Hills Reservoir

Hills Reservoir, located in Rock County, is a 10-acre reservoir with a watershed ratio of 50:1. Rock County has limited fishing opportunities and as a result the Windom Area DNR staff survey Hills in an effort to maintain a fishery. With that said, reservoirs in highly agricultural areas often have problems with silt filling the storage capacity. The community of Hills drained and dredged the reservoir in 1982 in an effort to create and improve the existing recreational fishery. This reservoir is managed primarily for black crappie and secondarily for bluegill. For the better part of 18 years, the panfish populations have been self-sustaining. Despite the lack of stocking, channel catfish, northern pike, walleye, and largemouth bass have been sampled at different times during previous surveys, which often times is a result of unauthorized stockings. Winterkill frequency has not been a substantial issue in Hills Reservoir because the reservoir maintains a maximum depth of 12 feet. A re-survey was conducted during the week of July 31, 2006 using 5 trap nets and 1 seine haul. The catch rate of black crappie in trap nets was 14.0 fish/trap net, which is greater than the normal range but down from the 2000 survey. Total lengths ranged from 5.6 to 15.8 inches and averaged 7.9 inches. Often times these small reservoirs can be suceptible to over harvest of predators. When this occurs, smaller fish become over-populated and "stunt" out, which leaves very few larger fish to catch. Our netting revealed some real trophy sized crappies. Most of the fish were quite plump and healthy, which indicated the fish had plenty of forage. This fishery is a real gem in Rock County for crappies due to the numbers of fish and the potential to catch a true trophy. If you are in the general vicinity and want the potential to catch a trophy sized crappie, try fishing on the north shore of this reservoir in the spring among the cattails. You may catch a trophy but I dont think you will be disappointed in the action. The catch rate of bluegill in trap nets was 10.0 fish/trap net, which was within the expected range. Total lengths ranged from 3.2 to 8.0 inches and averaged 4.2 inches. All of the fish that were caught in Hills are from natural reproduction as no stocking has occurred since 1988. It appeared that natural reproduction in 2006 was successful as 61 Age 0 bluegill were sampled. Although we didnt sample trophy sized fish, this reservoir will likely provide hours of fishing entertainment because of the numbers. Despite not being stocked since 1988, 10 northern pike were sampled during the 2006 survey. High water levels probably allowed northern pike to get into Hills. Since 4 year classes of northern pike were sampled, it is likely that natural reproduction occurred in Hills Reservoir or upstream of the inlet. Total lengths of northern pike sampled ranged from 16.8 to 30.2 inches and averaged 20.2 inches. While fishing panfish do not be surprised if you hook into a nice sized northern. Efforts to improve the health of the lake should focus on best management practices within the watershed. Improvements and education in land stewardship will often have secondary benefits to the lake in the way of quality and quantity of habitat. Generally, improvements in the quality and quantity of lake habitat will mean direct improvements of the fishery. Prepared by Ryan Doorenbos

Hills Reservoir is a 10 acre class 37 lake located in Rock County. This reservoir is managed primarily for black crappie and secondarily for bluegill. This system has not been stocked since 1990 which means the populations are self-sustaining. The community of Hills drained and dredged the reservoir in 1982 in an effort to create and improve the existing recreational fishery. The 1995 population assessment found walleye and yellow perch which were likely the result of extracurricular stocking by locals. Since the long range goals have been met the last two surveys, the extracurricular stockings that occurred in the past did not appear to have detrimental effects. However, it should be noted that illegal stockings should be strongly discouraged. Winterkill frequency has not been a substantial issue in Hills Reservoir because of the maximum depth of 12 feet. It should be noted that reservoirs in highly agricultural row cropping areas have a tendency to silt in and thus are susceptible to decreasing maximum depths. Local sponsorship should be encouraged for aeration to prevent future winterkill.Five trap nets were used to assess the black crappie relative abundance and size structure. The average black crappie catch per unit effort (CPUE) in trap nets was 112.00 fish/trap net in 2000, 49.80 fish/trap net in 1995, and 0.50 fish/trap net in 1991. The catch rate of black crappie in trap nets was more than 8 times the upper average range (13.00 fish/trap net) for this lake class. The population size structure was overwhelmingly dominated by small individuals. Most of the fish were from the 1996 (2 %), 1997 (82 %), and 1998 (15 %) year class. Based on age and growth data, it appears growth of black crappie was slightly depressed between Age 1 and 3. The average Age 2 black crappie was 5.1 inches while in South Dakota the regional mean was 5.5 inches. The average Age 3 black crappie in South Dakota was 7.4 inches whereas the Hills black crappie was only 6.3 inches at Age 3. It is possible that the black crappie population is becoming somewhat stunted due to the present high density population. Lots of small crappies could give the kids hours of entertainment.Five trap nets were used to assess bluegill relative abundance and size structure. The average bluegill catch rate in trap nets was 39.8 fish/trap net in 2000, 7.0 fish/trap net in 1995, and 1.75 fish/trap net in 1991. The catch rate of bluegill in trap nets was greater than the upper average range (24.94 fish/trap net) for this lake class. This was the highest catch rate for bluegill ever recorded in any of the previous Hills surveys. Most of the fish were from the 1997 (89 %) and 1998 (6 %) year classes. Bluegill growth in Hills Reservoir seems to be comparable to the Minnesota, Michigan, South Dakota, and Wisconsin mean growth rates for Age 1 (1.8 inches), Age 2 (3.4 inches), Age 3 (4.5 inches), and Age 4 (5.7 inches). Hills bluegill were 2.08 inches at Age 1, 3.82 inches at Age 2, 5.17 inches at Age 3, and 5.50 inches at Age 4. Seining caught 25 Age 0 bluegill which indicates natural reproduction. These fish will be nice "slabs" in a couple of years provided growth doesn't slow down. The predator stock consisted of largemouth bass, channel catfish, walleye, and northern pike. Five trap nets captured 5 adult largemouth bass which may indicate a relatively decent population exists since trap nets rarely capture bass. Total lengths ranged from 10.71 to 16.34 inches with a mean of 14.32 inches. Seining captured 25 Age 0 largemouth bass which were likely the result of natural reproduction of the adults caught in trap nets. I wouldn't count on catching a lot of predacious fish on Hills but the panfish action will likely provide some good action. To promote and maintain healthy fish populations, pollution and other inputs need to be controlled. Fish habitats are directly affected by water quality. Nutrient, sediment and other waste inputs can drastically alter the biological, chemical, and physical components of a lake. It is paramount to maintain if not improve the current water quality of Hills Reservoir through watershed management to preserve this fishery for future generations to enjoy.

Hills Reservoir is managed primarily for bluegill and black crappie.Bluegill numbers are considered normal compared to similar lakes in our area. Fish collected in our trapnets ranged in length from 3 to 8 inches with an average of approximately 5 inches. Although the bluegill population is dominated by smaller fish, a fair number of bluegill should be more than 8 inches in length for the 1996 fishing season. The population is comprised of five year classes which suggests good natural reproduction and a self-supporting population. Bluegill were last stocked in 1985. Black crappie numbers have been high in the past and remain high as suggested by data collected in 1995. Crappie collected in our trapnets ranged in length from 4 ? to 8 ? inches with an average of almost 7 inches. Five year classes were present which indicates good natural reproduction and a self-supporting population. Crappie were last stocked in 1988. Walleye numbers are considered average compared to lakes similar to Hills Reservoir. All walleye collected in our trapnets were of similar size with an average length of 19 inches. Natural reproduction of walleye appears limited in Hills Reservoir. Yellow perch numbers increased since our last survey conducted in 1991. Currently, perch numbers are considered normal. The population was dominated by age-1 fish which were around 6 inches in length. With good growth, this strong year class should produce good numbers of yellow perch of quality size (more than 8 inches in length) in following years. Black bullhead numbers have declined since our last survey and are currently considered normal compared to similar area lakes. The average size of bullhead has increased from approximately 6 inches in 1991 to 9 inches in 1995. The population decline may be attributed to poor natural reproduction probably during 1992 and 1993 when relatively cool weather patterns predominated. To promote and maintain a healthy fish population, pollution and other inputs need to be controlled. Fish habitat is directly affected by water quality. Nutrient, sediment and other waste inputs can drastically alter the chemical and physical components of a Lake. It is paramount to maintain if not improve the current water quality of Hills Reservoir through watershed management to preserve this fishery for future generations to enjoy.

Based on Minnesota DNR survey data, anglers target Black Crappie, White Crappie, Walleye, Largemouth Bass, and Yellow Perch in Hills Reservoir. See the full species list above for catch rates, size structure, and quality scores.

We don't have a confirmed public access point on record for Hills Reservoir. Check the DNR LakeFinder page for current access details before you go.

Hills Reservoir has a maximum depth of 12 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Hills Reservoir is from 2006. Surveys this old should be treated with some caution — fish populations change over time.

No invasive species are on record for Hills Reservoir in Minnesota DNR data. Always clean, drain, and dry your equipment to help keep it that way.