, and many others.

From mid-June through September 2019, the Minnesota Pollution Control Agency’s (MPCA) north and south Biological Monitoring Units sampled rivers, streams, and ditches across the State of Minnesota. Staff biologists sampled 235 (north) and 114 (south) unique stations for fish and 196 (north) and 126 (south) unique stations for macroinvertebrates. Sampling performed by the north unit targeted the Buffalo, Upper Red River, St. Louis River and Mississippi-St. Cloud Major Watersheds while the south unit targeted the Chippewa, Cedar, Lower-St. Croix and Shell Rock River Major Watersheds. Although these watersheds were the primary focus of the 2019 sampling, sporadic monitoring occurred in many other major watersheds for various follow up surveys and other projects.

Abnormally high rainfall patterns during the sampling season throughout much of Minnesota challenged crews’ ability to complete the monitoring. In the south, above average rainfall throughout the sampling season hindered work in nearly all watersheds. For example, the Chippewa River was above median flow nearly all summer, peaking on July 3 at five times the normal discharge for a season. As a result of the constant high water, the south unit spent significant time helping monitor the St. Louis River Watershed in the north. This area was one of the few in the state where high water did not affect sampling, in fact, according to the U.S. Drought Monitor, the St. Louis River was “abnormally dry” throughout the summer.

Conditions will require special follow-up monitoring in 2020

Although specific large rain events avoided the Mississippi River-St. Cloud and Buffalo River watersheds, moderate rain events throughout the summer kept rivers somewhat high but nothing like what the southern portions of the state experienced. Unfortunately, high water continued into the fall preventing crews from performing station reconnaissance for summer 2020 watersheds. As an example, the Nemadji River gage height went up 20 feet in 24 hours from Sept. 30 to Oct. 1. Due to these high flows across the state, several of the 2019 watersheds will have follow-up sampling performed in 2020 in addition to the regular scheduled sampling in other watersheds.

In spite of the difficult stream flow conditions, crews were still able to collect good samples from a majority of locations. Trout were sampled at 65 different stations, a majority of which were in the Root River Watershed, with over 70 percent of the total trout sampled being brown trout. Additionally, 36 unique species were sampled at one visit on the Le Sueur River near Mankato while 30 species were collected on the St. Francis River near Princeton. In total, 93 different species were sampled this season, 71 total species by the north unit and 81 species by the south unit. In total the two units sampled 108,360 individual fish, uniquely, roughly 54,000 by each unit. Several species of special concern were also collected including: least darter, northern and southern brook lamprey, black redhorse, Ozark minnow and gilt darter. Macroinvertebrate data was not finalized at the time of this story.

High water affected water quality monitoring unit too

MPCA’s Water Quality Monitoring Unit had a busy, successful summer as well, collecting water quality data monthly April through October. The MPCA’s Large River Monitoring Program crews monitored 30 sites on the Minnesota River from Ortonville to St. Paul, this work was impeded throughout the summer due to high flows within the basin preventing many trips from occurring. River monitoring related to metals included sites within the Red River Valley, St. Croix River basin and smaller tributaries on the southern Minnesota border. 

Field crews performed chloride monitoring on 37 lakes in the Twin Cities Metro area across four months of the season and also continued to support the sentinel lake monitoring network by sampling 15 lakes across the state during five months of the season. In total, various water chemistry data was collected from 88 lakes, 39 stream stations and eight groundwater wells. Local partners and citizen volunteers also contributed to the effort by collecting water samples from lakes and streams in many watersheds.

For more information on Biological Monitoring, please see:

For more information regarding Lakes and Stream Monitoring, please see: or