School Grove Lake Fishing guide

A winterkill of Black Crappie, Walleye, Common Carp, Black Bullhead and Channel Catfish occurred during February of 2010. The winterkill was not complete, but numbers of all fish species were significantly reduced. Low numbers of Black Bullhead, Common Carp, Yellow Perch and White Sucker were captured in the 2010 ice out trapnets. A significant winterkill occurred on nearby Cottonwood Lake during January of 2013, but not on School Grove or Lady Slipper. A significant winterkill of Common Carp occurred during the 2018-19 winter on School Grove. An intense blue-green algae bloom was present during the late fall just prior to ice up. Gamefish often become susceptible to winterkill when oxygen levels are less than 1 ppm for an extended period. Dissolved oxygen levels decreased rapidly to less than 1 ppm even though open water was present at the aeration site (not running) in early December of 2018. The aeration system was unable to be used due to open water at the site for signage during early December of 2018. The aeration system was on by January 3, 2019. There were low numbers of distressed and dying fish of all species near an inlet southwest of the nearby access on January 3, 2019. We observed numerous dead floating Common Carp during early May 2019 netting, but no Walleye or other gamefish. We caught one Black Crappie, three Yellow Perch and 3 Black Bullhead in the three 2019 May trapnets. Nearby Lady Slipper had low numbers of dead fish visible with a few Yellow Perch and abundant Black Bullhead and small Common Carp in the 2019 spring trapnets. No winterkills were observed in other nearby lakes such as Cottonwood, Wood Lake, and Tyson. Lake Elizabeth (shallow aerated lake) in Kandiyohi County had a similar 2019 winterkill result consisting of mostly dead Common Carp and lesser amounts of gamefish to that of School Grove. Winter oxygen levels were low in February of 2023 on School Grove due in part to heavy snowfall events. Gamefish often become susceptible to winterkill when oxygen levels are less than 1 ppm for an extended period. Ice out occurred in mid-March of 2023. There were reports of winterkill (Common Carp and Walleye) in the spring of 2023 in both School Grove and Lady Slipper. Nearby Sham Lake (Walleye rearing pond) also had a significant winterkill in 2023. Three trapnets were set in early May of 2023 to assess winterkill. Abundant numbers of Black Bullhead and low numbers of other species (White Sucker, Common Carp and Bigmouth Buffalo) were captured in the trapnets. No gamefish were captured. Winter oxygen levels were adequate during the 2023-2024 and 2024-2025 winters due to mild winter conditions. The aeration system was not operated during the 2025-26 mild winter due to high oxygen levels (14-17 ppm).

Walleye natural reproduction has been generally insignificant based on previous surveys for School Grove. Walleye fry (approximately 100,000 to 350,000) have been stocked into School Grove recently during 2016-2017, 2019, 2021-2025. Approximately 124,769 Walleye fry were stocked in 2025. Walleye fry are currently scheduled for annual stockings. In 2019, Walleye adults (826 fish, 793 pounds) and fingerlings (1,820 fish, 61 pounds) were stocked in School Grove. Walleye adults and yearlings were stocked in 2020 (33 adults, 65 pounds; 264 yearlings, 132 pounds).

Low numbers of small sized YOY Walleye were captured in 2025 fall night electrofishing survey (4.00 YOY/hour, 5.20 inches). Two-year-old (2023 year class) Walleye were abundant (54.00 fish/hour) but were stunted (7.11 inches) in 2025. Abundant small sized YOY Walleye numbers were captured in 2023 fall daytime electrofishing survey (84.00 YOY/hour, 4.51 inches). Low YOY Walleye numbers (12.00 YOY/hour, 8.07 inches) were captured in the 2019 fall night electrofishing survey. Abundant numbers of YOY Walleye from spring fry stockings were present in 2017 (186.00 YOY/hour, 4.38 inches average length) and 2014 (324.00 YOY/hour, 5.50 inches average length) fall night electrofishing surveys. No YOY Walleye were captured in the 2016 fall electrofishing survey. The fall electrofishing historical average catch rate and length are 87.46 YOY/hour and 5.69 inches respectively for School Grove. The highest fall night electrofishing catch rate of YOY Walleye for School Grove occurred in the 2012 fry stocked year (353.33 YOY/hour). No fall electrofishing surveys were conducted during 2020-2022 and 2024.

Walleye numbers were abundant in the 2022 survey (42.50 fish/gillnet). The historical catch rate is 18.02 fish/gillnet. The 2022 Walleye average weight and length were 2.18 pounds and 17.56 inches respectively from gillnets. The 2017 Walleye year class (fry and adult stockings) comprised 56% of the 2022 Walleye survey catch. The 2021 and 2019 Walleye year classes (fry, fingerling, yearling, and adult stockings from 2019-2021) comprised 24% and 12% respectively of the 2022 Walleye survey catch. It is unclear how many pre 2019 Walleye year classes survived the 2019 winterkill due to restocking of adults and fingerlings in 2019-2021. Adult Walleye numbers from 2022 year classes and prior were significantly reduced after 2023 due to the 2022-2023 winterkill.

Current fish management activities on School Grove include monitoring the fish population on a periodic basis, monitoring winter dissolved oxygen levels, assisting the sportsman's club with the operation of the aeration system, protecting aquatic vegetation through the permit process, assisting aquatic plant management and enforcement personnel in educating boaters and monitoring access sites for potential invasive species introductions, participating in local watershed initiatives, and stocking various fish species as warranted. The School Grove fishery will be sampled in the summer of 2027 for all fish species and periodically for YOY Walleye by fall electrofishing.