The clean water report cards are in, and lakes and rivers in the Detroit Lakes-Perham area generally did pretty well, but there is always room for improvement.
True, there is E. coli bacteria, suspended solids, low dissolved oxygen and other problems in some river stretches, but for the most part rivers and lakes in the Otter Tail River watershed basin “are in good condition, especially compared to some of the other Red River Basin watersheds,” said Scott Schroeder, project manager for the Otter Tail River watershed basin with the Minnesota Pollution Control Agency.
“Some of the differences are that about 45% (of the Otter Tail basin) is used for agriculture -- in neighboring districts it's 90% or more,” he said. “About 28% (of the Otter Tail River watershed) is forested and about 20% is water or wetlands -- there is a lot of variability, and it’s not overdeveloped or used mainly for one purpose,” he added.
The details are laid out in two recently-released MPCA studies, the Total Maximum Daily Load study and the Watershed Restoration and Protection Strategy study, which are available on the MPCA website and open to public comment until 4:30 p.m. June 9.
The problem stretches of river
Although things could be worse in the Otter Tail River watershed, there are still problems. “There are concerns,” Schroeder said. According to the MPCA, these are the impaired river stretches in this area:
- E. coli in a half-mile section of the Pelican River, basically from Highway 10 to where the Pelican River enters Big Detroit Lake.
- Campbell Creek has high levels of suspended sentiment in a several-mile section that flows into the upper part of Floyd Lake.
- A long stretch of Toad River has E. coli from Little Toad Lake to just past Highway 87. An unnamed creek a few miles southwest of there also has E. coli. About a 2-mile stretch of Toad River going into Big Pine Lake near Perham is also impaired with E. coli.
- A long stretch of the Otter Tail River, from Rice Lake to Mud Lake near Perham, has low levels of dissolved oxygen -- a problem because dissolved oxygen is needed to sustain fish and other aquatic life.
- South of this area, a long stretch of the Pelican River, roughly from Pelican Rapids to Fergus Falls, is impaired, the northern half with low levels of dissolved oxygen, and low biological integrity in the fish community, and the southern half with E. coli. (The MPCA doesn’t yet know where the E. coli fecal contamination is coming from. Limited source tracking done in 2019 suggests that it could be coming from birds, humans, cattle, or even beavers and other wildlife.)
- And about a 20 mile stretch of the Otter Tail River in Wilkin County, that was made into a ditch-like channel in the 1950s, is impaired with high levels of suspended sentiment and low biological integrity in the aquatic insect community.
Biological integrity, or the lack of it, simply measures how fish and aquatic insects are experiencing the entire spectrum of environmental conditions — physical, chemical, and biological. Evaluating the biological community is a key tool the MPCA uses to assess water quality. In the reports, it is called the Index of Biological Integrity.
How are the lakes doing?
Impaired lakes due to excessive nutrients -- often phosphorus that causes nuisance algae blooms -- in Becker County include: Lake St. Clair, Height of Land, and Wine lakes, as well as Mallard, Upper Egg and Waboose lakes -- those last three are all in the northernmost part of the Tamarac National Wildlife Refuge.
Excessive nutrient-impaired lakes in Otter Tail County include: West Spirit, Devils, Crooked, Gandrud, Hovland, Johnson, Long, East and West Norway, Oscar, and Twin.
Excess nutrients (phosphorus) in some lakes is fueling algae blooms, reducing water clarity and hurting recreation. Fish are being hurt by excess nutrients, habitat changes brought on by shoreland development, loss of lake vegetation, temperature changes, and decreased dissolved oxygen.
Low biological integrity scores in the fish community were found in 12 lakes. They are:
- Little, Middle and Big Cormorant, Eagle Lake by Frazee, Big and Little McDonald, Paul (near Big McDonald), West Silent, as well as Fish, Anna and Jewett lakes (all three north of Fergus Falls) and Walker Lake next to Otter Tail Lake. Seven other lakes were identified as not impaired but vulnerable.
Seems like a lot of problems, but keep those 30 or so lakes in perspective: The Otter Tail River watershed overall has more than 1,300 lakes and more than 2,800 miles of streams, the most in any Red River Basin watershed.
Part of the reason the watershed is in such good shape is that soil and water conservation districts, watershed districts, the DNR, the MPCA and other agencies have been busy, Schroeder said.
“There have been a lot of efforts by our partners -- about 3,500 projects implemented watershed-wide over the last 15 years,” Schroeder said. Those projects include agricultural and cropland practices, stream bank and shoreline restorations, septic system improvements, urban stormwater control practices, and others.
To improve upstream mobility among aquatic communities, some older dams and culverts can be modified to allow passage. A dam between Muskrat and Sallie lakes was among the first to be modified in the Otter Tail Watershed and serves as an example to what these projects can look like.
Three other dam projects on Fish, Lizzie and Prairie lakes together reconnected 20 miles of the Pelican River. Other dams and culverts will likely be removed or replaced, including the dam located in Pelican Rapids. The existing park and well-known “World’s Largest Pelican,” Pelican Pete, will be preserved and enhanced.
About $94 million in state and federal dollars have gone toward keeping the Otter Tail River watershed healthy from 2004 through 2019, Schroeder added. “That trend is going to continue and may increase after the One Watershed, One Plan process is complete,” he added.