Blackwater

Blackwater Lake is a 674 acre reservoir in the Mississippi River a few miles west of Grand Rapids, MN. The lake is mostly shallow with large beds of wild rice. Boswell Energy has a coal-fired electric plant on the north side that receives upstream water for cooling. This plant previously discharged heated water to an attached bay locally known as the "Hot Pond". This site was popular with anglers because warmwater fish would congregate in large numbers during cold weather months. Creel data was not collected, but anecdotal reports suggest that high angler harvest of sunfish regularly occurred. Warmwater discharge was discontinued in early 2019. The discontinuation of warmwater discharge is expected to result in less open water angling pressure, but creates additional ice fishing opportunities, so the overall impact on angling pressure is unknown. Bluegill are one of the primary management species on Blackwater Lake. The management goal is to maintain a minimum of 25% of the Bluegill exceeding 8 inches. Spring panfish surveys are conducted to document and monitor size quality, age structure, and growth. The 2019 targeted survey was one of four spring surveys targeting Bluegill since 2009. Spring trap netting in 2019 sampled Bluegill at a rate of 9.9/net resulting in a sample size of 248 Bluegill. The DNR panfish technical committee has defined exceptional size quality as having at least 10% of sampled Bluegill exceeding 8 inches with 9 inch or larger fish present. Previous surveys of Blackwater indicated exceptional size quality, despite perceived high angling pressure. Size structure remained exceptional in 2019. Thirty seven percent of the sample exceeded 8 inches. Sampled fish ranged from 2.8 to 10.1 inches and had a mean length of 7.4 inches. Scale analysis identified ages 2-9, with ages 4 to 7 well represented. Age 5 comprised 37% of the sample. Growth was similar to past surveys and relatively fast, exceeding the lake class averages. Bluegill averaged over 8 inches by age 7. Pumpkinseed are another common sunfish but are less popular with anglers because they generally do not grow as large as Bluegill. Pumpkinseed were captured at a rate of 2.2 per trap net in 2019. Lengths ranged from 4.3 to 8.2 inches and averaged 6.7 inches. The DNR panfish technical committee recommends using reduced bag limits to help maintain size quality on lakes with the biological potential for large sunfish and documented public support. Blackwater Lake was included in a proposal for a 5 sunfish bag limit in 2011, but there was insufficient public support to implement a regulation change at that time. Since then, public support for sunfish regulations has increased and Blackwater Lake is once again being considered for a reduced bag limit.

Blackwater Lake is a 674-acre impoundment on the Mississippi River located just south of Cohasset, MN. The Pokegama Dam, operated by the Corps of Engineers, controls the water level of the lake. The lake is broadly connected to Jay Gould Lake to the east, and is considered part of the Pokegama Reservoir system. The Minnesota Power and Light Clay-Boswell electrical generating plant draws water from the lake for cooling purposes and discharges heated water into Jay Gould Bay. The area of the warm water discharge stays ice-free during the winter months. The discharge bay also attracts and concentrates fish during the cooler months and is a popular spot for anglers. A special trap-net assessment was conducted in the spring of 2010 to evaluate bluegill age and size structure. Ten trap nets were set over three nights for a total of 30 net nights. Bluegill were measured for length and weight, scale samples were collected and sex and maturity were determined. This assessment was conducted approximately one week later than the previous one in 2009, and weather conditions prior to the assessment were warmer than in 2009. The bluegill trap-net catch rate was moderate at 6.3/net in spring 2010. Sampled bluegill ranged from 3.1 to 9.7 inches with a mean length of 6.7 inches. Size structure was modest with a PSD of 70, an RSD-P of 19 and RSD-M of 0. Size structure was slightly better in the 2009 assessment, with a PSD of 90, an RSD-P of 27 and RSD-M of 0. The catch rate in that assessment was comparable at 7.7/net. A mid-summer assessment in 2003 reported a similar catch rate and size structure. The bluegill trap-net catch in that survey was 8.8/net, with a mean length of 6.9 inches, a PSD of 76, an RSD-P of 11 and an RSD-M of 1. Recruitment appeared to be relatively consistent in 2010 assessment, with seven year classes represented from age 3 to age 9. However, individuals over age 5 only made up 14% of the sample. As in previous assessments, growth rates were above the lake class average for ages 2 through 5. Good growth rates and the presence of fish over 9 inches make Blackwater Lake a candidate for a special conservation regulation to maintain or improve the quality of the bluegill population. A five fish bag limit for sunfish will be proposed for Blackwater Lake and connected waters (upstream to the State Highway 6 bridge, downstream to the Pokegama dam, as well as Jay Gould and Little Jay Gould Lakes up to the County Road 63 bridge). Signs outlining the regulation will be posted at the accesses during the 2011 open water season. A public informational meeting will be held in the fall to gather more comments and answer questions. If implemented, the regulation would go into effect in March 2012.

Blackwater Lake is a 674-acre impoundment on the Mississippi River located just south of Cohasset, MN. The Pokegama Dam, operated by the Corps of Engineers, controls the water level of the lake. The lake is broadly connected to Jay Gould Lake to the east, and is considered part of the Pokegama Reservoir system. The Minnesota Power and Light Clay-Boswell electrical generating plant draws water from the lake for cooling purposes and discharges heated water into Jay Gould Bay. The area of the warm water discharge stays ice-free during the winter months. The discharge bay also attracts and concentrates fish and is a popular spot for anglers during the cooler months. A special trap-net assessment was conducted in the spring of 2009 to evaluate bluegill age and size structure. Twelve trap nets were set over three nights for a total of 36 net nights. Bluegill were measured for length and weight, scales samples were collected and sex and maturity were determined. Weather conditions prior to the assessment were cooler than normal for late May. Water temperatures in the sampled areas varied from 64 to 68 degrees, and sampled bluegill were still in prespawn condition. The bluegill trap-net catch rate was 7.7/net in spring 2009. Sampled bluegill ranged from 4.2 to 9.5 inches with a mean length of 7.3 inches. A mid-summer assessment in 2003 reported a similar catch rate and size structure. The bluegill trap-net catch in that survey was 8.8/net; sampled fish ranged from 3.3 to 10.2 inches with a mean length of 6.9 inches. Recruitment appeared to be relatively consistent in the 2009 assessment, with six year classes represented from age 3 to age 8. The 2005 year class made up 40% of the sample. As in the previous assessment, growth rates were above the lake class average for all ages. Good growth rates and the presence of fish over 9 inches make Blackwater Lake a candidate for a special conservation regulation to maintain or improve the quality of the bluegill population. The results from any one assessment can be affected by variability in recruitment as well as the timing of sampling. Additional spring assessments will likely be conducted to monitor the population and further evaluate the potential for a special regulation.

Based on Minnesota DNR survey data, anglers target Largemouth Bass, Northern Pike, Bluegill, Rock Bass, and Black Crappie in Blackwater. See the full species list above for catch rates, size structure, and quality scores.

Minnesota DNR records list public access for Blackwater. Check the DNR LakeFinder page for the launch type and directions before you go.

Blackwater has a maximum depth of 72 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Blackwater is from 2009. Surveys this old should be treated with some caution — fish populations change over time.

Yes — Blackwater has confirmed faucet snail. Clean, drain, and dry your equipment to avoid spreading invasives to other waters.